Pulmonary arterial hypertension secondary to chronic left-sided cardiac dysfunction in dogs.

Pulmonary arterial hypertension is a description of a physiological finding rather than a diagnosis. Pulmonary arterial pressure is the result of interactions among pulmonary blood flow (right ventricular cardiac output), pulmonary vascular impedance and post-capillary pressure (typically reflecting left atrial pressure). When elevations in pulmonary arterial pressure (systolic/diastolic pulmonary arterial pressure > approximately 30/19 mmHg at rest) are accompanied by increased left atrial pressure, pulmonary arterial hypertension may be considered secondary to left-heart failure. Introduction of Doppler methods to diagnose pulmonary arterial hypertension has increased the awareness of the prevalence and importance of pulmonary arterial hypertension dogs with left-heart failure. Increasing understanding of the mechanism of development of pulmonary venous hypertension and reactive pulmonary arterial hypertension in dogs with left-heart disease has led to the development of successful additive therapies for progressive clinical signs in the setting of chronic therapy for congestive heart failure due to left-sided valvular and myocardial dysfunction. Because effective therapies for pulmonary arterial hypertension secondary to chronic left-sided cardiac dysfunction are now available, screening for pulmonary arterial hypertension should be a regular part of the Doppler echocardiographic examination in a clinical setting of chronic therapy for left-sided congestive heart failure due to valvular or myocardial disease.