Abstract 20086: Influence of Central Apneas and Chemoreflex Activation on Heart Failure Related Pulmonary Arterial Hypertension

Introduction: Pulmonary arterial hypertension (PAH) is an acknowledged independent prognostic factor in patients with heart failure (HF). Beyond a “passive” component due to the increased left ventricular pressure, an “active” component due to pulmonary vascular reactivity is frequently observed. However, the mechanism behind pulmonary vasoconstriction is not fully understood. Hypothesis: We hypothesized that central apneas (Cheyne-Stokes respiration [[Unable to Display Character: –]] CSR) through chemoreflex stimulation may contribute to PAH in HF. Methods: we studied 56 HF patients (left ventricular ejection fraction Results: Thirteen patients (23%) showed CSR, as defined by a 24 hour AHI > of 15. HF patients with CSR compared with patients with normal breathing, presented higher systolic arterial pulmonary pressure (SPAP: 40.1±7.6 vs 33.1±5.9, p Conclusions: In patients with systolic HF, the presence of diurnal-nocturnal CSR, likely via recurrent hypoxia and hypercapnia cycles, may determine a chemoreflex mediated adrenergic discharge and a consequent pulmonary vasoconstriction, responsible of the undesirable increase in pulmonary arterial pressure.