OBJECTIVES: We present data on patients with syncope due to paroxysmal atrioventricular (AV) block unexplainable in terms of currently known mechanisms. BACKGROUND: Paroxysmal AV block is known to be due to intrinsic AV conduction disease or to heightened vagal tone. METHODS: We evaluated 18 patients presenting with unexplained syncope who had: 1) normal baseline standard electrocardiogram (ECG); 2) absence of structural heart disease; and 3) documentation, by means of prolonged ECG monitoring at the time of syncopal relapse, of paroxysmal third-degree AV block with abrupt onset and absence of other rhythm disturbances before or during the block. RESULTS: The study group consisted of 9 men and 9 women, mean age 55 ± 19 years, who had recurrent unexplained syncope for 8 ± 7 years and were subsequently followed up for as long as 14 years (4 ± 4 years on average). The patients had no structural heart disease, standard ECG was normal, and electrophysiological study was negative. In all patients, prolonged ECG monitoring documented paroxysmal complete AV block with 1 or multiple consecutive pauses (mean longest pause: 9 ± 7 s at the time of syncope); AV block occurred without P-P cycle lengthening or PR interval prolongation. During the observation time, no patient had permanent AV block; on permanent cardiac pacing, no patient had further syncopal recurrences. CONCLUSIONS: Common clinical and electrophysiological features define a distinct form of syncope due to idiopathic paroxysmal AV block characterized by a long history of recurrent syncope, absence of progression to persistent forms of AV block, and efficacy of cardiac pacing therapy.
OBJECTIVES: We present data on patients with syncope due to paroxysmal atrioventricular (AV) block unexplainable in terms of currently known mechanisms. BACKGROUND: Paroxysmal AV block is known to be due to intrinsic AV conduction disease or to heightened vagal tone. METHODS: We evaluated 18 patients presenting with unexplained syncope who had: 1) normal baseline standard electrocardiogram (ECG); 2) absence of structural heart disease; and 3) documentation, by means of prolonged ECG monitoring at the time of syncopal relapse, of paroxysmal third-degree AV block with abrupt onset and absence of other rhythm disturbances before or during the block. RESULTS: The study group consisted of 9 men and 9 women, mean age 55 ± 19 years, who had recurrent unexplained syncope for 8 ± 7 years and were subsequently followed up for as long as 14 years (4 ± 4 years on average). The patients had no structural heart disease, standard ECG was normal, and electrophysiological study was negative. In all patients, prolonged ECG monitoring documented paroxysmal complete AV block with 1 or multiple consecutive pauses (mean longest pause: 9 ± 7 s at the time of syncope); AV block occurred without P-P cycle lengthening or PR interval prolongation. During the observation time, no patient had permanent AV block; on permanent cardiac pacing, no patient had further syncopal recurrences. CONCLUSIONS: Common clinical and electrophysiological features define a distinct form of syncope due to idiopathic paroxysmal AV block characterized by a long history of recurrent syncope, absence of progression to persistent forms of AV block, and efficacy of cardiac pacing therapy.
Authors: Robert S Sheldon; Blair P Grubb; Brian Olshansky; Win-Kuang Shen; Hugh Calkins; Michele Brignole; Satish R Raj; Andrew D Krahn; Carlos A Morillo; Julian M Stewart; Richard Sutton; Paola Sandroni; Karen J Friday; Denise Tessariol Hachul; Mitchell I Cohen; Dennis H Lau; Kenneth A Mayuga; Jeffrey P Moak; Roopinder K Sandhu; Khalil Kanjwal Journal: Heart Rhythm Date: 2015-05-14 Impact factor: 6.343
Authors: Roland D Thijs; Michele Brignole; Cristian Falup-Pecurariu; Alessandra Fanciulli; Roy Freeman; Pietro Guaraldi; Jens Jordan; Mario Habek; Max Hilz; Anne Pavy-Le Traon; Iva Stankovic; Walter Struhal; Richard Sutton; Gregor Wenning; J Gert Van Dijk Journal: Clin Auton Res Date: 2021-03-19 Impact factor: 4.435