In tachycardia QTcFri ... Validation of paced P-wave morphology templates to guide atrial tachycardia localization ... SVC/Crista terminalis. 21. 85.7%. Interatrial ...
Poster session 1 P475
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Sensitivity at different sites
QT correction and predictive value of QTc in atrial fibrillation B. Vandenberk1; E. Vandael2; T. Robyns1; J. Vandenberghe3; C. Garweg1; V. Foulon2; J. Ector1; R. Willems1 1 University of Leuven, Cardiovascular sciences, Leuven, Belgium; 2University of Leuven, Department of Pharmaceutical and Pharmacological Sciences, Leuven, Belgium; 3University of Leuven, Department of Neurosciences, Leuven, Belgium Background: Integration of QT monitoring in a decision support system requires accurate QT interval correction including abnormal ECGs. The current knowledge on QT correcting formulas in atrial fibrillation is limited, therefore we studied the performance and predictive value of different correction formulas in AF. Methods: All patients >18y with AF and normal QRS duration ( 120ms) during a 6 year period were included (first ECG per patient). QT correction was performed with Bazett (QTcB), Fridericia (QTcFri), Framingham (QTcFra), Hodges (QTcH) and Rautaharju (QTcR). ECGs were divided into bradycardia (100bpm) and normal heart rates. Correction formulas were compared using QTc/ RR linear regression slopes. The slope closest to zero indicates the least remaining influence of the heart rate. Slopes were compared using one-way ANOVA with posthoc comparison. Cox Regression for 1-year all-cause mortality was adjusted for age, gender, heart rate, QRS duration and ambulatory contact type. Results: A total of 9167 ECGs were included: age 74612y; 44% females; 24% ambulatory patients and a mean heart rate of 96628bpm. Bradycardia was present in 3% and tachycardia in 50%. The 1-year all-cause mortality was 24%. QTcFri showed the best rate correction with lowest slopes and R2 values over the entire range of heart rates. In normal heart rates QTcFri had a significant lower slope when compared to QTcB (p0.0001) and QTcR (p0.01), but did not differ from QTcFra or QTcH. In bradycardia QTcFri performed better than all other formulas (QTcB and QTcH p0.01; QTcFra p0.05; QTcR p0.0001). In tachycardia QTcFri had comparable correction to QTcR, but was significantly better than QTcB, QTcFra and QTcH (p0.0001). In adjusted Cox regression a prolonged QTcFri was an independent predictor for 1year all-cause mortality (p¼0.003; HR 1.22, 95% CI 1.07-1.38), whereas QTcB was not (p¼0.069; HR 1.09, 95% CI 0.99-1.22). Conclusions: In patients with AF and normal QRS duration QTcFri showed the best rate correcting properties from all other formulas investigated and is related with 1year all-cause mortality. Comparison of QTc/RR slopes
QTcB QTcFri QTcFra QTcH QTcR
Bradycardia Slope
R2
Normal heart rate Slope R2
Tachycardia Slope
R2
-0,0486 6 0,0080 0,0035 6 0,0082 -0,0330 6 0,0086 0,0564 6 0,0086 -0,0620 6 0,0085
0,0645 0,0065 0,0473 0,0110 0,0938
-0,0737 6 0,0045 0,0126 6 0,0044 0,0165 6 0,0041 0,0195 6 0,0041 -0,0135 6 0,0041
-0,0809 6 0,0063 0,0630 6 0,0057 0,1107 6 0,0046 -0,1563 6 0,0047 0,0799 6 0,0046
0,0581 0,0019 0,0038 0,0053 0,0025
0,0345 0,0262 0,1132 0,1972 0,0618
AT site of origin
Number of patients
Sensitivity (%)
RA SVC/Crista terminalis Interatrial septum RAA/Superior TA Inferolateral TA Inferomedial TA/CS os
47 21 4 11 7 4
87.2% 85.7% 100% 90.9% 100% 50%
LA Medial MA/Mid CS Superior MA/LAA RSPV RIPV LSPV
24 2 7 9 1 5
100% 100% 100% 100% 100% 100%
Sensitivity of the algorithm at different atrial sites
P477 Is the r wave sign a predictor for ventricular tachyarrhythmia in patients with brugada syndrome ? AA. Ragab; JME Van Der Does; EAH Lanters; CA. Houck; DE. Burghouwt; AJQ Muskens; NMS De Groot Erasmus Medical Center, Department of Cardiology, Rotterdam, Netherlands Background: Brugada syndrome (BrS) is an autosomal dominant channelopathy which is responsible for a large number of sudden cardiac deaths in young individuals without structural abnormalities. The most challenging step in management of patients with BrS is identifying who is at risk for developing malignant ventricular tachyarrhythmia (VTA). Electrocardiographic parameters can be useful to detect these high risk patients. Conduction delay in the right ventricular outflow tract (RVOT) causes a prominent R wave in lead aVR. Purpose: The aim of this study is to test the significance of R wave elevation in lead aVR as a predictor for VTA in patients with BrS. Methods: In this retrospective study, we included 132 patients with BrS (47615 years, 65% male) who visited the outpatient clinic for cardiogenetic screening. Patients’ medical records were examined for the presence of a positive R wave sign in lead aVR and VTA. Results: A positive R wave sign in lead aVR was observed in 41 patients (31%). This sign was more frequently observed in patients who experienced VTA (N¼24) either before the initial diagnosis, during electrophysiological studies or during follow up (P< 0.001). The positive R wave sign occurred more frequently in symptomatic patients with a history of an out of hospital cardiac arrest, VTA or syncope, than asymptomatic patients (60% versus 26%; P¼ 0.002). During the follow up period, this sign was more frequently detected in patients who developed either de novo (50%) or recurrent (80%) VTA (P¼ 0.017). Multivariate analysis showed that R wave sign is an independent predictor for VTA development (OR 4.8). Conclusion: In patients with BrS, the presence of a positive R wave sign in lead aVR is associated with development of VTA. Our findings indicate that the positive R wave sign in lead aVR can be used to identify BrS patients at risk for malignant VTA.
P476 Validation of paced P-wave morphology templates to guide atrial tachycardia localization A. AbdelWahab1; D. Yahya2; J. Sapp1; H. Rizk2; R. Parkash1; M. Gardner1; C. Gray1; A. El-Damaty2 1 QE II Health Sciences Center, Heart Rhythm Service, Division of Cardiology, Halifax, Canada; 2Cairo University Hospitals, Department of Cardiovascular Medicine, Cairo, Egypt BACKGROUND: Surface ECG is a useful tool to guide mapping of focal atrial tachycardia (AT). We have previously proposed an algorithm based on paced P wave morphology templates by pacing from different anatomical sites in both atria. OBJECTIVE: Validation of this algorithm in a retrospective series of AT patients who underwent catheter ablation. METHODS: We prospectively enrolled consecutive patients who underwent electrophysiology study, had no heart disease and no atrial enlargement. Atrial pacing, at twice diastolic threshold, was carried out at different anatomical sites in both atria. Paced P wave morphology and duration were assessed. An algorithm was generated from the constructed templates of each pacing site. The algorithm was applied on a retrospective series of successfully ablated AT patients. Overall and site-specific accuracy were determined. RESULTS: Derivation cohort included 65 patients (25 men, age 37613 years). Atrial pacing was performed in 1025 sites in 61 patients (95%) in RA and in 15 patients (23%) in LA. The validation cohort included 71 patients (28 men, age 52619 years). AT were right atrial in 66.2%. The algorithm successfully predicted AT origin in 91.5% of patients (100% in LA and 87.2% in RA). It was off by 1 adjacent segment in the remaining 8.5%. Site-specific accuracies are shown in Table1. CONCLUSIONS: A simple ECG algorithm based on paced P-wave morphology templates was highly accurate in localizing sites of origin of focal atrial tachycardia particularly those of LA origin.
Abstract P477 Figure.
P478 Early repolarization pattern in patients with structural heart disease: can it really predict sudden cardiac death? A. Santos-Ortega; J. Perez-Rodon; N. Rivas-Gandara; I. Roca-Luque; J. FranciscoPascual; G. Martin-Sanchez; JG. Acosta-Velez; G. Oristrell-Santamaria; C. Alepuz; E. Galve-Basilio; D. Garcia-Dorado; A. Moya-Mitjans University Hospital Vall d’Hebron, Cardiology department, Barcelona, Spain Funding Acknowledgements: Grant from the Spanish Society of Cardiology Introduction: Identifying patients at risk for sudden cardiac death (SCD) remains a challenge. Early repolarization pattern in the inferolateral leads (ERP) has been
Europace Abstracts Supplement, 2017
