[AV Shunt: a rare cause of cardiac decompensation]

A 66-year-old man presented with signs of heart failure for the first time. Apart from a history of arterial hypertension for several years, no relevant disease was known so far. The initial physical examination revealed symptoms of right heart failure and an elevated systolic blood pressure.

X-ray of the chest showed an enlarged heart shadow and no definite signs of pulmonary congestion. Echocardiography revealed a dilated left ventricle (left ventricular end-diastolic diameter 59 mm) with moderately reduced contractility (ejection fraction 35%). Laboratory parameters were normal. An invasive investigation of the reduced contractility was prepared.

While measuring blood pressure, a murmur and a little scar in the left elbow flexure were discovered. The suspicion of a traumatic arteriovenous fistula after a mirror glass injury 8 years ago was confirmed by sono- and angiography. The shunt volume was calculated by oxymetry as 6.2 l/min. The fistula was surgically dissected and ligated. At follow-up 1 year later, the patient reported no complaints and showed good exercise capacity. Echocardiography revealed normal parameters.

This case demonstrates the reversibility of high-output heart failure after treatment of the underlying cause. It stresses the importance of careful interrogation and examination of the patient. Apparently obvious causal connections must be thoroughly worked up and critically questionned.