Echocardiographic Findings in Obesity Hypoventilation Syndrome

Objective: In Obesity Hypoventilation syndrome (OHS), pulmonary hypertension (PH) is an important morbidity and mortality reason compared to pure Obstructive Sleep Apnea syndrome (OSAS). However, few studies are available in the literature about this subject. For this reason, we evaluated OHS and pure OSAS cases in our study from the point of right heart-related echocardiographic parameters and PH. Materials and Methods: Obese [body mass index (BMI) >30 kg/m2] cases diagnosed by polysomnography were included in the study. The subjects were divided to two groups as OHS and pure OSAS. OHS criteria were defined as obesity (BMI >30 kg/m2) and for another reason unexplained (neuromuscular, chest wall, restrictive or obstructive pulmonary diseases) daytime hypercapnia (PaCO2 >45 mmHg). Patients with severe hypothyroidism, renal and heart insufficiency, cardiac drug anamnesis were not included in the study. Transthoracic echocardiography was performed to all cases and those with left-heart pathology were excluded from the study. Systolic pulmonary artery pressure (PABs) >35 mmHg was accepted as PH. Results: Of the 115 cases studied (mean age: 49.3±10.6/year, female/male: 53/62, BMI: 40.5±6.1 kg/m2), 70 were pure OSAS and 45 were OHS. In the OHS group, PABs, right ventricular diameter and pulmonary velocities were significantly higher than the pure OSAS group (p=0.002, p=0.015, p=0.012, respectively). The frequency of PH in OHS was significantly higher than group with pure OSAS (48.8% vs. 17.1%, p