Papillary muscle rupture
Papillary muscle rupture is a mechanical complication of myocardial infarction in which necrosis of a papillary muscle, usually the single-blood-supply posteromedial one, causes acute severe mitral regurgitation, flash pulmonary edema, and cardiogenic shock days after an infarct. Diagnosis is by urgent echocardiography, and treatment is afterload reduction and mechanical support as a bridge to emergent mitral valve surgery.
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What this article covers
- Overview
Definition: papillary muscle rupture is rupture of an infarcted papillary muscle causing acute, severe mitral regurgitation.
- Epidemiology
A rare but lethal mechanical complication of infarction, less common in the reperfusion era.
- Risk factors
Inferoposterior myocardial infarction affecting the posteromedial papillary muscle.
- Pathophysiology
Ischemic necrosis of the papillary muscle: the posteromedial muscle's single blood supply makes it vulnerable.
- Clinical features
Abrupt pulmonary edema: severe dyspnea and hypoxemia developing suddenly.
- Differential diagnosis
Ventricular septal rupture: a new murmur with a left-to-right shunt, a palpable thrill, and an oxygen step-up on right-heart catheterization, unlike the large v waves of papillary rupture (mechanical complications of MI).
- Diagnosis
Establish with urgent echocardiography showing a flail leaflet and acute severe mitral regurgitation: the diagnostic basis is transthoracic and often transesophageal echocardiography demonstrating a…
- Management
First, stabilize as a bridge to surgery, continuing support until the operating room: Afterload reduction with sodium nitroprusside 0.3 mcg/kg/min IV, titrated, when blood pressure permits.
- Complications
Cardiogenic shock and multiorgan failure.
- Prognosis
Poor without surgery: medical therapy alone is almost uniformly fatal.
- Prevention
Timely reperfusion of the infarct (primary PCI within 90 minutes) to limit necrosis.
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Related articles
- Mechanical complications of myocardial infarction
Mechanical complications of myocardial infarction are catastrophic structural ruptures, papillary muscle rupture, ventricular septal rupture, and free-wall rupture, occurring days after a usually large, late-reperfused infarct and presenting as abrupt hemodynamic collapse, often with a new murmur. Diagnosis is by urgent echocardiography, and survival depends on hemodynamic stabilization and emergent surgical repair.
- Mitral regurgitation
Mitral regurgitation is systolic backflow from the left ventricle into the left atrium, classified as primary (valve disease) or secondary (ventricular or annular disease). Chronic disease causes volume overload with an apical holosystolic murmur, while acute severe regurgitation causes pulmonary edema; severe primary disease is treated with valve repair or replacement.
- ST-elevation myocardial infarction (STEMI)
ST-elevation myocardial infarction is acute transmural myocardial ischemia from complete coronary occlusion, diagnosed by ischemic symptoms with diagnostic ST-segment elevation and a rising troponin. It is a time-critical emergency in which immediate reperfusion, primary PCI within 90 minutes or fibrinolysis when PCI is unavailable, plus antiplatelet and anticoagulant therapy, determines survival.
- Acute heart failure
Acute heart failure is the rapid onset or worsening of heart failure symptoms requiring urgent therapy, most often pulmonary congestion from a precipitant such as ischemia, arrhythmia, or nonadherence. Management is oxygen, intravenous diuretics, and vasodilators for the congested-but-perfused patient, with inotropes or support for the hypoperfused patient.
- Pulmonary embolism
Pulmonary embolism is thrombus, usually from a lower-extremity deep vein thrombosis, obstructing the pulmonary arterial circulation and causing V/Q mismatch, right ventricular strain, and hypoxemia. Diagnosis follows Wells criteria (with PERC in low-risk patients) to sequence D-dimer, CT pulmonary angiography, and V/Q scanning, and management is risk-stratified anticoagulation escalating to thrombolysis or embolectomy for hemodynamic instability.
- Aortic dissection
Aortic dissection is a tear in the aortic intima allowing blood to split the media, creating a false lumen, and is a surgical emergency. Type A (ascending) dissection needs emergency surgery, while type B (descending) is usually managed medically with rapid heart-rate and blood-pressure control; the priority is impulse control with a beta-blocker first.