Right-to-left ventricular diameter ratio at computed tomographic pulmonary angiography in acute pulmonary embolism and obstructive sleep apnea

Abstract

Introduction: Right ventricular (RV) dysfunction in acute pulmonary embolism (PE) is a critical determinant of outcome. Obstructive sleep apnea (OSA) is a common comorbidity of PE and might also affect RV function. Objective: To investigate RV dysfunction in patients presenting with acute PE in proportion to the severity of OSA. Methods: 197 PE patients were evaluated for sleep-disordered breathing by portable monitoring and nocturnal polysomnography. RV dysfunction was assessed by calculating the right-to-left ventricular (RV/LV) diameter ratio on computed tomographic pulmonary angiography (CTPA). RV dilatation was defined as a RV/LV ratio of ≥ 1.0. Results: RV dilatation was significantly more frequent in OSA patients compared to subjects with an AHI Conclusions: Patients with moderate or severe OSA might compensate PE-related RV strain better, as they are adapted to repetitive nocturnal right heart pressure overload. Potential LV dilatation due to coexisting CHF in severe OSA might prevent the RV/LV diameter ratio to be > 1 even in the presence of relevant RV enlargement. Thus, RV dysfunction might be underestimated in severe OSA when being evaluated by the RV/LV diameter ratio assessment on CTPA.