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Evolution of Ventriculo-Atrial Conduction in Patients With Dual Chamber Pacemakers
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Canadian Cardiovascular Society (CCS) Poster POSTER - CARDIAC ELECTRONIC IMPLANTABLE DEVICES Friday, October 18, 2013 259 PREDICTIVE FACTORS FOR COMPLETE AV BLOCK POST TRANSCATHETER AORTIC VALVE IMPLANTATION L Rivard, G Schram, A Asgar, P Khairy, J Le Polain De Waroux, M Dubuc, L Macle, M Talajic, K Dyrda, D Roy, P Guerra, H Leduc, B Thibault Montréal, Québec INTRODUCTION:
Transcatheter aortic valve implantation (TAVI) is an alternative therapy for patients with severe aortic valve stenosis (AS) at high surgical risk. High-degree atrioventricular block (AVB) requiring permanent pacemaker (PM) implantation is a common complication. Our aim was to explore predictive factors for complete AV block post TAVI, including parameters from electrophysiological (EP) studies. METHODS: We enrolled consecutive patients with TAVI procedures between 2009 and 2012 and EP studies before and after. The primary outcome was complete AV block or unexpected sudden cardiac death during follow-up. RESULTS: 75 patients (48 males), age 81.27.4 yrs, LVEF 54.310.9%, were followed for 377291 days post TAVI. Fifteen pts (20%) developed AV block: 12 during hospitalization and the remainder within 30 days after TAVI. AVB developed immediately post procedure in 5/6 pts with prior right bundle branch block (RBBB), 9/28 pts (32%) with new onset LBBB. One of 6 pts with a prior LBBB developed delayed AVB (2-30 days after TAVI) while 0/35 pts with a QRS<120 ms developed AVB. In multivariate analyses, delta HV (post minus pre TAVI) and HV post TAVI were the only predictors of AVB. Cut-off values with the greatest discriminatory accuracy were 15 ms and 65 ms, respectively [ROC analysis, figure]. CONCLUSION: EP studies provide important prognostic information post TAVI. A delta HV>15 ms from baseline or a post TAVI HV65 identify pts at increased risk for complete AV block.
Canadian Journal of Cardiology Volume 29 2013
260 EVOLUTION OF VENTRICULO-ATRIAL CONDUCTION IN PATIENTS WITH DUAL CHAMBER PACEMAKERS I Greiss, A Baranchuk, CS Simpson, H Abdollah, DP Redfearn, M Buys-Topart, R Nitzsche, B Thibault Montréal, Québec BACKGROUND: The CAN-SAVE R study compared long-term efficacy of the SafeR pacing mode (an AAI-DDD algorithm to avoid unnecessary right pacing) to DDD pacing with long atrio-ventricular (AV) delays in pacemaker (PM) patients not presenting persistent high degree AV blocks (AVB) or permanent atrial fibrillation. In a sub-study, ventriculo-atrial conduction (VA) was analyzed over a period of 3 years. METHODS: Patients were implanted with a Symphony DR 2550 PM from the Sorin Group. VA conduction was assessed at the 2-month randomization visit (baseline) and at 3 year (Y3) visit in VVI pacing at 630 msec (95 bpm), in patients not presenting atrial arrhythmias or faster heart rate at the time of evaluation. All electrograms were reviewed by a core center to classify VA conduction as 1:1 conduction (intact), Wenckebach, 2:1 or blocked (impaired). RESULTS: A total of 375 CAN-SAVE R patient files were reviewed. In 205 patients, VA conduction data were available at both baseline and at Y3. Mean age was 71 year-old, 133 patients (65%) were male. Indications for PM implantation were sinus node dysfunction (SND) in 90 cases (44%), AVB in 61 cases (30%), both SND and AVB in 29 cases (14%) and other in 25 cases (12%). A total of 77 patients (38%) showed intact VA conduction at baseline. Of those, 21 patients (27%) developed blocked VA conduction at Y3; one patient (1.2%) had Wenckebach. Of the 128 patients (62%) with impaired VA conduction at baseline, 15 patients (11.7%) recovered intact VA conduction at Y3, while 9 patients (7%) with either Wenckebach or 2:1 block further progressed to complete block. At the end of the follow-up period, 70 patients (34%) had intact conduction and 135 (66%) patients showed impaired VA conduction. The following table and figure summarize VA conduction observed at baseline and at Y3. CONCLUSION: In this series of PM patients, VA conduction was analyzed over a 3-year period. Retrograde conduction shows dynamic properties and changes overtime. Although some patients maintained or recovered an intact VA conduction, a majority of cases tended to deteriorate VA conduction and demonstrated conduction impairment, mainly complete block, over the follow-up period.
VA conduction over 3-year follow-up VA conduction at baseline Conduction at Y3 P Patients (%) Patients (%) 1:1 conduction
77 (38%)
70 (34%)
0.4588
Impaired VA conduction Wenckebach 2 :1 Blocked Total
6 5 117 128 (62%)
3 0 132 135 (66%)
0.1084
Abstracts
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77% and Denmark 50%; and who would enroll patients with PMAT of more than 48 hours: Canada 41%, the Netherlands 67%, Switzerland 85% and Denmark 42%. CONCLUSION: There is extensive variation in the use of OAC among patients with PMAT. However, the majority of physicians would enroll in a clinical trial of OAC; including patients with long episodes of PMAT and patients with a history of stroke.
262 UTILISATION OF A RIGHT VENTRICULAR APICAL LEAD FOR PACING BACKUP IN PATIENTS WITH A HIS-BUNDLE LEAD C Khoo, SK Tung Vancouver, British Columbia
261 CURRENT USE OF ORAL ANTICOAGULANTS THERAPY IN PACEMAKER PATIENTS WITH PACEMAKER-DETECTED ATRIAL FIBRILLATION: RESULTS FROM A FOUR-NATION PHYSICIAN SURVEY K Bami, JC Nielsen, M Alings, D Conen, A Verma, D Birnie, F Philippon, D Exner, SJ Connolly, CA Morillo, JS Healey Hamilton, Ontario BACKGROUND:
The ASSERT trial demonstrated an association between pacemaker-detected atrial tachyarrhythmias (PMAT) and stroke. However, ASSERT does not inform physicians if patients with PMAT, but without clinical atrial fibrillation, should receive treatment with oral anticoagulation (OAC). Data on the current clinical management of these patients are sparse. METHODS: We conducted a prospective survey of 181 physicians caring for pacemaker patients in centers across Canada, Switzerland, Denmark, and the Netherlands. We evaluated current clinical practices to determine how patients with PMAT are managed and to gauge interest in a randomized control trial of OAC for stroke prevention. RESULTS: A total of 91 surveys (50%) were completed. Just over half of the centres (52%) reported that physicians are routinely called to assess patients with PMAT and only 47% have a system in place to stratify risk and treat patients with PMAT. Only 19% report using OAC regularly for most patients with AHRE, while 91% state that they would be willing to enroll patients into a trial comparing OAC vs. ASA. Of physicians who would enroll patients in a clinical trial, 45% would enroll patients with a history of stroke or TIA and 36% would enroll such patients even if their stroke or TIA occurred in the prior 6 months. Among patients with a CHADS-2 score of 2, 75% of physicians would enroll patients whose longest episode of PMAT was up to 6 hours in duration, while 49% of physicians would still enroll patients despite a longest episode of more than 48 hours. There was little variation between countries in the proportion of physicians who would enroll patients in a clinical trial of OAC: Canada 94%, the Netherlands 81%, Switzerland 81% and Denmark 100%. However; there was variation in the proportion that would enroll patients with a history of stroke or TIA: Canada 35%, the Netherlands 44%, Switzerland
BACKGROUND: His-bundle pacing (HBP) is an alternative to right ventricular apical pacing (RVAP) in patients with atrioventricular (AV) conduction disease. RVAP-associated ventricular dysfunction may be prevented, at the cost of more rapid battery drainage due to higher capture thresholds. We report a case series of patients with low-output HBP where RVAP is utilised as a backup-pacing modality in case of loss of ventricular capture. METHODS: 3 patients at our institution had successful implantation of a HBP lead, 2 with a dual-chamber pacemaker, and 1 with an implantable cardioverter-defibrillator (ICD). A RVA lead was also implanted and plugged into the ventricular pacing port, while the HBP was plugged into the atrial pacing port. The devices were programmed to DDDR <-> AAIR (managed ventricular pacing/ MVP mode) and HBP output at between 1 - 2.5x capture threshold. RVAP output was kept at >¼ 2x capture threshold. RESULTS: Successful HBP resulted in narrow paced QRS complexes identical to underlying conducted QRS complexes (Figure 1A, B). Backup RVAP could be demonstrated with loss of HBP capture during “atrial” capture threshold testing (Figure 1B). This allowed for the use of a mean HBP output of 2.6 V at 0.47 msec (range: 1 - 4 V at 0.4 - 0.6 msec), which was a mean of 1.7x the capture threshold. Left ventricular ejection fraction (LVEF) improved from 28 4% to 38 2% after a mean follow-up of 22 26 months. CONCLUSION: The use of backup RVAP allows for the ability to use low-output HBP without concern of loss-of-pacing in patients with AV block. This strategy may be employed as an alternative to BiV pacing in patients with AV disease and ventricular dysfunction.
Canadian Cardiovascular Society (CCS) Poster POSTER - CARDIAC ELECTRONIC IMPLANTABLE DEVICES Friday, October 18, 2013 259 PREDICTIVE FACTORS FOR COMPLETE AV BLOCK POST TRANSCATHETER AORTIC VALVE IMPLANTATION L Rivard, G Schram, A Asgar, P Khairy, J Le Polain De Waroux, M Dubuc, L Macle, M Talajic, K Dyrda, D Roy, P Guerra, H Leduc, B Thibault Montréal, Québec INTRODUCTION:
Transcatheter aortic valve implantation (TAVI) is an alternative therapy for patients with severe aortic valve stenosis (AS) at high surgical risk. High-degree atrioventricular block (AVB) requiring permanent pacemaker (PM) implantation is a common complication. Our aim was to explore predictive factors for complete AV block post TAVI, including parameters from electrophysiological (EP) studies. METHODS: We enrolled consecutive patients with TAVI procedures between 2009 and 2012 and EP studies before and after. The primary outcome was complete AV block or unexpected sudden cardiac death during follow-up. RESULTS: 75 patients (48 males), age 81.27.4 yrs, LVEF 54.310.9%, were followed for 377291 days post TAVI. Fifteen pts (20%) developed AV block: 12 during hospitalization and the remainder within 30 days after TAVI. AVB developed immediately post procedure in 5/6 pts with prior right bundle branch block (RBBB), 9/28 pts (32%) with new onset LBBB. One of 6 pts with a prior LBBB developed delayed AVB (2-30 days after TAVI) while 0/35 pts with a QRS<120 ms developed AVB. In multivariate analyses, delta HV (post minus pre TAVI) and HV post TAVI were the only predictors of AVB. Cut-off values with the greatest discriminatory accuracy were 15 ms and 65 ms, respectively [ROC analysis, figure]. CONCLUSION: EP studies provide important prognostic information post TAVI. A delta HV>15 ms from baseline or a post TAVI HV65 identify pts at increased risk for complete AV block.
Canadian Journal of Cardiology Volume 29 2013
260 EVOLUTION OF VENTRICULO-ATRIAL CONDUCTION IN PATIENTS WITH DUAL CHAMBER PACEMAKERS I Greiss, A Baranchuk, CS Simpson, H Abdollah, DP Redfearn, M Buys-Topart, R Nitzsche, B Thibault Montréal, Québec BACKGROUND: The CAN-SAVE R study compared long-term efficacy of the SafeR pacing mode (an AAI-DDD algorithm to avoid unnecessary right pacing) to DDD pacing with long atrio-ventricular (AV) delays in pacemaker (PM) patients not presenting persistent high degree AV blocks (AVB) or permanent atrial fibrillation. In a sub-study, ventriculo-atrial conduction (VA) was analyzed over a period of 3 years. METHODS: Patients were implanted with a Symphony DR 2550 PM from the Sorin Group. VA conduction was assessed at the 2-month randomization visit (baseline) and at 3 year (Y3) visit in VVI pacing at 630 msec (95 bpm), in patients not presenting atrial arrhythmias or faster heart rate at the time of evaluation. All electrograms were reviewed by a core center to classify VA conduction as 1:1 conduction (intact), Wenckebach, 2:1 or blocked (impaired). RESULTS: A total of 375 CAN-SAVE R patient files were reviewed. In 205 patients, VA conduction data were available at both baseline and at Y3. Mean age was 71 year-old, 133 patients (65%) were male. Indications for PM implantation were sinus node dysfunction (SND) in 90 cases (44%), AVB in 61 cases (30%), both SND and AVB in 29 cases (14%) and other in 25 cases (12%). A total of 77 patients (38%) showed intact VA conduction at baseline. Of those, 21 patients (27%) developed blocked VA conduction at Y3; one patient (1.2%) had Wenckebach. Of the 128 patients (62%) with impaired VA conduction at baseline, 15 patients (11.7%) recovered intact VA conduction at Y3, while 9 patients (7%) with either Wenckebach or 2:1 block further progressed to complete block. At the end of the follow-up period, 70 patients (34%) had intact conduction and 135 (66%) patients showed impaired VA conduction. The following table and figure summarize VA conduction observed at baseline and at Y3. CONCLUSION: In this series of PM patients, VA conduction was analyzed over a 3-year period. Retrograde conduction shows dynamic properties and changes overtime. Although some patients maintained or recovered an intact VA conduction, a majority of cases tended to deteriorate VA conduction and demonstrated conduction impairment, mainly complete block, over the follow-up period.
VA conduction over 3-year follow-up VA conduction at baseline Conduction at Y3 P Patients (%) Patients (%) 1:1 conduction
77 (38%)
70 (34%)
0.4588
Impaired VA conduction Wenckebach 2 :1 Blocked Total
6 5 117 128 (62%)
3 0 132 135 (66%)
0.1084
Abstracts
S191
77% and Denmark 50%; and who would enroll patients with PMAT of more than 48 hours: Canada 41%, the Netherlands 67%, Switzerland 85% and Denmark 42%. CONCLUSION: There is extensive variation in the use of OAC among patients with PMAT. However, the majority of physicians would enroll in a clinical trial of OAC; including patients with long episodes of PMAT and patients with a history of stroke.
262 UTILISATION OF A RIGHT VENTRICULAR APICAL LEAD FOR PACING BACKUP IN PATIENTS WITH A HIS-BUNDLE LEAD C Khoo, SK Tung Vancouver, British Columbia
261 CURRENT USE OF ORAL ANTICOAGULANTS THERAPY IN PACEMAKER PATIENTS WITH PACEMAKER-DETECTED ATRIAL FIBRILLATION: RESULTS FROM A FOUR-NATION PHYSICIAN SURVEY K Bami, JC Nielsen, M Alings, D Conen, A Verma, D Birnie, F Philippon, D Exner, SJ Connolly, CA Morillo, JS Healey Hamilton, Ontario BACKGROUND:
The ASSERT trial demonstrated an association between pacemaker-detected atrial tachyarrhythmias (PMAT) and stroke. However, ASSERT does not inform physicians if patients with PMAT, but without clinical atrial fibrillation, should receive treatment with oral anticoagulation (OAC). Data on the current clinical management of these patients are sparse. METHODS: We conducted a prospective survey of 181 physicians caring for pacemaker patients in centers across Canada, Switzerland, Denmark, and the Netherlands. We evaluated current clinical practices to determine how patients with PMAT are managed and to gauge interest in a randomized control trial of OAC for stroke prevention. RESULTS: A total of 91 surveys (50%) were completed. Just over half of the centres (52%) reported that physicians are routinely called to assess patients with PMAT and only 47% have a system in place to stratify risk and treat patients with PMAT. Only 19% report using OAC regularly for most patients with AHRE, while 91% state that they would be willing to enroll patients into a trial comparing OAC vs. ASA. Of physicians who would enroll patients in a clinical trial, 45% would enroll patients with a history of stroke or TIA and 36% would enroll such patients even if their stroke or TIA occurred in the prior 6 months. Among patients with a CHADS-2 score of 2, 75% of physicians would enroll patients whose longest episode of PMAT was up to 6 hours in duration, while 49% of physicians would still enroll patients despite a longest episode of more than 48 hours. There was little variation between countries in the proportion of physicians who would enroll patients in a clinical trial of OAC: Canada 94%, the Netherlands 81%, Switzerland 81% and Denmark 100%. However; there was variation in the proportion that would enroll patients with a history of stroke or TIA: Canada 35%, the Netherlands 44%, Switzerland
BACKGROUND: His-bundle pacing (HBP) is an alternative to right ventricular apical pacing (RVAP) in patients with atrioventricular (AV) conduction disease. RVAP-associated ventricular dysfunction may be prevented, at the cost of more rapid battery drainage due to higher capture thresholds. We report a case series of patients with low-output HBP where RVAP is utilised as a backup-pacing modality in case of loss of ventricular capture. METHODS: 3 patients at our institution had successful implantation of a HBP lead, 2 with a dual-chamber pacemaker, and 1 with an implantable cardioverter-defibrillator (ICD). A RVA lead was also implanted and plugged into the ventricular pacing port, while the HBP was plugged into the atrial pacing port. The devices were programmed to DDDR <-> AAIR (managed ventricular pacing/ MVP mode) and HBP output at between 1 - 2.5x capture threshold. RVAP output was kept at >¼ 2x capture threshold. RESULTS: Successful HBP resulted in narrow paced QRS complexes identical to underlying conducted QRS complexes (Figure 1A, B). Backup RVAP could be demonstrated with loss of HBP capture during “atrial” capture threshold testing (Figure 1B). This allowed for the use of a mean HBP output of 2.6 V at 0.47 msec (range: 1 - 4 V at 0.4 - 0.6 msec), which was a mean of 1.7x the capture threshold. Left ventricular ejection fraction (LVEF) improved from 28 4% to 38 2% after a mean follow-up of 22 26 months. CONCLUSION: The use of backup RVAP allows for the ability to use low-output HBP without concern of loss-of-pacing in patients with AV block. This strategy may be employed as an alternative to BiV pacing in patients with AV disease and ventricular dysfunction.