Presentation	A 27-year-old man presented with lightheadedness, dyspnoea, orthopnoea, and bilateral lower extremity oedema
History	No similar problems in the past No significant past medical history Family history of Barth syndrome No alcohol or recreational drug use Active cigarette smoker
Physical exam	Hypotension, tachycardia, jugular venous distension, bilateral lower extremity oedema
Diagnostic workup	Leukopenia, neutropenia, monocytosis, hypocholesterolemia
	Electrocardiogram: sinus tachycardia, left atrial enlargement, prolonged QTc interval
	Echocardiogram: left ventricular ejection fraction (LVEF) 15–20%, global enlargement of all chambers, mild pulmonary hypertension
	Left heart catheterization: patent coronary arteries Right heart catheterization: mean pulmonary artery pressure 16 mmHg, cardiac index 2.02 L/min/m2
	Non-ischaemic cardiomyopathy workup, diuresis to euvolemia
Discharge	LifeVest wearable defibrillator Medications: furosemide, carvedilol, sacubitril-valsartan
Outpatient follow-up	Cardiology follow-up; addition of spironolactone to medication regimen
	Cardiac magnetic resonance imaging non-suggestive of infarction, infiltrate, or other abnormal enhancement; diagnosis confirmed by genetic testing
	Regular follow-up with advanced heart failure cardiologist
2 years later	Echocardiogram: LVEF improved to 45–50%