Papillary Muscle Infarction After Cardiopulmonary Resuscitation
A 43-year-old woman experienced a drowning event during swimming. Basic and advanced cardiopulmonary resuscitation were successfully accomplished. During hospitalization, cardiac troponin I peak was 0.22 μg/L (normal, ≤0.13 μg/L) and creatine kinase isoenzyme MB mass peak was 7.6 U/L (normal, ≤3.5 U/L). Coronary angiography was unremarkable. Color Doppler transthoracic echocardiography showed moderate eccentric mitral regurgitation. On Day 5, the patient underwent cardiovascular magnetic resonance imaging. Cine image of left ventricular inflow/outflow (Data Supplement Movie I) showed eccentric mitral regurgitation caused by posterior papillary muscle dysfunction. In T2 short-tau inversion-recovery weighted imaging (Figure, A), the posterior papillary muscle was strongly hyperintense, which indicated the presence of myocardial edema.1 After administration of gadolinium-DTPA, the presence of perfusion defect confined to posterior papillary muscle was clearly seen in first-pass perfusion imaging (Figure, B; Data Supplement Movie II). In post–contrast-enhanced inversion-recovery late imaging (Figure, C), strong enhancement of this cardiac structure was detectable. These findings indicate acute myocardial necrosis of posterior papillary muscle in an out-of-hospital cardiac arrest survivor without angiographic evidence of coronary artery disease. This abnormality caused significant mitral regurgitation as a result of the restrictive motion of posterior leaflet.
An increase of specific cardiac enzymes and cardiac troponins2 have been reported in out-of-hospital cardiac arrest survivors even when acute coronary syndrome is ruled out.3 Moreover, it has been shown that the levels of cardiac enzymes and troponins correlate positively with the duration of resuscitation maneuvers (an indirect measure of trauma by means of chest compression). These observations3,4 support the occurrence of myocardial damage in cardiac arrest survivors that can be caused by either resuscitation maneuvers or profound myocardial ischemia during the cardiocirculatory event. Although the myocardial injury is usually trivial when peculiar cardiac structures are involved, such as in the present case, hazardous cardiac abnormalities can occur. A comprehensive magnetic resonance imaging study enables depiction of subtle, but not always negligible, myocardial damage.
Dr Masci has received grant support from the European Society of Cardiology. Drs Dymarkowski and Bogaert have nothing to disclose.
The online-only Data Supplement, consisting of movies, can be found at http://circ.ahajournals.org/cgi/content/full/116/8/e308/DC1.
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