Master Cardiovascular System
for PLAB 1

What the PLAB 1 Tests in Cardiovascular System

PLAB 1 tests your ability to manage common cardiovascular presentations in UK primary and emergency care: chest pain (ACS, pericarditis, aortic dissection), breathlessness (heart failure, pulmonary oedema), palpitations (atrial fibrillation, SVT, VT), syncope, and murmurs. You must know NICE and ESC guidelines for diagnosis and first-line treatment, including drug doses, monitoring parameters (e.g., INR for warfarin, U&Es for ACEi/ARB), and when to refer. Decision points include selecting appropriate investigations (ECG, troponin, echo, CT aortogram), interpreting results (e.g., STEMI criteria, CHA₂DS₂-VASc, HAS-BLED), and choosing between conservative, medical, or interventional management. Safety-critical knowledge includes recognising red flags (e.g., hypotension in PE, tamponade signs) and contraindications to thrombolysis or anticoagulation.

High-Yield Concepts

• Acute Coronary Syndrome (ACS) Management: For STEMI, give aspirin 300 mg, ticagrelor 180 mg, and arrange primary PCI within 120 minutes. If PCI delayed >120 minutes, give tenecteplase (bolus) within 12 hours of symptom onset. For NSTEMI, use GRACE score to guide early invasive strategy; give fondaparinux 2.5 mg SC daily (avoid if CrCl <20). Dual antiplatelet therapy (DAPT) for 12 months post-PCI.
• Heart Failure with Reduced Ejection Fraction (HFrEF): First-line: ACE inhibitor (e.g., ramipril 2.5 mg BD) + beta-blocker (bisoprolol 1.25 mg OD). Add MRA (eplerenone 25 mg OD) if NYHA II-IV and LVEF ≤35%. Monitor U&Es and eGFR at initiation and after dose changes. SGLT2i (dapagliflozin 10 mg OD) recommended for all HFrEF regardless of diabetes.
• Atrial Fibrillation (AF) Stroke Prevention: Use CHA₂DS₂-VASc score: score ≥2 in men, ≥3 in women → anticoagulate. First-line: DOAC (apixaban 5 mg BD, rivaroxaban 20 mg OD). Warfarin if mechanical valve or rheumatic mitral stenosis. Target INR 2.0-3.0. Use HAS-BLED score to assess bleeding risk, but it should not preclude anticoagulation.
• Hypertension Diagnosis and Targets: Clinic BP ≥140/90 mmHg on two occasions. Offer ABPM (daytime average ≥135/85) or HBPM (average ≥135/85). Target clinic BP <140/90 in under-80s, <150/90 in 80+. First-line: ACEi/ARB if age <55 or Black; CCB (amlodipine 5 mg) if ≥55 or Black; add thiazide-like diuretic (indapamide 2.5 mg) if needed.
• Aortic Stenosis (AS) Key Features: Classic triad: exertional dyspnoea, angina, syncope. Examination: slow-rising carotid pulse, ejection systolic murmur radiating to carotids, reversed S2 splitting. Echo: peak velocity >4 m/s, mean gradient >40 mmHg, valve area <1.0 cm². Severe symptomatic AS requires surgical AVR (TAVI if high risk). Do not give vasodilators.
• Pulmonary Embolism (PE) Diagnosis and Treatment: Use Wells score: if >4, request CT pulmonary angiogram. If <4, do D-dimer. For confirmed PE with haemodynamic instability (sBP <90), give alteplase 50 mg IV bolus. For stable PE, start LMWH (enoxaparin 1.5 mg/kg OD) and warfarin or DOAC (apixaban 10 mg BD for 7 days then 5 mg BD).
• Pericarditis and Myocarditis Differentiation: Pericarditis: pleuritic chest pain relieved by leaning forward, PR depression and diffuse ST elevation on ECG. Treat with ibuprofen 600 mg TDS + colchicine 500 mcg BD. Myocarditis: recent viral illness, raised troponin, heart failure, arrhythmias. Avoid NSAIDs; treat heart failure and arrhythmias. MRI with gadolinium is diagnostic.
• Syncope Risk Stratification: Use the San Francisco Syncope Rule: high risk if any of: abnormal ECG, shortness of breath, haematocrit <30%, systolic BP <90 at triage, or history of heart failure. These patients need admission and urgent echo. For low-risk vasovagal syncope, reassure and advise increased salt/fluid intake.

Common Traps in Cardiovascular System Questions

• Giving fondaparinux in STEMI instead of heparin — fondaparinux is contraindicated in STEMI if PCI is planned.
• Starting a beta-blocker in acute decompensated heart failure before stabilisation — wait until euvolemic and off IV diuretics.
• Using aspirin alone for AF stroke prevention — aspirin is no longer recommended; use anticoagulation based on CHA₂DS₂-VASc.
• Interpreting a normal D-dimer as ruling out PE in a high-Wells-score patient — D-dimer is only valid in low/intermediate probability.
• Prescribing verapamil in heart failure with reduced ejection fraction — it is negatively inotropic and contraindicated.
• Assuming a murmur is always pathological — a Still's murmur (vibratory, early systolic, left sternal edge) in a child is innocent.

How to Revise Cardiovascular System for the PLAB 1

Prioritise knowing the latest NICE guidelines for ACS, AF, and heart failure by heart — including drug names, doses, and monitoring. Questions often present a clinical scenario (e.g., 65-year-old with chest pain and ST elevation) and ask the next step (e.g., 'Which antiplatelet?', 'When to thrombolyse?'). Practise calculating CHA₂DS₂-VASc and HAS-BLED quickly. Be comfortable interpreting ECGs for STEMI, AF, and heart block. Memorise the Wells and GRACE scores. Traps often involve confusing first-line treatments for different conditions (e.g., amiodarone vs. digoxin in AF with HF). Review contraindications to common drugs (e.g., ACEi in pregnancy, beta-blockers in asthma). Use NICE Clinical Knowledge Summaries for revision.

Practise it: MedLumen has 50 Cardiovascular System questions for the PLAB 1, each with a full explanation and references.