Cardiothoracic Imaging Findings in Obesity Hypoventilation Syndrome (Pickwickian Syndrome): A Case Series

This case series describes a recognizable multimodality cardiothoracic imaging pattern in five patients with obesity hypoventilation syndrome (OHS), also known as Pickwickian syndrome. All five patients had obesity, obstructive sleep apnea (OSA), daytime hypoxemia, and hypercapnia and underwent cardiothoracic imaging. The mean age was 56.8 ± 19 years, the mean BMI was 46.5 ± 7.4 kg/m², and 60% were male. Chest radiography (CXR) demonstrated enlargement of the interlobar pulmonary artery to greater than 16 mm and central pulmonary arterial dilatation. CT showed central pulmonary artery enlargement with relative attenuation of the peripheral pulmonary arterial branches. Mosaic lung attenuation was present in most cases. Cardiomegaly was present on 75% of the available chest radiographs, and right ventricular enlargement was present on CT in 60% of patients. When performed, echocardiography was limited or nondiagnostic. One patient underwent right heart catheterization, which confirmed mild pulmonary hypertension. Cardiac magnetic resonance (CMR) imaging, which was performed in only one patient, demonstrated main pulmonary artery enlargement and mildly reduced right ventricular systolic function without an alternative diagnostic explanation. In patients with obesity, sleep-disordered breathing, daytime hypercapnia, and hypoxemia, a multimodality imaging pattern comprising central pulmonary artery enlargement, relative peripheral vascular attenuation, mosaic lung attenuation, and variable right-sided cardiac remodeling should raise suspicion for possible OHS-associated pulmonary vascular disease and prompt further cardiopulmonary evaluation.