Purpose: The presence of spontaneous type 1 ECG pattern (BrECG) is considered a risk factor in Brugada syndrome, although it could be underestimated because of the well-known BrECG fluctuations. Aim of the study was to analyse in a large population of Brugada patients the prevalence of type 1 BrECG using 12-lead 24-hour Holter monitoring (12L-Holter) and to evaluate its reproducibility and correlation with the time of the day. Methods: We collected 234 12L-Holter recorded in 187 patients from the 679 of the Brugada Registry of a region of Italy. Thirty-six patients (19%) had from 2 to 3 12L-Holter. Among the patients included in the study, 67 (36%) exhibited spontaneous type 1 BrECG in at least one 12-lead ECG recorded before 12L-Holter, while 120 (64%) had only drug-induced type 1 BrECG. Twenty-four (13%) were symptomatic for syncope, 1 had aborted sudden death and 162 (86%) were asymptomatic. 12L-Holter were recorded in the right precordial leads both at 4th and 2rd intercostal space and were analysed independently by two cardiologists. In order to evaluate the circadian fluctuations of the BrECG, 4 periods were considered: 12 midnight-6 am, 6 am–12 noon, 12 noon-6 pm and 6 pm-12 midnight. The burden of type 1 BrECG was defined as “permanent” (>85% of the 12L-Holter recording), “intermittent” (between 60 seconds and 85% of the recording), “absent” (less than 60 seconds). Results: Twenty-three (19%) out of 120 patients with drug-induced type 1 BrECG, developed intermittent spontaneous type 1 BrECG in at least one 12L-Holter. Forty (59%) out of 67 patients with previously documented spontaneous type 1 BrECG on 12L-ECG showed intermittent type 1 in at least one 12L-Holter, 9 (13%) had persistent type 1 in all the 12L-Holter; 18 (27%) never had spontaneous type 1 at 12L-Holter: in 5 of them the type 1 BrECG had been documented only during fever. Spontaneous type 1 BrECG on 12L-Holter was present in 56% of symptomatic and 47% of asymptomatic patients (p=NS) and was most frequently recorded between 12-noon and 12-midnight (85%) than between 12 midnight and 12 noon (15%, p<0.001). Nine out of the 36 patients (25%) with more than one 12L-Holter showed discordant results concerning the presence of spontaneous type 1. Conclusions: 12L-Holter recording significantly increases the chances to identify spontaneous type 1 BrECG. Significant fluctuation of BrECG pattern is also present in serial 12L-Holter recordings. Type 1 BrECG was mainly documented between 12 noon–12 midnight. Further studies are needed to establish the correlation between spontaneous type 1 BrECG and ventricular arrhythmic events.
Prevalence of type 1 Brugada electrocardiographic pattern evaluated on 12-lead 24-hour Holter monitoring
CERRATO, Natascia;GIUSTETTO, Carla;ZEMA, Domenica;SCROCCO, Chiara;GAITA, Fiorenzo
2014-01-01
Abstract
Purpose: The presence of spontaneous type 1 ECG pattern (BrECG) is considered a risk factor in Brugada syndrome, although it could be underestimated because of the well-known BrECG fluctuations. Aim of the study was to analyse in a large population of Brugada patients the prevalence of type 1 BrECG using 12-lead 24-hour Holter monitoring (12L-Holter) and to evaluate its reproducibility and correlation with the time of the day. Methods: We collected 234 12L-Holter recorded in 187 patients from the 679 of the Brugada Registry of a region of Italy. Thirty-six patients (19%) had from 2 to 3 12L-Holter. Among the patients included in the study, 67 (36%) exhibited spontaneous type 1 BrECG in at least one 12-lead ECG recorded before 12L-Holter, while 120 (64%) had only drug-induced type 1 BrECG. Twenty-four (13%) were symptomatic for syncope, 1 had aborted sudden death and 162 (86%) were asymptomatic. 12L-Holter were recorded in the right precordial leads both at 4th and 2rd intercostal space and were analysed independently by two cardiologists. In order to evaluate the circadian fluctuations of the BrECG, 4 periods were considered: 12 midnight-6 am, 6 am–12 noon, 12 noon-6 pm and 6 pm-12 midnight. The burden of type 1 BrECG was defined as “permanent” (>85% of the 12L-Holter recording), “intermittent” (between 60 seconds and 85% of the recording), “absent” (less than 60 seconds). Results: Twenty-three (19%) out of 120 patients with drug-induced type 1 BrECG, developed intermittent spontaneous type 1 BrECG in at least one 12L-Holter. Forty (59%) out of 67 patients with previously documented spontaneous type 1 BrECG on 12L-ECG showed intermittent type 1 in at least one 12L-Holter, 9 (13%) had persistent type 1 in all the 12L-Holter; 18 (27%) never had spontaneous type 1 at 12L-Holter: in 5 of them the type 1 BrECG had been documented only during fever. Spontaneous type 1 BrECG on 12L-Holter was present in 56% of symptomatic and 47% of asymptomatic patients (p=NS) and was most frequently recorded between 12-noon and 12-midnight (85%) than between 12 midnight and 12 noon (15%, p<0.001). Nine out of the 36 patients (25%) with more than one 12L-Holter showed discordant results concerning the presence of spontaneous type 1. Conclusions: 12L-Holter recording significantly increases the chances to identify spontaneous type 1 BrECG. Significant fluctuation of BrECG pattern is also present in serial 12L-Holter recordings. Type 1 BrECG was mainly documented between 12 noon–12 midnight. Further studies are needed to establish the correlation between spontaneous type 1 BrECG and ventricular arrhythmic events.
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