The first heart sound (S1) is created by vibrations produced when the mitral and tricuspid valves close. It occurs at the end of diastole and the start of ventricular systole, coming before the upstroke of the carotid pulsation.

A sample of the normal heart sounds can be listened to here (courtesy of Littman stethoscopes).

A loud S1 can be associated with the following conditions:
– Increased transvalvular gradient (e.g. mitral stenosis, tricuspid stenosis)
– Increased force of ventricular contraction (e.g. tachycardia, hyperdynamic states like fever and thyrotoxicosis)
– Shortened PR interval (e.g. Wolff-Parkinson-White syndrome)
– Mitral valve prolapse
– Thin individuals

A soft S1 can be associated with the following conditions:
– Inappropriate apposition of the AV valves (e.g. mitral regurgitation, tricuspid regurgitation)
– Prolonged PR interval (e.g. heart block, digoxin toxicity)
– Decreased force of ventricular contraction (e.g. myocarditis, myocardial infarction)
– Increased distance from the heart (e.g. obesity, emphysema, pericardial effusion)

A split S1 can be associated with the following conditions:
– Right bundle branch block
– LV pacing
– Ebstein anomaly

The majority of dissections happen in individuals between the ages of 40 and 70, with the highest occurrence observed in the age group of 50 to 65.

Further Reading:

Aortic dissection is a life-threatening condition in which blood flows through a tear in the innermost layer of the aorta, creating a false lumen. Prompt treatment is necessary as the mortality rate increases by 1-2% per hour. There are different classifications of aortic dissection, with the majority of cases being proximal. Risk factors for aortic dissection include hypertension, atherosclerosis, connective tissue disorders, family history, and certain medical procedures.

The presentation of aortic dissection typically includes sudden onset sharp chest pain, often described as tearing or ripping. Back pain and abdominal pain are also common, and the pain may radiate to the neck and arms. The clinical picture can vary depending on which aortic branches are affected, and complications such as organ ischemia, limb ischemia, stroke, myocardial infarction, and cardiac tamponade may occur. Common signs and symptoms include a blood pressure differential between limbs, pulse deficit, and a diastolic murmur.

Various investigations can be done to diagnose aortic dissection, including ECG, CXR, and CT with arterial contrast enhancement (CTA). CT is the investigation of choice due to its accuracy in diagnosis and classification. Other imaging techniques such as transoesophageal echocardiography (TOE), magnetic resonance imaging/angiography (MRI/MRA), and digital subtraction angiography (DSA) are less commonly used.

Management of aortic dissection involves pain relief, resuscitation measures, blood pressure control, and referral to a vascular or cardiothoracic team. Opioid analgesia should be given for pain relief, and resuscitation measures such as high flow oxygen and large bore IV access should be performed. Blood pressure control is crucial, and medications such as labetalol may be used to reduce systolic blood pressure. Hypotension carries a poor prognosis and may require careful fluid resuscitation. Treatment options depend on the type of dissection, with type A dissections typically requiring urgent surgery and type B dissections managed by thoracic endovascular aortic repair (TEVAR) and blood pressure control optimization.

This ECG indicates changes that are consistent with an acute inferoposterior myocardial infarction (MI). There is ST elevation in leads I, II, aVF, and V6, along with reciprocal ST depression in leads V1-V4 and aVR. Additionally, there are tall dominant R waves in leads V2-V3 and upright T waves in leads V2-V3. Based on these findings, the most likely vessel involved in this case is the right coronary artery.

To summarize the vessels involved in different types of myocardial infarction see below:
ECG Leads – Location of MI | Vessel involved
V1-V3 – Anteroseptal | Left anterior descending
V3-V4 – Anterior | Left anterior descending
V5-V6 – Anterolateral | Left anterior descending / left circumflex artery
V1-V6 – Extensive anterior | Left anterior descending
I, II, aVL, V6 – Lateral | Left circumflex artery
II, III, aVF – Inferior | Right coronary artery (80%), Left circumflex artery (20%)
V1, V4R – Right ventricle | Right coronary artery
V7-V9 – Posterior | Right coronary artery

The clinical symptoms of mitral stenosis include shortness of breath, which tends to worsen during exercise and when lying flat. Tiredness, palpitations, ankle swelling, cough, and haemoptysis are also common symptoms. Chest discomfort is rarely reported.

The clinical signs of mitral stenosis can include a malar flush, an irregular pulse if atrial fibrillation is present, a tapping apex beat that can be felt as the first heart sound, and a left parasternal heave if there is pulmonary hypertension. The first heart sound is often loud, and a mid-diastolic murmur can be heard.

The mid-diastolic murmur of mitral stenosis is a rumbling sound that is best heard at the apex, in the left lateral position during expiration, using the bell of the stethoscope.

Mitral stenosis is typically caused by rheumatic heart disease, and it is more common in females, with about two-thirds of patients being female.

Some reversible metabolic causes of bradycardia include hypothyroidism, hyperkalaemia, hypermagnesemia, and hypothermia. These conditions can lead to a slow heart rate and can be treated or reversed.

Further Reading:

Causes of Bradycardia:
– Physiological: Athletes, sleeping
– Cardiac conduction dysfunction: Atrioventricular block, sinus node disease
– Vasovagal & autonomic mediated: Vasovagal episodes, carotid sinus hypersensitivity
– Hypothermia
– Metabolic & electrolyte disturbances: Hypothyroidism, hyperkalaemia, hypermagnesemia
– Drugs: Beta-blockers, calcium channel blockers, digoxin, amiodarone
– Head injury: Cushing’s response
– Infections: Endocarditis
– Other: Sarcoidosis, amyloidosis

Presenting symptoms of Bradycardia:
– Presyncope (dizziness, lightheadedness)
– Syncope
– Breathlessness
– Weakness
– Chest pain
– Nausea

Management of Bradycardia:
– Assess and monitor for adverse features (shock, syncope, myocardial ischaemia, heart failure)
– Treat reversible causes of bradycardia
– Pharmacological treatment: Atropine is first-line, adrenaline and isoprenaline are second-line
– Transcutaneous pacing if atropine is ineffective
– Other drugs that may be used: Aminophylline, dopamine, glucagon, glycopyrrolate

Bradycardia Algorithm:
– Follow the algorithm for management of bradycardia, which includes assessing and monitoring for adverse features, treating reversible causes, and using appropriate medications or pacing as needed.
https://acls-algorithms.com/wp-content/uploads/2020/12/Website-Bradycardia-Algorithm-Diagram.pdf

Tricuspid regurgitation is characterized by a continuous murmur that spans the entire systolic phase of the cardiac cycle. This murmur is best audible at the lower left sternal edge and has a low frequency. Interestingly, the intensity of the murmur increases during inspiration and decreases during expiration, a phenomenon referred to as Carvallo’s sign.

Further Reading:

Tricuspid regurgitation (TR) is a condition where blood flows backwards through the tricuspid valve in the heart. It is classified as either primary or secondary, with primary TR being caused by abnormalities in the tricuspid valve itself and secondary TR being the result of other conditions outside of the valve. Mild TR is common, especially in young adults, and often does not cause symptoms. However, severe TR can lead to right-sided heart failure and the development of symptoms such as ascites, peripheral edema, and hepatomegaly.

The causes of TR can vary. Primary TR can be caused by conditions such as rheumatic heart disease, myxomatous valve disease, or Ebstein anomaly. Secondary TR is often the result of right ventricular dilatation due to left heart failure or pulmonary hypertension. Other causes include endocarditis, traumatic chest injury, left ventricular systolic dysfunction, chronic lung disease, pulmonary thromboembolism, myocardial disease, left to right shunts, and carcinoid heart disease. In some cases, TR can occur as a result of infective endocarditis in IV drug abusers.

Clinical features of TR can include a pansystolic murmur that is best heard at the lower left sternal edge, Carvallo’s sign (murmur increases with inspiration and decreases with expiration), an S3 heart sound, and the presence of atrial arrhythmias such as flutter or fibrillation. Other signs can include giant C-V waves in the jugular pulse, hepatomegaly (often pulsatile), and edema with lung crepitations or pleural effusions.

The management of TR depends on the underlying cause and the severity of the condition. In severe cases, valve repair or replacement surgery may be necessary. Treatment may also involve addressing the underlying conditions contributing to TR, such as managing left heart failure or pulmonary hypertension.

The timing of the initial rise, peak, and return to normality of various cardiac enzymes can serve as a helpful guide. Creatine kinase, the main cardiac isoenzyme, typically experiences an initial rise within 4-8 hours, reaches its peak at 18 hours, and returns to normal within 2-3 days. Myoglobin, which lacks specificity due to its association with skeletal muscle damage, shows an initial rise within 1-4 hours, peaks at 6-7 hours, and returns to normal within 24 hours. Troponin I, known for its sensitivity and specificity, exhibits an initial rise within 3-12 hours, reaches its peak at 24 hours, and returns to normal within 3-10 days. HFABP, or heart fatty acid binding protein, experiences an initial rise within 1.5 hours, peaks at 5-10 hours, and returns to normal within 24 hours. Lastly, LDH, predominantly found in cardiac muscle, shows an initial rise at 10 hours, peaks at 24-48 hours, and returns to normal within 14 days.

Severe aortic stenosis (AS) is characterized by several distinct features. These include a slow rising pulse, an ejection systolic murmur that is heard loudest in the aortic area and may radiate to the carotids, and a soft or absent S2 heart sound. Additionally, patients with severe AS often have a narrow pulse pressure and may exhibit an S4 heart sound.

AS is commonly caused by hypertension, although blood pressure findings can vary. In severe cases, patients may actually be hypotensive due to impaired cardiac output. Symptoms of severe AS typically include Presyncope or syncope, exertional chest pain, and shortness of breath. These symptoms can be remembered using the acronym SAD (Syncope, Angina, Dyspnoea).

It is important to note that aortic stenosis primarily affects older individuals, as it is a result of scarring and calcium buildup in the valve. Age-related AS typically begins after the age of 60, but symptoms may not appear until patients are in their 70s or 80s.

Diastolic murmurs, on the other hand, are associated with conditions such as aortic regurgitation, pulmonary regurgitation, and mitral stenosis.

Further Reading:

Valvular heart disease refers to conditions that affect the valves of the heart. In the case of aortic valve disease, there are two main conditions: aortic regurgitation and aortic stenosis.

Aortic regurgitation is characterized by an early diastolic murmur, a collapsing pulse (also known as a water hammer pulse), and a wide pulse pressure. In severe cases, there may be a mid-diastolic Austin-Flint murmur due to partial closure of the anterior mitral valve cusps caused by the regurgitation streams. The first and second heart sounds (S1 and S2) may be soft, and S2 may even be absent. Additionally, there may be a hyperdynamic apical pulse. Causes of aortic regurgitation include rheumatic fever, infective endocarditis, connective tissue diseases like rheumatoid arthritis and systemic lupus erythematosus, and a bicuspid aortic valve. Aortic root diseases such as aortic dissection, spondyloarthropathies like ankylosing spondylitis, hypertension, syphilis, and genetic conditions like Marfan’s syndrome and Ehler-Danlos syndrome can also lead to aortic regurgitation.

Aortic stenosis, on the other hand, is characterized by a narrow pulse pressure, a slow rising pulse, and a delayed ESM (ejection systolic murmur). The second heart sound (S2) may be soft or absent, and there may be an S4 (atrial gallop) that occurs just before S1. A thrill may also be felt. The duration of the murmur is an important factor in determining the severity of aortic stenosis. Causes of aortic stenosis include degenerative calcification (most common in older patients), a bicuspid aortic valve (most common in younger patients), William’s syndrome (supravalvular aortic stenosis), post-rheumatic disease, and subvalvular conditions like hypertrophic obstructive cardiomyopathy (HOCM).

Management of aortic valve disease depends on the severity of symptoms. Asymptomatic patients are generally observed, while symptomatic patients may require valve replacement. Surgery may also be considered for asymptomatic patients with a valvular gradient greater than 40 mmHg and features such as left ventricular systolic dysfunction. Balloon valvuloplasty is limited to patients with critical aortic stenosis who are not fit for valve replacement.

This particular patient has a high risk of experiencing an acute coronary syndrome. Therefore, it is recommended to administer aspirin at a dosage of 300 mg and clopidogrel at a dosage ranging from 300-600 mg.

Further Reading:

Acute Coronary Syndromes (ACS) is a term used to describe a group of conditions that involve the sudden reduction or blockage of blood flow to the heart. This can lead to a heart attack or unstable angina. ACS includes ST segment elevation myocardial infarction (STEMI), non-ST segment elevation myocardial infarction (NSTEMI), and unstable angina (UA).

The development of ACS is usually seen in patients who already have underlying coronary heart disease. This disease is characterized by the buildup of fatty plaques in the walls of the coronary arteries, which can gradually narrow the arteries and reduce blood flow to the heart. This can cause chest pain, known as angina, during physical exertion. In some cases, the fatty plaques can rupture, leading to a complete blockage of the artery and a heart attack.

There are both non modifiable and modifiable risk factors for ACS. non modifiable risk factors include increasing age, male gender, and family history. Modifiable risk factors include smoking, diabetes mellitus, hypertension, hypercholesterolemia, and obesity.

The symptoms of ACS typically include chest pain, which is often described as a heavy or constricting sensation in the central or left side of the chest. The pain may also radiate to the jaw or left arm. Other symptoms can include shortness of breath, sweating, and nausea/vomiting. However, it’s important to note that some patients, especially diabetics or the elderly, may not experience chest pain.

The diagnosis of ACS is typically made based on the patient’s history, electrocardiogram (ECG), and blood tests for cardiac enzymes, specifically troponin. The ECG can show changes consistent with a heart attack, such as ST segment elevation or depression, T wave inversion, or the presence of a new left bundle branch block. Elevated troponin levels confirm the diagnosis of a heart attack.

The management of ACS depends on the specific condition and the patient’s risk factors. For STEMI, immediate coronary reperfusion therapy, either through primary percutaneous coronary intervention (PCI) or fibrinolysis, is recommended. In addition to aspirin, a second antiplatelet agent is usually given. For NSTEMI or unstable angina, the treatment approach may involve reperfusion therapy or medical management, depending on the patient’s risk of future cardiovascular events.

Fibrinolysis is a treatment option for patients with ST-elevation myocardial infarction (STEMI) if they are unable to receive primary percutaneous coronary intervention (PCI) within 120 minutes, but fibrinolysis can be administered within that time frame. Primary PCI is the preferred treatment for STEMI patients who present within 12 hours of symptom onset. However, if primary PCI cannot be performed within 120 minutes of the time when fibrinolysis could have been given, fibrinolysis should be considered. Along with fibrinolysis, an antithrombin medication such as unfractionated heparin (UFH), low molecular weight heparin (LMWH), fondaparinux, or bivalirudin is typically administered.

Further Reading:

Acute Coronary Syndromes (ACS) is a term used to describe a group of conditions that involve the sudden reduction or blockage of blood flow to the heart. This can lead to a heart attack or unstable angina. ACS includes ST segment elevation myocardial infarction (STEMI), non-ST segment elevation myocardial infarction (NSTEMI), and unstable angina (UA).

The development of ACS is usually seen in patients who already have underlying coronary heart disease. This disease is characterized by the buildup of fatty plaques in the walls of the coronary arteries, which can gradually narrow the arteries and reduce blood flow to the heart. This can cause chest pain, known as angina, during physical exertion. In some cases, the fatty plaques can rupture, leading to a complete blockage of the artery and a heart attack.

There are both non modifiable and modifiable risk factors for ACS. non modifiable risk factors include increasing age, male gender, and family history. Modifiable risk factors include smoking, diabetes mellitus, hypertension, hypercholesterolemia, and obesity.

The symptoms of ACS typically include chest pain, which is often described as a heavy or constricting sensation in the central or left side of the chest. The pain may also radiate to the jaw or left arm. Other symptoms can include shortness of breath, sweating, and nausea/vomiting. However, it’s important to note that some patients, especially diabetics or the elderly, may not experience chest pain.

The diagnosis of ACS is typically made based on the patient’s history, electrocardiogram (ECG), and blood tests for cardiac enzymes, specifically troponin. The ECG can show changes consistent with a heart attack, such as ST segment elevation or depression, T wave inversion, or the presence of a new left bundle branch block. Elevated troponin levels confirm the diagnosis of a heart attack.

The management of ACS depends on the specific condition and the patient’s risk factors. For STEMI, immediate coronary reperfusion therapy, either through primary percutaneous coronary intervention (PCI) or fibrinolysis, is recommended. In addition to aspirin, a second antiplatelet agent is usually given. For NSTEMI or unstable angina, the treatment approach may involve reperfusion therapy or medical management, depending on the patient’s risk of future cardiovascular events.

According to NICE guidelines, the usual threshold score for initiating anticoagulation in this case is 2.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting around 5% of patients over the age of 70-75 years and 10% of patients aged 80-85 years. While AF can cause palpitations and inefficient cardiac function, the most important aspect of managing patients with AF is reducing the increased risk of stroke.

AF can be classified as first detected episode, paroxysmal, persistent, or permanent. First detected episode refers to the initial occurrence of AF, regardless of symptoms or duration. Paroxysmal AF occurs when a patient has 2 or more self-terminating episodes lasting less than 7 days. Persistent AF refers to episodes lasting more than 7 days that do not self-terminate. Permanent AF is continuous atrial fibrillation that cannot be cardioverted or if attempts to do so are deemed inappropriate. The treatment goals for permanent AF are rate control and anticoagulation if appropriate.

Symptoms of AF include palpitations, dyspnea, and chest pain. The most common sign is an irregularly irregular pulse. An electrocardiogram (ECG) is essential for diagnosing AF, as other conditions can also cause an irregular pulse.

Managing patients with AF involves two key parts: rate/rhythm control and reducing stroke risk. Rate control involves slowing down the irregular pulse to avoid negative effects on cardiac function. This is typically achieved using beta-blockers or rate-limiting calcium channel blockers. If one drug is not effective, combination therapy may be used. Rhythm control aims to restore and maintain normal sinus rhythm through pharmacological or electrical cardioversion. However, the majority of patients are managed with a rate control strategy.

Reducing stroke risk in patients with AF is crucial. Risk stratifying tools, such as the CHA2DS2-VASc score, are used to determine the most appropriate anticoagulation strategy. Anticoagulation is recommended for patients with a score of 2 or more. Clinicians can choose between warfarin and novel oral anticoagulants (NOACs) for anticoagulation.

Before starting anticoagulation, the patient’s bleeding risk should be assessed using tools like the HAS-BLED score or the ORBIT tool. These tools evaluate factors such as hypertension, abnormal renal or liver function, history of bleeding, age, and use of drugs that predispose to bleeding.

Amiodarone is a medication that is recommended to be administered after the third shock in a shockable cardiac arrest (Vf/pVT) while chest compressions are being performed. The prescribed dose is 300 mg, given as an intravenous bolus that is diluted in 5% dextrose to a volume of 20 mL. It is important to note that amiodarone is not suitable for treating PEA or asystole.

In cases where VF/pVT persists after five defibrillation attempts, an additional dose of 150 mg of amiodarone should be given. However, if amiodarone is not available, lidocaine can be used as an alternative. The recommended dose of lidocaine is 1 mg/kg. It is crucial to avoid administering lidocaine if amiodarone has already been given.

Amiodarone is classified as a membrane-stabilizing antiarrhythmic drug. It works by prolonging the duration of the action potential and the refractory period in both the atrial and ventricular myocardium. This medication also slows down atrioventricular conduction and has a similar effect on accessory pathways.

Additionally, amiodarone has a mild negative inotropic action, meaning it weakens the force of heart contractions. It also causes peripheral vasodilation through non-competitive alpha-blocking effects.

It is important to note that while there is no evidence of long-term benefits from using amiodarone, it may improve short-term survival rates, which justifies its continued use.

After the return of spontaneous circulation (ROSC), there are two specific blood pressure targets that need to be achieved. The first target is to maintain a systolic blood pressure above 100 mmHg. The second target is to maintain the mean arterial pressure (MAP) within the range of 65 to 100 mmHg.

Further Reading:

Cardiopulmonary arrest is a serious event with low survival rates. In non-traumatic cardiac arrest, only about 20% of patients who arrest as an in-patient survive to hospital discharge, while the survival rate for out-of-hospital cardiac arrest is approximately 8%. The Resus Council BLS/AED Algorithm for 2015 recommends chest compressions at a rate of 100-120 per minute with a compression depth of 5-6 cm. The ratio of chest compressions to rescue breaths is 30:2.

After a cardiac arrest, the goal of patient care is to minimize the impact of post cardiac arrest syndrome, which includes brain injury, myocardial dysfunction, the ischaemic/reperfusion response, and the underlying pathology that caused the arrest. The ABCDE approach is used for clinical assessment and general management. Intubation may be necessary if the airway cannot be maintained by simple measures or if it is immediately threatened. Controlled ventilation is aimed at maintaining oxygen saturation levels between 94-98% and normocarbia. Fluid status may be difficult to judge, but a target mean arterial pressure (MAP) between 65 and 100 mmHg is recommended. Inotropes may be administered to maintain blood pressure. Sedation should be adequate to gain control of ventilation, and short-acting sedating agents like propofol are preferred. Blood glucose levels should be maintained below 8 mmol/l. Pyrexia should be avoided, and there is some evidence for controlled mild hypothermia but no consensus on this.

Post ROSC investigations may include a chest X-ray, ECG monitoring, serial potassium and lactate measurements, and other imaging modalities like ultrasonography, echocardiography, CTPA, and CT head, depending on availability and skills in the local department. Treatment should be directed towards the underlying cause, and PCI or thrombolysis may be considered for acute coronary syndrome or suspected pulmonary embolism, respectively.

Patients who are comatose after ROSC without significant pre-arrest comorbidities should be transferred to the ICU for supportive care. Neurological outcome at 72 hours is the best prognostic indicator of outcome.

Indications for drug treatment or pacing in patients with bradycardia include shock, syncope, myocardial ischemia, heart failure, and the presence of risk factors for asystole. If any of these adverse features are present, it is important to consider drug treatment or pacing. However, even if none of these adverse features are present, patients may still require drug treatment or pacing if they have risk factors for developing asystole, such as recent asystole, Mobitz II AV block, complete heart block with broad QRS, or a ventricular pause longer than 3 seconds.

Further Reading:

Causes of Bradycardia:
– Physiological: Athletes, sleeping
– Cardiac conduction dysfunction: Atrioventricular block, sinus node disease
– Vasovagal & autonomic mediated: Vasovagal episodes, carotid sinus hypersensitivity
– Hypothermia
– Metabolic & electrolyte disturbances: Hypothyroidism, hyperkalaemia, hypermagnesemia
– Drugs: Beta-blockers, calcium channel blockers, digoxin, amiodarone
– Head injury: Cushing’s response
– Infections: Endocarditis
– Other: Sarcoidosis, amyloidosis

Presenting symptoms of Bradycardia:
– Presyncope (dizziness, lightheadedness)
– Syncope
– Breathlessness
– Weakness
– Chest pain
– Nausea

Management of Bradycardia:
– Assess and monitor for adverse features (shock, syncope, myocardial ischaemia, heart failure)
– Treat reversible causes of bradycardia
– Pharmacological treatment: Atropine is first-line, adrenaline and isoprenaline are second-line
– Transcutaneous pacing if atropine is ineffective
– Other drugs that may be used: Aminophylline, dopamine, glucagon, glycopyrrolate

Bradycardia Algorithm:
– Follow the algorithm for management of bradycardia, which includes assessing and monitoring for adverse features, treating reversible causes, and using appropriate medications or pacing as needed.
https://acls-algorithms.com/wp-content/uploads/2020/12/Website-Bradycardia-Algorithm-Diagram.pdf

In order to gain a comprehensive understanding of AF management, it is crucial to familiarize oneself with the terminology used to describe its various subtypes. These terms help categorize different episodes of AF based on their characteristics and outcomes.

Acute AF refers to any episode that occurs within the previous 48 hours. It can manifest with or without symptoms and may or may not recur. On the other hand, paroxysmal AF describes episodes that spontaneously end within 7 days, typically within 48 hours. While these episodes are often recurrent, they can progress into a sustained form of AF.

Recurrent AF is defined as experiencing two or more episodes of AF. If the episodes self-terminate, they are classified as paroxysmal AF. However, if the episodes do not self-terminate, they are categorized as persistent AF. Persistent AF lasts longer than 7 days or has occurred after a previous cardioversion. To terminate persistent AF, electrical or pharmacological intervention is required. In some cases, persistent AF can progress into permanent AF.

Permanent AF, also known as Accepted AF, refers to episodes that cannot be successfully terminated, have relapsed after termination, or where cardioversion is not pursued. This subtype signifies a more chronic and ongoing form of AF.

By understanding and utilizing these terms, healthcare professionals can effectively communicate and manage the different subtypes of AF.

The first heart sound (S1) is created by vibrations produced when the mitral and tricuspid valves close. It occurs at the end of diastole and the start of ventricular systole, coming before the upstroke of the carotid pulsation.

A sample of the normal heart sounds can be listened to here (courtesy of Littman stethoscopes).

A loud S1 can be associated with the following conditions:
– Increased transvalvular gradient (e.g. mitral stenosis, tricuspid stenosis)
– Increased force of ventricular contraction (e.g. tachycardia, hyperdynamic states like fever and thyrotoxicosis)
– Shortened PR interval (e.g. Wolff-Parkinson-White syndrome)
– Mitral valve prolapse
– Thin individuals

A soft S1 can be associated with the following conditions:
– Inappropriate apposition of the AV valves (e.g. mitral regurgitation, tricuspid regurgitation)
– Prolonged PR interval (e.g. heart block, digoxin toxicity)
– Decreased force of ventricular contraction (e.g. myocarditis, myocardial infarction)
– Increased distance from the heart (e.g. obesity, emphysema, pericardial effusion)

A split S1 can be associated with the following conditions:
– Right bundle branch block
– LV pacing
– Ebstein anomaly

According to NICE guidelines, amiodarone is recommended as the initial choice for pharmacological cardioversion of atrial fibrillation (AF) in individuals who have evidence of structural heart disease.

Further Reading:

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting around 5% of patients over the age of 70-75 years and 10% of patients aged 80-85 years. While AF can cause palpitations and inefficient cardiac function, the most important aspect of managing patients with AF is reducing the increased risk of stroke.

AF can be classified as first detected episode, paroxysmal, persistent, or permanent. First detected episode refers to the initial occurrence of AF, regardless of symptoms or duration. Paroxysmal AF occurs when a patient has 2 or more self-terminating episodes lasting less than 7 days. Persistent AF refers to episodes lasting more than 7 days that do not self-terminate. Permanent AF is continuous atrial fibrillation that cannot be cardioverted or if attempts to do so are deemed inappropriate. The treatment goals for permanent AF are rate control and anticoagulation if appropriate.

Symptoms of AF include palpitations, dyspnea, and chest pain. The most common sign is an irregularly irregular pulse. An electrocardiogram (ECG) is essential for diagnosing AF, as other conditions can also cause an irregular pulse.

Managing patients with AF involves two key parts: rate/rhythm control and reducing stroke risk. Rate control involves slowing down the irregular pulse to avoid negative effects on cardiac function. This is typically achieved using beta-blockers or rate-limiting calcium channel blockers. If one drug is not effective, combination therapy may be used. Rhythm control aims to restore and maintain normal sinus rhythm through pharmacological or electrical cardioversion. However, the majority of patients are managed with a rate control strategy.

Reducing stroke risk in patients with AF is crucial. Risk stratifying tools, such as the CHA2DS2-VASc score, are used to determine the most appropriate anticoagulation strategy. Anticoagulation is recommended for patients with a score of 2 or more. Clinicians can choose between warfarin and novel oral anticoagulants (NOACs) for anticoagulation.

Before starting anticoagulation, the patient’s bleeding risk should be assessed using tools like the HAS-BLED score or the ORBIT tool. These tools evaluate factors such as hypertension, abnormal renal or liver function, history of bleeding, age, and use of drugs that predispose to bleeding.

Torsades de pointes is a condition that is linked to low levels of potassium (hypokalaemia) and magnesium (hypomagnesaemia). When potassium and magnesium levels are low, it can cause the QT interval to become prolonged, which increases the risk of developing Torsades de pointes.

Further Reading:

Torsades de pointes is an irregular broad-complex tachycardia that can be life-threatening. It is a polymorphic ventricular tachycardia that can lead to sudden cardiac death. It is characterized by distinct features on the electrocardiogram (ECG).

The causes of irregular broad-complex tachycardia include atrial fibrillation with bundle branch block, atrial fibrillation with ventricular pre-excitation (in patients with Wolff-Parkinson-White syndrome), and polymorphic ventricular tachycardia such as torsades de pointes. However, sustained polymorphic ventricular tachycardia is unlikely to be present without adverse features, so it is important to seek expert help for the assessment and treatment of this condition.

Torsades de pointes can be caused by drug-induced QT prolongation, diarrhea, hypomagnesemia, hypokalemia, and congenital long QT syndrome. It may also be seen in malnourished individuals due to low potassium and/or low magnesium levels. Additionally, it can occur in individuals taking drugs that prolong the QT interval or inhibit their metabolism.

The management of torsades de pointes involves immediate action. All drugs known to prolong the QT interval should be stopped. Amiodarone should not be given for definite torsades de pointes. Electrolyte abnormalities, especially hypokalemia, should be corrected. Magnesium sulfate should be administered intravenously. If adverse features are present, immediate synchronized cardioversion should be arranged. sought, as other treatments such as overdrive pacing may be necessary to prevent relapse once the arrhythmia has been corrected. If the patient becomes pulseless, defibrillation should be attempted immediately.

In summary, torsades de pointes is a dangerous arrhythmia that requires prompt management. It is important to identify and address the underlying causes, correct electrolyte abnormalities, and seek expert help for appropriate treatment.

Tietze’s syndrome is an uncommon condition that leads to localized pain and tenderness in one or more of the upper four ribs, with the second and third ribs being the most commonly affected. The exact cause of this syndrome is still unknown, although it has been suggested that it may be linked to repeated small injuries to the chest wall.

The pain experienced in Tietze’s syndrome is typically aggravated by movement, sneezing, and coughing, and it can also extend to the neck or shoulder on the affected side. In some cases, a firm swelling can be felt over the cartilage of the affected rib. While the pain usually diminishes after a few weeks or months, the swelling may persist.

Treatment for Tietze’s syndrome involves the use of pain-relieving medications, such as NSAIDs. In more severe or persistent cases, local steroid injections may be beneficial.

The timing of the initial rise, peak, and return to normality of various cardiac enzymes can serve as a helpful guide. Creatine kinase, the main cardiac isoenzyme, typically experiences an initial rise within 4-8 hours, reaches its peak at 18 hours, and returns to normal within 2-3 days. Myoglobin, which lacks specificity due to its association with skeletal muscle damage, shows an initial rise within 1-4 hours, peaks at 6-7 hours, and returns to normal within 24 hours. Troponin I, known for its sensitivity and specificity, exhibits an initial rise within 3-12 hours, reaches its peak at 24 hours, and returns to normal within 3-10 days. HFABP, or heart fatty acid binding protein, experiences an initial rise within 1.5 hours, peaks at 5-10 hours, and returns to normal within 24 hours. Lastly, LDH, predominantly found in cardiac muscle, shows an initial rise at 10 hours, peaks at 24-48 hours, and returns to normal within 14 days.

Adrenaline and isoprenaline are considered as second-line medications for the treatment of bradycardia. If atropine fails to improve the condition, transcutaneous pacing is recommended. However, if pacing is not available, the administration of second-line drugs becomes necessary. Adrenaline is typically given intravenously at a dosage of 2-10 mcg/minute, while isoprenaline is given at a dosage of 5 mcg/minute. It is important to note that glucagon is not mentioned as a treatment option for this patient’s bradycardia, as the cause of the condition is not specified as a beta-blocker overdose.

Further Reading:

Causes of Bradycardia:
– Physiological: Athletes, sleeping
– Cardiac conduction dysfunction: Atrioventricular block, sinus node disease
– Vasovagal & autonomic mediated: Vasovagal episodes, carotid sinus hypersensitivity
– Hypothermia
– Metabolic & electrolyte disturbances: Hypothyroidism, hyperkalaemia, hypermagnesemia
– Drugs: Beta-blockers, calcium channel blockers, digoxin, amiodarone
– Head injury: Cushing’s response
– Infections: Endocarditis
– Other: Sarcoidosis, amyloidosis

Presenting symptoms of Bradycardia:
– Presyncope (dizziness, lightheadedness)
– Syncope
– Breathlessness
– Weakness
– Chest pain
– Nausea

Management of Bradycardia:
– Assess and monitor for adverse features (shock, syncope, myocardial ischaemia, heart failure)
– Treat reversible causes of bradycardia
– Pharmacological treatment: Atropine is first-line, adrenaline and isoprenaline are second-line
– Transcutaneous pacing if atropine is ineffective
– Other drugs that may be used: Aminophylline, dopamine, glucagon, glycopyrrolate

Bradycardia Algorithm:
– Follow the algorithm for management of bradycardia, which includes assessing and monitoring for adverse features, treating reversible causes, and using appropriate medications or pacing as needed.
https://acls-algorithms.com/wp-content/uploads/2020/12/Website-Bradycardia-Algorithm-Diagram.pdf

Prinzmetal angina is a rare form of angina that typically occurs during periods of rest, specifically between midnight and early morning. The attacks can be severe and happen in clusters. This condition is caused by spasms in the coronary arteries, even though patients may have normal arteries. The main treatment options for controlling these spasms are calcium-channel blockers and nitrates. The spasms often follow a cyclical pattern and may disappear after a few months, only to reappear later on.

Unstable angina may present similarly to Prinzmetal angina, but it does not exclusively occur at night and the exercise tolerance test results are typically abnormal.

Decubitus angina, on the other hand, is angina that occurs when lying down. It is often a result of cardiac failure caused by increased intravascular volume, which puts extra strain on the heart.

Takotsubo cardiomyopathy, also known as acute stress cardiomyopathy, can present in a manner similar to an acute myocardial infarction. The cause of this condition is unknown, but it tends to occur in individuals who have recently experienced significant emotional or physical stress. The term Takotsubo refers to the shape the left ventricle takes on, resembling an octopus pot with a narrow neck and round bottom. ECGs often show characteristic changes, such as ST-elevation, but subsequent angiograms reveal normal coronary arteries. The diagnosis is confirmed when the angiogram shows the distinctive octopus pot shape of the left ventricle.

There is no indication of a psychogenic cause in this particular case.

Aortic regurgitation is a condition where the aortic valve fails to close tightly, resulting in the backflow of blood from the aorta into the left ventricle during ventricular diastole. This valvular lesion presents with various clinical symptoms and signs.

The clinical symptoms of aortic regurgitation include exertional dyspnea, orthopnea, and paroxysmal nocturnal dyspnea. These symptoms are experienced by patients during physical activity, while lying flat, and during episodes of sudden nighttime breathlessness, respectively.

On the other hand, the clinical signs of aortic regurgitation can be observed during physical examination. These signs include a collapsing pulse, widened pulse pressure, hyperkinetic laterally displaced apex beat, and a thrill in the aortic area. Additionally, an early diastolic murmur can be heard, which is loudest at the lower left sternal edge when the patient is sitting forward and exhaling.

Aortic regurgitation is also associated with several eponymous signs, which are named after the physicians who first described them. These signs include Corrigan’s sign, which is characterized by visible and forceful neck pulsation. De Musset’s sign refers to head nodding in time with the heartbeat. Quincke’s sign is the observation of visible nail bed capillary pulsation. Duroziez’s sign is the presence of a diastolic murmur heard proximal to femoral artery compression. Traube’s sign is the perception of a pistol shot sound over the femoral arteries. The Lighthouse sign is the blanching and flushing of the forehead. Becker’s sign is the pulsation seen in retinal vessels. Rosenbach’s sign is the presence of a pulsatile liver. Lastly, Muller’s sign refers to pulsations of the uvula.

In summary, aortic regurgitation is a valvular lesion that leads to the incomplete closure of the aortic valve. It manifests with various clinical symptoms, signs, and eponymous findings, which can be identified through careful examination and observation.

Adrenaline is recommended to be administered after the third shock in a shockable cardiac arrest (Vf/pVT) once chest compressions have been resumed. The recommended dose is 1 mg, which can be administered as either 10 mL of 1:10,000 or 1 mL of 1:1000 concentration. Subsequently, adrenaline should be given every 3-5 minutes, alternating with chest compressions, and it should be administered without interrupting the compressions. While there is no evidence of long-term benefit from the use of adrenaline in cardiac arrest, some studies have shown improved short-term survival, which justifies its continued use.

Wolff-Parkinson-White (WPW) syndrome is a condition that affects the electrical system of the heart. It occurs when there is an abnormal pathway, known as the bundle of Kent, between the atria and the ventricles. This pathway can cause premature contractions of the ventricles, leading to a type of rapid heartbeat called atrioventricular re-entrant tachycardia (AVRT).

In a normal heart rhythm, the electrical signals travel through the bundle of Kent and stimulate the ventricles. However, in WPW syndrome, these signals can cause the ventricles to contract prematurely. This can be seen on an electrocardiogram (ECG) as a shortened PR interval, a slurring of the initial rise in the QRS complex (known as a delta wave), and a widening of the QRS complex.

There are two distinct types of WPW syndrome that can be identified on an ECG. Type A is characterized by predominantly positive delta waves and QRS complexes in the praecordial leads, with a dominant R wave in V1. This can sometimes be mistaken for right bundle branch block (RBBB). Type B, on the other hand, shows predominantly negative delta waves and QRS complexes in leads V1 and V2, and positive in the other praecordial leads, resembling left bundle branch block (LBBB).

Overall, WPW syndrome is a condition that affects the electrical conduction system of the heart, leading to abnormal heart rhythms. It can be identified on an ECG by specific features such as shortened PR interval, delta waves, and widened QRS complex.

This patient is displaying symptoms consistent with a diagnosis of an acute myocardial infarction. It is important to provide pain relief as soon as possible. One option for pain relief is GTN, which can be taken sublingually or buccally. However, if there is suspicion of an acute myocardial infarction, it is recommended to offer intravenous opioids such as morphine.

Aspirin should be offered to all patients with unstable angina or NSTEMI as soon as possible and should be continued indefinitely, unless there are contraindications such as a bleeding risk or aspirin hypersensitivity. A loading dose of 300 mg should be administered promptly after presentation.

For patients without a high bleeding risk who do not have coronary angiography planned within 24 hours of admission, fondaparinux should be administered. However, for patients who are likely to undergo coronary angiography within 24 hours, unfractionated heparin can be offered as an alternative to fondaparinux. In cases of significant renal impairment (creatinine above 265 micromoles per litre), unfractionated heparin with dose adjustment guided by clotting function monitoring can also be considered as an alternative to fondaparinux.

Routine administration of oxygen is no longer recommended, but it is important to monitor oxygen saturation using pulse oximetry as soon as possible, preferably before hospital admission. Supplemental oxygen should only be offered to individuals with an oxygen saturation (SpO2) of less than 94% who are not at risk of hypercapnic respiratory failure, with a target SpO2 range of 94-98%. For individuals with chronic obstructive pulmonary disease who are at risk of hypercapnic respiratory failure, a target SpO2 range of 88-92% should be aimed for until blood gas analysis is available.

Bivalirudin, a specific and reversible direct thrombin inhibitor (DTI), is recommended by NICE as a possible treatment for adults with STEMI who are undergoing percutaneous coronary intervention.

For more information, please refer to the NICE guidelines on the assessment and diagnosis of chest pain of recent onset.

Aortic stenosis leads to the presence of a murmur during the ejection phase of the cardiac cycle. This murmur is most audible at the right second intercostal space and can be heard extending into the right neck.

Mitral regurgitation, on the other hand, produces a high-pitched murmur that occurs throughout the entire systolic phase of the cardiac cycle. This murmur is best heard at the apex of the heart and can be heard radiating into the axilla.

Tricuspid regurgitation is characterized by a blowing murmur that occurs throughout the entire systolic phase of the cardiac cycle. This murmur is most clearly heard at the lower left sternal edge.

Ventricular septal defect results in a harsh murmur that occurs throughout the entire systolic phase of the cardiac cycle. This murmur is best heard at the third or fourth left intercostal space and can be heard radiating throughout the praecordium.

Aortopulmonary shunts are an extremely rare cause of a murmur that occurs throughout the entire systolic phase of the cardiac cycle.

When treating adults with bradycardia, it is recommended to administer a maximum of 6 doses of atropine 500 mcg. These doses can be repeated every 3-5 minutes. The total cumulative dose of atropine should not exceed 3 mg in adults.

Further Reading:

Causes of Bradycardia:
– Physiological: Athletes, sleeping
– Cardiac conduction dysfunction: Atrioventricular block, sinus node disease
– Vasovagal & autonomic mediated: Vasovagal episodes, carotid sinus hypersensitivity
– Hypothermia
– Metabolic & electrolyte disturbances: Hypothyroidism, hyperkalaemia, hypermagnesemia
– Drugs: Beta-blockers, calcium channel blockers, digoxin, amiodarone
– Head injury: Cushing’s response
– Infections: Endocarditis
– Other: Sarcoidosis, amyloidosis

Presenting symptoms of Bradycardia:
– Presyncope (dizziness, lightheadedness)
– Syncope
– Breathlessness
– Weakness
– Chest pain
– Nausea

Management of Bradycardia:
– Assess and monitor for adverse features (shock, syncope, myocardial ischaemia, heart failure)
– Treat reversible causes of bradycardia
– Pharmacological treatment: Atropine is first-line, adrenaline and isoprenaline are second-line
– Transcutaneous pacing if atropine is ineffective
– Other drugs that may be used: Aminophylline, dopamine, glucagon, glycopyrrolate

Bradycardia Algorithm:
– Follow the algorithm for management of bradycardia, which includes assessing and monitoring for adverse features, treating reversible causes, and using appropriate medications or pacing as needed.
https://acls-algorithms.com/wp-content/uploads/2020/12/Website-Bradycardia-Algorithm-Diagram.pdf

People with chronic mitral regurgitation often experience atrial fibrillation.

Mitral Stenosis:
– Causes: Rheumatic fever, Mucopolysaccharidoses, Carcinoid, Endocardial fibroelastosis
– Features: Mid-late diastolic murmur, loud S1, opening snap, low volume pulse, malar flush, atrial fibrillation, signs of pulmonary edema, tapping apex beat
– Features of severe mitral stenosis: Length of murmur increases, opening snap becomes closer to S2
– Investigation findings: CXR may show left atrial enlargement, echocardiography may show reduced cross-sectional area of the mitral valve

Mitral Regurgitation:
– Causes: Mitral valve prolapse, Myxomatous degeneration, Ischemic heart disease, Rheumatic fever, Connective tissue disorders, Endocarditis, Dilated cardiomyopathy
– Features: pansystolic murmur radiating to left axilla, soft S1, S3, laterally displaced apex beat with heave
– Signs of acute MR: Decompensated congestive heart failure symptoms
– Signs of chronic MR: Leg edema, fatigue, arrhythmia (atrial fibrillation)
– Investigation findings: Doppler echocardiography to detect regurgitant flow and pulmonary hypertension, ECG may show signs of LA enlargement and LV hypertrophy, CXR may show LA and LV enlargement in chronic MR and pulmonary edema in acute MR.

Severe aortic stenosis is characterized by several distinct features. These include a narrow pulse pressure, which refers to the difference between the systolic and diastolic blood pressure readings. Additionally, individuals with severe aortic stenosis may exhibit a slow rising pulse, meaning that the pulse wave takes longer to reach its peak. Another common feature is a delayed ejection systolic murmur, which is a heart sound that occurs during the ejection phase of the cardiac cycle. The second heart sound (S2) may also be soft or absent in individuals with severe aortic stenosis. Another potential finding is the presence of an S4 heart sound, which occurs during the filling phase of the cardiac cycle. A thrill, which is a palpable vibration, may also be felt in severe cases. The duration of the murmur, as well as the presence of left ventricular hypertrophy or failure, are additional features that may be observed in individuals with severe aortic stenosis.

Further Reading:

Valvular heart disease refers to conditions that affect the valves of the heart. In the case of aortic valve disease, there are two main conditions: aortic regurgitation and aortic stenosis.

Aortic regurgitation is characterized by an early diastolic murmur, a collapsing pulse (also known as a water hammer pulse), and a wide pulse pressure. In severe cases, there may be a mid-diastolic Austin-Flint murmur due to partial closure of the anterior mitral valve cusps caused by the regurgitation streams. The first and second heart sounds (S1 and S2) may be soft, and S2 may even be absent. Additionally, there may be a hyperdynamic apical pulse. Causes of aortic regurgitation include rheumatic fever, infective endocarditis, connective tissue diseases like rheumatoid arthritis and systemic lupus erythematosus, and a bicuspid aortic valve. Aortic root diseases such as aortic dissection, spondyloarthropathies like ankylosing spondylitis, hypertension, syphilis, and genetic conditions like Marfan’s syndrome and Ehler-Danlos syndrome can also lead to aortic regurgitation.

Aortic stenosis, on the other hand, is characterized by a narrow pulse pressure, a slow rising pulse, and a delayed ESM (ejection systolic murmur). The second heart sound (S2) may be soft or absent, and there may be an S4 (atrial gallop) that occurs just before S1. A thrill may also be felt. The duration of the murmur is an important factor in determining the severity of aortic stenosis. Causes of aortic stenosis include degenerative calcification (most common in older patients), a bicuspid aortic valve (most common in younger patients), William’s syndrome (supravalvular aortic stenosis), post-rheumatic disease, and subvalvular conditions like hypertrophic obstructive cardiomyopathy (HOCM).

Management of aortic valve disease depends on the severity of symptoms. Asymptomatic patients are generally observed, while symptomatic patients may require valve replacement. Surgery may also be considered for asymptomatic patients with a valvular gradient greater than 40 mmHg and features such as left ventricular systolic dysfunction. Balloon valvuloplasty is limited to patients with critical aortic stenosis who are not fit for valve replacement.