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 > ∼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.