Correspondence

Myocardial Infarction in a Patient with Hypertrophic Cardiomyopathy

N Engl J Med 2000; 342:593-594February 24, 2000

Article

To the Editor:

An intramural coronary artery is defined as an arterial segment of variable length that, instead of lying subepicardially, courses deep in the myocardium and is covered by myocardial fibers (a “myocardial bridge”).1 On an angiogram, it may be marked by systolic compression with luminal narrowing. Although its pathophysiologic importance remains controversial, it has been shown that persistence of coronary-artery compression into diastole, when the largest fraction of coronary blood flow takes place, impairs myocardial perfusion.2

The recent study by Yetman et al.3 provided strong evidence that myocardial bridging is an important cause of myocardial ischemia in children with hypertrophic cardiomyopathy. We report a case that sheds light on myocardial ischemia — its pathophysiology and relation to arrhythmias and sudden death in patients with hypertrophic cardiomyopathy.4 Pathological studies of this disorder have provided evidence that ischemic damage may occur in the hypertrophied myocardium, in the form of large, fibrous scars that mimic healed infarction,5 even in the absence of epicardial coronary artery disease. Small-vessel disease, massive hypertrophy with extrinsic vessel constriction, and myocardial bridging have been proposed as explanations for myocardial ischemia in hypertrophic cardiomyopathy.

In support of myocardial bridging as a cause of myocardial ischemia in hypertrophic cardiomyopathy, we report the case of an eight-year-old, previously asymptomatic boy who, while at school, suddenly collapsed without relation to physical exertion. He arrived in the emergency room in a coma, and the clinical picture suggested cerebral hemorrhage. He died two days after admission with epileptic seizures and signs of irreversible cerebral damage. The family history was negative for sudden death and hypertrophic cardiomyopathy; genetic studies were not performed.

After cerebral causes of death were excluded, a postmortem investigation revealed cardiomegaly (weight of the heart, 200 g) with marked asymmetric septal hypertro-phy (25-mm septal thickness and 7-mm thickness of the left ventricular free wall), and a hemorrhagic acute septal myocardial infarction (Figure 1AFigure 1The Heart of a Boy with Hypertrophic Cardiomyopathy.). A 2-mm-deep and 20-mm-long intramural course of the left anterior descending coronary artery, corresponding to the region of the first and second septal perforators, was observed (Figure 1B); its position could plausibly explain the septal infarction. Histologic assessment revealed coagulation necrosis (Figure 1C), with interstitial hemorrhage and neutrophilic infiltrates superimposed on remarkable myocardial disarray, as well as areas of replacement-type fibrosis; the small arteries were dysplastic but not obstructed. Transient obliteration of the intramural left anterior descending coronary artery, followed by myocardial reperfusion, may explain the hemorrhagic appearance of the myocardial infarction. The clinical and pathological pictures are consistent with the occurrence of acute myocardial infarction related to coronary-artery compression caused by a myocardial bridge.

Franca Gori, M.D.
University of Florence Medical School, 50134 Florence, Italy

Cristina Basso, M.D., Ph.D.
Gaetano Thiene, M.D.
University of Padua Medical School, 35121 Padua, Italy

5 References

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Citing Articles (6)

Citing Articles

1. 1

   Marmar Vaseghi, Michael J. Ackerman, Ravi Mandapati. (2012) Restricting Sports for Athletes With Heart Disease: Are We Saving Lives, Avoiding Lawsuits, or Just Promoting Obesity and Sedentary Living?. Pediatric Cardiology
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2. 2

   Gaetano Thiene, Elisa Carturan, Domenico Corrado, Cristina Basso. (2010) Prevention of sudden cardiac death in the young and in athletes: dream or reality?. Cardiovascular Pathology 19:4, 207-217
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3. 3

   Martin S. Maron, Iacopo Olivotto, Barry J. Maron, Sanjay K. Prasad, Franco Cecchi, James E. Udelson, Paolo G. Camici. (2009) The Case for Myocardial Ischemia in Hypertrophic Cardiomyopathy. Journal of the American College of Cardiology 54:9, 866-875
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4. 4

   I. Olivotto, F. Cecchi, M. H. Yacoub. (2009) Myocardial bridging and sudden death in hypertrophic cardiomyopathy: Salome drops another veil. European Heart Journal 30:13, 1549-1550
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5. 5

   Iacopo Olivotto, Franco Cecchi, Roberta Bini, Silvia Favilli, Bruno Murzi, Ismail El-Hamamsy, Magdi H Yacoub. (2008) Tunneled left anterior descending artery in a child with hypertrophic cardiomyopathy. Nature Clinical Practice Cardiovascular Medicine 6:2, 134-139
   CrossRef

6. 6

   CRISTINA BASSO, DOMENICO CORRADO, GAETANO THIENE. (2001) Congenital Coronary Artery Anomalies as an Important Cause of Sudden Death in the Young. Cardiology in Review 9:6, 312-317
   CrossRef