An autopsy case of Parkes-Weber syndrome with high-output heart failure: Hemodynamic alterations following treatment for arteriovenous fistulas.

An autopsy case of Parkes-Weber syndrome presenting high-output heart failure in a patient who died at 52 years old, is reported. The patient had a tumor in the right buttock since childhood, that had grown up to a diameter of 40 cm diameter by the age of 43 years when he felt exertional dyspnea and was diagnosed as having high-output heart failure due to arteriovenous fistulas. Embolotherapy was attempted, which relieved the symptoms. After 4 years his heart failure deteriorated. We performed embolotherapy but his condition did not improve. He died 1.5 years later. The autopsy revealed the weight of the heart was 1040 g with abundant subendocardial and interstitial fibrosis. In this patient, the level of output had been over 16 L/min which lasted for nine years. The left ventricular ejection fraction (LVEF) decreased during the first five years. Each embolotherapy reduced the cardiac output (CO), which was achieved by a large decrease in heart rate (HR) and a small increase in stroke volume (SV) i.e. CO = HR × SV, and was reflected in the increase in LVEF. Learning objectives: •Parkes-Weber syndrome has occasionally extensive arteriovenous fistulas in the pelvis that show high-output heart failure.•Treatment of such cases is difficult, but embolotherapy has partial effects on improving hemodynamics.•A long-term high-output state induces interstitial myocardial fibrosis and collagenous subendocardial thickening.