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.

Acute performance of stylet driven leads for left bundle branch area pacing: A comparison with lumenless leads

Background

Lumenless leads (LLLs) are widely used for left bundle branch area pacing (LBBAP). Recently, stylet-driven leads (SDLs) have also been used for LBBAP.

Objective

The purpose of this study was to evaluate the acute performance of SDLs during LBBAP in comparison with LLLs.

Methods

Consecutive patients undergoing LBBAP for bradycardia or cardiac resynchronization therapy indications at 2 high-volume, early conduction system pacing adopters, tertiary centers were included from January 2019 to July 2023. Patients received either SDLs or LLLs at the discretion of the implanting physician. Acute performance and follow-up data of both lead types were evaluated.

Results

A total of 925 LBBAP implants were included, 655 using LLLs and 270 using SDLs. Overall, LBBAP acute success was significantly higher with LLLs than SDLs (95.3% vs 85.1%, respectively; P <.001) even after the learning curve (97% vs 86%; P = .013). LLLs were implanted in more mid-basal septal positions in comparison with SDLs, which tended to be implanted in more inferior and mid-apical septal positions. Acute lead-related complications were higher with SDLs than LLLs (15.9% vs 6.1%, respectively; P <.001) with 15 cases of lead damage during implant (4.4% vs 0.5%; P <.001) but decreased with acquired experience and were comparable in the last 100 patients included in each group. Lead implant and fluoroscopy times were shorter for SDLs, with lead dislodgment occurring in 0.9% with LLLs and 1.5% with SDLs (P = .489).

Conclusion

Acute lead performance proved to be different between LLLs and SDLs. A specific learning curve should be considered for SDLs even for implanters with extensive previous experience with LLLs.

Conduction System Pacing for Cardiac Resynchronization Therapy

Cardiac resynchronization therapy (CRT) via biventricular pacing (BiVP-CRT) is considered a mainstay treatment for symptomatic heart failure patients with reduced ejection fraction and wide QRS. However, up to one-third of patients receiving BiVP-CRT are considered non-responders to the therapy. Multiple strategies have been proposed to maximize the percentage of CRT responders including two new physiological pacing modalities that have emerged in recent years: His bundle pacing (HBP) and left bundle branch area pacing (LBBAP). Both pacing techniques aim at restoring the normal electrical activation of the ventricles through the native conduction system in opposition to the cell-to-cell activation of conventional right ventricular myocardial pacing. Conduction system pacing (CSP), including both HBP and LBBAP, appears to be a promising pacing modality for delivering CRT and has proven to be safe and feasible in this particular setting. This article will review the current state of the art of CSP-based CRT, its limitations, and future directions.

Response rate in cardiac resynchronization therapy patients implanted with a left ventricular quadripolar lead and the MultiPoint™ pacing feature early activated. QUARTO III

BACKGROUND

Although cardiac resynchronization therapy (CRT) is beneficial in most heart failure patients, up to 40% do not respond to CRT. It has been suggested that multipoint left ventricle pacing (MPP) would increase the response rate.

AIM

To assess the CRT response rate at 6 months in patients implanted with a CRT device with the MPP feature activated early after the implant.

METHODS

This was a multicentre, prospective, open-label and non-randomized study. The primary endpoint was response to biventricular pacing defined as >15% relative reduction in left ventricular end-systolic volume (LVESV) comparing echocardiography measurements performed at baseline and 6 months by a core laboratory. Among secondary endpoints the combined endpoint of mortality or all-cause hospitalizations was evaluated. Primary study endpoint and clinical outcomes were compared to a Quarto II control cohort.

RESULTS

Totally, 105 patients were included. The response rate was 64.6% (97.5% lower confidence bound 53%). Mean relative reduction in LVESV was 25.3%, and mean absolute increase in LVEF was 9.4%. The subjects with device programmed using anatomical approach showed a trend towards higher responder rate than those using the electrical approach (72% vs. 61.1%, p = 0.32). Finally, the combined incidence of mortality and or all-cause hospitalizations at 6 month was 12.4%.

CONCLUSIONS

Early activation of MPP was not associated to an advantage increasing echocardiography responders to CRT at 6 months of follow-up. Nevertheless, patients programmed using widest pacing cathodes had a numerically higher responder rate. Finally, early activation of MPP was associated to a low incidence of clinical endpoints at 6 months of follow-up.

Outcomes of leadless pacemaker implantation in patients with mechanical heart valves

Introduction

Device-related infections constitute a major complication of transvenous pacemaker implantation. Mechanical heart valves (MHV) increase the risk of infective endocarditis (IE) and pacemaker infection, worsening their outcomes.Leadless pacemakers (LP) have been associated with low infection rates and thus pose an attractive option in MHV patients requiring permanent pacing.

Methods and results

This is a multicenter, observational, retrospective study including all consecutive patients implanted with an LP at 5 tertiary referral centers between June 2015 and January 2020.Procedural outcomes, complications, performance during follow-up and episodes of bacteremia and IE were recorded and compared between patients with and without a MHV (MHV and non-MHV groups).Four hundred fifty-nine patients were included (74 in the MHV group, 16.1%, and 385 in the non-MHV group, 83.9%).Implantation success, procedural outcomes and acute electrical performance were comparable between groups.Vascular complications and cardiac perforation occurred in 2.7 vs. 2.3% (p=1) and 0% vs. 0.8% (p=1) in the MHV group and non-MHV group, respectively.During a median post-implant follow-up of 308 days for the MHV group and 416 days for non-MHV patients (p=0.029), one case of IE was reported in the MHV group and 2 in the non-MHV group. All three occurred in patients with abandoned transvenous leads.

Conclusion

LP implantation is feasible and safe in patients with MHV, with procedural outcomes and electrical performance comparable to the general LP population. Device-related infections, including IE, are rare in patients receiving an LP, including those with an MHV. LP implantation should be considered in MHV patients with an indication for pacing.

Funding Acknowledgement

Type of funding sources: None. Procedural outcomes and complicationsBaseline and follow-up parameters

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.

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.

Análisis de las publicaciones españolas sobre Documentación e Informática Médica

Se estudia la producción española de documentación e información médicas, en sus distintas áreas de especialización, hasta el año 1991. Se analiza el crecimiento de la producción de los diferentes tipos de documentos sobre la disciplina, así como las materias, instituciones de procedencia y distribución geográfica . Los resultados muestran la gran dispersión de los trabajos sobre el tema y el predominio de los estudios dedicados a la documentación clínica, producidos en instituciones hospitalarias.

Short-Time Estimation of Fractionation in Atrial Fibrillation with Coarse-Grained Correlation Dimension for Mapping the Atrial Substrate

Atrial fibrillation (AF) is currently the most common cardiac arrhythmia, with catheter ablation (CA) of the pulmonary veins (PV) being its first line therapy. Ablation of complex fractionated atrial electrograms (CFAEs) outside the PVs has demonstrated improved long-term results, but their identification requires a reliable electrogram (EGM) fractionation estimator. This study proposes a technique aimed to assist CA procedures under real-time settings. The method has been tested on three groups of recordings: Group 1 consisted of 24 highly representative EGMs, eight of each belonging to a different AF Type. Group 2 contained the entire dataset of 119 EGMs, whereas Group 3 contained 20 pseudo-real EGMs of the special Type IV AF. Coarse-grained correlation dimension (CGCD) was computed at epochs of 1 s duration, obtaining a classification accuracy of 100% in Group 1 and 84.0–85.7% in Group 2, using 10-fold cross-validation. The receiver operating characteristics (ROC) analysis for highly fractionated EGMs, showed 100% specificity and sensitivity in Group 1 and 87.5% specificity and 93.6% sensitivity in Group 2. In addition, 100% of the pseudo-real EGMs were correctly identified as Type IV AF. This method can consistently express the fractionation level of AF EGMs and provides better performance than previous works. Its ability to compute fractionation in short-time can agilely detect sudden changes of AF Types and could be used for mapping the atrial substrate, thus assisting CA procedures under real-time settings for atrial substrate modification.

Usefulness of Sodium Bicarbonate for the Prevention of Contrast-Induced Nephropathy in Patients Undergoing Cardiac Resynchronization Therapy

The use of contrast media during cardiac resynchronization therapy (CRT) devices implantation is associated with the risk of contrast-induced nephropathy (CIN). The aim of this study was to evaluate the possible beneficial role of periprocedural intravenous volume expansion with isotonic saline and sodium bicarbonate solution in patients who undergo CRT implantation. Eligible patients were randomly assigned in a 1:1 ratio to receive hydration plus one-sixth molar sodium bicarbonate (study group) or not (control group). Primary end point was CIN incidence. Secondary end points were (1) a combined end point of death, heart transplantation, or hospitalization for heart failure at 12 months, (2) incidence of death, and (3) the need for renal replacement therapy at 12 months. Final analysis was performed with 93 patients. In the hydration group CIN incidence was significantly reduced related to control group (0% vs 11%, p = 0.02). There was a trend to reduce the combined end point in hydration group (12.5% vs 22%, p = 0.14). Finally, CIN incidence was related to a higher 12 months mortality (25% vs 7%, p = 0.03). In conclusion, CIN incidence was 11% in a nonselected population of patients receiving a CRT device. CIN appearance could be reduced by using a hydration protocol based on sodium bicarbonate and isotonic saline.

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.

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.

Nonfluoroscopic Catheter Ablation. Results From a Prospective Multicenter Registry

INTRODUCTION AND OBJECTIVES

Nonfluoroscopic catheter ablation is feasible in most procedures. The aim of our registry was to evaluate the safety and feasibility of a zero-fluoroscopic approach to catheter ablation in several Spanish centers.

METHODS

Eleven centers prospectively included a minimum of 20 patients. Patients with an arrhythmic substrate deemed suitable by the operator for a zero-fluoroscopic approach throughout the procedure were recruited. Patients with intracardiac devices were not included. Attending electrophysiologists, fellows, and resident physicians participated in each procedure, as in usual care.

RESULTS

The study included 247 patients. Ablation was performed in 235 patients (95.2%). In 2 patients, who were not included in the analysis, fluoroscopy was performed as the first-line treatment. The arrhythmic substrate was located in the right chambers in most of the procedures (231 of 233 [99.15%]). Fluoroscopy was used in 24 procedures (10.3%). Catheter ablation was successful in 96.4% of the procedures and severe complications occurred in 2 patients (0.85%). Two variables were related to the need for fluoroscopy: the performing center (minimum 0% vs maximum 30.3%; P=.001) and procedural failure (13% vs 2.4%; P<.05).

CONCLUSIONS

The Spanish multicenter registry reveals that a zero-fluoroscopic approach is feasible in most right-sided catheter ablation procedures. Randomized trials are necessary to confirm the safety of this approach. The need for fluoroscopy was related to procedural failure, with significant differences among performing centers.

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.

Safety and Feasibility of a Minimally Fluoroscopic Approach for Ventricular Tachycardia Ablation in Patients With Structural Heart Disease: Influence of the Ventricular Tachycardia Substrate

BACKGROUND

We sought to evaluate the safety and feasibility of a minimally fluoroscopic approach using the CARTOUNIVU module during scar-related ventricular tachycardia (VT) ablation.

METHODS AND RESULTS

Consecutive patients with structural heart disease undergoing VT ablation using the CARTOUNIVU module were prospectively included and classified depending on their VT substrate: (1) ischemic VT (IVT) and (2) nonischemic VT and depending on the presence of an epicardial access. Radiation exposure parameters and major and minor procedure-related complications were registered. A near-zero fluoroscopy exposure was defined as those procedures with an effective dose ≤1 mSv. A total of 44 VT ablation procedures were performed in 41 patients (22 IVT and 19 nonischemic VT). The use of the CARTOUNIVU module resulted in low levels of radiation exposure: median total fluoroscopy time and effective dose of 6.08 (1.51-12.36) minutes and 2.15 (0.58-8.22) mSv, respectively. Patients with IVT had lower radiation exposure than patients with nonischemic VT (total fluoroscopy time, 2.53 [1.22-11.22] versus 8.51 [5.55-17.34] minutes; P=0.016). Epicardial access was associated with significantly higher levels of radiation exposure. Complications occurred in 4.9% patients, none of them being related to the use of the image integration tool. A near-zero fluoroscopy ablation could be performed in 14 of 44 procedures (32%), 43% of IVT procedures, and 50% of procedures with endocardial access only.

CONCLUSIONS

The use of the CARTOUNIVU module during scar-related VT ablation resulted in low levels of radiation exposure. A near-zero fluoroscopy approach can be achieved in up to half of the procedures, especially in IVT patients with endocardial ablation.

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.

Electrical Isolation of Pulmonary Veins Using Laser Catheter in the Treatment of Paroxysmal and Persistent Atrial Fibrillation. One-year Results

INTRODUCTION AND OBJECTIVES

A new laser balloon that allows visualization of atrial tissue has recently been introduced for pulmonary vein electrical isolation. The aim of this study was to evaluate the mid-term safety and efficacy of this catheter in the treatment of atrial fibrillation.

METHODS

Laser balloon ablation was performed in 71 patients with paroxysmal (80%) or persistent (20%) atrial fibrillation. Arrhythmia recurrence was defined as any episode lasting longer than 30 seconds. During follow-up, regular visits were performed every 3 months with 24- to 48-hour Holter tests.

RESULTS

Isolation was possible in 275 of 278 (99%) of pulmonary veins. Mean procedure and fluoroscopy times were 154 ± 25 and 34 ± 15minutes, respectively. A total of 89% of veins were isolated during the first attempt. The most common complication was phrenic nerve paralysis (5.6%), which appeared in only the first 18 cases. A total of 59 patients received follow-up for a mean of 420 ± 193 days, with a rate of arrhythmia recurrence of 12% and 30%, respectively, in paroxysmal and persistent atrial fibrillation (P = .155).

CONCLUSIONS

The laser balloon is a safe and effective system for pulmonary vein electrical isolation. Its advantages include the capacity to adapt to pulmonary vein anatomy using a single catheter, the efficacy with which pulmonary vein electrical isolation is achieved, and the favorable mid-term clinical progress, even for patients with persistent atrial fibrillation.

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.

Failure of the active-fixation mechanism during removal of active-fixation pacing leads

BACKGROUND

 Active-fixation pacing leads are being widely employed due to their theoretical advantages when compared with traditional passive-fixation leads: easy fixation and reposition, possible deployment in alternative pacing sites, lower rates of dislodgment, and chronic removability. However, the behavior of the active-fixation mechanism during lead removal has not been yet systematically studied and may have important clinical implications.

OBJECTIVE

 To evaluate if the active-fixation mechanism was still working properly in pacing leads that were removed due to different causes.

METHODS

 Thirty-one consecutive patients undergoing active-fixation lead removal (40 leads) were studied. Before lead removal, the helix was retracted using the appropriate tool, and fluoroscopy signs were evaluated. After removal, the helix status was examined, and the active-fixation mechanism was once again retested when possible.

RESULTS

 In nine of 40 leads (22.5%), the helix remained extended after lead removal in spite of having applied the number of rotations recommended by the manufacturer with the clip-on tool. There was no linear relationship between lead longevity and the presence of an extended helix after lead removal. However, failure of the active-fixation mechanism was more frequent among leads implanted <1 year before versus >1 year before (OR 6.8, 95% CI 1.1-42.7, P = 0.043). In 38% of patients with failure of the active-fixation mechanism, a previous lead reposition had been attempted before lead removal due to significant pacing threshold rise.

CONCLUSIONS

 In our series, the active-fixation mechanism failed in up to 22.5% of explanted leads. This may have important clinical implications during active-fixation lead removal and reposition.

Nuclear magnetic resonance imaging in patients with cardiac pacing devices

Currently, nuclear magnetic resonance imaging is contraindicated in patients with a pacemaker or implantable cardioverter-defibrillator. This study was carried out because the potential risks in this situation need to be clearly defined. This prospective study evaluated clinical and electrical parameters before and after magnetic resonance imaging was performed in 33 patients (five with implantable cardioverter-defibrillators and 28 with pacemakers). In these patients, magnetic resonance imaging was considered clinically essential. There were no clinical complications. There was a temporary communication failure in two cases, sensing errors during imaging in two cases, and a safety signal was generated in one pacemaker at the maximum magnetic resonance frequency and output level. There were no technical restrictions on imaging nor were there any permanent changes in the performance of the cardiac pacing device.

Morbidity associated with three different antiplatelet regimens in patients undergoing implantation of cardiac rhythm management devices

AIMS

Perioperative management of antiplatelet (AP) therapy in patients undergoing implantation of cardiac rhythm management devices (CRMD) remains an issue of concern that has not been prospectively evaluated in a large series. We sought to describe the morbidity associated with three different AP regimens in this setting.

METHODS AND RESULTS

We conducted a prospective observational study including 849 consecutive patients who were classified in three groups according to the presence of any AP treatment: Group 1 (n= 220): single AP therapy; Group 2 (n= 60): dual AP therapy; and Group 3 (n= 40): oral anticoagulant (OAC) + enoxaparin 'bridging' + AP therapy. Two other groups served as controls: Group 4 (n= 375): no AP or OAC therapy; and Group 5 (n= 154): OAC + enoxaparin 'bridging'. The incidence of pocket haematoma, pocket revisions, hospital stays duration, and unscheduled follow-up visits due to pocket-related complications were compared. Patients on Groups 2, 3 and 5 had significantly higher incidences of pocket haematoma (13.3, 15, and 14.9%, respectively) when compared with Groups 1 and 4 (3.2 and 2.4%, respectively), as well as longer hospital stays and more unscheduled follow-up visits. Of note, only patients on enoxaparin 'bridging' required surgical revision of the pocket. Dual AP therapy (P< 0.001), enoxaparin 'bridging' (P< 0.001) and renal insufficiency (P= 0.02) were independent predictors of pocket haematoma in multivariate analysis.

CONCLUSION

Dual AP therapy and OAC + AP therapy is strongly associated with a significant risk of pocket haematoma, longer hospital stays, and unscheduled follow-up visits. Importantly, surgical revision of the pocket was associated with enoxaparin 'bridging' strategy but was never necessary in patients taking exclusively antiaggregant agents.

Comparison of effectiveness of right ventricular septal pacing versus right ventricular apical pacing

Chronic right ventricular apical pacing (RVAP) has been associated with negative hemodynamic and clinical effects. The aim of the present study was to compare RVAP with right ventricular septal pacing (RVSP) in terms of echocardiographic features and clinical outcomes. A total of 93 patients without structural heart disease and with an indication for a permanent pacemaker were randomly assigned to receive a screw-in lead either in the RV apex (n = 46) or in the RV mid-septum (n = 47). The patients were divided into 3 subgroups according to the percentage of ventricular pacing: control group (n = 21, percentage of ventricular pacing < or =10%), RVAP group (n = 28), or RVSP group (n = 32; both latter groups had a percentage of ventricular pacing >10%). The RVAP group had more intraventricular dyssynchrony and a trend toward a worse left ventricular ejection fraction compared to the RVSP and control groups at 12 months of follow-up (maximal delay to peak systolic velocity between any of the 6 left ventricular basal segments was 57.8 +/- 38.2, 35.5 +/- 20.6, and 36.5 +/- 17.8 ms for RVAP, RVSP, and control group, respectively; p = 0.006; mean left ventricular ejection fraction 62.9 +/- 7.9%, 66.5 +/- 7.2%, and 66.6 +/- 7.2%, respectively, p = 0.14). Up to 48.1% of the RVAP patients showed significant intraventricular dyssynchrony compared to 19.4% of the RVSP patients and 23.8% of the controls (p = 0.04). However, no overt clinical benefits from RVSP were found. In conclusion, RVAP was associated with increased dyssynchrony compared to the RVSP and control patients. RVSP could represent an alternative pacing site in selected patients to reduce the harmful effects of traditional RVAP.