Yu Hai-bo

GW28-e1153 Study of Intrinsic QRS Complex Duration Changes 6 Months After Cardiac Resynchronization Therapy

Cardiac resynchronization therapy (CRT) is one of the important advances in the treatment of ventricular systolic heart failure (HF) in recent years. It can reduce the mortality and improve the quality of life of patients. Patients who had response to CRT were often accompanied with a reversal of

GW24-e1773 Application of a novel pacing guide wire in cardiac resynchronisation therapy

Objectives The implantation of left ventricular (LV) lead was the most complicated process in the cardiac resynchronisation therapy (CRT), the aim of this study was to investigate the availability of a novel Visionwire guide wire in the implantation of LV lead in CRT. Methods Five heart failure patients selected for CRT were involved in the study. The pacing threshold, R-wave sensing, phrenic nerve stimulation at local coronary sinus (CS) branch were measured by the Visionwire guide wire and LV lead separately. Results The pacing parameters were analysed through the Visionwire guide wire and LV lead separately at the 16 CS branches in 5 patients. There were no significant difference between the pacing parameters measured by the two methods. Significant correlation was found between LV pacing threshold assessed by the Visionwire guide wire and LV lead (r = 0.90, P < 0.01). Correlation for R wave sensing was also significant (r = 0.67, P < 0.01). The pacing sites accompanied with phrenic nerve stimulation while pacing at 10 V/0.42 ms were similar by the two methods. Visionwire guide wire could be used for local potential electrical mapping. The procedure time for pacing test in a single coronary sinus branch by Visionwire guide wire was much less than that by LV lead. (12.4 ± 7.5min vs 18.3 ± 12.2min, P < 0.01). Conclusions Visionwire guide wire facilitated transvenous LV lead implantation by prediction of pacing parameter and locate the target CS branch quickly. The electrophysiological mapping function of Visionwire guide wire as a unipolar lead might have further potential usefulness.

GW24-e1774 Long-term performance of active fixation pacing leads in right atrium

Objectives More and more active-fixation leads were used in the right atrium during the implantation of pacemaker, the aim of this study was to explore the feasibility of active-fixation right atrial leads in the application of pacemaker and observe the changes of long-term pacing parameters. Methods Sixty patients (32 males and 28 females, mean aged 65.25 ± 13.95 years) were involved in this study, 4 cases implanted with single-chamber pacemaker (AAIR) and 56 cases implanted with dual-chamber pacemaker (DDDR), who underwent the active-fixation leads implantation in the right atrium for permanent pacing. The follow-up period was 12 months after implantation. Results The active-fixation atrial leads were successful implanted in all patients and there were no complication during the operation, 52 leads implanted in the right atrial appendage, 3 in the right atrial septum and 5 in the right atrial lateral wall. The pacing thresholds at the implanted moment were obviously higher and declined rapidly. No thresholds change occurred at the end of the operation, in 48 hours, 3 months, 6 months, 12 months after operation. The impedances were quickly decreased at the end of the operation and 48 hours after the operation, no obvious sense parameters changed. 1 patient (1.7%) with acute atrial electrode dislodgment at 2 hours after operation, we resetted the active -fixation lead successfully. No complications such as lead perforation and cardiac tamponade occurred. Conclusions It was safe and feasible in the implantation of active- fixation leads in right atrium. The pacing parameters of active-fixation leads in right atrium were stable during the periods of 12 months after operation.

ASSA13-02-4 Electrophysiological Characteristic and Ablation of Epicardial Idiopathic Ventricular Arrhythmias Arising Around Left Fibrous Triangle

Background The success rate of radiofrequency catheter ablation of ventricular arrhythmias originating from left fibrous triangle (LFT) is not high. This article was to discuss the characteristics of sueface electrocardiogram and the strategy of ablation of ventricular arrhythmias originating from LFT. Methods From February 2002 to March 2012, total 323 patients with outflow ventricular arrhythmias were ablated in our hospital, incluing 46 patients whose ventricular arrhythmias originated from the LFT. The mean age of the 46 patients was 44 ± 13 years (16–87 years), and 24 of them (52.2%) were male. Thirty patients had frequent premature ventricular contractions (PVCs) and 16 patients had both PVCs and nonsustained or sustained ventricular tachycardia (VT). All the patients were examined with ECG, electrophysiology, active mapping and pace mapping. The computer tomography angiogram (CTA) 3D reconstruction of coronary artery, venouswas completed in 20 patients. Results Successful ablation was achieved in 41 of the 46 patients (89.1%, 41/46) targeting left coronary cusp (LCC, 30 patients), infra aortic valve (infra AV, 6 patients) and great cardiac vein (GCV, 5 patients). The surface ECG in all the three groups presented with inferior axis and R/S-transition in lead V1 and V2. There were no differentces in the total QRS duration in the three groups. Most of the patients presented with right bundle branch block (RBBB) morphology in infra AV group and GCV group compared with LCC group (67%, 80% vs 15%, P = 0.002). Regarding to the classification of the LFT according to CTA, the patterns of distribution were as follows: “closed” in 10 (50%, 10/20) hearts; “completely opened” in 2 (10%, 2/20); “inferiorly opened” in 5 (25%, 5/20) hearts and “superiorly opened” in 1 (5%, 1/20) hearts. In the remaining 2 (10%, 2/20), there were not any distances between cardiac vein and artery. The closest distance between the corner of the GCV and LCC is 17.6 ± 4.2 mm (9.1mm ∼ 26.3mm). Conclusions Ventricular arrhythmias originating from the LFT can be ablated in the nadir of the LCC, infra AV and the GCV. The success rate may be impacted by the distance from the GCV and the LCC.

ASSA13-02-22 Application of a Novel Pacing Guide Wire in Cardiac Resynchronization Therapy

Background The implantation of left ventricular (LV) lead was the most complicated process in the cardiac resynchronization therapy (CRT), the aim of this study was to investigate the availability of a novel Visionwire guide wire in the implantation ofLVlead in CRT. Methods Five heart failure patients selected for CRT were involved in the study. The pacing threshold, R-wave sensing, phrenic nerve stimulation at local coronary sinus (CS) branch were measured by the Visionwire guide wire and LV lead separately. Results The pacing parameters were analysed through the Visionwire guide wire and LV lead separately at the 16 CS branches in 5 patients. There was no significant difference between the pacing parameters measured by the two methods. Significant correlation was found betweenLVpacing threshold assessed by the Visionwire guide wire andLVlead (r = 0.90, P < 0.01). Correlation for R wave sensing was also significant (r = 0.67, P < 0.01). The pacing sites accompanied with phrenic nerve stimulation while pacing at 10 V/0.42 ms were similar by the two methods. Visionwire guide wire could be used for local potential electrical mapping. The procedure time for pacing test in a single coronary sinus branch by Visionwire guide wire was much less than that by LV lead (12.4 ± 7.5min vs 18.3 ± 12.2min, P < 0.01). Conclusions Visionwire guide wire facilitated transvenousLVlead implantation by prediction of pacing parameter and locate the target CS branch quickly. The electrophysiological mapping function of Visionwire guide wire as a unipolar lead might have further potential usefulness.

ASSA13-02-27 Long-Term Performance of Active Fixation Pacing Leads in Right Atrium

Background More and more active-fixation leads were used in the right atrium during the implantation of pacemaker, the aim of this study was to explore the feasibility of active-fixation right atrial leads in the application of pacemaker and observe the changes of long-term pacing parameters. Methods Sixty patients (32 males and 28 females, mean aged 65.25 ± 13.95 years) were involved in this study, 4 cases implanted with single-chamber pacemaker (AAIR) and 56 cases implanted with dual-chamber pacemaker (DDDR), who underwent the active-fixation leads implantation in the right atrium for permanent pacing. The follow-up period was 12 months after implantation. Results The active-fixation atrial leads were successful implanted in all patients and there were no complication during the operation, 52 leads implanted in the right atrial appendage, 3 in the right atrial septum and 5 in the right atrial lateral wall. The pacing thresholds at the implanted moment were obviously higher and declined rapidly. No thresholds change occurred at the end of the operation, in 48 hours, 3 months, 6 months, 12 months after operation. The impedances were quickly decreased at the end of the operation and 48 hours after the operation, no obvious sense parameters changed. 1 patient (1.7%) with acute atrial electrode dislodgment at 2 hours after operation, we resetted the active -fixation lead successfully. No complications such as lead perforation and cardiac tamponade occurred. Conclusions It was safe and feasible in the implantation of active- fixation leads in right atrium. The pacing parameters of active-fixation leads in right atrium were stable during the periods of 12 months after operation.

ASSA13-02-14 The Comparison Between the Active-Fixation Leads and Passive-Fixation Leads in Right Ventricular Apical Pacing

Background More and more active-fixation leads were used in the implantation of pacemaker, but compared with the traditional passive-fixation leads, the differences of the pacing parameter were not clearly known. Objective The aim of this study was to compare the pacing parameters of active-fixation leads and passive-fixation leads in right ventricular apical pacing. Methods There were 54 patients implanted with single or dual chamber pacemaker involved in this study from January 2010 to May 2010 followed up for 3 months after operation. In these patients 21 with passive-fixation lead (Group I) and 33 with active-fixation lead (Group II). All the leads were implanted in right ventricle apex, the average age was 66.23 ± 13.90 years old, 21 patients with single chamber pacemaker and 33 with dual chamber pacemaker. Results There were no obvious changes in the pacing parameters between the two groups not only during the operation (thresholds: 0.56 ± 0.20 vs 0.57 ± 0.21; pacing impedances : 818.25 ± 267.71 vs 823.59 ± 284.46; R Wave: 10.64 ± 3.08 vs 10.47 ± 3.10) but also at 1 month (thresholds: 0.55 ± 0.18 vs 0.55 ± 0.18; pacing impedances: 542.72 ± 190.30 vs 531.91 ± 189.48; R Wave: 10.53 ± 3.60 vs 10.22 ± 3.63) and 3 months after the operation (thresholds : 0.57 ± 0.17 vs 0.56 ± 0.17; pacing impedances: 499.80 ± 135.37 vs 494.29 ± 135.74; R Wave: 10.72 ± 3.48 vs 10.47 ± 3.53)(P > 0.05). But there were 1 of 33 patients in Group II (1/33.3%) with higher pacing threshold after operation. The threshold reached to 6.0 V at the second day after operation and the patient was dealt with dexamethasone for 1week, and there was no change of the higher pacing threshold, so we had to implant the new passive-fixation lead in the right ventricular apex and extract the old active-fixation lead simultaneously. The pacing thresholds were stable followed for 3 months. No patients with severely higher pacing thresholds in Group I. Conclusions There were no obvious differences in the pacing parameters between the passive-fixation leads and active-fixation leads in right ventricular apical pacing. But it was possible that the stimulation thresholds were individually higher in patients with active-fixation leads than those with passive-fixation leads (3.3% vs 0). The long-term parameter changes still were observed.

ASSA13-02-7 Effect of Radiofrequency Catheter Ablation of Left Bundle Potential on Cardiac Electrical and Mechanical Functions in Canines

Background Animal model of left bundle branch block (LBBB) is very important for basic study about cardiac resynchronization therapy (CRT). But the preparation of LBBB model was difficult. Objective This study was to explore the effect of radiofrequency catheter ablation of left bundle potential (LBP) on cardiac conduction and mechanical function in canines and evaluate the preparation method of LBBB model by RF catheter ablation. Methods LBP was mapped and ablated by radiofrequency catheter in the left ventricular endocardium in 10 canines. The influence of LBP ablation on cardiac conduction and whether canine LBBB model was successfully created or not were observed. To assess the systolic and diastolic function of left ventricle, echocardiography was performed before and after LBBB model was successfully created. Results After LBP ablation, LBBB was successfully created in 8 (80%) canines. Atrial and ventricular amplitude ratio (A/V) was less than 1:10 at successful ablation site and the interval of LBP to local ventricular potential (LBP-V) was 17.1 ± 3.2 msec, range from 12 to 22 msec. The QRS duration increased from 52.8 ± 4.8ms to 100.5 ± 11.1ms (P < 0.001) after LBBB created in these 8 canines, but there were no significant changes in PR intervals, AH and HV intervals after LBP ablation. In the remain 2 canines, a similar LBP potential was identified with LBP-V 30 and 32 msec, but complete AV block was produced during or after RF energy application. In 8 LBBB canines, echocardiography showed that systolic and diastolic functions were all decreased, includingleft ventricular ejection fraction and aortic blood flow velocity time integral reducing (P < 0.05), E/A lowering to < 1, E wave deceleration time and isovolumetric relaxation time prolonging (P < 0.05). Significant prolongation of septal-to-posterior wall motion delay and the increased difference of pre-ejection time (P < 0.001) implied intraventricular and interventricular desynchronization after LBBB. Conclusions Radiofrequency catheter ablation of LBP can made a high success rate of LBBB model in canine, but the risk of complete AV block exists. Immediately after isolated LBBB model was created, intraventricular and interventricular desynchronization and left ventricular electrical activation delay occurred, which resulted in decreased cardiac systolic and diastolic functions.

ASSA13-02-1 The Feasibility and Curative Effect of Cardiac Resynchronization Therapy by Targeted Left Ventricular Lead Placement to the Latest Ventricular Electrical Activating Site Mapped in the Coronary Sinus Branches

Background A nonoptimal left ventricular (LV) pacing lead position may be a potential cause for nonresponse to cardiac resynchronization therapy (CRT). Objective The aim of the current study was to investigate the feasibility and curative effect of CRT by targeted LV lead placement to the latest ventricular electrical activating site mapped in the coronary sinus (CS) branches. Methods Ten patients with moderate to severe congestive heart failure, depressed left ventricular ejection fraction (LVEF) in the CS branchs, and the latest ventricular electrical activating site was considered as the target site for LV lead placement. The feasibility and curative effect of this kind of CRT were observed. The clinical variables assessed in this study included QRS duration, NYHA class, 6-min walk test and echocardiography index. Results Seven patients were diagnosed as dilated cardiomyopathy and 3 patients as ischemic cardiomyopathy. Electrophysiological mapping were performed in 28 CS branches which were considered as a possible site for LV lead placement and LV lead was successfully placed at the latest LV electrical activating site in all 10 patients. There were 116 ± 28ms activating time delay at the latest LV electrical activiating site than the QRS onset of ECG. QRS complex were significantly narrowed immediately after CRT than before CRT (121 ± 17ms vs 153 ± 30ms, P(8/9, 89%) and 3 patients as super responders (3/9, 33%), the other 1 ischemic cardiomyopathy patient who died of acute myocardial infarction 2 months after CRT procedure was classified as non-responder to CRT (1/9, 11%). The following clinical variables 3 months after CRT procedure were markedly improved than variables before CRT in these 8 responders (all PNYHA class was improved (1.6 ± 0.5 vs 3.3 ± 0.5) and the 6-min walk test was increased (405 ± 92m vs 307 ± 82m). Echocardiography demonstrated LVEF was improved (0.42 ± 0.06 vs 0.30 ± 0.04), left ventricular end-systolic volume (LVESV) was reduced (121 ± 38ml vs 153 ± 44ml) and mitral regurgitation velocity (MRV) was decreased (3.9 ± 1.2m/s vs 4.5 ± 1.5m/s). Conclusions Targeted left ventricular lead placement to the latest venticular electrical activating site guided by electrophysiological mapping in the CS branches was feasible. This CRT method was effective for improving heart founction of heart failure patients during short-term follow-up.