In the U.S., each year, there are more than 500,000 new cases of all types of heart failure. With high output
cardiac failure, there is an elevated cardiac output associated with several conditions and diseases, including
obesity, chronic anemia, systemic arterio-venous fistula, hypercapnia, mitochondrial dysfunction, and
hyperthyroidism. The underlying pathophysiologic mechanisms relate to a reduction in systemic vascular
resistance from arterio-venous shunting or peripheral vasodilation. Often there is a decrease in systemic
arterial blood pressure and neurohormonal activation leading to heart failure symptoms of dyspnea and
fatigue. In a persistent high output state, patients may experience tachycardia, valvular abnormalities, and
ventricular dilatation and/or hypertrophy. In this article, there is a review of high output heart failure,
including the prevalence, pathophysiology, and common clinical causes of this disease.