Hemodynamics of Acute Right Heart Failure in Mechanically Ventilated Patients with Acute Respiratory Distress Syndrome.

In critically ill patients with circulatory shock, the role of the left ventricle has long been appreciated and the object of measurement and therapeutic targeting. The right ventricle is often under appreciated and dysfunction may be overlooked. Generally, the right ventricle operates passively to support the ejection of the left ventricular diastolic volume. A loss of right ventricular wall compliance secondary to pulmonary pressures may result in an alteration in the normal pressure-volume relationship, ultimately affecting the stroke volume and cardiac output. Traditional right heart filling indices may increase because of decreasing compliance, further complicating the picture. The pathophysiology of pulmonary vascular dysfunction in acute respiratory distress syndrome combined with the effects of a mean airway pressure strategy may create an acute cor pulmonale.