Improved diagnosis and characterization of postinfarction left ventricular pseudoaneurysm by cardiac magnetic resonance imaging.

A patient with a ruptured left ventricular pseudoaneurysm complicating an acute posteroinferior myocardial infarction is described. Left ventricular pseudoaneurysms are a rare complication of acute myocardial infarction, usually occurring with inferior and/or posterior infarction. In contrast to true aneurysms, pseudoaneurysms are much more likely to rupture, regardless of size, causing hemopericardium and death. Therefore, once the diagnosis has been confirmed, prompt surgical resection is the current accepted treatment. The most accurate noninvasive diagnostic method has been echocardiography, with recent reports suggesting improved diagnosis with color flow Doppler echocardiography. Ventriculography confirms the diagnosis with more accurate anatomic detail, but is an invasive procedure. In our patient, two-dimensional and color Doppler echocardiography could not demonstrate the suspected pseudoaneurysm, which was demonstrated by ventriculography. However, magnetic resonance imaging (MRI) demonstrated the pseudoaneurysm, showing detailed anatomy not obvious on ventriculography. Before surgery could be performed, the patient died and was autopsied. Heart sections corresponding to MRI planes confirmed the MRI findings. A review of the literature has revealed no similar reports using MRI in the diagnosis of postinfarction pseudoaneurysms. Major advantages of MRI are generation of three-dimensional soft tissue images noninvasively, and generation of tissue contrast by rapid imaging sequences, obviating the need for contrast injection. Major disadvantages of MRI are the high cost of instrumentation, nonportability, and a requirement for patient immobility during the study. In cases of suspected pseudoaneurysm with equivocal echocardiography findings, MRI could provide early diagnosis, leading to early surgical intervention and increased patient survival.