Kussmaul Physiology in Patients With Heart Failure

Background-A paradoxical inspiratory rise in right atrial pressure (in contrast to the normal fall during inspiration), Kussmaul sign, has been described in congestive heart failure (CHF). However, the clinical and hemodynamic characteristics and clinical outcomes of patients with CHF and Kussmaul physiology have not been studied. Methods and Results-This is a single-center study of consecutive ambulant patients with CHF (New York Heart Association class III/IV) referred for assessment for heart transplantation between November 2011 and April 2013. Kussmaul physiology was defined as inspiratory rise in right atrial pressure during right heart catheterization. Clinical, biochemical, echocardiographic, and hemodynamic correlates were studied and outcomes assessed in patients with or without Kussmaul physiology after a mean follow-up of 379 +/- 227 days. Ninety ambulant patients (age, 53 +/- 12 years; 86% men) with CHF were studied. Kussmaul physiology was demonstrated in 39 (43%) patients, and it was associated with higher pulmonary pressures and lower cardiac index and pulmonary capacitance (all P<0.05). Patients with Kussmaul physiology were more likely to be treated with higher doses of diuretics, while higher filling pressures, N-terminal pro-B natriuretic peptide levels, and hyponatremia reflected greater neurohormonal activation. Echocardiography revealed greater left and right ventricular dimensions/volumes, restrictive transmitral filling pattern, and lower left ventricular ejection fraction and lower tricuspid annular plane systolic excursion. Peak oxygen uptake was low and comparable in both groups, but ventilation slope was higher in patients with Kussmaul physiology who also had a higher incidence of post-transplant right ventricular failure and overall mortality (P<0.05). Conclusions-Kussmaul physiology is common in patients with CHF referred for heart transplantation and is associated with adverse cardiopulmonary hemodynamics. As a result of the latter, Kussmaul physiology is associated with poorer clinical outcomes. Kussmaul physiology may be useful during assessment of right heart function and pulmonary pressures before transplantation.