Myocardial Infarction: Complications

Key points

• Ventricular fibrillation is the most common cause of death post-MI → manage per ALS with defibrillation; AV block is commoner after inferior MI.
• Pericarditis in the first 48 hours (~10% of transmural MIs); Dressler's syndrome at 2–6 weeks (autoimmune: fever, pleuritic pain, pericardial effusion, ↑ ESR) → NSAIDs.
• LV free wall rupture ~3% of MIs at 1–2 weeks → tamponade (↑ JVP, pulsus paradoxus, diminished heart sounds) → urgent pericardiocentesis + thoracotomy.
• Post-MI VSD ~1–2%, usually first week: acute heart failure + pan-systolic murmur → echo (excludes acute MR) → urgent surgical correction; acute MR (papillary muscle ischaemia/rupture, infero-posterior MI) gives an early-to-mid systolic murmur → vasodilators, often emergency repair.
• LV aneurysm: persistent ST elevation + LV failure → anticoagulate (mural thrombus/stroke risk); cardiogenic shock → inotropic support ± intra-aortic balloon pump.