Dilated cardiomyopathy with cardiogenic shock in a child with Kearns-Sayre syndrome

Abstract

Kearns-Sayre syndrome (KSS) is a mitochondrial myopathy resulting from mitochondrial DNA deletion. This syndrome primarily involves the central nervous system, eyes, skeletal muscles and the heart. The most well-known cardiac complications involve the conduction system; however, there have been case reports describing cardiomyopathy. We describe a case of a child with KSS who presented with decompensated cardiac failure from dilated cardiomyopathy representing cardiomyocyte involvement of KSS. Our patient had a rapidly progressing course, despite maximal medical management, requiring emergent institution of extracorporeal membrane oxygenation and transition to a ventricular assist device. To the best of our knowledge, this is the youngest patient in the literature to have dilated cardiomyopathy in KSS.

Figure 1

Rhythm strip on admission showing diffuse intraventricular conduction delay with normal PR interval.

Figure 2

Still frame image from the echocardiogram on arrival showing a dilated left ventricle (A) on apical four-chamber view and (B) with moderate to severe mitral and tricuspid regurgitation on apical four-chamber view in colour.

Figure 3

ECG 1 year prior to presentation.

Figure 4

Myocardial morphology. (A) Light microscopy demonstrating myocardial fibrosis (lighter stained areas) and cardiomyocyte atrophy with cytoplasm vacuolisation, and accumulation of microgranules that correspond to abnormal mitochondria (arrowheads). Gomori-trichrome stain; ×400. (B) Electron microscopy showing a locus of vacuolated cytoplasm with myofibrils (left) pushed by numerous abnormally shaped polymorphous mitochondria (centre). Electron microscopy ×28 000.