Upgrade from leadless to transvenous pacemaker with left bundle branch area pacing: A case report.

An 80-years-old patient with permanent atrial fibrillation and symptomatic, paroxysmal atrioventricular blocks (AVBs) underwent leadless pacemaker (L-PM) implantation. Seven years after implantation, as a consequence of a progression of the AVB towards a persistent form, resulting in an increased need for pacing, he developed a pacing-induced cardiomyopathy. He then underwent a successful upgrade from L-PM to a transvenous pacemaker (T-PM) with left bundle branch area pacing (LBBAP). The L-PM did not interfere with the T-PM and was turned off and abandoned. One month after the upgrading the patient showed a significant improvement in cardiac function and functional capacity.

Possible systolic fascicular potentials in patients with left bundle branch block undergoing left bundle branch area pacing: A case series.

INTRODUCTION: In left bundle branch area pacing (LBBAP), several methods allow determination of lead depth during active fixation inside the septum: among these, visualization of a Purkinje potential indicates that the subendocardial area has been reached. In LBB block (LBBB) patients, fascicular potentials are visible as presystolic only in rare conditions. METHODS AND RESULTS: Since October 2022 until August 2023, LBBAP was attempted in 21 patients with LBBB at our Center: among the 18 consecutive patients (86%) in which it was successful, focusing on the terminal part of the unipolar ventricular electrogram (VEGM) recorded in the LBBA (where fixation beats occurred and conduction system (CS) capture was confirmed), we always observed discrete high-frequency, low-amplitude signals during spontaneous rhythm with LBBB morphology, showing a consistent coupling with the QRS onset, falling in a portion of QRS interval ranging from 58% to 80% of its overall duration, and disappearing during pacing. As found in a recently published case report, these sharp signals could represent the activation of left ventricular CS fibers, occurring passively from the septal working myocardium, and thus appearing lately in the VEGM. CONCLUSION: The possibility of recognizing discrete high-frequency, low-amplitude signals within the terminal portion of the unipolar VEGM, possibly representing left CS potentials, even in patients with LBBB, may constitute a useful additional means to notice operators about having reached the LBBA, thus helping to avoid perforation in the left ventricle.

Optimization of the atrioventricular delay in conduction system pacing.

INTRODUCTION: In patients receiving conduction system pacing (CSP), it is not well established how to program the sensed atrioventricular delay (sAVD), with respect to the type of capture obtained (selective, nonselective His-bundle [HB] capture or left bundle branch [LBB] capture). The aim of this study was to acutely assess the effectiveness of an electrophysiology (EP)-guided method for sAVD optimization by comparing it with the echocardiogram-guided optimization. METHODS AND RESULTS: Consecutive patients undergoing HB or LBB pacing were enrolled. The EP-guided sAVD was defined as the sAVD leading to a PR interval of 150 ms on surface electrocardiogram (ECG). In HB pacing patients, EP-guided sAVD was obtained subtracting the time from the onset of the P wave on ECG to the local atrial electrogram (EGM) recorded by the atrial lead (right atrial sensing latency, RASL) and the His-ventricular interval from 150 ms; in LBB pacing patients, subtracting RASL from 150 ms. Transmitral flow assessment by pulsed wave Doppler was used to find the echo-optimized sAVD by a modified iterative method. The discordance between the EP-guided and the echo-optimized sAVD was recorded. RESULTS: Seventy-one patients were enrolled: 12 with selective, 32 nonselective HB capture, and 27 LBB capture. Overall, the rate of concordance between the EP-guided and the echo-optimized sAVD was 71.8%, with no significant differences between the three groups. CONCLUSION: In CSP patients, an optimal sAVD can be programmed, in more than 70% of cases, considering only simple EGM intervals to obtain a physiological PR interval on surface ECG.

The PhysioVP-AF study, a randomized controlled trial to assess the clinical benefit of physiological ventricular pacing vs. managed ventricular pacing for persistent atrial fibrillation prevention in patients with prolonged atrioventricular conduction: design and rationale.

AIMS: In patients with prolonged atrioventricular (AV) conduction and pacemaker (PM) indication due to sinus node disease (SND) or intermittent AV-block who do not need continuous ventricular pacing (VP), it may be difficult to determine which strategy to adopt. Currently, the standard of care is to minimize unnecessary VP by specific VP avoidance (VPA) algorithms. The superiority of this strategy over standard DDD or DDD rate-responsive (DDD/DDDR) in improving clinical outcomes is controversial, probably owing to the prolongation of the atrialventricular conduction (PR interval) caused by the algorithms. Conduction system pacing (CSP) may offer the most physiological-VP approach, providing appropriate AV conduction and preventing pacing-induced dyssynchrony. METHODS AND RESULTS: PhysioVP-AF is a prospective, controlled, randomized, single-blind trial designed to determine whether atrial-synchronized conduction system pacing (DDD-CSP) is superior to standard DDD-VPA pacing in terms of 3-year reduction of persistent-AF occurrence. Cardiovascular hospitalization, quality-of-life, and safety will be evaluated. Patients with indication for permanent DDD pacing for SND or intermittent AV-block and prolonged AV conduction (PR interval > 180 ms) will be randomized (1:1 ratio) to DDD-VPA (VPA-algorithms ON, septal/apex position) or to DDD-CSP (His bundle or left bundle branch area pacing, AV-delay setting to control PR interval, VPA-algorithms OFF). Approximately 400 patients will be randomized in 24 months in 13 Italian centres. CONCLUSION: The PhysioVP-AF study will provide an essential contribution to patient management with prolonged AV conduction and PM indication for sinus nodal disease or paroxysmal 2nd-degree AV-block by determining whether CSP combined with a controlled PR interval is superior to standard management that minimizes unnecessary VP in terms of reducing clinical outcomes.

Superior approach from the pocket for atrioventricular junction ablation performed at the time of conduction system pacing implantation.

BACKGROUND: Conduction system pacing (CSP) and atrioventricular junction ablation (AVJA) improve outcomes in patients with symptomatic, refractory atrial fibrillation (AF). Superior approach (SA) from the pocket via axillary or subclavian vein has been proposed as an alternative to the conventional femoral venous access (FA) to perform AVJA. OBJECTIVE: To assess the feasibility and safety of SA for AVJA performed simultaneously with CSP, and to compare this approach with FA. METHODS: A prospective, observational study, enrolling consecutive patients with symptomatic, refractory AF undergoing simultaneous CSP and AVJA. RESULTS: A total of 107 patients were enrolled: in 50, AVJA was primarily attempted with SA, in 69 from FA. AVJA with SA was successful in 38 patients (76.0%), while in 12 patients, a subsequent FA was required. AVJA from FA was successful in 68 patients (98.5%), while in one patient, a left-sided approach via femoral artery was required. Compared with FA, SA was associated with a significantly longer duration of ablation (238.0 ± 218.2 vs. 161.9 ± 181.9 s; p = .035), a significantly shorter procedure time (28.1 ± 19.8 vs. 19.8 ± 16.8 min; p = .018), an earlier ambulation (2.7 ± 3.2 vs. 19.8 ± 0.1 h; p < .001), and an earlier discharge from procedure completion (24.0 ± 2.7 vs. 27.1 ± 5.1 h; p < .001). After a median follow-up of 12 months, the rate of complications was similar in the two groups (2.0% in SA, 4.3% in FA; p = .483). CONCLUSION: Simultaneous CSP and AVJA with SA is feasible, with a safety profile similar to FA. Compared to FA, this approach reduces the procedure times and allows earlier ambulation and discharge.

Left bundle branch pacing versus biventricular pacing for cardiac resynchronization therapy: A systematic review and meta-analysis.

INTRODUCTION: Cardiac resynchronization therapy (CRT) reduces heart failure (HF) hospitalization and all-cause mortality in HF patients with left bundle branch block (LBBB). Biventricular pacing (BVP) is the gold standard for achieving CRT, but about 30%-40% of patients do not respond to BVP-CRT. Recent studies showed that left bundle branch pacing (LBBP) provided remarkable results in CRT. Therefore, we conducted a meta-analysis aiming to compare LBBP-CRT versus BVP-CRT in HF patients. METHODS: We systematically searched the electronic databases for studies published from inception to December 29, 2022 and focusing on LBBP-CRT versus BVP-CRT in HF patients. The primary endpoint was HF hospitalization. The effect size was estimated using a random-effect model as Risk Ratio (RR) and mean difference (MD). RESULTS: Ten studies enrolling 1063 patients met the inclusion criteria. Compared to BVP-CRT, LBBP-CRT led to significant reduction in HF hospitalization [7.9% vs.14.5%; RR: 0.60 (95%CI: 0.39-0.93); p = .02], QRSd [MD: 30.26 ms (95%CI: 26.68-33.84); p < .00001] and pacing threshold [MD: -0.60 (95%CI: -0.71 to -0.48); p < .00001] at follow up. Furthermore, LBBP-CRT improved LVEF [MD: 5.78% (95%CI: 4.78-6.77); p < .00001], the rate of responder [88.5% vs.72.5%; RR: 1.19 (95%CI: 1.07-1.32); p = .002] and super-responder [60.8% vs. 36.5%; RR: 1.56 (95%CI: 1.27-1.91); p < .0001] patients and the NYHA class [MD: -0.42 (95%CI: -0.71 to -0.14); p < .00001] compared to BVP-CRT. CONCLUSION: In HF patients, LBBP-CRT was superior to BVP-CRT in reducing HF hospitalization. Further significant benefits occurred within the LBBP-CRT group in terms of QRSd, LVEF, pacing thresholds, NYHA class and the rate of responder and super-responder patients.

High power short duration versus low power long duration ablation in patients with atrial fibrillation: A meta-analysis of randomized trials.

BACKGROUND: High-power-short-duration (HPSD) radiofrequency (RF) ablation is a viable alternative to low-power-long-duration (LPLD) RF for pulmonary vein isolation (PVI). Nevertheless, trials showed conflicting results regarding atrial fibrillation (AF) recurrences and few data concerning complications. Therefore, we conducted a meta-analysis of randomized trials comparing HPSD versus LPLD. METHODS: We systematically searched the electronic databases for studies published from inception to March 31, 2023 focusing on HPSD versus LPLD. The study endpoints were AF recurrence, procedural times and overall complications. RESULTS: Five studies enrolling 424 patients met the inclusion criteria (mean age 61.1 years; 54.3% paroxysmal AF; mean LVEF 58.2%). Compared to LPLD, HPSD showed a significantly lower AF recurrence rate [16.3% vs. 30,1%; RR: 0.54 (95% CI: 0.38-0.79); p = 0.001] at a mean 10.9 months follow-up. Moreover, HPSD led to a significant reduction in total procedural time [MD: -26.25 min (95%CI: -42.89 to -9.61); p = 0.002], PVI time [MD: -26.44 min (95%CI: -38.32 to -14.55); p < 0.0001], RF application time [MD: -8.69 min (95%CI: -11.37 to -6.01); p < 0.00001] and RF lesion number [MD: -7.60 (95%CI: -10.15 to -5.05); p < 0.00001]. No difference was found in either right [80.4% vs. 78.2%; RR: 1.04 (95% CI: 0.81-1.32); p = 0.77] or left [92.3% vs. 90.2%; RR: 1.02 (95% CI: 0.94-1.11); p = 0.58] first-pass isolation and overall complications [6% vs. 3.7%; RR: 1.45 (95%CI: 0.53-3.99); p = 0.47] between groups. CONCLUSION: In our metanalysis of randomized trials, HPSD ablation appeared to be associated to a significantly improved freedom from AF and shorter procedures, without increasing the risk of complications.

Ablate and pace: Comparison of outcomes between conduction system pacing and biventricular pacing.

BACKGROUND: Conduction system pacing (CSP), including His-bundle pacing (HBP) and left bundle branch area pacing (LBBAP), have been proposed as alternatives to biventricular pacing (BVP) in patients scheduled for ablate and pace (A&P) strategy. The aim of this study was to compare the clinical outcomes, including the rate and nature of device-related complications, between BVP and CSP in a cohort of patients undergoing A&P. METHODS: Prospective, multicenter, observational study, enrolling consecutive patients undergoing A&P. The risk of device-related complications and of heart failure (HF) hospitalization was prospectively assessed. RESULTS: A total of 373 patients (75.3 ± 8.7 years, 53.9% male, 68.9% with NYHA class ≥III) were enrolled: 263 with BVP, 68 with HBP, and 42 with LBBAP. Baseline characteristics of the three groups were similar. Compared to BVP and HBP, LBBAP was associated with the shortest mean procedural and fluoroscopy times and with the lowest acute capture thresholds (all p < .05). At 12-month follow-up LBBAP maintained the lowest capture thresholds and showed the longest estimated residual battery longevity (all p < .05). At 12-months follow-up the three study groups showed a similar risk of device-related complications (5.7%, 4.4%, and 2.4% for BVP, HBP, and LBBAP, respectively; p = .650), and of HF hospitalization (2.7%, 1.5%, and 2.4% for BVP, HBP, and LBBAP, respectively; p = .850). CONCLUSIONS: In the setting of A&P, CSP is a feasible pacing modality, with a midterm safety profile comparable to BVP. LBBAP offers the advantage of reducing procedural times and obtaining lower and stable capture thresholds, with a positive impact on the device longevity.

Impact of atrioventricular junction ablation and CRT-D on long-term mortality in patients with left ventricular dysfunction, permanent, refractory atrial fibrillation, and narrow QRS: Results of a propensity-matched analysis.

INTRODUCTION: In patients with symptomatic permanent atrial fibrillation (PEAF) and narrow QRS, atrio-ventricular junction ablation (AVJA) plus cardiac resynchronization therapy (CRT) is superior to medical therapy in reducing heart failure (HF) hospitalization and all-cause mortality. To compare the mortality of a population of patients with HF, reduced EF (rEF), and PEAF treated with AVJA plus CRT with that of a contemporary cohort of patients in sinus rhythm (SR) with similar baseline characteristics. METHODS AND RESULTS: In this prospective, multicentre, observational study, all-cause mortality in a group of consecutive patients undergoing AVJA and implantable cardioverter-defibrillator (ICD) combined with CRT implantation for HFrEF, narrow QRS, and PEAF with uncontrolled ventricular rate was compared with that of a contemporary cohort of patients in SR undergoing ICD implantation (not combined with CRT) for HFrEF and narrow QRS. Individual 1:1 propensity matching of baseline characteristics was performed. A total of 824 patients were enrolled. Propensity matching yielded 107 matched pairs. After a median follow-up of 52 months, all-cause mortality was similar in patients treated with AVJA plus CRT and in the control group (p = .434). In AVJA plus CRT patients, mortality was significantly lower than in control group patients with a history of paroxysmal/persistent AF (n = 45, p = .020), and similar to that of patients without a history of AF (n = 62, p = .459). CONCLUSIONS: After adjustment for patient characteristics, the long-term prognosis of patients with HFrEF, narrow QRS, and PEAF who underwent AVJA plus CRT was similar to that of a population of patients in SR with similar characteristics.

Is His-optimized superior to conventional cardiac resynchronization therapy in improving heart failure? Results from a propensity-matched study.

BACKGROUND: His bundle pacing (HBP), alone or optimized in association with coronary sinus pacing (HBP+LV) has recently been proposed as an alternative to conventional cardiac resynchronization therapy (CRT). However, there is lack of controlled studies that assessed clinical outcome. METHODS: We did a single-center, propensity-score matched, case-control study of comparison of HBP and HBP+LV versus conventional CRT in patients with heart failure (HF) and standard indications for CRT. The study group patients were consecutively enrolled in the year 2019. The control group patients were selected, by propensity score matching, among those CRT implantations performed in the years 2015-2018. RESULTS: There were 27 patients in each group. In the active group, 12 (44%) patients received HBP alone and 12 (44%) patients HBP+LV pacing. HBP failed in three (11%) patients. In the control group, conventional CRT was achieved in 26 (96%) patients and failed in one. Paced QRS width was shorter in the active than in the control group (128 ± 18 vs. 148 ± 27 ms, p = .004). During a mean of 9.6 months of follow-up, a composite clinical outcome of death, hospitalization for HF or worsening HF occurred in three (11%) in the active group and in four (15%) in the control group, p = .58. No difference was also observed with softer endpoints: NYHA class (1.9 ± 0.7 vs. 2.1 ± 0.7), subjective improvement (74% vs. 74%) and LV ejection fraction (40.7% vs. 40.7%). CONCLUSION: Compared with conventional CRT, a shorter QRS width can be obtained with HBP alone or in association with coronary sinus pacing but we were unable to show a better clinical outcome. There is urgent need for large, randomized trials.

Left bundle branch area pacing in a young athlete with progressive cardiac conduction (Lev-Lenegre) disease.

We present the case of a professional soccer player affected by right bundle branch block and symptomatic 2:1 atrio-ventricular block during effort, due to progressive cardiac conduction disease (Lev-Lenegre disease), who received successful left bundle branch area pacing after a failed attempt at His bundle pacing. The electrocardiographic outcome of paced QRS was consistent with a rapid electrical activation of the left ventricle through the Purkinje system. The pursue of physiological pacing was preferred over conventional, given the young age of our patient and the expectedly high burden of stimulation, to reduce the long-term risk of pacing-induced cardiomyopathy.

The relationship between anatomy and electrical parameters in His bundle pacing: A transthoracic echocardiography evaluation.

PURPOSE: The implantation site of the His bundle (HB) lead may influence pacing parameters. Our aim was to characterize the anatomical location of the HB lead tip and its relationship with acute electrical parameters. METHODS: Consecutive patients who underwent HB lead implantation, guided by standard fluoroscopy and electrophysiology, were prospectively enrolled. The relationship between HB lead tip and tricuspid valve plane (TVP) was assessed with post-procedure transthoracic echocardiography. RESULTS: Twenty-five patients were studied. In 11 patients (44%), the HB lead tip did not cross the TVP (A group): in 7 cases it was screwed in the right atrium at a mean distance of -6.1 mm from the TVP and, in 4 cases, at the level of the tricuspid annulus. In the remaining 14 patients (56%), the lead tip crossed the TVP (V group): it was screwed in the right ventricle at a mean distance of 9.3 mm from the TVP. A and V groups had comparable HB capture thresholds (1.6 ± 1 V vs 1.7 ± 0.7 V, 1 ms pulse-width; p = 0.66); selective HB capture was significantly more represented in the A group (91% vs 21%; p = 0.001). Significantly higher R-wave amplitudes were seen in the V group (6.7 ± 3 vs 2.5 ± 1.7 mV; p = 0.0004), and they positively correlated with the distance from the TVP (p = 0.0038). Atrial oversensing was never observed. CONCLUSION: In a consecutive cohort of HB pacing recipients, the rate of patients who had an effective HB capture in the atrium was substantial and was characterized by different electrophysiological properties than in the ventricle.

Additional benefits of nonconventional modalities of cardiac resynchronization therapy using His bundle pacing.

INTRODUCTION: Dyssynchrony persists in many patients despite cardiac resynchronization therapy (CRT). Aim of this proof-of-concept study was to achieve better CRT, with a QRS approximating the normal width and axis, by using His bundle pacing (HBP) and nonconventional pacing configurations. METHODS AND RESULTS: In 20 patients with CRT indications, we performed an acute intrapatient comparison between conventional biventricular (CONV) and three nonconventional pacing modalities: HBP alone, His bundle, and coronary sinus pacing (HBP + CS), and HBP + CS plus right ventricular pacing (TRIPLE). Electrical dyssynchrony was assessed by means of QRS width and axis; "quasi-normal" axis meant an R/S ratio ≥ 1 in leads I and V6 and ≤1 in V1. Mechanical dyssynchrony was assessed by speckle tracking echocardiography. QRS width was 153 ± 18 ms on CONV, shortened to 137 ± 16 ms on HBP + CS (P = .001) and to 130 ± 14 ms on TRIPLE (P = .001), while it remained unchanged on HBP (159 ± 32 ms; P = .17). The rate of patients with "quasi-normal" axis was 5% on CONV, and increased to 90% on HBP (P = .0001), to 63% on HBP + CS (P = .001), and to 44% on TRIPLE (P = .02). On radial strain analysis, the time-to-peak difference between anteroseptal and posterolateral segments was 143 ± 116 ms on CONV, shortened to 121 ± 127 ms on HBP (P = .79), to 67 ± 70 ms on HBP + CS (P = .02), and to 76 ± 55 ms on TRIPLE (P = .05). On discharge, HBP was chosen in 15% of patients, HBP + CS in 55%, and TRIPLE in 30%; CONV was never chosen. CONCLUSION: Nonconventional modalities of CRT provide acute additional electrical and mechanical resynchronization. An interpatient variability exists.

The nightmare ECG of a spontaneously aborted sudden cardiac death.

We present the case of a spontaneously aborted sudden cardiac death related to an high-rate ventricular tachycardia in an healthy man with bileaflet mitral valve prolapse. An effective treatment of the patient, with complete suppression of ventricular ectopic activity, was achieved only combining medical therapy, ICD and catheter ablation, thus overcoming the limitations of each approach.

Paucisymptomatic post COVID-19 myocarditis in a young athlete during return to play workflow: possible usefulness of global longitudinal strain analysis.

A young competitive athlete undergoes the diagnostic investigations protocol before returning to competitive practice (return to play protocol) after COVID-19 infection. Despite the paucisymptomatic presentation of COVID-19 infection and the absence of relevant anomalies in standard first-level diagnostic investigations, echocardiographic examination findings especially speckle tracking analysis (global longitudinal strain) along with some clinical aspects suggested further second-level investigations eventually allowing the identification of inflammatory myocardial damage.