Pathophysiology and potential clinical applications for testing of peripheral chemosensitivity in heart failure

Enhanced peripheral chemosensitivity (PChS) is a common finding in congestive heart failure (CHF). Although initially it may be regarded as a compensatory mechanism to maintain adequate oxygenation and tissue perfusion, importantly it also contributes to disease progression. The magnitude of PChS is related to the severity of CHF but does not depend on its etiology. Numerous methodologies have been developed to assess PChS reliably; however, only two methods based on acute hypoxia have proven to be clinically and prognostically useful. The pathophysiology behind increased PChS is complex and involves disturbances in regional blood flow, gaseous neurotransmission, redox processes, and angiotensin signaling. Augmented PChS is believed to translate into sympathetic overactivity, decreased barosensitivity, reduced exercise tolerance, more arrhythmic events, and poor outcomes. In this review, we present current knowledge regarding the pathophysiology of peripheral chemoreflex, available methods for assessment, and clinical significance of increased PChS.