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INTRODUCTION: Much clinical evidence has shown that right ventricular (RV) apical pacing is detrimental to left ventricular function. Preservation of the use of the His-Purkinje (H-P) system may be ideal in heart block that is restricted to the AV node, but may be of no benefit when H-P disease exists. AIM: To investigate the feasibility of direct His-bundle pacing (DHBP) using a new system consisting of a steerable catheter and a new 4.1 F screw-in lead. METHOD: Between May and December 2004, 26 patients (19 male, mean age: 77 +/- 5 years) with a standard pacemaker (PM) indication and preserved His-bundle conduction were enrolled and DHBP was attempted. RESULTS: DHBP was achieved in 24 patients (92%); two patients were paced in the His area, but the paced QRS morphology and duration were different from the native QRS. The mean time for lead positioning was 19 +/- 17 minutes, the mean fluoroscopy time was 11 +/- 8 minutes, and the total procedure time (skin-to-skin including positioning of a quadripolar diagnostic catheter for His recording) was 75 +/- 18 minutes. In DHBP pacing, the acute pacing threshold was 2.3 +/- 1.0 V at a pulse duration of 0.5 msec, and the sensed potentials were 2.9 +/- 2.0 mV. At a 3-month follow-up examination, the same QRS duration and morphology recorded on implantation were observed in all patients. The pacing threshold was 2.8 +/- 1.4 V, and sensed potentials were 2.5 +/- 1.8 mV; the sensing configuration was changed from bipolar to unipolar in 6 patients to resolve undersensing issues. No major complications were observed. CONCLUSIONS: This feasibility study shows that DHBP can be accomplished with a new system consisting of a steerable catheter and an active fixation lead in 92% of the patients in whom it was attempted. [ABSTRACT FROM AUTHOR]

The present study applies a non-invasive method to the quantitative evaluation of left ventricular stiffness in normal subjects and in patients with ischaemic heart disease (IHD). We have studied 20 patients with IHD and 25 healthy subjects. The third heart sound (S3) was detectable in all patients. We have correlated the energy spectrum of S3, divided into 15 Hz bands, with a series of echocardiographic parameters. The existence of a significant correlation between the spectrum energy and the diameter and thickness of the left ventricle at the moment of S3 allowed us to explore the possibility of interpreting the origin of S3 based on a mathematical model. Our hypothesis has been that, once the left ventricle starts vibrating, it behaves as a simple physical model composed of a mass and an elastic element. To this purely elastic model one can add a factor accounting for viscosity, with a damping effect, to obtain a more complex viscoelastic model. The stiffness coefficient ‘k’ was computed in both models from the peak frequency of S3 and the left ventricular mass at the moment of S3. Furthermore, in the viscoelastic model, the damping element ‘c’ was also computed. Both parameters —- k and c — were significantly increased in the group with IHD compared with the control group. Although a simplification of the vibrating system, these models make it possible to obtain non-invasively information on the characteristics of the left ventricle through the combined use of echocardiography and spectral analysis of S3. [ABSTRACT FROM PUBLISHER]

An abstract of the article "Anathomical determinants of left ventricle dissincrony," by S. Aggio and colleagues is presented.

An abstract of the article "Cardiac resynchronisation therapy in heart failure: evaluation of clinical outcome and survival in our experience," by E. Baracca and colleagues is presented.

Since 1999, 174 pts (135 male, mean age 71.1±8.6 y - range 36-92) underwent to CRT (64 with ICD back-up) for severe CHF: 56% had ischemic cardiomyopathy. At implant 31 pts were in AF, 47 were previously paced with right apical pacing. In 18 subjects CRT were a bridge to heart transplant. Clinical (NYHA class, Minnesota Quality Life Score-QLS) and echocardiographic evaluation (end systolic-diastolic [ESD]-[EDD] diameters, ejection fraction [EF] inter and intra-ventricular delay, % of mitral regurgitation area in left atrium [MR]) was scheduled every three month for the first year and then twice a year. The procedure success was 98,7%: coronary dissection and lead instability were the causes of failure. The mean follow-up was 25±16 months (range 1-66). After CRT, a significant reduction of the electric (QRS: 189±32 vs. 143±21ms, p<.001) and the mechanical (55±33 vs. 25±19ms, p<.001) delays was observed immediately after the procedure. The following parameters were significantly (p<.001) improved after CRT: Follow-up Implant 6 months 1 year 2 years 3 years 4 years n subjects 174 150 132 81 42 23 Mortality T. 1 (0,57%) 5 (3,34%) 8 (6,06%) 9 (11, 1%) 7 (16,7%) 5 (21,7%) NYHA 3,16±0.61 2,15±0.48 2,04±0.45 2,09±0.41 2,13±0.47 2,23±0,4 QLS 59±12 35±9 33±8 32±8 31±10 33±7 EF% 26,3±6,9 35,6±7,9 37,0±8,4 38,8±10 36,1±11 31,6±4,1 Moreover at 2 years (n=42) a significant reduction of ESD (63,1±10,6 vs. 55,2±9.8, p<.001), EDD (74,1±10,1 vs. 70,7±11,3, p<.001), MR% (21±18% vs. 12±12%, p<.001) has been observed. A marked decreased in hospitalization for CHF were observed during the first year follow-up (3.08±1.9 vs. 0.76±0.5, p<.001). Our real world experience confirms the benefit of CRT in a large unselected population in terms of clinical and echocardiographic improvements and reduction of both mortality and hospitalization rate. [ABSTRACT FROM PUBLISHER]

Cardiac resynchronization therapy (CRT) has become one of the main therapeutic alternatives for advanced congestive heart failure (CHF), but the effects on morbidity and mortality are still unclear.Aim of the Study was to analyze hospitalization rate and mortality - total mortality (TM) and cardiac mortality (CM) - in a wide patient population implanted in our institution in the last six years. Methods since 1999, 187 pts (158 male) underwent CRT for severe CHF (EF 26.3% ± 6.9). In 82 pts a backup ICD was associated. The mean age was 71.1 ± 8.8 years (range 36 to 92); 103 pts (53%) had ischemic heart disease (IHD) while 84 were non ischemic (NIHD); 36 pts were in atrial fibrillation at the time of implant; 46 were previously paced via the right ventricular apex; 16 were candidates for heart transplantation. All the pts were evaluated in our clinic and the follow-up was scheduled every three month for the first year and then twice a year. Results the implant success rate was 98.9%. The mean follow-up was 29±16 months (range 1 – 74 months). Compared to the year before CRT, a significant decrease in hospitalization rate was observed during the first year of follow-up (2.38±1.6 vs. 0.56±0.7, p<.001). TM was 10.7%, CM was 8.0 %. The ICD group shows a reduction of TM compared to the group without: 7.3% vs. 13.3%: - 46 %. Conclusions 1) the benefit of CRT is similar in IHD and NIHD; 2) IHD seems to have a worse prognosis than NIHD in term of TM and CM; 3) CRT decreases the hospitalization rate and increases survival; 4) the association with a back-up ICD strongly reduces the mortality in this population. [ABSTRACT FROM PUBLISHER]

Cardiac resynchronization therapy (CRT) by biventricular pacing is still challenging in terms of successful coronary sinus (CS) cannulation and left ventricular (LV) lead positioning. Thus, a system to facilitate the cannulation and the positioning may be preferable.Aim of the Study A new approach for coronary sinus cannulation and left ventricular lead positioning has been evaluated. This system consists of a guiding and an inner catheter as a telescopic way to cannulate the CS ostium and the target collateral vein (Dual-Catheter System-RAPIDO). Methods Forty-four consecutive patients with cardiomyopathy of any etiology (34 males, 72±9 yrs, QRS 169±23 ms, LV ejection fraction 27.6 ± 5.2%) underwent CRT (23 ICD) under standards indications. Results Successful cannulation was achieved in 100% of cases. The mean time from insertion of the telescopic system into the subclavian vein to cannulation of the CS was 1.3±2.5 min. The mean LV lead positioning time, measured from CS cannulation to lead positioning in the final LV lead location, was 6.3±7 min. The total fluoroscopy and total procedural time were 16±11 min and 87±35 min, respectively. No major complications were observed. Conclusion This approach using a dual telescopic catheter system leads to a high percentage of success procedure rates. It is safe and feasible with a reduction of fluoroscopy time, procedural time and contrast agent volume. In our experience this system is superior in terms of time consuming and success rate compared to the traditional approach. [ABSTRACT FROM PUBLISHER]

EPASS Pilot study compared right atrial appendage (RAA) and Interatrial Septum (IAS) pacing in patients (Pts) with SSS and atrial fibrillation (AF), in relation with the electrophysiologic study (EP) and pacing mode.Method 42 Pts (72±7 years old, 15M, 27F) were submitted to EP before randomization of pacing site and algorithms. The difference between basal and incremental conduction times (CT) was measured between the RAA and the coronary sinus os (csos) (delta-ctos). Pts with A2>100ms, ERP/A2<2,2, P wave duration >110ms and delta-ctos>60ms were group A. The remaining pts were group B. The number of AF episodes lasting more than 7 minutes (AF-Ep) was collected at 2 follow-ups of 3 months each by the pacemaker Selection 9000 (Vitatron). Results Group A (IAS) showed a reduction of AF-Ep/day with algorithms (p = 0,049) as to standard DDD. Group A (RAA) showed an increase of AF-Ep/day (p = 0,046) when continuously paced. Group B did not show statistically significant differences between DDD and DDD + Algorithms. Conclusion Pts with RA severe conduction delay may benefit of continuous pacing in the IAS, but not in the RAA. [ABSTRACT FROM PUBLISHER]

Background Right ventricular apical pacing alters impulse conduction producing an intraventricular desynchronization that could be detrimental for LV function. Direct His bundle pacing (DHBP) represents a novel approach to cardiac pacing in pts with normal His-Purkinje activation because it maintains or restores the physiological activation of the ventricular muscle during cardiac pacing. Methods 13 pts (mean age 76±3 years; 2 females; QRS duration 118±24 ms; LV EF% 60±11; LV end-diastolic volume 61±22 ml/m2) have been investigated. At baseline and after DHBP Tissue Doppler Imaging was performed to evaluate the intraventricular dyssynchrony [defined as the interval between the earliest LV wall motion and the latest (intra LV delay) or as standard deviation (SD, modified Yu index) of all time intervals]. Tei index, E/A ratio, dP/dT, MR (mitral regurgitation-diameter of vena contracta) were also obtained. Baseline intra-LV desynchronization (intra-LV delay above 40 ms) was observed in 2 pts with normal QRS and in all 4 pts who had intraventricular conduction delay (QRS > 120 ms). Results in table are displayed the values at baseline and after DHBP: [ABSTRACT FROM PUBLISHER]

Introduction: Restoring physiological cardiac electrical activity in patients with conduction disease can be crucial for the survival and quality of life. Conduction system pacing (CSP) is a valuable option, although it is limited by technical challenges in difficult anatomies. 3D electroanatomical mapping (3D-EAM) can support CSP ensuring high electro-anatomical precision and low fluoroscopy., Objectives: We evaluated the feasibility and effectiveness of a systematic 3D-EAM use to guide CSP in difficult anatomical scenarios (highly dilated atria, congenital cardiomyopathies, failed biventricular implants (BiV) and pacing-induced cardiomyopathy (PICM))., Methods: Forty-three consecutive patients (27 males, 75 ± 10 years old) with standard pacing indications and difficult anatomical scenarios were included. The right atrium, His cloud, and atrio-ventricular septum were reconstructed by 3D-EAM. The His bundle (HB) was the initial target, while left bundle branch area pacing (LBBAP) was aimed at in case of unsatisfactory parameters, sub-optimally paced QRS, or impossibility of reaching the HB., Results: CSP was successful in 37 (86%) patients (15 HBP; 22 LBBAP). Mean mapping, fluoroscopy, and procedural times were 18 ± 7 min, 7 ± 5 min, 98 ± 47 min, respectively. The mean pacing threshold, R wave sensing, and pacing impedance of CSP lead were 1.2 ± 0.5V@0.5ms, 11.4 ± 6.2 mV, 736 ± 306 Ω, respectively. Baseline and paced QRS were 139 ± 38 ms and 114 ± 23 ms, respectively. No procedural complications were observed., Conclusions: 3D-EAM allowed the accurate definition of the His cloud and high ventricular septum and effectively guided CSP. It facilitated CSP in complex anatomies, with a procedural success rate of 86%. The results were satisfactory and reproducible, with acceptable fluoroscopy and procedural times., (Copyright © 2023 Indian Heart Rhythm Society. Published by Elsevier B.V. All rights reserved.)

His Bundle Pacing (HBP) is a form of physiologic pacing achieved through implantation of a pacing electrode into the His bundle. HBP began 20 years ago without any dedicated tools. As specific tools became available HBP quickly spread and proved to be a viable alternative to traditional right ventricle pacing. HBP is reliable and effective in preserving the physiologic ventricular synchrony with clinical benefits particularly evident when a high percentage of pacing is required. Unipolar signals from the lead tip guide the implant. 3D electroanatomical mapping could further assist the procedure., Competing Interests: Disclosure F. Zanon reports speaker fees (modest) from Abbott, Biotronik, Boston Scientific, Medtronic, and Microport. Other authors report no disclosure., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: Incidence and prognostic value of new-onset atrial fibrillation after single versus double stent strategy in bifurcation left main disease has not been yet investigated., Methods: We retrospectively analyzed the procedural and medical data of patients referred to our center for complex left main bifurcation disease, treated using crossover provisional stenting, T or T-and-Protrusion, Culotte, and Nano-inverted-T techniques between January 1, 2008, and May 1, 2018. Multivariate Cox-regression analysis was used to assess the role of different stent strategies, adjusted for confounders, on the risk of new-onset atrial fibrillation during the follow-up period., Results: Five hundred two patients (316 males, mean age 70.3 ± 12.8 years, mean Syntax score 31.6 ± 6.3) were evaluated. At a mean follow-up of 37.1 ± 10.8 months (range: 22.1- 39.3 months); Target lesion failure rate was 10.1%. Stent thrombosis and cardiovascular mor- tality were observed in 1.2% and 3.6% in of cases, respectively. New-onset atrial fibrillation occurred in 23 out of 502 patients (4.6%). Patients with new-onset atrial fibrillation resulted more frequently female, older, obese, and diabetic and more frequently experienced target lesion failure and cardiovascular death. New-onset atrial fibrillation-free survival favored single versus double stent technique and among double stent techniques nano-inverted-T tech- niques compared to the others. Single stent strategy had a lower risk of new-onset atrial fibril- lation compared to double stent technique on multivariate analysis (Hazard Ratio (HR): 1.14, 95% CI: 1.10-1.19, P < .001 vs. HR: 1.28, 95% CI: 1.23-1.32, P < .0001)., Conclusion: New-onset atrial fibrillation in distal left main bifurcation disease treated with per- cutaneous coronary intervention had a low incidence but resulted more frequently after double than after single stenting technique and was associated with worse outcomes.

Introduction: In patients with sinus node disease (SND), the dual-chamber pacemaker (PM) is programmed in DDDR mode with an algorithm to avoid unnecessary right ventricular (RV) pacing. This pacing mode may prolong PR interval with consequently atrioventricular (AV) asynchrony which is associated with a higher risk of atrial fibrillation (AF). We evaluate whether preserving AV synchrony by setting a fixed AV delay during physiological RV pacing, that is, His bundle pacing (HBP), could reduce the risk of AF occurrence in comparison with a standard pacing mode with an algorithm to avoid unnecessary RV pacing (DDD-VPA)., Methods and Results: We collected retrospective data from 313 consecutive patients who had undergone PM for SND. The first occurrence of persistent AF (>7 consecutive days) as a function of the pacing mode was evaluated. HBP and DDD-VPA were implemented in 82 and 231 patients, respectively. Persistent AF occurred in 128 (40.9%) patients over a median follow-up of 70 months (67-105). The DDD-VPA pacing mode was significantly correlated with the occurrence of persistent AF only when the basal PR was long (>180 ms). The risk of persistent AF was significantly lower in patients on HBP than in those on DDD-VPA, adjusted HR = .57 (95% CI, .36- .89, p=.014). Other independent predictors of persistent AF occurrence were: A history of AF (HR = 3.91; 95% CI, 2.48-6.19, p = .001), age, and long PR interval (HR = 2.98; 95% CI, 2.00-4.43, p=.001)., Conclusion: In SND patients and long basal PR interval, the HBP may reduce the risk of persistent AF in comparison with the DDD-VPA., (© 2020 Wiley Periodicals LLC.)

Non-left bundle branch block (non-LBBB) remains an uncertain indication for cardiac resynchronization therapy (CRT). Non-LBBB includes right bundle branch block (RBBB) and non-specific LV conduction delay (NSCD), two different electrocardiogram (ECG) patterns which are not generally considered to be associated with LV conduction delay as judged by the invasive assessment of the Q-LV interval. We evaluated whether a novel ECG interval (QR-max index) correlated with the degree of LV conduction delay regardless of the type of non-LBBB ECG pattern, and could, therefore, predict CRT response. In 173 non-LBBB patients on CRT (92 NSCD, 81 RBBB), the QR-max index was measured as the maximum interval from QRS onset to R-wave offset in the limb leads. The correlation between QR-max index and Q-LV interval and the impact of the QR-max index on time to first heart failure hospitalization during 3-year follow-up were assessed. Q-LV correlated better with the QR-max index than with QRSd, particularly in the RBBB group (r = 0.91; p < 0.001 vs. r = 0.19; p < 0.089), while the correlations were r = 0.79 (p < 0.01) and r = 0.68 (p < 0.01), respectively, in the NSCD group. In both groups, the QR-max index was significantly more able than QRSd to identify CRT responders (AUC 0.825 vs. 0.576; p = 0.0008 in RBBB; AUC 0.738 vs. 0.701; p = 0.459 in NSCD). A QR-max index exceeding a cutoff value of 120 ms was associated with CRT response, with predictive values of 86.8 and 81.4% in RBBB and NSCD, respectively. The QR-max index reflects the degree of LV electrical delay regardless of QRS duration in RBBB and NSCD patients and is a useful indicator of suitability for CRT in non-LBBB patients.

His bundle pacing (HBP) preserves physiological ventricular synchrony, with clinical benefits particularly evident when a high percentage of ventricular pacing is required. First experiences with standard leads and manually shaped stylets produced the impression that HBP is highly complex and time-consuming. However, with dedicated leads and sheaths, reliable HBP can be achieved in routine clinical practice. Implantation success in more than 90% of patients can be reached with current technology and has been shown to be reliable and effective, both at implantation and during long-term follow-up. At the same time, fluoroscopy and total procedural time can be reduced. New customized technologies will continue to improve the implant success rate and system performance. Large randomized trials will prove the long-term clinical benefits of HBP definitively and may render HBP the first choice in patients requiring ventricular pacing.

Introduction: His bundle pacing (HBP) is the most physiological pacing. The standard technique based on fluoroscopic approach might be challenging and fluoro consuming. Targeting the His guided exclusively by the electrical signals could enable a precise lead implant, thus reducing fluoroscopy time (FT) and X-ray dose, desirable both for patients and operators. The aim of the study is to evaluate the feasibility, efficacy, and safety both acutely and at 30 days of the electrogram (EGM)-guided HBP with minimal or no fluoroscopy., Methods and Results: Between October and December 2018, 41 consecutive patients underwent EGM-guided HBP. Successful HBP was obtained in 39 (95%) patients, (30 males, 78 ± 10 years). Selective HBP (S-HBP) was achieved in 23 (59%), nonselective HBP (NS-HBP) in 16 (41%) patients. The final HBP lead position was reached in 31 (79.4%) patients without fluoroscopy, only guided by electrical signals. In eight patients a minimal fluoroscopy (mean, 8 seconds) has been required. The sheath's cutting and the slack of the lead were routinely performed under fluoroscopy. No difference was observed in FT for HBP lead placement in S-HBP and NS-HBP (mean, 8.1 ± 25 vs 7.5 ± 20 seconds, P = .8; median value 0 vs 0 seconds). No differences were observed in FT for the entire procedure, total dose area product and total procedural time in S-HBP and NS-HBP. Lead dislodgement occurred in one (2.6%) patient 1 day after the procedure., Conclusions: HBP could be performed safely and efficiently using the EGMs, with minimal or no fluoroscopy. Fluoroscopy was required during sheath removal and atrial lead placement., (© 2020 Wiley Periodicals, Inc.)

Background: The optimal strategy for treating ostial left anterior descending coronary artery (LAD) disease remains matter of speculation. We evaluated the impact on long-term outcomes of ostial LAD disease treated by means of ostial stenting (the floating-stent) or left main (LM)-to-LAD cross-over stenting., Methods: Clinical and instrumental records of 74 consecutive patients with isolated ostial LAD disease, enrolled between the 1st January 2012 and the 1st January 2017 were reviewed. Patients have been stratified according the stenting techniques adopted: ostial stenting (OS) or LM cross-over (CO)., Results: Seventy-four consecutive patients (54 males, mean age 73.39 ± 9.54 years old) have been analyzed. In CO patients the SYNTAX score (16.2 ± 3.3 vs 24.1 ± 2.5, p < 0.0001) and the percentages of rotablation resulted higher than in OS group. IVUS has been predominantly used in CO groups revealing a significant extension of plaque burden of at least 10 mm of LM proximal to the LAD ostium in all the 18 out of 21 patients (85.7%) undergone IVUS-guided procedure. Fluoroscopy time and contrast medium volume were higher in OS versus CO group of patients. On a mean follow-up of 49.7 ± 7.9 months, MACE and target vessel revascularization (TVR) were 21.0% and 21.0% in OS groups versus 10.1 and 5.6% in the CO group (p = 0.20 and p = 0.04, respectively). Restenosis was higher in the OS than in CO group of patients and was located angiographically at the ostium., Conclusions: On long-term follow-up CO seems to be superior to OS technique for isolated ostial LAD disease especially in the presence of heavy calcification., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Introduction: Several single-center short-term studies have demonstrated the feasibility, safety, and positive clinical outcomes of permanent His bundle pacing (HBP). We performed a retrospective study to evaluate long-term technical and safety performances of HBP in a large population of pacemaker patients from two different centers., Methods and Results: The analysis includes 844 patients (345 female, mean age = 75 ± 9 years) who underwent successful permanent HBP for pacemaker indications from 2004 to 2016. The main endpoints were long term electrical performances including pacing threshold, sensing, impedance, and freedom from pacing related complications. The pacing indication was AV Block in 348 (41.2%) patients, sinus node disease in 147 (17.4%), any bradycardia indication in patients with atrial fibrillation in 335 (39.7%) patients and need for cardiac resynchronization therapy in 14 (1.7%) patients. Mean pacing capture thresholds and sensed R waves were 1.6 V and 5.8 mV, respectively at implant and 2.0 V and 6.1 mV at chronic follow-up. During the median follow up of 3 years (interquartile range = 1-6 years), HBP was free of any complication in 91.6% of patients. In the first 368 patients, HBP was achieved using a deflectable curve delivery system, while in 476 using the fixed curve sheath. A significant difference was found in the thresholds (2.4 ± 1.0 V and 1.7 ± 1.1 V, P < .001, respectively) and complications (11.9% and 4.2%, P < .001, respectively) between the two groups., Conclusions: Permanent HBP was safe and effective during long-term follow-up. The fixed curved delivery sheath offered significantly better electrical parameters and reliability over time. The results of this multicenter study are consistent with recent studies., (© 2019 Wiley Periodicals, Inc.)

Aims: Right bundle branch block (RBBB) typically presents with only delayed right ventricular activation. However, some patients with RBBB develop concomitant delayed left ventricular (LV) activation. Such patients may show a specific electrocardiographic (ECG) pattern resembling RBBB in the precordial leads in association with an insignificant S-wave in lateral limb leads (atypical RBBB). We therefore postulated that the ECG pattern of atypical RBBB might be able to identify a subgroup of patients likely to respond to cardiac resynchronization therapy (CRT). The purpose of this study was to assess the impact of RBBB ECG morphology on CRT response in patients with heart failure (HF)., Methods and Results: We evaluated the echocardiographic clinical response of 66 patients with RBBB treated with CRT and followed up for almost 2 years. The patients were divided electrocardiographically into 2 groups: 31 with typical RBBB and 35 with atypical RBBB. Responders were classified in terms of reduction in LV end-systolic volume index (ESVi) ≥ 15% or reduction in the New York Heart Association (NYHA) Class ≥ 1 or Packer score variation (NYHA response with no HF-related hospitalization events or death). The atypical RBBB group presented a longer LV activation time compared with the typical RBBB group (111.9 ± 17.6 vs. 73.2 ± 15.4 ms; P < 0.001). In the atypical and typical RBBB groups, respectively, 71.4% and 19.4% of patients were ESVi responders (P = 0.001) 74.3% and 32.3% were NYHA responders (P = 0.002); similarly, 71.4% and 29.0% of patients exhibited a 2-year Packer score of 0 (P = 0.002)., Conclusion: Patients with atypical RBBB, which is a pattern highly suggestive of concomitant delayed LV conduction, may show a satisfactory response to CRT.

Purpose: In order to increase the responder rate to CRT, stimulation of the left ventricular (LV) from multiple sites has been suggested as a promising alternative to standard biventricular pacing (BIV). The aim of the study was to compare, in a group of candidates for CRT, the effects of different pacing configurations-BIV, triple ventricular (TRIV) by means of two LV leads, multipoint (MPP), and multipoint plus a second LV lead (MPP + TRIV) pacing-on both hemodynamics and QRS duration., Methods: Fifteen patients (13 male) with permanent AF (mean age 76 ± 7 years; left ventricular ejection fraction 33 ± 7%; 7 with ischemic cardiomyopathy; mean QRS duration 178 ± 25 ms) were selected as candidates for CRT. Two LV leads were positioned in two different branches of the coronary sinus. Acute hemodynamic response was evaluated by means of a RADI pressure wire as the variation in LVdp/dtmax., Results: Per patient, 2.7 ± 0.7 veins and 5.2 ± 1.9 pacing sites were evaluated. From baseline values of 998 ± 186 mmHg/s, BIV, TRIV, MPP, and MPP-TRIV pacing increased LVdp/dtmax to 1200 ± 281 mmHg/s, 1226 ± 284 mmHg/s, 1274 ± 303 mmHg, and 1289 ± 298 mmHg, respectively (p < 0.001). Bonferroni post-hoc analysis showed significantly higher values during all pacing configurations in comparison with the baseline; moreover, higher values were recorded during MPP and MPP + TRIV than at the baseline or during BIV and also during MPP + TRIV than during TRIV. Mean QRS width decreased from 178 ± 25 ms at the baseline to 171 ± 21, 167 ± 20, 168 ± 20, and 164 ± 15 ms, during BIV, TRIV, MPP, and MPP-TRIV, respectively (p < 0.001)., Conclusions: In patients with AF, the acute response to CRT improves as the size of the early activated LV region increases.

The electric signals detected by intracardiac electrodes provide information on the occurrence and timing of myocardial depolarization, but are not generally helpful to characterize the nature and origin of the sensed event. A novel recording technique referred to as intracardiac ECG (iECG) has overcome this limitation. The iECG is a multipolar signal, which combines the input from both atrial and ventricular electrodes of a dual-chamber pacing system in order to assess the global electric activity of the heart. The tracing resembles a surface ECG lead, featuring P, QRS and T waves. The time-course of the waveform representing ventricular depolarization (iQRS) does correspond to the time-course of the surface QRS with any ventricular activation modality. Morphological variants of the iQRS waveform are specifically associated with each activity pattern, which can therefore be diagnosed by evaluation of the iECG tracing. In the event of tachycardia, SVTs with narrow QRS can be distinguished from other arrhythmia forms based upon the preservation of the same iQRS waveform recorded in sinus rhythm. In ventricular capture surveillance, real pacing failure can be reliably discriminated from fusion beats by the analysis of the area delimited by the iQRS signal. Assessing the iQRS waveform correspondence with a reference template could be a way to check the effectiveness of biventricular pacing, and to discriminate myocardial capture alone from additional His bundle recruitment in para-Hisian stimulation. The iECG is not intended as an alternative to conventional intracavitary sensing, which remains the only tool suitable to drive the sensing function of a pacing device. Nevertheless, this new electric signal can add the benefits of morphological data processing, which might have important implications on the quality of the pacing therapy.

Background: Estimating left ventricular electrical delay (Q-LV) from a 12-lead ECG may be important in evaluating cardiac resynchronization therapy (CRT)., Objective: The purpose of this study was to assess the impact of Q-LV interval on ECG configuration., Methods: One hundred ninety-two consecutive patients undergoing CRT implantation were divided electrocardiographically into 3 groups: left bundle branch block (LBBB), right bundle branch block (RBBB), and nonspecific intraventricular conduction delay (IVCD). The IVCD group was further subdivided into 81 patients with left (L)-IVCD and 15 patients with right (R)-IVCD (resembling RBBB, but without S wave in leads I and aVL). The Q-LV interval in the different groups and the relationship between ECG parameters and the maximum Q-LV interval were analyzed., Results: Patients with LBBB presented a long Q-LV interval (147.7 ± 14.6 ms, all exceeding cutoff value of 110 ms), whereas RBBB patients presented a very short Q-LV interval (75.2 ± 16.3 ms, all <110 ms). Patients with an IVCD displayed a wide range of Q-LV intervals. In L-IVCD, mid-QRS notching/slurring showed the strongest correlation with a longer Q-LV interval, followed, in decreasing order, by QRS duration >150 ms and intrinsicoid deflection >60 ms. Isolated mid-QRS notching/slurring predicted Q-LV interval >110 ms in 68% of patients. The R-IVCD group presented an unexpectedly longer Q-LV interval (127.0 ± 12.5 ms; 13/15 patients had Q-LV >110 ms)., Conclusion: Patients with LBBB have a very prolonged Q-LV interval. Mid-QRS notching in lateral leads strongly predicts a longer Q-LV interval in L-IVCD patients. Patients with R-IVCD constitute a subgroup of patients with a long Q-LV interval., (Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Approximately one-third of the patients with heart failure (HF) treated with cardiac resynchronization therapy (CRT) fail to respond. Positioning the left ventricular (LV) pacing lead in the area of the latest electrical delay may improve the response to CRT. Multipoint pacing (MPP) of the LV has been shown to improve the acute hemodynamic response., Objective: The purpose of this study was to test the hypothesis that patients treated with MPP in whom LV pacing location is optimized have better long-term clinical outcomes than do patients treated with conventional CRT., Methods: We evaluated the echocardiographic and clinical response of 110 patients with HF treated for nearly 1 year with either conventional CRT (standard [STD] group, n = 54, 49%), CRT with hemodynamic and electrical optimization of the LV pacing site (optimized [OPT] group, n = 36, 33%), or OPT combined with MPP (OPT + MPP group, n = 20, 18%). Responders were classified in terms of reduction in end-systolic volume index ≥15%, reduction in New York Heart Association (NYHA) class ≥1, and Packer score variation (NYHA response with no HF-related hospitalization events or death)., Results: In STD, OPT, and OPT + MPP groups, 56%, 72%, and 90% of patients, respectively, were end-systolic volume index responders (P = .004) and 67%, 78%, and 95% were NYHA class responders (P = .012); 59%, 67%, and 90% of patients exhibited a 1-year Packer score of 0 (P = .018). These trends remained significant after adjustment for confounding factors by multivariate logistic analysis., Conclusion: Combining MPP with optimal positioning of the LV lead on the basis of electrical delay and hemodynamics enhances reverse remodeling and improves clinical outcomes beyond the effect due to conventional CRT., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)