Cardiac PACING is the only effective therapy for patients with symptomatic bradycardia in the absence of reversible etiologies. Right ventricular PACING (RVP) has been widely used for almost 60 years. However, RVP causes electric and mechanical dyssynchrony. Due to such effects, RVP is associated with an increased risk of heart failure and atrial fibrillation development. For these reasons, there is increasing interest in physiological PACING techniques that directly activate the specialized conduction system. There are two main methods for conduction system PACING: 1) His Bundle PACING (HBP) 2) Left Bundle PACING (LBP) HBP has gained prominence. Multiple studies have demonstrated the feasibility and clinical benefits of this technique...

Background: Right Ventricular Septal (RVS) PACING is often recommended as a more physiological alternative to Right Ventricular Apical (RVA) PACING. Objectives: This study aimed to determine the long-term outcomes in patients persistently paced following Atrioventricular Node (AVN) ablation. Materials and Methods: This study was conducted on 200 patients who underwent Permanent Pacemaker (PPM) implantation prior to AVN ablation with either RVA-or RVS-PACING. Primary endpoints were hospitalization due to Heart Failure (HF) and death. Secondary endpoints included changes in Ejection Fraction (EF), inter-and intraventricular dyssynchrony measures, and paced QRS duration. Demographic data were obtained from all patients. In addition, CT chest examinations were analyzed to confirm RVS lead position. Results: The mean survival time from AVN ablation was 6. 32 ± 4. 294 years in the RVA group and 3. 00 ± 2. 546 years in the RVS group (hazard ratio = 3. 512, P = 0. 0001). The results showed no significant differences between the two sites regarding hospitalization due to HF. Baseline and follow-up EFs were respectively 48. 4 ± 13. 8% and 53. 1 ± 8. 5% for RVA PACING and 52. 0 ± 10. 6% and 55. 2 ± 11. 3% for RVS PACING (P = 0. 911). Moreover, 76% of the patients in the RVS group had a septal lead confirmed on CT chest review. Twentyfour percent of the RVS leads were in alternate sites, including the RVA and free wall. Conclusions: The results revealed was no diminution in EF with either lead position at long-term follow-up. The mortality rate was significantly less in RVA PACING compared to documented septal PACING although a quarter of the RVS leads were found in alternate sites on CT chest review.

The overall rate of atrial PACING lead dislodgement is estimated to be about 3%. These leads are generally repositioned via a second operation through opening the pacemaker pocket. Some operators have introduced percutaneous techniques using snare system or deflectable catheters for this purpose. In this article we present our experience with five cases of percutaneous lead repositioning. Three cases were performed using deflectable ablation catheters and in two cases we used a specially designed urologic basket. The procedural success rate was 100% at the beginning but the long term success rate was 60%.

BACKGROUND: Atrioventricular node (AVN) is an interatrial septum structure located at the apex of triangle of Koch that modulates the transmission of impulses from atria to the ventricles. Vagally mediated AVN block with high frequency stimulation (HFS) was investigated in a few animal and human studies, but prolonged ventricular asystole that was induced by a low frequency proximal coronary sinus (CS) overdrive PACING has rarely been reported. CASE REPORT: A 40-year-old man was admitted in our hospital for evaluation of syncope and palpitation. He presented with prolonged ventricular asystole by proximal CS PACING during electrophysiological study (EPS). CONCLUSION: There is no comprehensive clinical study to investigate the association of vasovagal syncope with vagally mediated atrioventricular block (AVB) which is induced by posteroseptal area stimulation. Radiofrequency catheter ablation of ganglionated plexi (GP) located close to sinus node and AVN was reported to eliminate the vagal efferent output during vasovagal syncope as a new treatment strategy.

Background: Considering the many reports of elevated threshold levels and left ventricular dysfunction in epicardial leads, the evaluation of the short-and long-term efficacy of this type of leads is necessary in comparison with the coronary sinus (CS) leads. The present study compared left ventricular epicardial PACING via surgery and CS PACING in patients with triplechamber pacemakers. Methods: This retrospective cohort study was performed on patients referred for cardiac resynchronization therapy. The patients were re-evaluated with ECG after pacemaker implantation and before discharge. The evaluations were performed in 2 patient groups under left ventricular epicardial PACING and CS PACING. Results: At 12 months’ follow-up, the mean left ventricular PACING lead threshold was significantly higher in the patients with epicardial lead PACING than in those with endocardial lead PACING. Additionally, regarding the ECG pattern after lead PACING, the morphology of QRS at V1 lead and also the type of the QRS axis significantly differed between epicardial PACING and CS PACING 6– 12 months after pacemaker implantation. The mean left ventricular PACING lead threshold was at its highest in the posterolateral area and at its lowest in the anterolateral area, but without any significant difference. Conclusions: Comparisons between the results and the long-term effects of CS PACING and surgical epicardial lead PACING in the present study indicated that the increase and changes in the left ventricular leading threshold in the epicardial PACING lead were much more pronounced than those in CS PACING through the CS. Therefore, the use of CS leads might be preferred to pericardial leads due to the stability of left ventricular leads.