One of the clinical features of mitral stenosis is malar flush, which refers to a reddening or flushing of the cheeks. Other clinical features include a mid-late diastolic murmur that is best heard during expiration, a loud S1 heart sound with an opening snap, a low volume pulse, atrial fibrillation, and signs of pulmonary edema such as crepitations or the presence of white or pink frothy sputum.

Further Reading:

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.

Atropine is a medication that slows down the movement of the digestive system and is not recommended for use in individuals with intestinal blockage. It works by blocking the effects of a neurotransmitter called acetylcholine, which is responsible for promoting gastrointestinal motility and the emptying of the stomach. Therefore, atropine should not be given to patients with gastrointestinal obstruction as it can further hinder the movement of the intestines.

Further Reading:

Types of Heart Block:

1. Atrioventricular (AV) Blocks:
– Disrupt electrical conduction between the atria and ventricles at the AV node.
– Three degrees of AV block: first degree, second degree (type 1 and type 2), and third degree (complete) AV block.

– First degree AV block: PR interval > 0.2 seconds.
– Second degree AV block:
– Type 1 (Mobitz I, Wenckebach): progressive prolongation of the PR interval until a dropped beat occurs.
– Type 2 (Mobitz II): PR interval is constant, but the P wave is often not followed by a QRS complex.
– Third degree (complete) AV block: no association between the P waves and QRS complexes.

Features of complete heart block: syncope, heart failure, regular bradycardia (30-50 bpm), wide pulse pressure, JVP (jugular venous pressure) cannon waves in neck, variable intensity of S1.

2. Bundle Branch Blocks:
– Electrical conduction travels from the bundle of His to the left and right bundle branches.
– Diagnosed when the duration of the QRS complex on the ECG exceeds 120 ms.

– Right bundle branch block (RBBB).
– Left bundle branch block (LBBB).
– Left anterior fascicular block (LAFB).
– Left posterior fascicular block (LPFB).
– Bifascicular block.
– Trifascicular block.

ECG features of bundle branch blocks:
– RBBB: QRS duration > 120 ms, RSR’ pattern in V1-3 (M-shaped QRS complex), wide S wave in lateral leads (I, aVL, V5-6).
– LBBB: QRS duration > 120 ms, dominant S wave in V1, broad, notched (‘M’-shaped) R wave in V6, broad monophasic R wave in lateral leads (I, aVL, V5-6), absence of Q waves in lateral leads, prolonged R wave peak time > 60 ms in leads V5-6.

WiLLiaM MaRROW is a useful mnemonic for remembering the morphology of the QRS in leads V1 and V6 for LBBB.

Atropine should not be given to patients with certain conditions, including heart transplant, angle-closure glaucoma, gastrointestinal motility disorders, myasthenia gravis, severe ulcerative colitis, toxic megacolon, bladder outflow obstruction, and urinary retention. In heart transplant patients, atropine will not have the desired effect as the denervated hearts do not respond to vagal blockade. Giving atropine in these patients may even lead to paradoxical sinus arrest or high-grade AV block.

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

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

Currently, there are three beta-blockers that have been approved for the treatment of chronic heart failure. These medications include bisoprolol, carvedilol, and nebivolol.

Chronic HF is a common clinical syndrome resulting from coronary artery disease (CAD), HTN, valvular heart disease, and/or primary cardiomyopathy. There is now conclusive evidence that β-blockers, when added to ACE inhibitors, substantially reduce mortality, decrease sudden death, and improve symptoms in patients with HF. Despite the overwhelming evidence and guidelines that mandate the use of β-blockers in all HF patients without contraindications, many patients do not receive this treatment.

Adenosine is a type of purine nucleoside that is primarily utilized in the diagnosis and treatment of paroxysmal supraventricular tachycardia. Its main mechanism of action involves stimulating A1-adenosine receptors and opening acetylcholine-sensitive potassium channels. This leads to hyperpolarization of the cell membrane in the atrioventricular (AV) node and slows down conduction in the AV node by inhibiting calcium channels.

When administering adenosine, it is given rapidly through an intravenous bolus, followed by a saline flush. The initial dose for adults is 6 mg, and if necessary, additional doses of 12 mg or 18 mg can be given at 1-2 minute intervals until the desired effect is observed. It is important to note that the latest ALS guidelines recommend 18 mg for the third dose, while the BNF/NICE guidelines suggest 12 mg.

One of the advantages of adenosine is its very short half-life, which is less than 10 seconds. This means that its effects are rapid, typically occurring within 10 seconds. However, the duration of action is also short, lasting only 10-20 seconds. Due to its short half-life, any side effects experienced are usually brief. These side effects may include a sense of impending doom, facial flushing, dyspnea, chest discomfort, and a metallic taste.

There are certain contraindications to the use of adenosine. These include 2nd or 3rd degree AV block, sick sinus syndrome, long QT syndrome, severe hypotension, decompensated heart failure, chronic obstructive lung disease, and asthma. It is important to exercise caution when administering adenosine to patients with a heart transplant, as they are particularly sensitive to its effects. In these cases, a reduced initial dose of 3 mg is recommended, followed by 6 mg and then 12 mg.

It is worth noting that the effects of adenosine can be potentiated by dipyridamole, a medication commonly used in combination with adenosine. Therefore, the dose of adenosine should be adjusted and reduced in patients who are also taking dipyridamole.

Distinguishing between unstable angina and other acute coronary syndromes can be determined by normal troponin results. Unstable angina is characterized by new onset angina or a sudden worsening of previously stable angina, often occurring at rest. This condition typically requires hospital admission. On the other hand, stable angina is predictable and occurs during physical exertion or emotional stress, lasting for a short duration of no more than 10 minutes and relieved within minutes of rest or sublingual nitrates.

To diagnose unstable angina, it is crucial to consider the nature of the chest pain and negative cardiac enzyme testing. The presence or absence of chest pain at rest and the response to rest and treatment with GTN are the most useful descriptors in distinguishing between stable and unstable angina. It is important to note that patients with unstable angina may not exhibit any changes on an electrocardiogram (ECG).

If troponin results are abnormal, it indicates a myocardial infarction rather than unstable angina.

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.

Lown-Ganong-Levine (LGL) syndrome is a condition that affects the electrical conducting system of the heart. It is classified as a pre-excitation syndrome, similar to the more well-known Wolff-Parkinson-White (WPW) syndrome. However, unlike WPW syndrome, LGL syndrome does not involve an accessory pathway for conduction. Instead, it is believed that there may be accessory fibers present that bypass all or part of the atrioventricular node.

When looking at an electrocardiogram (ECG) of a patient with LGL syndrome in sinus rhythm, there are several characteristic features to observe. The PR interval, which represents the time it takes for the electrical signal to travel from the atria to the ventricles, is typically shortened and measures less than 120 milliseconds. The QRS duration, which represents the time it takes for the ventricles to contract, is normal. The P wave, which represents the electrical activity of the atria, may be normal or inverted. However, what distinguishes LGL syndrome from other pre-excitation syndromes is the absence of a delta wave, which is a slurring of the initial rise in the QRS complex.

It is important to note that LGL syndrome predisposes individuals to paroxysmal supraventricular tachycardia (SVT), a rapid heart rhythm that originates above the ventricles. However, it does not increase the risk of developing atrial fibrillation or flutter, which are other types of abnormal heart rhythms.

The second heart sound (S2) is created by vibrations produced when the aortic and pulmonary valves close. It marks the end of systole. It is normal to hear a split in the sound during inspiration.

A loud S2 can be associated with certain conditions such as systemic hypertension (resulting in a loud A2), pulmonary hypertension (resulting in a loud P2), hyperdynamic states (like tachycardia, fever, or thyrotoxicosis), and atrial septal defect (which causes a loud P2).

On the other hand, a soft S2 can be linked to decreased aortic diastolic pressure (as seen in aortic regurgitation), poorly mobile cusps (such as calcification of the aortic valve), aortic root dilatation, and pulmonary stenosis (which causes a soft P2).

A widely split S2 can occur during deep inspiration, right bundle branch block, prolonged right ventricular systole (seen in conditions like pulmonary stenosis or pulmonary embolism), and severe mitral regurgitation. However, in the case of atrial septal defect, the splitting is fixed and does not vary with respiration.

Reversed splitting of S2, where P2 occurs before A2 (paradoxical splitting), can occur during deep expiration, left bundle branch block, prolonged left ventricular systole (as seen in hypertrophic cardiomyopathy), severe aortic stenosis, and right ventricular pacing.

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.

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.

Beta blockers are the primary treatment for long QT syndrome (LQTS). This patient probably has an undiagnosed congenital LQTS because there is no obvious cause. If there is a known cause of LQTS that can be removed, removing it may be the only necessary treatment. However, in all other cases, beta blockers are usually needed to prevent ventricular arrhythmias. Ventricular arrhythmias happen because of increased adrenergic activity. Beta blockers reduce the effects of adrenergic stimulation.

Further Reading:

Long QT syndrome (LQTS) is a condition characterized by a prolonged QT interval on an electrocardiogram (ECG), which represents abnormal repolarization of the heart. LQTS can be either acquired or congenital. Congenital LQTS is typically caused by gene abnormalities that affect ion channels responsible for potassium or sodium flow in the heart. There are 15 identified genes associated with congenital LQTS, with three genes accounting for the majority of cases. Acquired LQTS can be caused by various factors such as certain medications, electrolyte imbalances, hypothermia, hypothyroidism, and bradycardia from other causes.

The normal QTc values, which represent the corrected QT interval for heart rate, are typically less than 450 ms for men and less than 460ms for women. Prolonged QTc intervals are considered to be greater than these values. It is important to be aware of drugs that can cause QT prolongation, as this can lead to potentially fatal arrhythmias. Some commonly used drugs that can cause QT prolongation include antimicrobials, antiarrhythmics, antipsychotics, antidepressants, antiemetics, and others.

Management of long QT syndrome involves addressing any underlying causes and using beta blockers. In some cases, an implantable cardiac defibrillator (ICD) may be recommended for patients who have experienced recurrent arrhythmic syncope, documented torsades de pointes, previous ventricular tachyarrhythmias or torsades de pointes, previous cardiac arrest, or persistent syncope. Permanent pacing may be used in patients with bradycardia or atrioventricular nodal block and prolonged QT. Mexiletine is a treatment option for those with LQT3. Cervicothoracic sympathetic denervation may be considered in patients with recurrent syncope despite beta-blockade or in those who are not ideal candidates for an ICD. The specific treatment options for LQTS depend on the type and severity of the condition.

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.

Post myocardial infarction ventricular septal defect (VSD) is a rare but serious complication that occurs when the cardiac wall ruptures. It typically develops 2-3 days after a heart attack, and if left untreated, 85% of patients will die within two months. The murmur associated with VSD is a continuous sound throughout systole, and it is loudest at the lower left sternal edge. A palpable vibration, known as a thrill, is often felt along with the murmur.

Dressler’s syndrome, on the other hand, is a type of pericarditis that occurs 2-10 weeks after a heart attack or cardiac surgery. It is characterized by sharp chest pain that is relieved by sitting forwards. Other signs of Dressler’s syndrome include a rubbing sound heard when listening to the heart, pulsus paradoxus (an abnormal drop in blood pressure during inspiration), and signs of right ventricular failure.

Mitral regurgitation also causes a continuous murmur throughout systole, but it is best heard at the apex of the heart and may radiate to the axilla (armpit).

Tricuspid stenosis, on the other hand, causes an early diastolic murmur that is best heard at the lower left sternal edge during inspiration.

Lastly, mitral stenosis causes a rumbling mid-diastolic murmur that is best heard at the apex of the heart. To listen for this murmur, the patient should be in the left lateral position, and the stethoscope bell should be used during expiration.

This patient is likely experiencing an acute coronary syndrome, possibly a non-ST-elevation myocardial infarction (NSTEMI) or unstable angina. The troponin test will help confirm the diagnosis. The patient’s ECG showed ST depression in the inferior leads, but this normalized after treatment with GTN and morphine, ruling out a ST-elevation myocardial infarction (STEMI).

Immediate pain relief should be provided. GTN (sublingual or buccal) can be used, but intravenous opioids like morphine should be considered, especially if a heart attack is suspected.

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

Fondaparinux should be given to patients without a high bleeding risk, unless coronary angiography is planned within 24 hours of admission. Unfractionated heparin can be an alternative to fondaparinux for patients who will undergo coronary angiography within 24 hours. For patients with significant renal impairment, unfractionated heparin can also be considered, with dose adjustment based on clotting function monitoring.

Routine administration of oxygen is no longer recommended, but oxygen saturation should be monitored using pulse oximetry as soon as possible, preferably before hospital admission. Supplemental oxygen should only be offered to individuals with oxygen saturation (SpO2) below 94% who are not at risk of hypercapnic respiratory failure, aiming for a SpO2 of 94-98%. For individuals with chronic obstructive pulmonary disease at risk of hypercapnic respiratory failure, a target SpO2 of 88-92% should be achieved 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 undergoing percutaneous coronary intervention.

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

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 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.

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.

For the exam, it is important to be familiar with the statistics regarding the outcomes of outpatient and inpatient cardiac arrest in the UK.

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.

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

One of the signs of digoxin toxicity is yellow-green vision. Other clinical features include feeling generally unwell, lethargy, nausea and vomiting, loss of appetite, confusion, and the development of arrhythmias such as AV block and bradycardia.

Further Reading:

Digoxin is a medication used for rate control in atrial fibrillation and for improving symptoms in heart failure. It works by decreasing conduction through the atrioventricular node and increasing the force of cardiac muscle contraction. However, digoxin toxicity can occur, and plasma concentration alone does not determine if a patient has developed toxicity. Symptoms of digoxin toxicity include feeling generally unwell, lethargy, nausea and vomiting, anorexia, confusion, yellow-green vision, arrhythmias, and gynaecomastia.

ECG changes seen in digoxin toxicity include downsloping ST depression with a characteristic Salvador Dali sagging appearance, flattened, inverted, or biphasic T waves, shortened QT interval, mild PR interval prolongation, and prominent U waves. There are several precipitating factors for digoxin toxicity, including hypokalaemia, increasing age, renal failure, myocardial ischaemia, electrolyte imbalances, hypoalbuminaemia, hypothermia, hypothyroidism, and certain medications such as amiodarone, quinidine, verapamil, and diltiazem.

Management of digoxin toxicity involves the use of digoxin specific antibody fragments, also known as Digibind or digifab. Arrhythmias should be treated, and electrolyte disturbances should be corrected with close monitoring of potassium levels. It is important to note that digoxin toxicity can be precipitated by hypokalaemia, and toxicity can then lead to hyperkalaemia.

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.

The second heart sound (S2) is created by vibrations produced when the aortic and pulmonary valves close. It marks the end of systole. It is normal to hear a split in the sound during inspiration.

A loud S2 can be associated with certain conditions such as systemic hypertension (resulting in a loud A2), pulmonary hypertension (resulting in a loud P2), hyperdynamic states (like tachycardia, fever, or thyrotoxicosis), and atrial septal defect (which causes a loud P2).

On the other hand, a soft S2 can be linked to decreased aortic diastolic pressure (as seen in aortic regurgitation), poorly mobile cusps (such as calcification of the aortic valve), aortic root dilatation, and pulmonary stenosis (which causes a soft P2).

A widely split S2 can occur during deep inspiration, right bundle branch block, prolonged right ventricular systole (seen in conditions like pulmonary stenosis or pulmonary embolism), and severe mitral regurgitation. However, in the case of atrial septal defect, the splitting is fixed and does not vary with respiration.

Reversed splitting of S2, where P2 occurs before A2 (paradoxical splitting), can occur during deep expiration, left bundle branch block, prolonged left ventricular systole (as seen in hypertrophic cardiomyopathy), severe aortic stenosis, and right ventricular pacing.

Atropine acts as an antagonist to the parasympathetic neurotransmitter acetylcholine at muscarinic receptors. This means that it blocks the effects of the vagus nerve on both the SA node and the AV node, resulting in increased sinus automaticity and improved AV node conduction.

The side effects of atropine are dependent on the dosage and may include dry mouth, nausea and vomiting, blurred vision, urinary retention, and tachyarrhythmias. Elderly patients may also experience acute confusion and hallucinations.

Atropine is recommended for use in cases of sinus, atrial, or nodal bradycardia or AV block when the patient’s hemodynamic condition is unstable due to the bradycardia. According to the ALS bradycardia algorithm, an initial dose of 500 mcg IV is suggested if any adverse features such as shock, syncope, myocardial ischemia, or heart failure are present. If this initial dose is unsuccessful, additional 500 mcg doses can be administered at 3-5 minute intervals, with a maximum dose of 3 mg. It is important to avoid doses exceeding 3 mg as they can paradoxically slow the heart rate.

Asystole during cardiac arrest is typically caused by primary myocardial pathology rather than excessive vagal tone. Therefore, there is no evidence supporting the routine use of atropine in the treatment of asystole or PEA. Consequently, atropine is no longer included in the non-shockable part of the ALS algorithm.

Aside from its use in cardiac conditions, atropine also has other applications. It can be used topically in the eyes as a cycloplegic and mydriatic, to reduce secretions during anesthesia, and in the treatment of organophosphate poisoning.

The diagnosis in this particular case is malignant (accelerated) hypertension. The patient’s blood pressure is greater than 220/110, and they also have retinal haemorrhages and papilloedema. During the examination, it is important to look for other features such as the presence of a 3rd heart sound, ankle oedema, bilateral basal crepitations, and any focal neurological deficit.

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.

Aortic sclerosis is a condition that occurs when the aortic valve undergoes senile degeneration. Unlike aortic stenosis, it does not result in any obstruction of the left ventricular outflow tract. To differentiate between aortic stenosis and aortic sclerosis, the following can be used:

Feature: Aortic stenosis
– Symptoms: Can be asymptomatic, but may cause angina, breathlessness, and syncope if severe.
– Pulse: Slow rising, low volume pulse.
– Apex beat: Sustained, heaving apex beat.
– Thrill: Palpable thrill in the aortic area can be felt.
– Murmur: Ejection systolic murmur loudest in the aortic area.
– Radiation: Radiates to carotids.

Feature: Aortic sclerosis
– Symptoms: Always asymptomatic.
– Pulse: Normal pulse character.
– Apex beat: Normal apex beat.
– Thrill: No thrill.
– Murmur: Ejection systolic murmur loudest in the aortic area.
– Radiation: No radiation.

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.

There is no known connection between the use of cannabis and aortic dissection. Some factors that are recognized as increasing the risk of aortic dissection include hypertension, atherosclerosis, aortic coarctation, the use of sympathomimetic drugs like cocaine, Marfan syndrome, Ehlers-Danlos syndrome, Turner’s syndrome, tertiary syphilis, and pre-existing aortic aneurysm.

Lidocaine is commonly used as both an anti-arrhythmic medication and a local anesthetic. However, it is important to note that it should not be used as an anti-arrhythmic therapy in patients with Local Anesthetic Systemic Toxicity (LAST). This is because lidocaine can potentially worsen the toxicity symptoms in these patients.

Further Reading:

Local anaesthetics, such as lidocaine, bupivacaine, and prilocaine, are commonly used in the emergency department for topical or local infiltration to establish a field block. Lidocaine is often the first choice for field block prior to central line insertion. These anaesthetics work by blocking sodium channels, preventing the propagation of action potentials.

However, local anaesthetics can enter the systemic circulation and cause toxic side effects if administered in high doses. Clinicians must be aware of the signs and symptoms of local anaesthetic systemic toxicity (LAST) and know how to respond. Early signs of LAST include numbness around the mouth or tongue, metallic taste, dizziness, visual and auditory disturbances, disorientation, and drowsiness. If not addressed, LAST can progress to more severe symptoms such as seizures, coma, respiratory depression, and cardiovascular dysfunction.

The management of LAST is largely supportive. Immediate steps include stopping the administration of local anaesthetic, calling for help, providing 100% oxygen and securing the airway, establishing IV access, and controlling seizures with benzodiazepines or other medications. Cardiovascular status should be continuously assessed, and conventional therapies may be used to treat hypotension or arrhythmias. Intravenous lipid emulsion (intralipid) may also be considered as a treatment option.

If the patient goes into cardiac arrest, CPR should be initiated following ALS arrest algorithms, but lidocaine should not be used as an anti-arrhythmic therapy. Prolonged resuscitation may be necessary, and intravenous lipid emulsion should be administered. After the acute episode, the patient should be transferred to a clinical area with appropriate equipment and staff for further monitoring and care.

It is important to report cases of local anaesthetic toxicity to the appropriate authorities, such as the National Patient Safety Agency in the UK or the Irish Medicines Board in the Republic of Ireland. Additionally, regular clinical review should be conducted to exclude pancreatitis, as intravenous lipid emulsion can interfere with amylase or lipase assays.