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1.  A new method of building permanent A-V block model: ablating his-bundle potential through femoral artery with pre-implanted biventricular pacemaker 
Background
To explore the feasibility of a new method of achieving a permanent A-V block animal model.
Methods
16 beagles were randomly divided into two groups based on the method of their pre-implanted biventricular pacemakers. (1) In the first group (8 beagles), the A-V block model was achieved by ablating his-bundle potential at the site of the left ventricular superior-septum, under the aortic sinus, through femoral artery. (2) In the second group (8 beagles), the A-V block model was achieved by ablating his-bundle potential at the triangle of Koch, through femoral vein. A complete A-V block model was achieved as a standard in this study. The success rates, intraoperative arrhythmias, operative and X-ray exposure time, intraoperative bleeding amount were assessed in this two groups, both animal models were followed up for four weeks and then fasted to monitor myocardial pathological changes.
Results
The success rate of the first group, which with fewer intraoperative arrhythmias, and less operative and X-ray exposure time, was significantly higher than the second group.
Conclusions
Compared with traditional animal method, our new method of ablating his-bundle potential at the left ventricle from the femoral artery has a higher success rate, fewer occurrence of malignant arrhythmias, and less operation and X-ray time. Thus, our new method should be preferred in the building of Permanent A-V Block Model.
doi:10.1186/1471-2261-14-164
PMCID: PMC4246545  PMID: 25410685
A-V block; His-bundle potential; Biventricular pacemaker; Radiofrequency ablation; Beagle; Disease models
2.  Idiopathic premature ventricular contractions and ventricular tachycardias originating from the vicinity of tricuspid annulus: Results of radiofrequency catheter ablation in thirty-five patients 
Background
In recent years, catheter ablation has increasingly been used for ablation of idiopathic premature ventricular complexes (PVCs) or ventricular tachycardias (IVTs). However, the mapping and catheter ablation of the arrhythmias originating from the vicinity of tricuspid annulus (TA) may not be fully understood. This study aimed to investigate electrophysiologic characteristics and effects of radiofrequency catheter ablation (RFCA) for patients with symptomatic PVCs and IVTs originating from the vicinity of TA.
Methods
Characteristics of body surface electrocardiogram (ECG) and electrophysiologic recordings were analyzed in 35 patients with symptomatic PVCs/ IVTs originating from the vicinity of TA. RFCA was performed using pace mapping and activation mapping.
Results
Among the 35 patients with PVCs/IVTs arising from the vicinity of TA, complete elimination of PVCs/IVTs could be achieved by RFCA in 32 patients (success rate 91.43%) during a median follow-up period of 21 months. PVCs/IVTs originating from the vicinity of TA had distinctive ECG characteristics that were useful for identifying the precise origin. An rS pattern was recorded in lead V1 in 93.1% of patients with PVCs/IVTs from the free wall of TA, vs 16.7% of patients with PVCs/IVTs from the septal TA, whereas a QS pattern in lead V1 occurred in 83.3% of patients with PVCs/IVTs from the septal TA vs 6.9% of patients with PVCs from the free wall of the TA. The precordial R wave transition occurred by lead V3 or earlier in all patients with PVCs/IVTs originating from the septal portion of the TA, as compared to transition beyond V3 in all patients with PVCs/IVTs from the free wall of the TA.
Conclusions
RFCA is an effective curative therapy for symptomatic PVCs/IVTs originating from the vicinity of TA. There are specific characteristics in ECG and the ablation site could be located by ECG analysis.
doi:10.1186/1471-2261-12-32
PMCID: PMC3393631  PMID: 22551200
3.  Premature ventricular contractions originating from the left ventricular septum: Results of Radiofrequency Catheter Ablation in twenty patients 
Background
RFCA has been established as an effective and curative therapy for severely symptomatic PVC from the outflow tract in structurally normal hearts. However, it is unknown whether PVCs originating from the left ventricular septum, are effectively eliminated by RFCA. This study aimed to investigate electrophysiologic characteristics and effects of Radiofrequency catheter ablation (RFCA) for patients with symptomatic premature ventricular contraction (PVC) originating from the left ventricular septum without including fascicular PVCs.
Methods
Characteristics of body surface electrocardiogram (ECG) and electrophysiologic recordings endocardiogram in a successful RFCA target were analyzed in 20 patients with symptomatic PVCs originating from the left ventricular septum. RFCA was performed using pace mapping and activation mapping.
Results
The QRS morphology of PVCs originating from the left ventricular septum is similar to that seen in fascicular tachycardia. Most of the PVCs originated from the left septum appears in the form of ventricular parasystole. The incidence of ventricular parasystole was 70%. Sustained ventricular tachycardia was not inducible by electrical stimulation and isoproterenol infusion in all 20 patients, ablation at the site recording the earliest Purkinje potential was not effective in all 20 patients, and Purkinje potentials were not identified at successful sites during point mapping. Sixteen patients were successful with RFCA using pace mapping and activation mapping, 3 failed, and 1 recurrent.
Conclusion
Although the ECG characteristics of the PVCs arising from the left ventricular septum are similar to that seen in fascicular tachycardia, the electrophysiologic characteristics are different between the two types of PVCs. The distinguishing characteristic of the PVCs is that Purkinje potentials were not present at the site of successful ablation, suggesting a myocardial as opposed to fascicular substrate. RFCA is an effective curative therapy for symptomatic PVCs originating from the left ventricular septum (not from the left anterior and posterior fascicle).
doi:10.1186/1471-2261-11-27
PMCID: PMC3123650  PMID: 21635765
4.  Establishment of a canine model of cardiac memory using endocardial pacing via internal jugular vein 
Background
Development of experimental animal models has played an important role in understanding the mechanisms of cardiac memory. The purpose of this study was to evaluate a new canine model of cardiac memory using endocardial ventricular pacing via internal jugular vein.
Methods
Twelve Beagle dogs underwent placement of a permanent ventricular pacemaker mimicking the use of pacemakers in humans and induction of cardiac memory by endocardial ventricular pacing.
Results
Cardiac memory was achieved in 11 of 12 attempts overall. Procedural mortality due to cardiac tamponade (n = 1) occurred in the first attempt. The T-wave memory persisted for 96 ± 17 minutes and 31 ± 6 days in the short-term and long-term cardiac memory groups, respectively. There were no significant differences in the heart rate, blood pressure and echocardiographic parameters in the animals between before and after ventricular pacing in the short-term and long-term cardiac memory groups. No significant pathologic changes with the light microscopy were found in the present study in all dogs.
Conclusion
The model does require surgery but is not as invasive as an open-chest model. This canine model can serve as a useful tool for studying mechanisms of cardiac memory.
doi:10.1186/1471-2261-10-30
PMCID: PMC2906410  PMID: 20569432

Results 1-4 (4)