Narrow QRS complex tachycardia is a term used to describe a fast heart rhythm with a pulse rate over 100 bpm and a QRS duration shorter than 120 ms.

Further Reading:

Supraventricular tachycardia (SVT) is a type of tachyarrhythmia that originates from the atria or above the bundle of His in the heart. It includes all atrial and junctional tachycardias, although atrial fibrillation is often considered separately. SVT typically produces a narrow QRS complex tachycardia on an electrocardiogram (ECG), unless there is an underlying conduction abnormality below the atrioventricular (AV) node. Narrow complex tachycardias are considered SVTs, while some broad complex tachycardias can also be SVTs with co-existent conduction delays.

SVT can be classified into three main subtypes based on where it arises: re-entrant accessory circuits (the most common type), atrial tachycardias, and junctional tachycardias. The most common SVTs are AVNRT (AV nodal re-entry tachycardia) and AVRT (AV re-entry tachycardia), which arise from accessory circuits within the heart. AVNRT involves an accessory circuit within the AV node itself, while AVRT involves an accessory pathway between the atria and ventricles that allows additional electrical signals to trigger the AV node.

Atrial tachycardias originate from abnormal foci within the atria, except for the SA node, AV node, or accessory pathway. Junctional tachycardias arise in the AV junction. The ECG features of SVTs vary depending on the type. Atrial tachycardias may have abnormal P wave morphology, an isoelectric baseline between P waves (in atrial flutter), and inverted P waves in certain leads. AVNRT may show pseudo R waves in V1 or pseudo S waves in certain leads, with an RP interval shorter than the PR interval. AVRT (WPW) may exhibit a delta wave on a resting ECG and retrograde P waves in the ST segment, with an RP interval shorter than the PR interval. Junctional tachycardias may have retrograde P waves before, during, or after the QRS complex, with inverted P waves in certain leads and upright P waves in others.

Treatment of SVT follows the 2021 resuscitation council algorithm for tachycardia with a pulse. The algorithm provides guidelines for managing stable patients with SVT.

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.

This patient’s ECG shows signs consistent with hyperkalemia, including broad QRS complexes, tall-peaked T waves, and bizarre p waves. It is estimated that around 10% of patients with SLE have hyperkalemia, which is believed to be caused by hyporeninemic hypoaldosteronism. Additionally, the patient has been taking a high dose of ibuprofen, which can also contribute to the development of hyperkalemia. NSAIDs are thought to induce hyperkalemia by reducing renin secretion, leading to decreased potassium excretion.

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.

Having Mobitz II AV block increases the risk of developing asystole. Other risk factors for asystole include recent asystole, third degree AV block (complete heart block) with a broad QRS complex, and a ventricular pause lasting 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

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 primary location for aortic dissection, which is being considered in this case, is the ascending aorta.

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.

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.

Mitral stenosis is a condition characterized by a narrowing of the mitral valve in the heart. One of the key features of this condition is a loud first heart sound, which is often described as having an opening snap. This sound is typically heard during mid-late diastole and is best heard during expiration. Other signs of mitral stenosis include a low volume pulse, a flushed appearance of the cheeks (known as malar flush), and the presence of atrial fibrillation. Additionally, patients with mitral stenosis may exhibit signs of pulmonary edema, such as crepitations (crackling sounds) in the lungs and the production of white or pink frothy sputum. It is important to note that a water hammer pulse is associated with a different condition called aortic regurgitation.

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.

Tricuspid regurgitation is commonly caused by right ventricular dilatation, often as a result of heart failure. Other factors that can contribute to this condition include right ventricular infarction and cor pulmonale. The clinical signs of right-sided heart failure are frequently observed, such as an elevated jugular venous pressure, peripheral edema, hepatomegaly, and ascites.

The murmur associated with tricuspid regurgitation is a pansystolic murmur that is most audible at the tricuspid area during inspiration. A thrill may also be felt at the left sternal edge. Reverse splitting of the second heart sound can occur due to the early closure of the pulmonary valve. Additionally, a third heart sound may be present due to rapid filling of the right ventricle.

Stable angina is characterized by chest pain in the center of the chest that is triggered by activities such as exercise and emotional stress. The pain may spread to the jaw or left arm and can be relieved by resting for a few minutes. Typically, the pain is brought on by a predictable amount of exertion.

On the other hand, unstable angina is defined by the presence of one or more of the following: angina of effort occurring over a few days with increasing frequency, episodes of angina occurring recurrently and predictably without specific provocation, or an unprovoked and prolonged episode of cardiac chest pain. In unstable angina, the ECG may appear normal or show T wave / ST segment changes, and cardiac enzymes are usually normal.

Prinzmetal angina is a rare form of angina that typically occurs at rest between midnight and early morning. These attacks can be severe and happen in clusters. It is caused by spasms in the coronary arteries, and patients with this condition often have normal coronary arteries.

It is important to note that gastro-esophageal reflux (GORD) is not relevant to this question and is included in the patient’s history to distract the candidate. Typical symptoms of GORD include heartburn and acid regurgitation, and it can also present with non-cardiac chest pain, dyspepsia, and difficulty swallowing.

Lastly, Ludwig’s angina is a serious and potentially life-threatening infection in the submandibular area. It most commonly occurs due to an infection in the floor of the mouth that spreads into the submandibular space.

The classic ECG features of atrial fibrillation include an irregularly irregular rhythm, the absence of p-waves, an irregular ventricular rate, and the presence of fibrillation waves. This irregular rhythm occurs because the atrial impulses are filtered out by the AV node.

In addition, Ashman beats may be observed in atrial fibrillation. These beats are characterized by wide complex QRS complexes, often with a morphology resembling right bundle branch block. They occur after a short R-R interval that is preceded by a prolonged R-R interval. Fortunately, Ashman beats are generally considered harmless.

The disorganized electrical activity in atrial fibrillation typically originates at the root of the pulmonary veins.

The ECG shows the following findings:
– There is ST depression in leads V1-V4 and aVR.
– There is ST elevation in leads V5-V6, II, III, and aVF.
– There is a positive R wave in leads V1 and V2, which indicates a reverse Q wave.
These ECG changes indicate that there is an acute inferoposterior myocardial infarction.

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.

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 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.

Mitral regurgitation is characterized by a continuous murmur throughout systole that is often heard loudest at the apex and can be heard radiating to the left axilla.

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.

A summary of the vessels involved in different types of myocardial infarction, along with the corresponding ECG leads and the location of the infarction.

For instance, an anteroseptal infarction involving the left anterior descending artery is indicated by ECG leads V1-V3. Similarly, an anterior infarction involving the left anterior descending artery is indicated by leads V3-V4.

In cases of anterolateral infarctions, both the left anterior descending artery and the left circumflex artery are involved, and this is reflected in ECG leads V5-V6. An extensive anterior infarction involving the left anterior descending artery is indicated by leads V1-V6.

Lateral infarcts involving the left circumflex artery are indicated by leads I, II, aVL, and V6. Inferior infarctions, on the other hand, involve either the right coronary artery (in 80% of cases) or the left circumflex artery (in 20% of cases), and this is shown by leads II, III, and aVF.

In the case of a right ventricular infarction, the right coronary artery is involved, and this is indicated by leads V1 and V4R. Lastly, a posterior infarction involving the right coronary artery is shown by leads V7-V9.

Pericardial friction rub is a common finding in pericarditis and is often described as a sound similar to squeaking leather. This patient exhibits symptoms that are consistent with acute pericarditis, including flu-like illness with muscle pain and fatigue, chest pain that worsens when lying down and improves when sitting up or leaning forward, and the presence of a pleural rub. The gradual onset of symptoms rules out conditions like pulmonary embolism or acute myocardial ischemia. It is important to note that while the pericardial rub is often considered part of the classic triad of clinical features, it is only present in about one-third of patients. Additionally, the rub may come and go, so repeated examinations may increase the chances of detecting this sign.

Further Reading:

Pericarditis is an inflammation of the pericardium, which is the protective sac around the heart. It can be acute, lasting less than 6 weeks, and may present with chest pain, cough, dyspnea, flu-like symptoms, and a pericardial rub. The most common causes of pericarditis include viral infections, tuberculosis, bacterial infections, uremia, trauma, and autoimmune diseases. However, in many cases, the cause remains unknown. Diagnosis is based on clinical features, such as chest pain, pericardial friction rub, and electrocardiographic changes. Treatment involves symptom relief with nonsteroidal anti-inflammatory drugs (NSAIDs), and patients should avoid strenuous activity until symptoms improve. Complicated cases may require treatment for the underlying cause, and large pericardial effusions may need urgent drainage. In cases of purulent effusions, antibiotic therapy is necessary, and steroid therapy may be considered for pericarditis related to autoimmune disorders or if NSAIDs alone are ineffective.

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.

Dressler’s syndrome is a form of pericarditis that occurs within 2 to 10 weeks following a heart attack or cardiac surgery. It is distinguished by intense chest pain that is usually alleviated by assuming an upright position. Additionally, individuals may experience a mild fever, a pericardial rub, pulsus paradoxus, and indications of right ventricular failure.

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.

When treating adults with bradycardia, a maximum of 6 doses of atropine 500 mcg can be administered. Each dose is given intravenously every 3-5 minutes. The total dose should not exceed 3mg.

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

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

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 should be administered promptly once access to the circulatory system has been established in cases of non-shockable cardiac arrests such as PEA or asystole. The recommended dose is 1 mg, which can be given either as 10 mL of a 1:10,000 solution or as 1 mL of a 1:1000 solution through the intravenous (IV) or intraosseous (IO) routes.

In cases of shockable cardiac arrests like ventricular fibrillation (Vf) or pulseless ventricular tachycardia (pVT), adrenaline should be administered after the third shock has been delivered and chest compressions have been resumed. The same dose of 1 mg can be given using the same concentration options as mentioned earlier.

Subsequently, adrenaline should be administered every 3-5 minutes, alternating with chest compressions, without interrupting the compressions. The alpha-adrenergic effects of adrenaline cause constriction of blood vessels throughout the body, leading to increased pressures in the coronary and cerebral circulation.

The beta-adrenergic effects of adrenaline have positive effects on the heart, increasing its contractility (inotropic) and heart rate (chronotropic), which may also enhance blood flow to the coronary and cerebral arteries. However, it is important to note that these benefits may be counteracted by increased oxygen consumption by the heart, the potential for abnormal heart rhythms, temporary decrease in oxygen levels due to abnormal blood flow in the lungs, impaired microcirculation, and increased dysfunction of the heart after the cardiac arrest.

While there is no evidence supporting the long-term benefits of adrenaline use in cardiac arrest cases, some studies have shown improved short-term survival rates, which justifies its continued use.

Supraventricular tachycardia (SVT) is the most common arrhythmia that occurs in children and infants, causing cardiovascular instability. According to the current APLS guidelines, if a patient with SVT shows no signs of shock and remains stable, initial attempts should be made to use vagal maneuvers. If these maneuvers are unsuccessful, the following steps are recommended:

– Administer an initial dose of 100 mcg/kg of adenosine.
– After two minutes, if the child is still in stable SVT, administer another dose of 200 mcg/kg of adenosine.
– After an additional two minutes, if the child remains in stable SVT, administer another dose of 300 mcg/kg of adenosine.

If these measures do not resolve the SVT, the guidelines suggest considering the following options:

– Administer adenosine at a dose of 400-500 mcg/kg.
– Perform a synchronous DC shock.
– Administer amiodarone.

When using amiodarone, the initial dose should be 5-10 mg/kg given over a period of 20 minutes to 2 hours. This should be followed by a continuous infusion of 300 mcg/kg/hour, with adjustments made based on the response, increasing by 1.5 mg/kg/hour. The total infusion rate should not exceed 1.2 g in a 24-hour period.

If defibrillation is necessary for the treatment of SVT in children, it should be performed as a DC synchronous shock at a dosage of 1-2 J/kg.

The ratio of chest compressions to ventilations is 15:2. This ratio has not been proven through experiments, but it has been validated through mathematical studies. When performing chest compressions on a child, it is recommended to make them at least 1/3 of the depth of the child’s chest. Additionally, the optimal compression rate is between 100 and 120 compressions per minute.
To protect the airway of an unconscious child, the oropharyngeal (Guedel) airway is the best option. However, it should not be used on awake patients as there is a risk of vomiting and aspiration.
In children, asystole is the most common arrest rhythm. This occurs when the young heart responds to prolonged hypoxia and acidosis by progressively slowing down, eventually resulting in asystole.

In stable patients with SVT, it is recommended to first try vagal manoeuvres before resorting to drug treatment. This approach is particularly applicable to patients who do not exhibit any adverse features, as mentioned in the case above.

Further Reading:

Supraventricular tachycardia (SVT) is a type of tachyarrhythmia that originates from the atria or above the bundle of His in the heart. It includes all atrial and junctional tachycardias, although atrial fibrillation is often considered separately. SVT typically produces a narrow QRS complex tachycardia on an electrocardiogram (ECG), unless there is an underlying conduction abnormality below the atrioventricular (AV) node. Narrow complex tachycardias are considered SVTs, while some broad complex tachycardias can also be SVTs with co-existent conduction delays.

SVT can be classified into three main subtypes based on where it arises: re-entrant accessory circuits (the most common type), atrial tachycardias, and junctional tachycardias. The most common SVTs are AVNRT (AV nodal re-entry tachycardia) and AVRT (AV re-entry tachycardia), which arise from accessory circuits within the heart. AVNRT involves an accessory circuit within the AV node itself, while AVRT involves an accessory pathway between the atria and ventricles that allows additional electrical signals to trigger the AV node.

Atrial tachycardias originate from abnormal foci within the atria, except for the SA node, AV node, or accessory pathway. Junctional tachycardias arise in the AV junction. The ECG features of SVTs vary depending on the type. Atrial tachycardias may have abnormal P wave morphology, an isoelectric baseline between P waves (in atrial flutter), and inverted P waves in certain leads. AVNRT may show pseudo R waves in V1 or pseudo S waves in certain leads, with an RP interval shorter than the PR interval. AVRT (WPW) may exhibit a delta wave on a resting ECG and retrograde P waves in the ST segment, with an RP interval shorter than the PR interval. Junctional tachycardias may have retrograde P waves before, during, or after the QRS complex, with inverted P waves in certain leads and upright P waves in others.

Treatment of SVT follows the 2021 resuscitation council algorithm for tachycardia with a pulse. The algorithm provides guidelines for managing stable patients with SVT.

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.