Document Type : Case Report
1 Associate Professor, Department of Cardiac Electrophysiology AND Cardiac Electrophysiology Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
2 Assistant Professor, Heart Failure Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran
3 Assistant Professor, Department of Cardiology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
4 Assistant Professor, Department of Cardiac Electrophysiology AND Cardiac Electrophysiology Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
BACKGROUND: Atrioventricular node (AVN) is an interatrial septum structure located at the apex of triangle of Koch that modulates the transmission of impulses from atria to the ventricles. Vagally mediated AVN block with high frequency stimulation (HFS) was investigated in a few animal and human studies, but prolonged ventricular asystole that was induced by a low frequency proximal coronary sinus (CS) overdrive pacing has rarely been reported.CASE REPORT: A 40-year-old man was admitted in our hospital for evaluation of syncope and palpitation. He presented with prolonged ventricular asystole by proximal CS pacing during electrophysiological study (EPS).CONCLUSION: There is no comprehensive clinical study to investigate the association of vasovagal syncope with vagally mediated atrioventricular block (AVB) which is induced by posteroseptal area stimulation. Radiofrequency catheter ablation of ganglionated plexi (GP) located close to sinus node and AVN was reported to eliminate the vagal efferent output during vasovagal syncope as a new treatment strategy.
- Basso C, Ho SY, Thiene G. Anatomic and histopathological characteristics of the conductive tissues of the heart. In: Gussak I, Antzelevitch C, Wilde AAM, Friedman PA, Ackerman MJ, Shen WK, editors. Electrical diseases of the heart: genetics, mechanisms, treatment, prevention. London, UK: Springer London; 2008. p. 37-51.
- Kurian T, Ambrosi C, Hucker W, Fedorov VV, Efimov IR. Anatomy and electrophysiology of the human AV node. Pacing Clin Electrophysiol 2010; 33(6): 754-62.
- Issa ZF, Miller JM, Zipes DP. Atrioventricular conduction abnormalities. In: Issa ZF, Miller JM, Zipes DP, editors. Clinical arrhythmology and electrophysiology. Philadelphia, PA: Elsevier; 2012. P. 175-93.
- Anderson RH, Ho SY, Becker AE. Anatomy of the human atrioventricular junctions revisited. Anat Rec 2000; 260(1): 81-91.
- Alboni P, Holz A, Brignole M. Vagally mediated atrioventricular block: pathophysiology and diagnosis. Heart 2013; 99(13): 904-8.
- Bianchi S, Rossi P, Della SA, Kornet L, Pulvirenti R, Monari G, et al. Atrioventricular (AV) node vagal stimulation by transvenous permanent lead implantation to modulate AV node function: safety and feasibility in humans. Heart Rhythm 2009; 6(9): 1282-6.
- Bianchi S, Rossi P, Schauerte P, Elvan A, Blomstrom-Lundqvist C, Kornet L, et al. Increase of ventricular interval during atrial fibrillation by atrioventricular node vagal stimulation: Chronic clinical atrioventricular-nodal stimulation download study. Circ Arrhythm Electrophysiol 2015; 8(3): 562-8.
- Aksu T, Guler TE, Bozyel S, Yalin K. Potential usage of cardioneuroablation in vagally mediated functional atrioventricular block. SAGE Open Med 2019; 7: 2050312119836308.