Can tricuspid regurgitation cause pulmonary hypertension?

Tricuspid regurgitation does not cause pulmonary hypertension. Tricuspid regurgitation is typically due to tricuspid valve insufficiency, whereby, during right ventricular systole, blood flows retrograde into the right atrium, resulting in reduced pulmonary arterial blood flow and consequently decreased pulmonary arterial pressure. In contrast, pulmonary hypertension often leads to right ventricular hypertrophy and dilation, causing functional (relative) tricuspid valve insufficiency and subsequent regurgitation. Pulmonary hypertension is commonly caused by chronic pulmonary vasoconstriction secondary to hypoxia; chronic obstructive pulmonary disease (COPD) is a frequent underlying condition.