Master Cardiology
for PLAB 1

Core Concepts

Cardiology for PLAB 1 covers a broad spectrum of conditions affecting the heart and vascular system. Key areas include Ischaemic Heart Disease (IHD), Heart Failure (HF), Arrhythmias, Valvular Heart Disease, Hypertension (HTN), and Pericardial/Myocardial diseases. Understanding the underlying pathophysiology is crucial: atherosclerosis is central to IHD and peripheral arterial disease; cardiac remodelling is key in HF progression; and electrical abnormalities underpin arrhythmias. Risk factors like smoking, hypertension, dyslipidaemia, diabetes, obesity, and family history are consistently high-yield. Conditions like infective endocarditis and aortic dissection are critical for acute presentations.

Clinical Presentation

• Chest Pain:
  • Anginal: Central, crushing, radiating to arm/jaw, exertional, relieved by rest/GTN. Suggests IHD.
  • Pleuritic: Sharp, localized, worse on inspiration/coughing. Suggests pericarditis, PE.
  • Tearing/Ripping: Sudden onset, radiates to back. Suggests aortic dissection.
• Dyspnoea:
  • Exertional: Common in HF, valvular disease.
  • Orthopnoea & Paroxysmal Nocturnal Dyspnoea (PND): Hallmark of left HF.
  • Acute onset: Pulmonary oedema (HF), PE, pneumothorax.
• Palpitations: Awareness of one's own heartbeat. Irregular, fast, slow, pounding. Suggests arrhythmias (e.g., AF, ectopics), anxiety, hyperthyroidism.
• Syncope/Dizziness: Transient loss of consciousness due to global cerebral hypoperfusion. Can be vasovagal, orthostatic, or cardiac (arrhythmias, severe aortic stenosis, HOCM).
• Oedema: Peripheral (ankles, sacrum). Bilateral pitting suggests right HF, liver/kidney disease. Unilateral suggests DVT.
• Cyanosis: Bluish discolouration. Central (tongue, lips) implies low arterial oxygen saturation. Peripheral implies poor perfusion.
• Fatigue: Non-specific, but common in HF, anaemia, hypothyroid.
• Key Signs:
  • Elevated JVP: Right HF, fluid overload, cardiac tamponade.
  • Murmurs: Valvular disease (systolic, diastolic), septal defects.
  • Gallop Rhythms (S3/S4): HF.
  • Crepitations (Crackles): Pulmonary oedema.
  • Peripheral pulses: Strength, character (e.g., collapsing pulse in AR).
  • Blood Pressure: Hypertension/hypotension. Unequal arm BPs (aortic dissection).

Diagnosis (Gold Standard)

Diagnosis in cardiology often involves a combination of clinical assessment, ECG, imaging, and biomarkers.

• Electrocardiogram (ECG): First-line for arrhythmias (e.g., AF, VT), ischaemia (ST depression), infarction (ST elevation, Q waves), hypertrophy, pericarditis (widespread saddle-shaped ST elevation).
• Echocardiography (Echo): Gold standard for assessing cardiac structure, valve function, ventricular function (EF for HF), pericardial effusions, and congenital heart disease. Transoesophageal echo (TOE) offers better views for specific structures (e.g., left atrial appendage thrombus, endocarditis vegetations).
• Cardiac Biomarkers:
  • Troponins (I or T): Gold standard for myocardial injury/infarction (ACS). Levels rise within 3-12 hours, peak at 24-48 hours.
  • BNP/NT-proBNP: Diagnoses/rules out Heart Failure. Elevated in ventricular stretch.
• Coronary Angiography: Gold standard for diagnosing Coronary Artery Disease (CAD) and identifying suitable lesions for intervention.
• Stress Testing (Exercise Tolerance Test, Myocardial Perfusion Scintigraphy, Stress Echo): To assess for inducible ischaemia in suspected CAD.
• Ambulatory ECG (Holter Monitor): 24-48 hour recording for paroxysmal arrhythmias (e.g., AF, syncope workup).
• Ambulatory Blood Pressure Monitoring (ABPM): Gold standard for diagnosing hypertension (white coat HTN, masked HTN) and assessing control.
• Cardiac MRI (CMR): Detailed assessment of myocardial tissue characterisation (e.g., myocarditis, amyloidosis, infiltrative diseases), viability, and complex congenital heart disease.

Management (First Line)

• Acute Coronary Syndromes (ACS):
  • STEMI: Immediate reperfusion (Primary PCI is preferred, thrombolysis if PCI not available within recommended window). MONA (Morphine, Oxygen if SpO2 < 94%, Nitrates, Aspirin + P2Y12 inhibitor).
  • NSTEMI/Unstable Angina: Dual antiplatelet therapy (DAPT: Aspirin + P2Y12 inhibitor), anticoagulation (e.g., fondaparinux), nitrates, beta-blockers, statins. Risk stratification for early invasive strategy.
  • Post-ACS: Lifestyle modification, DAPT, high-dose statin, ACEi, beta-blocker, aldosterone antagonist (if HF/DM).
• Heart Failure (HFrEF):
  • First-line (Triple Therapy): ACE inhibitor (or ARB if intolerant), Beta-blocker, Mineralocorticoid Receptor Antagonist (MRA – spironolactone/eplerenone).
  • Additional (Quadruple Therapy): SGLT2 inhibitor (dapagliflozin/empagliflozin).
  • Symptom relief: Loop diuretics (furosemide) for congestion/oedema.
  • Device therapy: CRT-D (Cardiac Resynchronisation Therapy with Defibrillator) for selected patients with LBBB, reduced EF.
• Hypertension:
  • Lifestyle modifications (diet, exercise, weight loss, reduced salt/alcohol).
  • Pharmacological (NICE guidance): Stepwise approach based on age/ethnicity.
  • Step 1: ACEi/ARB (under 55, non-black) OR CCB (over 55, black).
  • Step 2: Add the other class.
  • Step 3: Add a Thiazide-like diuretic (indapamide).
  • Step 4: Consider alpha-blocker, beta-blocker, or MRA (spironolactone if K+ monitored).
• Atrial Fibrillation (AF):
  • Rate Control: First-line for most (e.g., Beta-blocker, Rate-limiting CCB like diltiazem/verapamil, Digoxin for sedentary/HF).
  • Rhythm Control: Indicated for symptomatic patients despite rate control (e.g., cardioversion, anti-arrhythmic drugs like flecainide/amiodarone, ablation).
  • Anticoagulation: Assess CHA2DS2-VASc score. NOACs (DOACs - apixaban, rivaroxaban, dabigatran, edoxaban) are preferred over Warfarin unless contraindicated or mechanical heart valves.
• Valvular Heart Disease: Surveillance. Surgical repair/replacement for symptomatic severe disease or asymptomatic severe disease with specific indications (e.g., reduced EF in AR/MR, LV dilation).
• Pericarditis: NSAIDs (e.g., ibuprofen) ± colchicine.

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