Cardiology Letters 2023, 32(6):373-379

The role of vasoactive hormones in pathogenesis of vasovagal syncope

Lazúrová Z^{1, 2}, Lukáčová M¹, Popovňáková M³, Wedel MA⁴, Mitro P¹

¹ 1. kardiologická klinika UPJŠ LF a VÚSCH, a. s., Košice

² 4. interná klinika UPJŠ LF a UNLP, Košice

³ Laboratórium Medirex a. s., Košice

⁴ Lekárská fakulta UPJŠ, Košice, Slovenská republika

Background: Vasovagal syncope (VVS) is the most common type of syncope. In the pathogenesis, the excessive activation of the autonomic nervous system plays a role, but there is also increasing evidence of the significant role of neurohumoral mechanisms. An imbalance in the levels of vasoactive hormones which are involved in the regulation of blood pressure, such as catecholamines, adenosine, neuropeptide Y (NPY), endothelin (ET-1), angiotensinogen (ANG) or apelin (APE), and others, may participate in the manifestation of VVS.

Aim: To clarify the importance of vasoactive hormones - NPY, ET-1, ANG and APE in the pathogenesis of VVS.

Patients and methods: 69 patients with a history of at least one syncope who underwent the head-up tilt (HUT) test as part of the differential diagnosis of syncope were included in the study. The group consisted of 41 women and 28 men, the average age was 39.6 + 3.2 years. All patients underwent venous blood sampling to determine the levels of NPY, ET-1, ANG and APE before HUT and immediately after HUT. Vasoactive hormones were determined by ELISA methodology.

Results: HUT was positive in 50 patients, in 19 there was no induction of VVS during HUT. We found significantly lower levels of NPY at the onset of syncope in patients with positive HUT compared to patients with negative HUT (36.7±2.1 vs 44.4±3.2, p=0.02): basal values of NPY did not differ significantly. Basal ANG was lower in patients who manifested VVS in HUT (251.2±9.9 vs 289±15.8, p=0.03). ANG values after HUT were not significantly different. The levels of ET-1 and AP before or after HUT were not significantly different between the patient group and the control group.

Conclusion: Reduced levels of vasoconstrictors responsible for maintaining blood pressure probably participate in the development of VVS. Based on the results of our study, it can be assumed that defective compensatory production of neuropeptide Y during orthostasis could be involved in the pathogenesis of VVS. Also, lower basal angiotensin levels may predispose these patients to hypotension and syncope.

Keywords: vasovagal syncope; head-up tilt test; neuropeptide Y; endothelin angiotensinogen; apelin

Published: June 1, 2023  Show citation