Vectorcardiographic assessment of acute hypoxia effects in pulmonary hypertension due to chronic bronchitis.

Objective: Vectorcardiography (VCG) QRS loop area is thought to reflect hemodynamic abnormalities in cardiac lesions. The aim of the present study was to evaluate the response of VCG QRS loop area and intrapulmonary flow (PF) to acute hypoxia in patients with chronic bronchitis (CB) and pulmonary arterial hypertension (PAH).

Methods: One-hundred and eleven patients (mean age 45.