Treating heart failure with sildenafil

Sildenafil is a selective inhibitor of type 5 phosphodiesterase, the main phosphodiesterase isoform responsible for hydrolysis of intracellular cyclic guanosine monophosphate in the pulmonary vasculature. It improves exercise capacity and quality of life in patients with systolic heart failure, especially in those who develop secondary pulmonary hypertension. It improves peak oxygen consumption, reduces minute ventilation/carbon dioxide output slope, and acts as a selective pulmonary vasodilator during rest and exercise in patients with heart failure and pulmonary hypertension. It improves flow-mediated maximal dilatation, ergoreflex on ventilation, and breathlessness both after 3 and 6months of treatment. Sildenafil, by improving endothelial activity and muscle perfusion, improves signaling and ventilatory efficiencies, potentially indicating a novel approach in the therapeutic management of heart failure.