Pulmonary hypertension in patients with severe obstructive sleep apnea.

Abstract Thirty-seven patients (35 men and two women) with obstructive sleep apnea–hypopnea syndrome (OSAHS) without any known cardiovascular and lung diseases were examined by Doppler echocardiography. Eight of the 37 (21.6%) patients experienced daytime pulmonary hypertension (PH), and all of them had severe OSAHS with an apnea–hypopnea index of > 30. The study suggested that one-third of patients with severe OSAHS had daytime PH.