Serum Asymmetric Dimethylarginine Levels in Patients with Vasovagal Syncope.

Adem Atıcı,Mustafa Sahin,Ahmet Kaya Bilge,Gonul Aciksari,Ramazan Asoglu,Hasan Ali Barman,Mehmet Rasih Sonsöz,Şeref Kul,Baris Gungor,Irfan Sahin,Ahmet Demirkıran,Omer Faruk Baycan,Eser Durmaz

doi:10.3390/medicina55110718

Abstract

Background and Objectives: Vasovagal syncope (VVS) is the most common cause of syncope and has multiple pathophysiological mechanisms. Asymmetric dimethylarginine (ADMA) is the major inhibitor of nitric oxide (NO). In this study, we aimed to investigate the relationship between plasma ADMA levels and syncope during the head-up tilt (HUT) test. Materials and Methods: Overall, 97 patients were included in this study. They were above 18 years of age and were admitted to our clinic with the complaint of at least one episode of syncope consistent with VVS. The HUT test was performed in all patients. Patients were divided into the following two groups based on the HUT test results: group 1 included 57 patients with a positive HUT test and group 2 included 35 patients with a negative HUT test. Blood samples were taken before and immediately after the HUT test to measure ADMA levels. Results: No significant intergroup differences were observed concerning gender and age (female gender 68% vs 60%; mean age 24.85 ± 4.01 vs 25.62 ± 3.54 years, respectively, for groups 1 and 2). ADMA values were similar between groups 1 and 2 before the HUT test [ADMA of 958 (544–1418) vs 951 (519–1269); p = 0.794]. In the negative HUT group, no significant differences were observed in ADMA levels before and after the HUT test [ADMA of 951 (519–1269) vs 951 (519–1566); p = 0.764]. However, in the positive HUT group, ADMA levels were significantly decreased following the HUT test [pretest ADMA of 958 (544–1418) vs post-test ADMA of 115 (67–198); p < 0.001]. Conclusion: ADMA levels significantly decreased after the HUT test in patients with VVS.

Highlights

Medicina2019, 55, x FOR PEER REVIEWSyncope is defined as the transient loss of consciousness, loss of muscle tone, and inability to sustain activity because of cerebral hypoperfusion, which reverses spontaneously [1]
heart rate (HR) and systolic and diastolic blood pressures before and after the head-up tilt (HUT) test were similar between groups (SBP 111.28 ± 11.37 mmHg vs 114.57 ± 6.68 mmHg, p = 0.124; DBP 69.87 ± 8.49 mmHg vs 71.28 ± 5.46 mmHg, p = 0.335; HR 73.56 ± 3.63 beats/min vs 74.62 ± 2.98 beats/min, p = 0.148, all respectively for groups 1 and 2)
Of the 57 patients with positive HUT, 30 were diagnosed with vasodepressor type syncope, and the remaining were diagnosed with mixed type

Summary

Introduction

Medicina2019, 55, x FOR PEER REVIEWSyncope is defined as the transient loss of consciousness, loss of muscle tone, and inability to sustain activity because of cerebral hypoperfusion, which reverses spontaneously [1]. Neurohumoral activation increases the plasma levels of several vasoactive substrates,syncope such as is the most common subtype of syncope and has multiple pathophysiologic. NO exerts a powerful vasodilatory effect and plays a critical role in patients with VVS [7]. Vasovagal syncope (VVS) is the most common cause of syncope and has multiple pathophysiological mechanisms. We aimed to investigate the relationship between plasma ADMA levels and syncope during the head-up tilt (HUT) test. Materials and Methods: Overall, 97 patients were included in this study They were above 18 years of age and were admitted to our clinic with the complaint of at least one episode of syncope consistent with VVS. In the negative HUT group, no significant differences were observed in ADMA levels before and after the HUT test [ADMA of 951

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Discussion

Conclusion