Transesophageal Echocardiographic Findings in Papillary Muscle Rupture

A 39-yr-old man presented to our hospital with a 4-h history of chest pain. Despite percutaneous coronary intervention with stenting of occluded circumflex and right coronary arteries and placement of an intraaortic balloon pump, he remained hypotensive and in pulmonary edema. Two transthoracic echocardiograms performed within the first 24 h of admission failed to show any significant structural cardiac abnormality. Forty-eight hours after presentation he was admitted to our cardiac intensive care unit for tracheal intubation and ventilation. At this point, we performed a transesophageal echocardiogram (TEE), which revealed papillary muscle (PM) rupture. He subsequently underwent successful mitral valve replacement and was discharged home 3 wk later. TEE showed many of the cardinal features of PM rupture. The PM head was clearly seen prolapsing into the left atrium in systole in the midesophageal 4-chamber view (Fig. 1) (video loop can be accessed at www.anesthesia-analgesia.org) and the midesophageal 2-chamber view. Examination of the left ventricle in diastole also revealed large-amplitude erratic motion of the ruptured PM head in the midesophageal 4-chamber and midesophageal 2-chamber views. These TEE results are found in 65% and 90% of cases, respectively (1). Therefore, although left atrial prolapse of the papillary muscle head is diagnostic, this finding is absent in 35% of cases and careful examination of the left ventricular cavity will reduce the risk of a false negative study.Figure 1.: Midesophageal 4-chamber view in systole. The posteromedial papillary muscle head (arrow) is seen in the left atrium.Left ventricular function was hyperdynamic, although the inferior wall was less hyperdynamic. Two-dimensional examination of the mitral valve revealed flail P3 and A3 segments with prolapse of P2 and A2 segments consistent with rupture of the posteromedial PM. Posteromedial rupture was confirmed at surgery. Transmitral continuous wave Doppler revealed a systolic signal that was complete and of equal intensity to the diastolic signal, suggesting severe regurgitation (Fig. 2). A late systolic reduction in the regurgitant velocity was also seen, giving the Doppler map an asymmetrical shape. This is known as the “V wave cut-off sign” (2) and implies regurgitation of a large volume of blood into the left atrium, causing a late systolic reduction in the transmitral gradient because of a sharp increase in the left atrial pressure. A peak early diastolic filling velocity (Emax) of up to 1.5 m/s was seen (Fig. 2). An Emax more than 1.2 m/s is indicative of severe mitral regurgitation and reflects volume loading of the left atrium.Figure 2.: Transesophageal transmitral continuous wave Doppler profile showing the “V wave cut-off sign” (arrow) and a peak early diastolic filling velocity of up to 1.5 m/s (dotted line). Note also mirror-image artifact duplicating the mitral regurgitant signal in the reverse channel.Color flow Doppler imaging revealed a broad-based laterally directed mitral regurgitant jet (video loop). Appreciation of the color flow map was enhanced by using the maximum Nyquist limit available (82 cm/s). Lower limits resulted in an excessive mosaic pattern. This phenomenon, coupled with tachycardia (heart rate, 140 to 160 bpm) and the late systolic reduction in the mitral regurgitation, would reduce color flow Doppler temporal resolution and could have contributed to the negative transthoracic findings.