AV-optimized conduction system pacing for treatment of AV dromotropathy: A randomized, cross-over study.

BACKGROUND: Severe first-degree atrioventricular (AV) block may produce symptoms similar to heart failure due to AV dyssynchrony, a syndrome termed AV dromotropathy. According to guidelines, it should be considered for permanent pacemaker implantation, yet evidence supporting this treatment is scarce. OBJECTIVES: This study aimed to determine the impact of AV-optimized conduction system pacing (CSP) in patients with symptomatic severe first-degree AV block and echocardiographic signs of AV dyssynchrony. METHODS: Patients with symptomatic first-degree AV block (PR > 250 ms), preserved left ventricular ejection fraction, narrow QRS, and AV dyssynchrony were included in the study. In a single-blind cross-over design, patients were randomized to AV sequential CSP or backup VVI pacing with a base rate of 40 bpm. We compared exercise capacity, echocardiographic parameters, and symptom occurrence at the end of 3 months of each period. RESULTS: Fourteen patients completed the study. During the AV-optimized CSP compared to the backup pacing period, patients achieved a higher workload on exercise test (147.2 ± 50.9 vs. 140.7 ± 55.8 W; p = .032), with a trend towards higher peak VO2 (23.3 ± 7.1 vs. 22.8 ± 7.1 mL/min/kg; p = .224), and higher left ventricular stroke volume (LVSV 74.5 ± 13.8 vs. 66.4 ± 12.5 mL; p < .001). Symptomatic improvement was recorded, with fewer patients reporting general tiredness and 71% of patients preferring the AV-optimized CSP (p = .008). CONCLUSIONS: AV-optimized CSP could improve symptoms, exercise capacity and LVSV in patients with severe first-degree AV block.

Impact of preventive substrate catheter ablation on implantable cardioverter-defibrillator interventions in patients with ischaemic cardiomyopathy and infarct-related coronary chronic total occlusion.

AIMS: Primary prevention patients with ischaemic cardiomyopathy and chronic total occlusion of an infarct-related coronary artery (CTO) are at a particularly high risk of implantable cardioverter-defibrillator (ICD) therapy occurrence. The trial was designed to evaluate the efficacy of preventive CTO-related substrate ablation strategy in ischaemic cardiomyopathy patients undergoing primary prevention ICD implantation. METHODS AND RESULTS: The PREVENTIVE VT study was a prospective, multicentre, randomized trial including ischaemic patients with ejection fraction ≤40%, no documented ventricular arrhythmias (VAs), and evidence of scar related to the coronary CTO. Patients were randomly assigned 1:1 to a preventive substrate ablation before ICD implantation or standard therapy with ICD implantation only. The primary outcome was a composite of appropriate ICD therapy or unplanned hospitalization for VAs. Secondary outcomes included the primary outcome's components, the incidence of appropriate ICD therapies, cardiac hospitalization, electrical storm, and cardiovascular (CV) mortality. Sixty patients were included in the study. During the mean follow-up of 44.7 ± 20.7 months, the primary outcome occurred in 5 (16.7%) patients undergoing preventive substrate ablation and in 13 (43.3%) patients receiving only ICD [hazard ratio (HR): 0.33; 95% confidence interval (CI): 0.12-0.94; P = 0.037]. Patients in the preventive ablation group also had fewer appropriate ICD therapies (P = 0.039) and the electrical storms (Log-rank: P = 0.01). While preventive ablation also reduced cardiac hospitalizations (P = 0.006), it had no significant impact on CV mortality (P = 0.151). CONCLUSION: Preventive ablation of the coronary CTO-related substrate in patients undergoing primary ICD implantation is associated with the reduced risk of appropriate ICD therapy or unplanned hospitalization due to VAs.

Zero-Fluoroscopy Catheter Ablation of Supraventricular Tachycardias in the Pediatric Population.

Catheter ablation (CA) of supraventricular tachycardias (SVTs) is conventionally performed with the aid of X-ray fluoroscopy. Usage of a three-dimensional (3D) electro-anatomical mapping (EAM) system and intracardiac echocardiography (ICE) enables zero-fluoroscopy ablation, eliminating the harmful effects of radiation. We retrospectively analyzed the feasibility, effectiveness and safety of zero-fluoroscopy radiofrequency and cryoablation of various types of SVTs in pediatric patients. Overall, in 171 consecutive patients (12.5 ± 3.9 years), 175 SVTs were diagnosed and 201 procedures were performed. The procedural success rate was 98% (193/197), or more precisely, 100% (86/86) for AVNRT, 95.8% (91/95) for AVRT, 94.1% (16/17) for AT and 100% (2/2) for AFL. No complications were recorded. Follow-up was complete in 100% (171/171) of patients. During the mean follow-up period of 488.4 ± 409.5 days, 98.2% of patients were arrhythmia-free with long-term success rates of 98.7% (78/79), 97.5% (78/80), 100% (13/13) and 100% (2/2) for AVNRT, AVRT, AT and AFL, respectively. Zero-fluoroscopy CA of various types of SVTs in the pediatric population is a feasible, effective and safe treatment option.

Biventricular versus His bundle pacing after atrioventricular node ablation in heart failure patients with narrow QRS.

Background: His bundle pacing (HBP) is a physiological alternative to biventricular (BiV) pacing. We compared short-term results of both pacing approaches in symptomatic atrial fibrillation (AF) patients with moderately reduced left ventricular (LV) ejection fraction (EF ≥35% and <50%) and narrow QRS (≤120 ms) who underwent atrioventricular node ablation (AVNA).Methods: Thirty consecutive AF patients who received BiV pacing or HBP in conjunction with AVNA between May 2015 and January 2020 were retrospectively assessed. Electrocardiographic, echocardiographic, and clinical data at baseline and 6 months after the procedure were assessed.Results: Twenty-four patients (age 68.8 ± 6.5 years, 50% female, EF 39.6 ± 4%, QRS 95 ± 10 ms) met the inclusion criteria, 12 received BiV pacing and 12 HBP. Both groups had similar acute procedure-related success and complication rates. HBP was superior to BiV pacing in terms of post-implant QRS duration, implantation fluoroscopy times, reduction of indexed LV volumes (EDVi 63.8 (49.6-81) mL/m2 vs. 79.9 (66-100) mL/m2, p = 0.055; ESVi 32.7 (25.6-42.6) mL/m2 vs. 46.4 (42.9-68.1) mL/m2, p = 0.009) and increase in LVEF (46 (41-55) % vs. 38 (35-42) %, p = 0.005). However, the improvement of the NYHA class was similar in both groups.Conclusions: In symptomatic AF patients with moderately reduced EF and narrow QRS undergoing AVNA, HBP could be a conceivable alternative to BiV pacing. Further prospective studies are warranted to address the outcomes between both 'ablate and pace' strategies.

Intracardiac echocardiography-guided transseptal puncture for fluoroless catheter ablation of left-sided tachycardias.

BACKGROUND: Integration of intracardiac echocardiography (ICE) and 3D electroanatomic mapping (EAM) system allows transseptal punctures (TSP) without the use of fluoroscopy. Compared with fluoroscopy, ICE provides better visualization of the anatomy relevant to TSP and early recognition of complications. The aim was to evaluate efficacy and safety of entirely ICE-guided TSPs in patients who underwent fluoroless catheter ablation of left-sided tachycardias. METHODS: Consecutive 524 adult and pediatric patients referred to our institution from July 2014 to December 2019 were analyzed. Patients with cardiac implantable electronic devices (CIEDs) were also included. All procedures were performed with ICE-guided TSP combined with 3D EAM. Adverse events following TSP and within 30 days of the procedure were analyzed. RESULTS: Altogether 949 TSPs (363 double punctures, 76.5%) were performed in 586 fluoroless ablation procedures: 451 (77%) were ablation of atrial fibrillation or atypical flutter, 75 (12.8%) of left-sided accessory pathway, 33 (5.6%) of ventricular tachycardia, and 27 (4.6%) of focal atrial tachycardia. Forty-six (7.8%) procedures were performed in pediatric population and 36 procedures (6.1%) in patients with CIED. Only 2 TSPs were unsuccessful (2/949, 0.2%). Overall procedural complication rate was 1.9% (11/586 procedures). There was only 1 TSP-related pericardial tamponade (2/949, 0.2%). In CIED patients, there was 1 lead dislocation following TSP. CONCLUSIONS: Entirely ICE-guided TSPs for different left-sided tachycardias can be safely and effectively performed in adult and pediatric population without the use of fluoroscopy. However, caution is advised in CIED patients due to possible lead dislocation risk.

His bundle pacing in a young child guided by electroanatomical mapping.

Pediatric patients with complete congenital atrio-ventricular (AV) block are generally exposed to life-long dyssynchronous right ventricular (RV) pacing. His bundle pacing (HBP) is an alternative method of pacing that better restores physiological ventricular activation which could prevent pacing-induced cardiomyopathy. We present a case of a 5-year-old child with complete AV block who underwent successful permanent HBP implantation. Three-dimensional electro-anatomical mapping system was used to facilitate the procedure and reduce the fluoroscopy time. There were no acute procedure-related complications, and electrical parameters were stable at short-term follow-up.

Resynchronization therapy with His bundle pacing in a patient after coronary sinus reducer implantation.

Symptomatic heart failure patients with ischemic heart disease may require both coronary sinus reducer (CSR) implantation due to refractory angina pectoris and cardiac resynchronization therapy (CRT). Optimal approach to CRT in these patients is unknown as CSR implantation in the distal coronary sinus could deter left ventricular lead placement and thus preclude conventional CRT with biventricular pacing. We present a 70-year-old patient with ischemic cardiomyopathy and wide QRS complex after CSR implantation in whom we achieved successful cardiac resynchronization with His bundle pacing (HBP). HBP led to acute improvement in hemodynamic parameters and exercise capacity that persisted at follow-up. This case represents the first description of successful CRT with HBP in a patient after CSR implantation. HBP could present a feasible and safe resynchronization approach in these patients. .

Intra-cardiac ultrasound guided approach for catheter ablation of typical right free wall accessory pathways.

BACKGROUND: Right free wall accessory pathways (AP) are difficult to treat with catheter ablation as ablation catheter (AC) instability at the tricuspid annulus often precludes successful procedure. The aim of our study was to test a novel intra-cardiac echocardiography (ICE) guided technique for AC placement. Feasibility and success rates were observed. METHODS: Eight consecutive patients (aged 29 ± 21 years, 4 female) with Wolff-Parkinson-White syndrome and a right free wall AP were included in the study. ICE, three-dimensional (3D) electro-anatomic mapping (EAM) system, and a steerable long sheath were used together with either an irrigated or a non-irrigated tip radio-frequency AC to achieve a "loop" manoeuvre which provided AC tip stability at the ventricular aspect of the tricuspid annulus. X-ray fluoroscopy was not used. RESULTS: Three patients had an anterior and five had a lateral location of the right free wall AP. Procedures were successful in all patients, without recurrences during the mean follow-up of 397 ± 363 days. Average procedural duration was 90 ± 31 min. On average, 6.6 ± 5.7 ablations were needed. Average time to terminate AP conduction after the start of ablation was 4.8 ± 4.2 s. In five patients (62%) AP conduction was successfully terminated with the first ablation. There were no procedural complications. CONCLUSIONS: The novel ICE-guided approach with concomitant use of the steerable sheath and the 3D EAM system for zero-fluoroscopy mapping and ablation of the right free wall APs proved feasible and resulted in excellent acute and long-term outcomes.

Combined use of electro-anatomic mapping system and intracardiac echocardiography to achieve zero-fluoroscopy catheter ablation for treatment of paroxysmal atrial fibrillation: a single centre experience.

Fluoroscopy is the principal imaging method for catheter ablation (CA) of atrial fibrillation (AF). However, radiation exposure carries potential health risk to patients and operators alike. Our aim was to study safety and efficacy of zero-fluoroscopy CA of paroxysmal AF with a combined use of electroanatomic mapping system (EAM) and intracardiac echocardiography (ICE). In addition, impact of ICE/EAM automatic integration system and contact force (CF) sensing technology on procedural times were assessed. We included 144 consecutive patients (69% males, age 60 ± 10 years, BMI 29 ± 4,6) referred for CA of symptomatic paroxysmal AF. All procedures were performed only with EAM system and ICE. No fluoroscopy was used. The acute procedural success of complete pulmonary vein isolation was achieved in all patients (100%) and adverse events were detected in eight patients (5.6%). In 53 (37%) patients the use of ICE/EAM automatic integration system shortened procedural times compared to those performed without it (148 ± 35 vs. 187 ± 44 min, p < 0.05). Similarly, 89 (60%) procedures where CF sensing catheter was used were shorter compared to those performed without it (163 ± 41 vs. 188 ± 46 min, p < 0.05). Zero-fluoroscopy approach for treatment of paroxysmal AF seems feasible, safe, and acutely effective. Additional reduction of procedural times could be achieved with the use of ICE/EAM automatic integration system and CF sensing technology.