Normal left ventricular ejection fraction in systemic arteriovenous fistula. Implications for the use of noninvasive methods in differential diagnosis of heart failure.

Heart failure is frequently a result of impaired systolic ventricular performance. We describe a patient with heart failure and a systemic arteriovenous fistula who had left ventricular enlargement and a normal left ventricular ejection fraction, demonstrated by gated cardiac blood pool scanning. The heart failure was relieved by surgical repair of the fistula, but the left ventricular ejection fraction did not change. These observations show that volume overload rather than impaired systolic function was the mechanism by which heart failure occurred in this patient with a systemic high output state and illustrate the value of gated cardiac blood scanning in noninvasively elucidating the mechanism of heart failure.