Left Ventricular Free Wall Rupture

Free wall rupture is full thickness myocardial rupture after infarction, causing haemopericardium and tamponade. It is the most lethal mechanical complication.

Incidence is under 1% of STEMI today. Accounts for about 10% of in hospital infarct deaths.

Timing: acute (within 24 hours), or subacute (days to 2 weeks, peak days 3 to 6).

Risk factors: age over 70, female sex, first transmural anterior or lateral infarct, hypertension, lack of collaterals, late thrombolysis, use of steroids or NSAIDs, absence of prior angina.

Forms: acute rupture (sudden death, electromechanical dissociation), subacute contained rupture, and pseudoaneurysm.

Mortality exceeds 90% for acute rupture. Subacute rupture offers a chance for surgery.

• Sudden collapse with electromechanical dissociation, shock, jugular venous distension and muffled heart sounds.
• Subacute rupture: recurrent chest pain, nausea, hypotension, syncope, pericardial pain or friction rub, and rapid progression.
• Persistent or recurrent ST elevation, T wave changes.
• Tamponade signs: pulsus paradoxus, raised venous pressure.

• Bedside echocardiography is the key test: pericardial effusion with clot, tamponade, visible myocardial tear or pseudoaneurysm (narrow neck).
• Contrast echo or CT if the diagnosis is uncertain and the patient is stable.
• Pericardiocentesis yielding blood supports the diagnosis, but should not delay surgery.
• ECG shows low voltage, electrical alternans, persistent ST elevation.
• Coronary angiography is performed when stable.

• Immediate recognition and activation of the cardiac surgical team.
• Volume resuscitation with blood and crystalloid, vasopressors (norepinephrine 0.05 to 0.5 micrograms/kg/min), avoid positive pressure ventilation and beta blockers where possible.
• Pericardiocentesis for pre arrest tamponade as a bridge, removing small volumes to maintain pressure; risk of increased bleeding with large volume drainage.
• Emergency thoracotomy or sternotomy for arrested patients.
• Surgery: sutureless repair with biological glue and patch (Teflon or pericardium), infarctectomy with patch closure, with or without cardiopulmonary bypass, plus bypass grafts.
• Pseudoaneurysm: surgical resection and patch repair.
• Postoperative: standard post infarct therapy, heart failure therapy and monitoring for recurrence.
• Prevention: early reperfusion, blood pressure and heart rate control after infarction, and avoidance of NSAIDs and steroids in the acute phase.