Arrhythmic Risk in Biventricular Pacing Compared With Left Bundle Branch Area Pacing: Results From the I-CLAS Study.

BACKGROUND: Left bundle branch area pacing (LBBAP) may be associated with greater improvement in left ventricular ejection fraction and reduction in death or heart failure hospitalization compared with biventricular pacing (BVP) in patients requiring cardiac resynchronization therapy. We sought to compare the occurrence of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) and new-onset atrial fibrillation (AF) in patients undergoing BVP and LBBAP. METHODS: The I-CLAS study (International Collaborative LBBAP Study) included patients with left ventricular ejection fraction ≤35% who underwent BVP or LBBAP for cardiac resynchronization therapy between January 2018 and June 2022 at 15 centers. We performed propensity score-matched analysis of LBBAP and BVP in a 1:1 ratio. We assessed the incidence of VT/VF and new-onset AF among patients with no history of AF. Time to sustained VT/VF and time to new-onset AF was analyzed using the Cox proportional hazards survival model. RESULTS: Among 1778 patients undergoing cardiac resynchronization therapy (BVP, 981; LBBAP, 797), there were 1414 propensity score-matched patients (propensity score-matched BVP, 707; propensity score-matched LBBAP, 707). The occurrence of VT/VF was significantly lower with LBBAP compared with BVP (4.2% versus 9.3%; hazard ratio, 0.46 [95% CI, 0.29-0.74]; P<0.001). The incidence of VT storm (>3 episodes in 24 hours) was also significantly lower with LBBAP compared with BVP (0.8% versus 2.5%; P=0.013). Among 299 patients with cardiac resynchronization therapy pacemakers (BVP, 111; LBBAP, 188), VT/VF occurred in 8 patients in the BVP group versus none in the LBBAP group (7.2% versus 0%; P<0.001). In 1194 patients with no history of VT/VF or antiarrhythmic therapy (BVP, 591; LBBAP, 603), the occurrence of VT/VF was significantly lower with LBBAP than with BVP (3.2% versus 7.3%; hazard ratio, 0.46 [95% CI, 0.26-0.81]; P=0.007). Among patients with no history of AF (n=890), the occurrence of new-onset AF >30 s was significantly lower with LBBAP than with BVP (2.8% versus 6.6%; hazard ratio, 0.34 [95% CI, 0.16-0.73]; P=0.008). The incidence of AF lasting >24 hours was also significantly lower with LBBAP than with BVP (0.7% versus 2.9%; P=0.015). CONCLUSIONS: LBBAP was associated with a lower incidence of sustained VT/VF and new-onset AF compared with BVP. This difference remained significant after adjustment for differences in baseline characteristics between patients with BVP and LBBAP. Physiological resynchronization by LBBAP may be associated with lower risk of arrhythmias compared with BVP.

Left bundle branch pacing versus left ventricular septal pacing as a primary procedural endpoint during left bundle branch area pacing: Evaluation of two different implant strategies.

INTRODUCTION: Implant procedure features and clinical implications of left bundle branch pacing (LBBP) and left ventricular septal pacing (LVSP) have not been yet fully described. We sought to compare two different left bundle branch area pacing (LBBAP) implant strategies: the first one accepting LVSP as a procedural endpoint and the second one aiming at achieving LBBP in every patient in spite of evidence of previous LVSP criteria. METHODS: LVSP was accepted as a procedural endpoint in 162 consecutive patients (LVSP strategy group). In a second phase, LBBP was attempted in every patient in spite of achieving previous LVSP criteria (n = 161, LBBP strategy group). Baseline patient characteristics, implant procedure, and follow-up data were compared. RESULTS: The final capture pattern was LBBP in 71.4% and LVSP in 24.2% in the LBBP strategy group compared to 42.7% and 50%, respectively, in the LVSP strategy group. One hundred and eighty-four patients (57%) had proven LBB capture criteria with a significantly shorter paced QRS duration than the 120 patients (37%) with LVSP criteria (115 ± 9 vs. 121 ± 13 ms, p < .001). Implant parameters were comparable between the two strategies but the LBBP strategy resulted in a higher rate of acute septal perforation (11.8% vs. 4.9%, p = .026) without any clinical sequelae. Patients with CRT indications significantly improved left ventricular ejection fraction (LVEF) during follow-up irrespective of the capture pattern (from 35 ± 11% to 45 ± 14% in proven LBBP, p = .024; and from 39 ± 13% to 47 ± 12% for LVSP, p = .003). The presence of structural heart disease and baseline LBBB independently predicted unsuccessful LBB capture. CONCLUSION: The LBBP strategy was associated with comparable implant parameters than the LVSP strategy but resulted in higher rates of septal perforation. Proven LBB capture and LVSP showed comparable effects on LVEF during follow-up.

EHRA clinical consensus statement on conduction system pacing implantation: endorsed by the Asia Pacific Heart Rhythm Society (APHRS), Canadian Heart Rhythm Society (CHRS), and Latin American Heart Rhythm Society (LAHRS).

Conduction system pacing (CSP) has emerged as a more physiological alternative to right ventricular pacing and is also being used in selected cases for cardiac resynchronization therapy. His bundle pacing was first introduced over two decades ago and its use has risen over the last five years with the advent of tools which have facilitated implantation. Left bundle branch area pacing is more recent but its adoption is growing fast due to a wider target area and excellent electrical parameters. Nevertheless, as with any intervention, proper technique is a prerequisite for safe and effective delivery of therapy. This document aims to standardize the procedure and to provide a framework for physicians who wish to start CSP implantation, or who wish to improve their technique.

EHRA clinical consensus statement on conduction system pacing implantation: executive summary. Endorsed by the Asia-Pacific Heart Rhythm Society (APHRS), Canadian Heart Rhythm Society (CHRS) and Latin-American Heart Rhythm Society (LAHRS).

Conduction system pacing (CSP) has emerged as a more physiological alternative to right ventricular pacing and is also being used in selected cases for cardiac resynchronization therapy. His bundle pacing was first introduced over two decades ago and its use has risen over the last years with the advent of tools which have facilitated implantation. Left bundle branch area pacing is more recent but its adoption is growing fast due to a wider target area and excellent electrical parameters. Nevertheless, as with any intervention, proper technique is a prerequisite for safe and effective delivery of therapy. This document aims to standardize the procedure and to provide a framework for physicians who wish to start CSP implantation, or who wish to improve their technique. A synopsis is provided in this print edition of EP-Europace. The full document may be consulted online, and a 'Key Messages' App can be downloaded from the EHRA website.

Left bundle branch area pacing outcomes: the multicentre European MELOS study.

AIMS: Permanent transseptal left bundle branch area pacing (LBBAP) is a promising new pacing method for both bradyarrhythmia and heart failure indications. However, data regarding safety, feasibility and capture type are limited to relatively small, usually single centre studies. In this large multicentre international collaboration, outcomes of LBBAP were evaluated. METHODS AND RESULTS: This is a registry-based observational study that included patients in whom LBBAP device implantation was attempted at 14 European centres, for any indication. The study comprised 2533 patients (mean age 73.9 years, female 57.6%, heart failure 27.5%). LBBAP lead implantation success rate for bradyarrhythmia and heart failure indications was 92.4% and 82.2%, respectively. The learning curve was steepest for the initial 110 cases and plateaued after 250 cases. Independent predictors of LBBAP lead implantation failure were heart failure, broad baseline QRS and left ventricular end-diastolic diameter. The predominant LBBAP capture type was left bundle fascicular capture (69.5%), followed by left ventricular septal capture (21.5%) and proximal left bundle branch capture (9%). Capture threshold (0.77 V) and sensing (10.6 mV) were stable during mean follow-up of 6.4 months. The complication rate was 11.7%. Complications specific to the ventricular transseptal route of the pacing lead occurred in 209 patients (8.3%). CONCLUSIONS: LBBAP is feasible as a primary pacing technique for both bradyarrhythmia and heart failure indications. Success rate in heart failure patients and safety need to be improved. For wider use of LBBAP, randomized trials are necessary to assess clinical outcomes.

Influence of baseline inducibility and activation mapping on ablation outcomes in patients with structural heart disease and ventricular tachycardia.

INTRODUCTION: Stand-alone substrate ablation has become a standard ventricular tachycardia (VT) ablation strategy. We sought to evaluate the influence of baseline VT inducibility and activation mapping on ablation outcomes in patients with structural heart disease (SHD) undergoing VT ablation. METHODS: Single center, observational and retrospective study including consecutive patients with SHD and documented VT undergoing ablation. Baseline VT induction was attempted before ablation in all patients and VT activation mapping performed when possible. Ablation was guided by activation mapping for mappable VTs plus substrate ablation for all patients. Ablation outcomes and complications were evaluated. RESULTS: One hundred and sixty patients were included and were classified in three groups according to baseline VT inducibility:group 1 (non inducible, n = 18), group 2 (1 VT morphology induced, n = 53), and group 3 (>1 VT morphology induced, n = 89). VT activation mapping was possible in 35%. After a median follow-up of 38.5 months, baseline inducibility of greater than 1 VT morphology was associated with a significant incidence of VT recurrence (42% for group 3 vs. 15.1% for group 2% and 5.6% for group 1, Log-rank p < .0001) and activation mapping with a lower rate of VT recurrence (24% vs. 36.3%, Log-rank p = .035). Baseline inducibility of greater than 1 VT morphology (hazards ratio [HR]: 12.05, 95% confidence interval [CI]: 1.60-90.79, p = .016) was an independent predictor of VT recurrence while left ventricular ejection fraction less than 30% (HR: 1.93, 95% CI: 1.13-3.25, p = .014) and advanced heart failure (HR: 4.69, 95% CI: 2.75-8.01, p < .0001) were predictors of mortality or heart transplantation. Complications occurred in 11.2% (5.6% hemodynamic decompensation). CONCLUSION: Baseline VT inducibility and activation mapping may add significant prognostic information during VT ablation procedures.

Safety and feasibility of conduction system pacing in patients with congenital heart disease.

INTRODUCTION: Conduction system pacing (CSP) has emerged as an ideal physiologic pacing strategy for patients with permanent pacing indications. We sought to evaluate the safety and feasibility of CSP in a consecutive series of unselected patients with congenital heart disease (CHD). METHODS: Consecutive patients with CHD in which CSP was attempted were included. Safety and feasibility, implant tools and electrical parameters at implant and at follow-up were evaluated. RESULTS: A total of 20 patients were included (10 with a previous device). A total of 10 patients had complex forms of CHD, 9 moderate defects and 1 a simple defect. CSP was achieved in 75% of cases (10 His bundle pacing, 5 left bundle branch pacing) with left ventricular septal pacing in the remaining 5 patients. Procedure times and fluoroscopy times were prolongued (126 ± 82 min and 27 ± 30 min, respectively). Ventricular lead implant times widely varied ranging from 4 to 115 min, (mean 31 ± 28 min) and the use of multiple delivery sheaths was frequent (50%). The QRS width was reduced from 145 ± 36 ms at baseline to 116 ± 18 ms with CSP. Implant electrical parameters included: CSP pacing threshold 0.95 ± 0.65 V; R wave amplitude 9.2 ± 8.8 mV and pacing impedance 632 ± 183 Ohms, and remained stable at a median follow-up of 478 days (interquartile range: 225-567). Systemic ventricle systolic function and NYHA class (1.50 ± 0.51 vs. 1.10 ± 0.31; p = .008) significantly improved at follow-up. Lead revision was required in one patient at Day 4. CONCLUSIONS: Permanent CSP is safe and feasible in patients with CHD although implant technique is complex.

Left Bundle Branch Area Pacing: Implant Technique, Definitions, Outcomes, and Complications.

PURPOSE OF REVIEW: Conduction system pacing (CSP) has emerged during the last few years as the cornerstone of physiological pacing. Two different CSP modalities have been described so far: His bundle pacing (HBP) and left bundle branch area pacing (LBBAP). This review will be focused on the description of LBBAP technique, definitions, outcomes, and complications. RECENT FINDINGS: Large observational studies have demonstrated the safety and feasibility of LBBAP in different scenarios. LBBAP has been associated with excellent pacing electrical parameters (pacing threshold and R wave sensing) and low complication rates including lead revision < 1%. In patients with cardiac resynchronization therapy (CRT) indication, LBBAP has shown significant improvement of functional class and left ventricular ejection fraction during short-term follow-up. LBBAP is a relatively new CSP modality showing excellent results for patients with conventional bradycardia pacing indications and promising expectations about its potential role for CRT.

Characterization of Changes in P-Wave VCG Loops Following Pulmonary-Vein Isolation.

Atrial fibrillation is the most common type of cardiac arrhythmia in clinical practice. Currently, catheter ablation for pulmonary-vein isolation is a well-established treatment for maintaining sinus rhythm when antiarrhythmic drugs do not succeed. Unfortunately, arrhythmia recurrence after catheter ablation remains common, with estimated rates of up to 45%. A better understanding of factors leading to atrial-fibrillation recurrence is needed. Hence, the aim of this study is to characterize changes in the atrial propagation pattern following pulmonary-vein isolation, and investigate the relation between such characteristics and atrial-fibrillation recurrence. Fifty patients with paroxysmal atrial fibrillation who had undergone catheter ablation were included in this study. Time-segment and vectorcardiogram-loop-morphology analyses were applied to characterize P waves extracted from 1 min long 12-lead electrocardiogram segments before and after the procedure, respectively. Results showed that P-wave vectorcardiogram loops were significantly less round and more planar, P waves and PR intervals were significantly shorter, and heart rate was significantly higher after the procedure. Differences were larger for patients who did not have arrhythmia recurrences at 2 years of follow-up; for these patients, the pre- and postprocedure P waves could be identified with 84% accuracy.

Impact of anticoagulation therapy on outcomes in patients with cardiac implantable resynchronization devices undergoing transvenous lead extraction: A substudy of the ESC-EHRA EORP ELECTRa (European Lead Extraction ConTRolled) Registry.

INTRODUCTION: Little data are available on anticoagulation (AC) management in patients with cardiac resynchronization (CRT) devices who undergo transvenous lead extraction (TLE) procedure. We investigated the impact of AC on periprocedural complications in CRT patients undergoing TLE, enrolled in the ESC-EHRA European Lead Extraction ConTrolled (ELECTRa) registry. METHODS AND RESULTS: All CRT patients treated with TLE enrolled in the registry were considered. Perioperative AC management was left to the discretion of the Center. Major and minor intraprocedural and postprocedural complications were compared between patients without AC (Gp1) and patients with AC (Gp2). Regression analyses were performed to identify predictors of complications for Gp2. Out of 734 CRT pts, 328 (44.7%) were under AC (Gp2). Patients from Gp2 presented lower LVEF (Gp2 32.5 ± 10.9 vs Gp1 34.5 ± 11.9%; P = 0.03), more advanced heart failure disease (NYHA III/IV: Gp2 42.0 vs Gp1 31.5%; P = 0.02), and renal impairment (Gp2 39.0 vs Gp1 24.3%; P < 0.001). Perioperative regimens included AC interruption (Gp2A: n = 169, 51.5%), "bridging" (Gp2B: n = 135, 41.2%), or continued AC (Gp2C: n = 24, 7.3%). TLE complete success rates (98% in both groups) and major complication rates were comparable for both groups; minor bleeding events were more frequent in Gp2 (5.5%) compared to Gp1 (2.5%; P = 0.051). No independent predictors were identified for Gp2, but minor complications were associated with "bridging" approach (Gp2B: 16 events vs Gp2A/C: 9 events; P = 0.020). CONCLUSION: CRT patients treated with TLE under AC were more compromised but did not present more major complications compared to patients without AC. More minor complications were associated with "bridging" AC regimen.

Transvenous lead extraction procedures in women based on ESC-EHRA EORP European Lead Extraction ConTRolled ELECTRa registry: is female sex a predictor of complications?

AIMS: Female sex is considered an independent risk factor of transvenous leads extraction (TLE) procedure. The aim of the study was to evaluate the effectiveness of TLE in women compared with men. METHODS AND RESULTS: A post hoc analysis of risk factors and effectiveness of TLE in women and men included in the ESC-EHRA EORP ELECTRa registry was conducted. The rate of major complications was 1.96% in women vs. 0.71% in men; P = 0.0025. The number of leads was higher in men (mean 1.89 vs. 1.71; P < 0.0001) with higher number of abandoned leads in women (46.04% vs. 34.82%; P < 0.0001). Risk factors of TLE differed between the sexes, of which the major were: signs and symptoms of venous occlusion [odds ratio (OR) 3.730, confidence interval (CI) 1.401-9.934; P = 0.0084], cumulative leads dwell time (OR 1.044, CI 1.024-1.065; P < 0.001), number of generator replacements (OR 1.029, CI 1.005-1.054; P = 0.0184) in females and the number of leads (OR 6.053, CI 2.422-15.129; P = 0.0001), use of powered sheaths (OR 2.742, CI 1.404-5.355; P = 0.0031), and white blood cell count (OR 1.138, CI 1.069-1.212; P < 0.001) in males. Individual radiological and clinical success of TLE was 96.29% and 98.14% in women compared with 98.03% and 99.21% in men (P = 0.0046 and 0.0098). CONCLUSION: The efficacy of TLE was lower in females than males, with a higher rate of periprocedural major complications. The reasons for this difference are probably related to disparities in risk factors in women, including more pronounced leads adherence to the walls of the veins and myocardium. Lead management may be key to the effectiveness of TLE in females.

Utility of high density multielectrode mapping during ablation of scar-related ventricular tachycardia.

INTRODUCTION: Multielectrode mapping catheters (MEMC) allow the performance of high resolution and density maps but the utility of these catheters in ventricular tachycardia (VT) ablation procedures has not been yet widely described. We sought to evaluate the utility of a MEMC during scar-related VT ablation procedures. METHODS: Eighty-five consecutive scar-related VT ablation procedures were performed in 81 patients. In the first 26 procedures, a standard 3.5-mm tip linear catheter was employed for endocardial/epicardial mapping (control group). In the following 59 procedures mapping was performed with a MEMC (study group). Procedural time, LV endocardial and epicardial mapping time, complications and ablation outcomes were compared. RESULTS: The use of the MEMC resulted in a significant shortening of the endocardial and epicardial mapping times (38 ± 15 minutes vs. 56 ± 24 minutes for endocardial LV mapping in the study and control group, respectively, P = 0.001; and 28 ± 9 minutes vs 41 ± 16 minutes, for epicardial mapping, P = 0.011) as well as the total procedural time (177 ± 53 minutes vs. 206 ± 50 minutes, respectively, P = 0.02). The mapping density was also significantly increased in the study group (mean endocardial LV points: 2,143 ± 1,419 vs. 485 ± 174, for the study and control group, respectively, P < 0.0001), specially within the scar area (49.6 ± 34 points/cm2 vs. 8.4 ± 4.6 points/cm2 , P < 0.001). No differences in acute and long-term follow-up outcomes were observed. CONCLUSIONS: High-density multielectrode mapping is associated with a significant reduction of procedural and mapping times and a significant increase of mapping density without affecting outcomes in patients with scar-related VT.

Incidence and predictors of clinically relevant cardiac perforation associated with systematic implantation of active-fixation pacing and defibrillation leads: a single-centre experience with over 3800 implanted leads.

AIMS: Active-fixation leads have been associated with higher incidence of cardiac perforation. Large series specifically evaluating this complication are lacking. We sought to evaluate the incidence and predictors of clinically relevant cardiac perforation in a consecutive series of patients implanted with active-fixation pacing and defibrillation leads. METHODS AND RESULTS: We conducted a retrospective observational study including all consecutive patients implanted with an active-fixation pacing/defibrillation lead at our institution from July 2008 to July 2015. The incidence of clinically relevant cardiac perforation and cardiac tamponade was evaluated. Univariate and multivariate analyses were used to identify predictors of cardiac perforation. Acute and long-term management of these patients was also investigated. A total of 3822 active-fixation pacing (n = 3035) and defibrillation (n = 787) leads were implanted in 2200 patients. Seventeen patients (0.8%) had clinically relevant cardiac perforation (13 acute and 4 subacute perforations), and 13 (0.5%) had cardiac tamponade resolved with pericardiocentesis. None of the patients with cardiac perforation required surgical treatment. In multivariate analysis, an age >80 years (OR 3.84, 95% CI 1.14-12.87, P = 0.029), female sex (OR 3.14, 95% CI 1.07-9.22, P = 0.037), and an apical position of the right ventricular lead (OR 3.37, 95% CI 1.17-9.67, P = 0.024) were independent predictors of cardiac perforation. CONCLUSIONS: Implantation of active-fixation leads is associated with a low incidence of clinically relevant cardiac perforation. Older and female patients have a higher risk of perforation as well as those patients receiving the ventricular lead in an apical position.

The Role of Conventional and Right-Sided ECG Screening for Subcutaneous ICD in a Tetralogy of Fallot Population.

BACKGROUND: Information regarding suitability for subcutaneous implantable cardioverter-defibrillator (S-ICD) implant in tetralogy of Fallot (ToF) population is scarce and needs to be further explored. THE AIMS OF OUR STUDY WERE: (1) to determine the proportion of patients with ToF eligible for S-ICD, (2) to identify the optimal sensing vector in ToF patients, (3) to test specifically the eligibility for S-ICD with right-sided screening, and (4) to compare with the proportion of eligible patients in a nonselected ICD population. METHODS: We recruited 60 consecutive patients with ToF and 40 consecutive nonselected patients. Conventional electrocardiographic screening was performed as usual. Right-sided alternative screening was studied by positioning the left arm and right arm electrodes 1 cm right lateral to the xiphoid midline. The Boston Scientific electrocardiogram (ECG) screening tool was utilized. RESULTS: We found a higher proportion of patients with right-sided positive screening in comparison with standard screening (77 ± 0.4% vs. 67 ± 0.4%; P < 0.0001) and a trend to higher number of appropriate leads in right-sided screening (1.3 ± 1 vs. 1.1 ± 1 ms; P = 0.07). Patients who failed the screening had a longer QRS duration and longer QT interval. Standard and right-sided screening showed a higher percent of positive patients in the control group compared to ToF patients (P < 0.001). CONCLUSION: Right-sided screening was associated with a significant 10% increase in S-ICD eligibility in ToF patients. When comparing with an acquired cardiomyopathies group, ToF showed a lower eligibility for S-ICD. The most appropriate ECG vector was the alternate vector in contrast to what is observed in the general population.

Conventional and right-sided screening for subcutaneous ICD in a population with congenital heart disease at high risk of sudden cardiac death.

BACKGROUND: Information regarding suitability for subcutaneous defibrillator (sICD) implantation in tetralogy of Fallot (ToF) and systemic right ventricle is scarce and needs to be further explored. The main objective of our study was to determine the proportion of patients with ToF and systemic right ventricle eligible for sICD with both, standard and right-sided screening methods. Secondary objectives were: (i) to study sICD eligibility specifically in patients at high risk of sudden cardiac death, (ii) to identify independent predictors for sICD eligibility, and (iii) to compare the proportion of eligible patients in a nonselected ICD population. METHODS: We recruited 102 patients with ToF, 33 with systemic right ventricle, and 40 consecutive nonselected patients. Conventional electrocardiographic screening was performed as usual. Right-sided alternative screening was studied by positioning the left-arm and right-arm electrodes 1 cm right lateral of the xiphoid midline. The Boston Scientific ECG screening tool was utilized. RESULTS: In high-risk patients with ToF, eligibility was higher with right-sided screening in comparison with standard screening (61% vs. 44%; p = .018). Eligibility in high-risk right ventricle population was identical with both screening methods (77%, p = ns). The only independent predictor for sICD eligibility was QRS duration. CONCLUSION: In high-risk patients with ToF, right-sided implantation of the sICD could be an alternative to a conventional ICD. In patients with a systemic right ventricle, implantation of a sICD is an alternative to a conventional sICD.

Essential ECG clues in patients with congenital heart disease and arrhythmias.

The prevalence of adults with congenital heart disease has dramatically increased during the last decades due to significant advances in the surgical correction of these conditions. As a result, patient's survival has been prolonged and arrhythmias have become one of the principal causes of morbidity and mortality for these patients. The surface 12-lead ECG may play a critical role in the identification of the underlying heart disease of the patient, the recognition of the arrhythmia mechanism and may also help in the planification of the ablation procedure in this setting. Finally, important prognostic information can be also obtained from the ECG in these patients. The present review will offer an overview of the principal utilities of the surface ECG in the diagnosis and management of patients with CHD and arrhythmias.

The use of multisite left ventricular pacing via quadripolar lead improves acute haemodynamics and mechanical dyssynchrony assessed by radial strain speckle tracking: initial results.

AIMS: The objective of the present study was to evaluate the effect of multipoint pacing (MPP) on acute haemodynamics, cardiac contractility, and left ventricle (LV) dyssynchrony, in comparison with conventional cardiac resynchronization therapy (CRT). METHODS AND RESULTS: An open-label, non-randomized, single-centre, prospective study was designed. Twenty-seven consecutive patients were included. Evaluation of pacing configurations was performed in a random order. Transthoracic echocardiography was used to obtain haemodynamic and dyssynchrony parameters. Left ventricular ejection fraction (LVEF) was significantly superior in MPP compared with baseline (38.4 ± 1.8% vs. 26.1 ± 2.2%; P < 0.001), and in conventional pacing configuration compared with baseline (33.2 ± 1.8% vs. 26.1 ± 2.2%; P = 0.007). Cardiac index (CI) was increased by 21.8 ± 5.4% and 34.7 ± 5.1% in conventional and MPP configurations, respectively (P = 0.19). Percentage of acute responders (CI increase ≥10%) was 62.9 and 85.2% in conventional and MPP, respectively (P < 0.001). LV dyssynchrony was defined by radial strain rate parameters. Baseline anteroseptal-to-posterior wall time delay was 168 ± 21 ms. It was reduced until 70.4 ± 29 ms in conventional and -6.6 ± 11 ms in MPP (conventional vs. baseline P = 0.04; MPP vs. conventional P = 0.05). Standard deviation of the time-to-peak radial strain of the 6 LV basal segments was 101 ± 9.7, 80.3 ± 9.2, and 66 ± 8.03 ms in baseline, conventional, and MPP configurations, respectively (MPP vs. basal P = 0.012). Finally, we observed a positive correlation (r = 0.69) between reduction in dyssynchrony and CI increase (P < 0.0001). CONCLUSION: MPP showed a further reduction in LV dyssynchrony compared with conventional biventricular pacing. Moreover, MPP resulted in an additional improvement in LVEF and in CI, and this was translated into a higher number of acute responders to CRT.

Initial Experience with a New Image Integration Module Designed for Reducing Radiation Exposure During Electrophysiological Ablation Procedures.

INTRODUCTION: Reduction of radiation exposure during cardiac arrhythmia ablation procedures is desirable. We sought to evaluate the utility of a new image integration module (CARTOUNIVU(TM) ) in reducing fluoroscopy times and dosages during left atrial arrhythmia (LAA) and ventricular tachycardia (VT) ablation procedures. METHODS AND RESULTS: Consecutive patients undergoing LAA (n = 28)/VT (n = 13) ablation using the CARTOUNIVU(TM) module were included. Total fluoroscopy time, radiation dose (total dose area product [tDAP], effective dose [ED]), and procedure duration were evaluated. A retrospective cohort of patients who underwent LAA (n = 16)/VT(n = 8) ablation without the new image integration module served as a control group. The use of the new image integration module significantly reduced mean fluoroscopy time (5.2 minutes [IQR 1.9;6.8] in the LAA ablation UNIVU group vs. 28.2 minutes [IQR 15.3;37.8] in the control group, P<0.001; 9.8 minutes [IQR 4.5;13.1] vs. 25.5 minutes [IQR 14.1;30.9] for VT ablation, P = 0.013), tDAP (2,088 cGy*cm(2) [IQR 664;2911] vs. 5,893 cGy*cm(2) [IQR 3088;8483], P< 0.001 for LAA ablation; 3,917 cGy*cm(2) [IQR 948;4217] vs. 12,377 cGy*cm(2) (IQR 3385;23157) for VT ablation patients, P = 0.025) and ED (4.1 mSv [IQR 1;5.8] vs. 11.8 mSv [IQR 6.2;16.9] for LAA ablation patients, P< 0.001; 7.8 mSv [IQR 1.9;8.4] vs. 24.7 mSv [IQR 6.8;46.3] for VT ablation patients, P = 0.025). Procedure duration did not significantly change (174 ± 45 minutes vs. 197 ± 36 minutes for LAA ablation, P = 0.083; 201 ± 51 minutes vs. 201 ± 63 minutes for VT ablation, P = 0.860). No serious adverse events related to the use of the CARTOUNIVU(TM) module occurred. CONCLUSIONS: The new image integration module significantly reduced total fluoroscopy time and mean radiation dose without influence in procedure duration during ablation of complex atrial and ventricular arrhythmias.

The use of quadripolar left ventricular leads improves the hemodynamic response to cardiac resynchronization therapy.

BACKGROUND: The objective of the present study was to evaluate the usefulness of a left ventricle (LV) quadripolar lead in improving the hemodynamic response to cardiac resynchronization therapy (CRT). METHODS AND RESULTS: We included 27 consecutive patients implanted with a CRT device with an LV quadripolar lead. Hemodynamic parameters were evaluated at 3-month follow-up by using impedance cardiography. We assessed the highest cardiac output and the highest stroke volume (SV) obtained after atrioventricular and interventricular optimization with pacing from each of the four electrodes of the LV lead. Each patient was evaluated according to three different pacing configurations: unipolar-simulated, bipolar, and quadripolar. Biventricular pacing improved hemodynamics in comparison to the nonpaced measurements: cardiac index (CI): 2.69 L/min/m(2) versus 2.17 L/min/m(2) (P = 0.001). The hemodynamic response was highest in the quadripolar in comparison to unipolar-simulated and bipolar configurations, with an increase of 29%, 23%, and 27%, respectively, in relation to the reference CI and with an increase of 22%, 11%, and 18%, respectively, in relation to the reference indexed SV (P < 0.05, for the comparison between unipolar-simulated and quadripolar configurations). Twelve patients (44%) showed the best hemodynamic response by pacing from any of the two distal electrodes and 15 patients (56%) by pacing from the two proximal electrodes. Finally, CRT responder rates were higher in quadripolar versus bipolar and unipolar-simulated configurations: 90%, 85%, and 75%, respectively. CONCLUSIONS: The quadripolar LV lead was associated with a better hemodynamic response and higher CRT responder rates when compared with unipolar-simulated and bipolar LV leads.