Effects of hypocapnia and hypercapnia on myocardial contractility

Abstract

Moderate elevations of pCO 2 (61–75 mm Hg) did not consistently depress myocardial contractility as determined by standard ventricular function curves. With an altered preparation in which heart rate and left atrial pressure were held constant, a pCO 2 of 60–75 mm Hg was accompanied by an average reduction in stroke work to 73.6% of its control value, while hypocapnia with an alveolar pCO 2 of 6–13 mm Hg was unaccompanied by any consistent reduction in stroke work.