A case of heart failure and diarrhoea

A 20-year-old man with no significant medical history presented with a 5-day history of intermittent chest pain and dyspnoea. He also reported a 3-month history of daily diarrhoea characterised by multiple, loose, watery, non-bloody stools. Physical examination was notable for tachycardia and a soft systolic murmur at the apex. Laboratory evaluation was significant for microcytic anaemia (serum iron 17 μg/dL; normal range 50–150 μg/dL) and an NT-proBNP (N-terminal pro-brain natriuretic peptide) of 18 995 pg/mL (normal <51 pg/mL). A colonoscopy with random biopsies for evaluation of diarrhoea was unremarkable. Esophagogastroduodenoscopy demonstrated a scalloped and mosaic pattern in the second and third portions of the duodenum (figure 1A), while biopsies showed a malabsorption pattern with total villous atrophy, increased intraepithelial lymphocytes and crypt hyperplasia (figure 1B). During hospitalisation, the patient experienced 2:1 heart block and non-sustained ventricular tachycardia. Transthoracic echocardiogram demonstrated an ejection fraction of 21% and severe...