A FOLLOW-UP-STUDY OF MYOCARDIAL INVOLVEMENT IN PATIENTS WITH MITOCHONDRIAL ENCEPHALOMYOPATHY, LACTIC-ACIDOSIS, AND STROKE-LIKE EPISODES (MELAS)

Objective-To investigate cardiac function in patients with mitochondri al encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS ) and clarify the clinical features of cardiomyopathy in MELAS. Patien ts-Il consecutive patients with MELAS (mean age at initial examination 11.3 years, range 4 to 16 gears) were enrolled in the study. Six were followed for more than five years. Results-On echocardiographic exami nation, three patients showed increased left ventricular end diastolic posterior wall thickness (LVPWTd), exceeding 140% of the normal value . Four patients, including these three, had an ejection fraction of le ss than 50%, and two also had increased left ventricular end diastolic volume (LVEDV) exceeding 140% of the normal value (%N). The LVPWTd%N was correlated positively with the LVEDV%N (R = 0.669, p < 0.05) and n egatively with the ejection fraction (R = -0.6701, p < 0.05). One pati ent died of heart failure aged 22 years. Conclusions-The cardiomyopath y in MELAS is characterised by an abnormally thick left ventricular wa ll with progressive dilatation and poor left ventricular contraction d eveloping over several years, indicating hypertrophic cardiomyopathy a dvancing to dilated cardiomyopathy.