Risk factors for right ventricular dysfunction in patients with lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare disease characterized by diffuse cystic lesions of the lung. The present study was designed to evaluate the right ventricular (RV) function in LAM patients via single-beat real-time three-dimensional echocardiography (RT-3DE) and to investigate the factors affecting RV function in LAM patients. According to tricuspid regurgitation velocity (TRV), forty-five female LAM patients [(44.07 ± 10.22) years old] were divided into TRV ≤ 2.8 m/s group (n = 29) and TRV > 2.8 m/s group (n = 16). Relative echocardiography parameters were assessed by conventional transthoracic echocardiography, Doppler tissue imaging (DTI) and RT-3DE, respectively. Pulmonary function tests and the six-minute walk tests (SMWT) were also performed for LAM patients. We found that most of RV functional parameters in LAM patients were worse than that in control patients, although left ventricular dysfunction was not significantly observed. Correlation analysis showed that 3D echocardiographic RV ejection fraction (RVEF) was negatively correlated with pulmonary vascular resistance (PVR), TRV, and the decrease of oxygen saturation (SpO₂) post SMWT, and positively correlated with Forced expiratory volume in the first second/forced vital capacity, carbon monoxide diffusion predicted value, SMWT distance, and resting SpO₂ in LAM patients. Multivariate stepwise linear regression analysis showed that PVR and SpO2 before SMWT were independent influence factors of RVEF in LAM patients. In this study, we found that RV dysfunction was presented in LAM patients, although left ventricular dysfunction was not significantly obvious. The main influence factors of RVEF were PVR and hypoxia. RT-3DE is a low-cost and noninvasive way to evaluate RV function in LAM patients.