Evaluation of neurocardiogenic syncope patients using ecocardiography

Aim: We aimed to investigate the contribution of ventricular function to the pathogenesis of syncope by measuring left and right ventricular function with echocardiography (TTE) in patients presenting with syncope. Methods: The study included 74 patients who were admitted to the cardiology outpatient clinic of Karadeniz Technical University Farabi Hospital between 2023 and 2024 due to syncope and underwent Head-up tilt table (HUTT) test. Patients were divided into two groups as HUTT test's result positive and negative. Right and left ventricular systolic and diastolic functions and the size of the cardiac cavities were compared between these two groups by TTE. Results: The mean age of the patients included in the study was 38.3±13.8 years and 54.1% were female. HUTT test was negative in 36 patients and positive in 38 patients. On TTE, left ventricular end-systolic diameter (LVESD) was significantly lower in the positive group than in the negative group (26,8±3,8mm, 28,9±3,6mm, respectively, p=0,034). Ejection fraction (EF) and global longitudinal strain (GLS) values were similar between the two groups. There was no statistically significant difference in the parameters representing the diastolic function of the left ventricle. A (42,7±7,8cm/s, 39,4±6,1cm/s, p=0,047) and A' (11,9±2,8cm/s, 10,3±3,1cm/s, p=0,032) waves representing the diastolic late phase of the right heart were significantly higher in the syncope group. No significant difference was observed between the groups in parameters representing systolic and diastolic functions of the right heart. Conclusion: In our study, an increase in the A value indicating right atrial contraction was observed in patients with syncope. The increase of this value is thought to represent increased contractility as compensation for the reduced preload, which is the hypothesis of syncope development. While the decrease in LVESD value in the syncope group was an expected finding in hypercontractility, no significant difference was observed in other left and right ventricle systolic function values representing contractility. In conclusion, decreased preload affects the dynamics of not only the left but also the right heart.