BACKGROUND: Conduction system pacing (CSP), including both left bundle branch area pacing (LBBAP) and His-bundle pacing (HBP) has been proposed as an alternative therapy option for patients with indication for cardiac pacing to treat bradycardia or heart failure. OBJECTIVE: The purpose of this study was to evaluate implant success, safety, and electrical performances of HBP and LBBAP in the multinational Physiological Pacing Registry. METHODS: The international prospective observational registry included 44 sites from 16 countries globally between November 2018 and May 2021. RESULTS: Of 870 subjects enrolled, CSP lead implantation was attempted in 849 patients. Subjects with successful CSP lead implantation were followed for 6 months (5 ± 2 months). CSP lead implantation was successful in 768 patients (90.4%). Implant success was 95.2% (239/251) for LBBAP and 88.5% (529/598) for HBP (P = .002). Procedural duration and fluoroscopy duration were comparable between LBBAP and HBP (P = .537). Capture threshold at implant was 0.69 ± 0.39 V at 0.46 ± 0.15 ms in LBBAP and 1.44 ± 1.03 V at 0.71 ± 0.33 ms in HBP (P <.001). Capture threshold at 6 months was 0.79 ± 0.33 V at 0.44 ± 0.13 ms in LBBAP and 1.59 ± 0.97 V at 0.67 ± 0.31 ms in HBP (P <.001). Pacing threshold rise ≥1 V was observed at 6 months in 3 of 208 (1.4%) of LBBAP and 55 of 418 (13.2%) of HBP (P <.001). Serious adverse events related to implant procedure or CSP lead occurred in 5 of 251 (2.0%) with LBBAP and 25 of 598 (4.2%) with HBP (P = .115). CONCLUSION: This large prospective multicenter study demonstrates that CSP is technically feasible in most patients with relatively higher implant success and suggests that, with current technology, LBBAP may have better pacing parameters than HBP.

• Klíčová slova
• Cardiac resynchronization therapy, Complications, Conduction system pacing, His-bundle pacing, Left bundle branch area pacing,
• MeSH
• elektrokardiografie metody   MeSH
• Hisův svazek * MeSH
• kardiostimulace umělá * metody   MeSH
• lidé MeSH
• nemoci převodního systému srdečního etiologie   MeSH
• prospektivní studie MeSH
• registrace MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• pozorovací studie MeSH
• práce podpořená grantem MeSH

BACKGROUND: Several studies have shown that unnecessary right ventricular pacing has detrimental effects. OBJECTIVE: To evaluate whether minimization of ventricular pacing as compared with standard dual-chamber pacing (DDD) improves clinical outcomes in patients referred for pacemaker or implantable cardioverter-defibrillator (ICD) replacement. METHODS: In an international single-blind, multicenter, randomized controlled trial, we compared DDD with managed ventricular pacing (MVP), a pacing mode developed to minimize ventricular pacing by promoting intrinsic atrioventricular conduction. We included patients referred for device replacement with >40% ventricular pacing, no cardiac resynchronization therapy upgrade indication, no permanent atrial fibrillation (AF), and no permanent complete atrioventricular block. Follow-up was for 2 years. The primary end point was cardiovascular hospitalization. The intention-to-treat analysis was performed by using Kaplan-Meier method and the log-rank test. RESULTS: We randomized 605 patients (556 referred for pacemaker and 49 referred for ICD replacement; mean age 75 ± 11 years; 365 [60%] men, at 7.7 ± 3.3 years from first device implantation) to MVP (n = 299) or DDD (n = 306). We found no significant differences in the primary end point cardiovascular hospitalization (MVP: 16.3% vs DDD: 14.5%; P = .72) and the secondary end point persistent AF (MVP: 15.4% vs DDD: 11.2%; P = .08), permanent AF (MVP: 4.1% vs DDD: 3.1%; P = .44), and composite of death and cardiovascular hospitalization (MVP: 23.9% vs DDD: 20.2%; P = .48). MVP reduced right ventricular pacing (median 5% vs 86%; Wilcoxon, P < .0001) as compared with DDD. CONCLUSIONS: In patients referred for pacemaker and ICD replacement with clinically well-tolerated long-term exposure to >40% ventricular pacing in the ventricle, a strategy to minimize ventricular pacing is not superior to standard DDD in reducing incidence of cardiovascular hospitalizations.

• Klíčová slova
• Cardiac pacing, Dual-chamber pacing, Managed ventricular pacing, Outcomes, Randomized controlled trial,
• MeSH
• analýza podle původního léčebného záměru MeSH
• defibrilátory implantabilní MeSH
• fibrilace komor terapie   MeSH
• kardiostimulace umělá metody   MeSH
• kardiostimulátor MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• výsledek terapie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• srovnávací studie MeSH

The right ventricular apex has been used as the traditional pacing site since the development of transvenous pacing in 1959. Some studies suggest that pacing the right ventricular apex may cause remodeling and is harmful. In the past decade, there have been a multitude of studies of the hemodynamic, electrophysiological, electrocardiographic, and clinical effects of ventricular pacing at other sites. Pacing of the left ventricle singly or with biventricular pacing has emerged as an effective and safe therapy for moderate to severe congestive heart failure in patients with prolonged QRS complexes. Studies of alternate right ventricular sites, like the right ventricular outflow tract, have given mixed results. Not all patients can be treated with left ventricular pacing, which is a time-consuming and difficult procedure. Right ventricular pacing is easier and less expensive than left ventricular pacing and further study of additional right ventricular sites seems warranted.

• MeSH
• elektrofyziologické techniky kardiologické MeSH
• elektrokardiografie MeSH
• Hisův svazek MeSH
• kardiostimulace umělá metody   MeSH
• lidé MeSH
• srdeční komory MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Biventricular pacing nowadays represents a recognized method of nonpharmacological treatment of severe congestive heart failure refractory to medication. A growing number of biventricular implants is likely to bring an increasing demand for the extraction of specially designed coronary sinus (CS) leads for left ventricular pacing. There is a lot of data regarding conventional pacing or defibrillation lead extractions, but only very limited experience with the CS lead extractions. We describe the pathological-anatomical findings of a woman who died after 26 months postimplantation due to refractory ventricular fibrillation with focus on the left ventricular pacing lead course and feasibility of extraction.

• MeSH
• kardiostimulace umělá metody   MeSH
• koronární cévy * anatomie a histologie   MeSH
• lidé MeSH
• senioři MeSH
• srdeční selhání terapie   MeSH
• Check Tag
• lidé MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH

BACKGROUND: Cardiac resynchronization therapy (CRT) with biventricular pacing (BVP) is a well established therapy in patients with reduced left ventricular ejection fraction (LVEF), heart failure, and wide QRS or expected frequent ventricular pacing. Left bundle branch area pacing (LBBAP) has recently been shown to be a safe alternative to BVP. OBJECTIVES: The aim of this study was to compare the clinical outcomes between BVP and LBBAP among patients undergoing CRT. METHODS: This observational study included patients with LVEF ≤35% who underwent BVP or LBBAP for the first time for Class I or II indications for CRT from January 2018 to June 2022 at 15 international centers. The primary outcome was the composite endpoint of time to death or heart failure hospitalization (HFH). Secondary outcomes included endpoints of death, HFH, and echocardiographic changes. RESULTS: A total of 1,778 patients met inclusion criteria: 981 BVP, 797 LBBAP. The mean age was 69 ± 12 years, 32% were female, 48% had coronary artery disease, and mean LVEF was 27% ± 6%. Paced QRS duration in LBBAP was significantly narrower than baseline (128 ± 19 ms vs 161 ± 28 ms; P < 0.001) and significantly narrower compared to BVP (144 ± 23 ms; P < 0.001). Following CRT, LVEF improved from 27% ± 6% to 41% ± 13% (P < 0.001) with LBBAP compared with an increase from 27% ± 7% to 37% ± 12% (P < 0.001) with BVP, with significantly greater change from baseline with LBBAP (13% ± 12% vs 10% ± 12%; P < 0.001). On multivariable regression analysis, the primary outcome was significantly reduced with LBBAP compared with BVP (20.8% vs 28%; HR: 1.495; 95% CI: 1.213-1.842; P < 0.001). CONCLUSIONS: LBBAP improved clinical outcomes compared with BVP in patients with CRT indications and may be a reasonable alternative to BVP.

• Klíčová slova
• biventricular pacing, cardiac resynchronization therapy, heart failure hospitalization, left bundle branch area pacing, mortality,
• MeSH
• elektrokardiografie MeSH
• funkce levé komory srdeční MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• srdeční resynchronizační terapie * MeSH
• srdeční selhání * terapie   MeSH
• tepový objem MeSH
• výsledek terapie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH

BACKGROUND: Cardiac resynchronization therapy (CRT) using biventricular pacing (BVP) is effective in patients with heart failure, left bundle branch block (LBBB), and reduced left ventricular function. Left bundle branch area pacing (LBBAP) has been reported as an alternative option for CRT. OBJECTIVE: The purpose of this study was to assess the feasibility and outcomes of LBBAP in patients who failed conventional BVP because of coronary venous (CV) lead complications or who were nonresponders to BVP. METHODS: At 16 international centers, LBBAP was attempted in patients with conventional CRT indication who failed BVP because of CV lead complications or lack of therapeutic response to BVP. Heart failure hospitalization (HFH) and death, echocardiographic outcomes, procedural data, pacing parameters, and lead complications including CV lead failure are reported. RESULTS: LBBAP was successfully performed in 200 patients (CV lead failures 156; nonresponders 44) (age 68 ± 11 years; female 35%; LBBB 55%; right ventricular pacing 23%; ischemic cardiomyopathy 28%; nonischemic cardiomyopathy 63%; left ventricular ejection fraction [LVEF] ≤35% in 80%). Procedural duration was 119.5 ± 59.6 minutes, and fluoroscopy duration was 25.7 ± 18.5 minutes. LBBAP threshold and R-wave amplitudes were 0.68 ± 0.35 V @ 0.45 ms and 10.4 ± 5 mV at implant, respectively, and remained stable during mean follow-up of 12 ± 10.1 months. LBBAP resulted in significant QRS narrowing from 170 ± 28 ms to 139 ± 25 ms (P <.001) with V6 R-wave peak times of 85 ± 17 ms. LVEF improved from 29% ± 10% at baseline to 40% ± 12% (P <.001) during follow-up. The risk of death or HFH was lower in those with CV lead failure than in nonresponders (hazard ratio 0.357; 95% confidence interval 0.168-0.756; P = .007) CONCLUSION: LBBAP is a viable alternative to CRT in patients who failed conventional BVP due to CV lead failure or who were nonresponders.

• Klíčová slova
• Biventricular pacing failure, Cardiac resynchronization therapy, Heart failure, Left bundle branch area pacing, Nonresponder,
• MeSH
• blokáda Tawarova raménka diagnóza   etiologie   terapie   MeSH
• elektrokardiografie metody   MeSH
• funkce levé komory srdeční fyziologie   MeSH
• Hisův svazek MeSH
• kardiostimulace umělá metody   MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• srdeční arytmie terapie   MeSH
• srdeční resynchronizační terapie * metody   MeSH
• srdeční selhání * diagnóza   etiologie   terapie   MeSH
• tepový objem MeSH
• výsledek terapie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

INTRODUCTION: Left bundle branch area pacing (LBBAP) comprises pacing at the left ventricular septum (LVSP) or left bundle branch (LBBP). The aim of the present study was to investigate the differences in ventricular electrical heterogeneity between LVSP, LBBP, right ventricular pacing (RVP) and intrinsic conduction with different dyssynchrony measures using the ECG, vectorcardiograpy, ECG belt, and Ultrahigh frequency (UHF-)ECG. METHODS: Thirty-seven patients with a pacemaker indication for bradycardia or cardiac resynchronization therapy underwent LBBAP implantation. ECG, vectorcardiogram, ECG belt and UHF-ECG signals were recorded during RVP, LVSP and LBBP, and intrinsic activation. QRS duration (QRSd) was measured from the ECG, QRS area was calculated from the vectorcardiogram, LV activation time (LVAT) and standard deviation of activation time (SDAT) from ECG belt and electrical dyssynchrony (e-DYS16) from UHF-ECG. RESULTS: Both LVSP and LBBP significantly reduced ventricular electrical heterogeneity as compared to underlying LBBB and RV pacing in terms of QRS area (p < .001), SDAT (p < .001), LVAT (p < .001) and e-DYS16 (p < .001). QRSd was only reduced as compared to RV pacing(p < .001). QRS area was similar during LBBP and normal intrinsic conduction, e-DYS16 was similar during LVSP and normal intrinsic conduction, whereas SDAT was similar for LVSP, LBBP and normal intrinsic conduction. For all these variables there was no significant difference between LVSP and LBBP. CONCLUSION: Both LVSP and LBBP resulted in a more synchronous LV activation than LBBB and RVP. Especially LBBP resulted in levels of LV synchrony comparable to normal intrinsic conduction.

• Klíčová slova
• bradycardia pacing, cardiac resynchronization therapy, conduction system pacing, dyssynchrony, left bundle branch area pacing,
• MeSH
• akční potenciály * MeSH
• blokáda Tawarova raménka patofyziologie   terapie   diagnóza   MeSH
• bradykardie patofyziologie   terapie   diagnóza   MeSH
• časové faktory MeSH
• elektrofyziologické techniky kardiologické MeSH
• elektrokardiografie MeSH
• funkce levé komory srdeční * MeSH
• Hisův svazek * patofyziologie   MeSH
• kardiostimulace umělá * MeSH
• lidé středního věku MeSH
• lidé MeSH
• mezikomorová přepážka * patofyziologie   MeSH
• prediktivní hodnota testů * MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• srdeční frekvence * MeSH
• srdeční resynchronizační terapie MeSH
• vektorkardiografie * metody   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

BACKGROUND: Nonselective His-bundle pacing (nsHBp), nonselective left bundle branch pacing (nsLBBp), and left ventricular septal myocardial pacing (LVSP) are recognized as physiological pacing techniques. OBJECTIVE: The purpose of this study was to compare differences in ventricular depolarization between these techniques using ultra-high-frequency electrocardiography (UHF-ECG). METHODS: In patients with bradycardia, nsHBp, nsLBBp (confirmed concomitant left bundle branch [LBB] and myocardial capture), and LVSP (pacing in left ventricular [LV] septal position without proven LBB capture) were performed. Timings of ventricular activations in precordial leads were displayed using UHF-ECG, and electrical dyssynchrony (e-DYS) was calculated as the difference between the first and last activation. Duration of local depolarization (Vd) was determined as width of the UHF-QRS complex at 50% of its amplitude. RESULTS: In 68 patients, data were collected during nsLBBp (35), LVSP (96), and nsHBp (55). nsLBBp resulted in larger e-DYS than did LVSP and nsHBp [- 24 ms (-28;-19) vs -12 ms (-16;-9) vs 10 ms (7;14), respectively; P <.001]. nsLBBp produced similar values of Vd in leads V5-V8 (36-43 ms vs 38-43 ms; P = NS in all leads) but longer Vd in leads V1-V4 (47-59 ms vs 41-44 ms; P <.05) as nsHBp. LVSP caused prolonged Vd in leads V1-V8 compared to nsHBp and longer Vd in leads V5-V8 compared to nsLBBp (44-51 ms vs 36-43 ms; P <.05) regardless of R-wave peak time in lead V5 or QRS morphology in lead V1 present during LVSP. CONCLUSION: nslbbp preserves physiological LV depolarization but increases interventricular electrical dyssynchrony. LV lateral wall depolarization during LVSP is prolonged, but interventricular synchrony is preserved.

• Klíčová slova
• Depolarization duration, Dyssynchrony, His-bundle pacing, Left bundle branch pacing, Left ventricular septal myocardial pacing, Ultra-high-frequency electrocardiography,
• MeSH
• blokáda Tawarova raménka patofyziologie   terapie   MeSH
• elektrokardiografie metody   MeSH
• funkce levé komory srdeční fyziologie   MeSH
• Hisův svazek patofyziologie   MeSH
• kardiostimulace umělá metody   MeSH
• lidé MeSH
• mezikomorová přepážka patofyziologie   MeSH
• následné studie MeSH
• prospektivní studie MeSH
• senioři MeSH
• srdeční komory patofyziologie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

BACKGROUND: Targets for right-sided conduction system pacing (CSP) include His bundle and right bundle branch. Electrocardiographic patterns, diagnostic criteria, and outcomes of right bundle branch pacing (RBBP) are not known. OBJECTIVE: Our aims were to delineate electrocardiographic and electrophysiological characteristics of RBBP and to compare outcomes between RBBP and His bundle pacing (HBP). METHODS: Patients with confirmed right CSP were divided according to the conduction system potential to QRS complex interval at the pacing lead implantation site. Six hypothesized RBBP criteria as well as pacing parameters, echocardiographic outcomes, and all-cause mortality were analyzed. RESULTS: All analyzed criteria discriminated between HBP and RBBP: double QRS complex transition during the threshold test, selective paced QRS complex different from conducted QRS complex, stimulus to selective-QRS complex > potential-QRS complex, small increase in V6 R-wave peak time (V6RWPT) during QRS complex transition, equal capture thresholds of CSP and myocardium, and stimulus-V6RWPT > potential-V6RWPT (adopted as the diagnostic standard). According to the last criterion, RBBP was observed in 19.2% of patients (64 of 326) who had been targeted for HBP, present mainly among patients with potential to QRS complex interval <35 ms (90.6% [48 of 53]) and occasionally among the remaining patients (5.6% [16 of 273]). RBBP was characterized by longer QRS complex (by 10.5 ms), longer V6RWPT (by 11.6 ms), and better sensing (by 2.6 mV) compared with HBP. During a median follow-up duration of 29 months, no differences in capture threshold, echocardiographic outcomes, or mortality were found. CONCLUSION: RBBP has distinct features that separate it from HBP and is observed in approximately a fifth of patients in whom HBP is intended.

• Klíčová slova
• Capture criteria, Conduction system pacing, ECG, His bundle pacing, Right bundle branch pacing,
• MeSH
• echokardiografie MeSH
• elektrokardiografie MeSH
• Hisův svazek MeSH
• kardiostimulace umělá * MeSH
• lidé MeSH
• nemoci převodního systému srdečního MeSH
• převodní systém srdeční * MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Adoption and outcomes for conduction system pacing (CSP), which includes His bundle pacing (HBP) or left bundle branch area pacing (LBBAP), in real-world settings are incompletely understood. We sought to describe real-world adoption of CSP lead implantation and subsequent outcomes. METHODS: We performed an online cross-sectional survey on the implantation and outcomes associated with CSP, between November 15, 2020, and February 15, 2021. We described survey responses and reported HBP and LBBAP outcomes for bradycardia pacing and cardiac resynchronization CRT indications, separately. RESULTS: The analysis cohort included 140 institutions, located on 5 continents, who contributed data to the worldwide survey on CSP. Of these, 127 institutions (90.7%) reported experience implanting CSP leads. CSP and overall device implantation volumes were reported by 84 institutions. In 2019, the median proportion of device implants with CSP, HBP, and/or LBBAP leads attempted were 4.4% (interquartile range [IQR], 1.9-12.5%; range, 0.4-100%), 3.3% (IQR, 1.3-7.1%; range, 0.2-87.0%), and 2.5% (IQR, 0.5-24.0%; range, 0.1-55.6%), respectively. For bradycardia pacing indications, HBP leads, as compared to LBBAP leads, had higher reported implant threshold (median [IQR]: 1.5 V [1.3-2.0 V] vs 0.8 V [0.6-1.0 V], p = 0.0008) and lower ventricular sensing (median [IQR]: 4.0 mV [3.0-5.0 mV] vs. 10.0 mV [7.0-12.0 mV], p < 0.0001). CONCLUSION: In conclusion, CSP lead implantation has been broadly adopted but has yet to become the default approach at most surveyed institutions. As the indications and data for CSP continue to evolve, strategies to educate and promote CSP lead implantation at institutions without CSP lead implantation experience would be necessary.

• Klíčová slova
• Conduction system pacing, His bundle pacing, Left bundle branch area pacing,
• MeSH
• bradykardie * terapie   MeSH
• elektrokardiografie MeSH
• Hisův svazek * MeSH
• kardiostimulace umělá MeSH
• lidé MeSH
• nemoci převodního systému srdečního MeSH
• převodní systém srdeční MeSH
• průřezové studie MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH