A 53-year-old woman is hospitalized with acute inferior ST elevation myocardial infarction. She did not undergo a revascularization procedure due to delayed presentation. The patient has a distant history of deep vein thrombosis and is a factor V Leiden carrier. Echocardiogram shows inferior and inferolateral wall akinesis with left ventricular ejection fraction of 45%. Before discharge on day 3, she develops severe shortness of breath and is evaluated urgently.
Blood pressure is 84/60 mm Hg and pulse is 112/min and regular. The apical impulse is hyperdynamic and there is a faint early systolic murmur heard at the apex. There is no precordial thrill. Bilateral crackles are heard on lung auscultation. The extremities are cold and clammy.
ECG shows sinus tachycardia with Q waves in leads II, III, and aVF.
Which of the following is the most likely diagnosis?

Question

A 53-year-old woman is hospitalized with acute inferior ST elevation myocardial infarction.  She did not undergo a revascularization procedure due to delayed presentation.  The patient has a distant history of deep vein thrombosis and is a factor V Leiden carrier.  Echocardiogram shows inferior and inferolateral wall akinesis with left ventricular ejection fraction of 45%.  Before discharge on day 3, she develops severe shortness of breath and is evaluated urgently.
Blood pressure is 84/60 mm Hg and pulse is 112/min and regular.  The apical impulse is hyperdynamic and there is a faint early systolic murmur heard at the apex.  There is no precordial thrill.  Bilateral crackles are heard on lung auscultation.  The extremities are cold and clammy.
ECG shows sinus tachycardia with Q waves in leads II, III, and aVF.
Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec193a_96be_6454_853d_a1bfe9bffbc5_MD0002_00 This patient's clinical presentation - delayed onset of acute hypotensive left ventricular heart failure following inferior myocardial infarction (MI) - is most consistent with acute mitral regurgitation due to papillary muscle rupture. Papillary muscle rupture is a life-threatening complication of acute MI that most commonly occurs 2-7 days after the infarct. Rupture of the posteromedial papillary muscle (supplied by the right coronary artery or dominant left circumflex) is much more common than anterolateral papillary muscle (with dual blood supply from the left anterior descending artery and left circumflex arteries) and can occur in both ST elevation and non-ST elevation MI. Patients usually have a dramatic presentation with sudden onset of cardiogenic shock and pulmonary edema with a hyperdynamic precordium and a systolic murmur. Patients with severe mitral regurgitation have early equalization of left atrial and left ventricular pressures; there may be a soft or inaudible murmur (silent mitral regurgitation) in up to 50% of cases. Diagnosis is typically confirmed by transthoracic or transesophageal echocardiography. (Choice A) Recurrent myocardial ischemia (or post-infarction angina) presents with recurrent chest pain and new or worsening ECG changes of ischemia. (Choice B) Rupture of the left ventricular free wall is a catastrophic complication of MI and usually occurs several days to 2 weeks after the initial infarct. Abrupt rupture of the left ventricle leads to hemopericardium and cardiac tamponade and presents with sudden onset of chest pain and profound shock, with rapid progression to pulseless electrical activity and death. (Choice D) Acute massive pulmonary embolism can cause sudden onset of dyspnea, hypotension, right heart failure, and syncope. Patients do not typically develop acute pulmonary edema. (Choice E) Ventricular septal rupture typically presents with sudden onset of hypotension, congestive heart failure (predominantly right heart failure), and a harsh, loud holosystolic murmur with widespread radiation heard best at the left lower sternal border. Educational objective: Papillary muscle rupture (with acute mitral regurgitation) is a life-threatening complication of acute myocardial infarction. It presents with sudden onset of hypotension and pulmonary edema with a hyperdynamic precordium and a systolic murmur. The murmur can be soft or inaudible (silent mitral regurgitation) in up to 50% of patients. __________ References: Complications of myocardial infarction. (http://www.ncbi.nlm.nih.gov/pubmed/17667459)

A 53-Year-Old Woman Is Hospitalized with Acute Inferior ST Elevation