Is There A Structural Basis For Vasovagal Syncope? Cardiac Functions In Patients With Vasovagal Syncope

Abstract

Aim: The pathophysiology of vasovagal syncope (VVS) is not completely understood. Some echocardiographic parameters have been defined to contribute to its pathophysiology. However. whether right atrial (RA) and right ventricular (RV) functions have any impact on development of VVS is not well known. In this study we aimed to evaluate the baseline echocardiographic parameters in patients with VVS with special focus on right ventricle and atrium functions. Material and methods: We evaluated the medical records of 42 patients with VVS and 41 age and sex matched healthy subjects. Patients with at least two syncopal attack and positive head-up-tilt test were enrolled in the study. All medical records of echocardiography and head-up-tilt test were obtained. Results: Among left ventricular function parameters, there were no significant difference between the groups. Right ventricle myocardial performance index (p= 0.003) and maximal pulmoner systolic flow velocity (PVmax) (p=0.03) were significantly differ between the groups. RAA was significantly larger (p=0.04) and the ratio of tricuspid filling velocities (E/A), (p=0.01) was significantly lower in VVS group. Conclusions: The findings of the present study indicate a subtle right atrial diastolic dysfunction in patients with VVS. Decreased right atrial contribution to RV filling may cause a lower RV stroke volüme which explains the lower PVmax values in our VVS group. All together, those findings may serve for a tendency to low output states and hypotension as in VVS.