Although it has the same inotropic effect on the failing right ventricular myocardium as it does on a failing left ventricular myocardium, the clinical results are overshadowed by the pulmonary disease. Also, digitalis may contribute to atrial arrhythmias in patients with COPD and acute respiratory failure. Diuretics are undoubtedly useful in cor pulmonale when gross fluid retention has occurred, but the clinical benefits are not as great as they are in left ventricular failure. Because the symptoms in patients with cor pulmonale are caused by the lung disease, which is not reversible, there is less opportunity to relieve dyspnea and orthopnea in such patients by reducing pulmonary vascular congestion. The hemodynamic changes are relatively slight, however.
Vasodilators also appear to produce relatively little improvement.