Cardiomyopathy associated with mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome

It is critical to find out the etiology in patients presenting with heart failure (HF) and cardiomyopathy. Echocardiography is the primary diagnostic test to make a diagnosis and to guide treatment. Cardiac magnetic resonance (CMR) imaging is of value in providing information about tissue characterization. We report a case of mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS)-related cardiomyopathy to emphasize the importance of history taking as well as multi-modality imaging studies. A 27-year-old woman was admitted due to aggravating dyspnea for 3 months. She was diagnosed with MELAS syndrome 6 years ago after successive development of cerebral infarction and seizure attacks and positive mitochondrial DNA sequence analysis revealing m.3243A>G mutation. The patient arbitrarily discontinued all medications 3 years ago but has been neurologically silent except bilateral sensorineural hearing loss in the last 1 year. She denied family history of cardiomyopathy or sudden cardiac death. On physical examination, her blood pressure was 144/109 mmHg, heart rate 98 bpm, height 154 cm and body weight 40 kg. A chest radiograph showed cardiomegaly with a cardiothoracic ratio of 0.58. An electrocardiogram revealed sinus rhythm with left ventricular hypertrophy (LVH) by voltage criteria. Laboratory test showed elevated serum creatinine of 1.77 mg/dl and N-terminal pro-brain natriuretric peptide of 5751 pg/ml. An echocardiogram disclosed global hypokinesia with a severely reduced LV ejection fraction of 31%, concentric LVH (16 mm at end-diastole; LV mass index, 272 g/m2) and mildly dilated LV cavity and reduced global longitudinal strain of −6.9% (reference range, −22.3 ± 1.6%) on speckle tracking echocardiography (Figure 1A). CMR imaging study showed concentric thickening of LV walls and systolic dysfunction without evidence of late gadolinium enhancement (LGE; Figure 1B).