Avoiding Papillary Muscle Infarction With Myocardial Contrast Echocardiographic Guidance of Nonsurgical Septal Reduction Therapy for Hypertrophic Obstructive Cardiomyopathy
Intracoronary myocardial contrast echocardiography (MCE) can be used to guide the delivery of ethanol during nonsurgical septal reduction therapy for hypertrophic obstructive cardiomyopathy. The echocardiographic contrast agent is injected immediately before the injection of ethanol, down the lumen of the inflated balloon that resides in the target septal coronary artery. This is the artery that supplies the area of the septum involved with the mitral leaflet(s) in causing dynamic outflow tract obstruction. MCE provides a direct visualization of the myocardial territory that should receive ethanol and consequently undergo infarction. In rare instances, the cannulated vessel does not supply the culprit septal segment(s) but supplies instead other myocardial territories. It is important to avoid the injection of ethanol in these instances because infarction of myocardial segments not involved with obstruction will occur, the dynamic gradient will not be relieved, and the patient will be subjected to the detrimental effects of a potentially large myocardial infarction.
We present here a case in which the initially cannulated vessel was supplying a papillary muscle, a situation that was readily identified by MCE (Figures 1 through 7⇓⇓⇓⇓⇓⇓). Ethanol injection was aborted, and the balloon was disengaged from the vessel. Subsequently, a smaller, more proximal artery was successfully cannulated, and MCE confirmed its limited distribution to the culprit septal segments with no papillary muscle opacification. After ethanol injection, the dynamic gradient decreased dramatically in the catheterization laboratory.
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The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD. Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
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