A rare cause of mixed hypertrophic and dilated phenotype cardiomyopathy – the MELAS syndrome

Abstract

Abstract Introduction MELAS is a systemic hereditary condition that can present as hypertrophic or mixed hypertrophic and dilated phenotype cardiomyopathy in young individuals, although a late-onset form is also described in the literature. Genetic testing is essential for correct diagnosis and appropriate management. Case presentation We present the case of a 22-year-old male who was referred to our center after being diagnosed with NYHA class III heart failure with a mixed hypertrophic and dilated cardiomyopathy. His medical history included stroke episodes, seizures, progressive hypoacusis, neurocognitive impairment, and muscle atrophy. Lactic acidosis and elevated CK levels were also noted. The ECG revealed short PR interval and delta wave in lateral leads. TTE showed mildly dilated and hypertrophied LV and RV with severe biventricular systolic impairment. The CMR study was relevant for ring-like subepicardial fibrosis, predominantly in the medium and apical segments. Brain MRI showed multifocal supratentorial subcortical stroke-like lesions in both cerebral hemispheres, involving multiple vascular territories and following a migratory pattern. Genetic testing confirmed a pathogenic MT-TL1 mutation (m.324A>G) and the patient was diagnosed with MELAS. Further management included specific lifestyle recommendations and cascade genetic screening, as well as starting GDMT for HFrEF. Three months after discharge, his clinical status improved. However, the LVEF remained reduced. After careful consideration, an ICD was implanted for primary prevention. Conclusion A red-flag approach in this young patient, which took into consideration the stroke-like episodes, lactic acidosis, seizures, hypoacusis, myopathy, as well as the short PR interval, led to the correct diagnosis, further confirmed by using the appropriate genetic test. Failure to diagnose affects the patient’s prognosis, as their prognosis and clinical status are influenced by enforcing specific recommendations.