Indication For Permanent Pacemaker Research Articles

Electrophysiologic effects of left bundle branch area pacing: comparing left ventricular septal pacing and left bundle branch pacing

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Medtronic Background Left bundle branch area pacing(LBBAP) has been introduced as a more physiological pacing alternative to anti-bradycardia pacing and as an alternative to biventricular pacing in cardiac resynchronization therapy (CRT). LBBAP is the common denominator of left ventricular septal pacing(LVSP) and left bundle branch pacing(LBBP). In LVSP, there is only capture of the myocardium on the left side of the interventricular septum, whereas in LBBP there is additional capture of the left bundle branch(LBB) and subsequent Purkinje fibers. Purpose To investigate the electrophysiological differences between LBBP and LVSP. Methods Patients with a permanent pacemaker indication due to bradycardia or heart failure according to current guidelines were included and underwent LBBAP implantation. At baseline and during implantation, electrical activation parameters were recorded pacing at different sites (Right ventricle, LVSP and LBBP), using the standard 12-lead ECG and the ECG BELT. Electrophysiologic measures included: QRS duration, QRSarea calculated from the vectorcardiogram after conversion from the ECG using the Kors matrix, and standard deviation of activation time(SDAT) measured through the ECG BELT. Both QRS area and SDAT are known markers of ventricular dyssynchrony. Results 28 patients (17 male), with an age of 67±7 yrs underwent LBBAP. 21(75%) had a pacing indication for bradycardia with a baseline narrow QRS and 7(25%) for heart failure with a baseline LBBB. In 17 patients (61%) LBB capture was achieved. The remaining patients were treated with LVSP. In patients with baseline narrow QRS, both LVSP and LBBP showed a significant increase in QRS duration(p<0.001, p<0.001 resp.), without a significant difference in QRS duration between LVSP and LBBP(fig. 1 A). There was no significant difference in SDAT between LVSP and LBBP compared to baseline narrow QRS, and a significant SDAT reduction in patients with underlying LBBB (p=0.005, p<0.001 resp.) Furthermore, there was no significant SDAT difference between LVSP and LBBP(fig. 1 B). LVSP showed a small but significant increase in QRSarea compared to baseline narrow QRS (p=0.011) where LBBP showed no difference compared to baseline narrow QRS. Compared to baseline LBBB both LVSP and LBBP showed a significant QRSarea reduction (p=0.003, p<0.001 resp.). Moreover, there was a small but significant reduction in QRSarea when LBBP was achieved over LVSP(p=0.044) (fig. 1 C). Conclusion LVSP and LBBP showed a similar effect on ventricular synchrony in terms of SDAT, with levels of synchrony comparable to normal physiologic activation. Left bundle branch capture resulted in a small, but significant improvement in QRSarea over LVSP. Fig. 1 Relative changes in QRS duration(A), SDAT (B) and QRS area (C) compared to baseline narrow QRS (bradypacing) and baseline heart failure with LBBB. *p<0.05 compared to baseline, **p<0.05 for bradypacing and heart failure with LBBB combined.

PO-05-022 OUTCOMES FOR POST-TRANSCATHETER AORTIC VALVE REPLACEMENT CONDUCTION ABNORMALITIES WITHOUT CLEAR INDICATION FOR PERMANENT PACING

Patients undergoing transcatheter aortic valve replacement (TAVR) often develop conduction abnormalities in the postprocedural period. While high-grade AV block (HAVB), which includes 3rd degree & 2nd degree type 2 Mobitz AV block, is a clear indication for permanent pacemaker (PPM) implantation, other conduction abnormalities do not have a clear indication for PPM. Outcomes and predictors for subsequent PPM in this population is lacking. To investigate outcomes of non-HAVB conduction abnormalities in the immediate post-TAVR setting. We conducted a single-center retrospective study on patient characteristics and outcomes of patients without PPM who underwent TAVR between June 2020 and March 2022 that developed non-HAVB conduction abnormalities without a clear indication for pacing (Table 1A). All these patients received thirty-day ambulatory event monitoring (AEM) at discharge. A total of a hundred and sixty patients underwent TAVR; thirteen patients outright received a new PPM for HAVB while thirty-six patients developed non-HAVB and were discharged with AEM. Mean age was 79.8 ± 6.1 years, mean ejection fraction (EF) was 62.1 ± 9.1%, mean maximum aortic valve velocity was 3.9 ± 0.5 m/sec, average mean gradient across the valve was 36.8 ± 10.0 mmHg, and mean aortic valve area was 0.76 ± 0.18 cm2 for these patients. Among the patients who developed non-HAVB conduction abnormalities after TAVR, four subsequently required PPM implantation. Pre-existing right bundle branch block (RBBB) was more frequent in the group requiring eventual PPM vs. the group not requiring PPM (Table 1B). There were no statistically significant differences between several electrocardiogram metrics, demographics, and valve measurements, outlined in Table 1B. Details of those who received subsequent PPM can be found in Table 1C. Of patients who developed persistent non-HAVB conduction abnormalities in the immediate post-TAVR setting the incidence of pre-existing RBBB was higher in patients who required eventual permanent pacing versus those who did not require eventual permanent pacing.

Pros and Cons of Left Bundle Branch Pacing: A Single-Center Experience.

Left bundle branch pacing (LBBP) has recently emerged as a promising alternative modality for conduction system pacing. However, limited real-world data exists on the advantages and complications associated with LBBP. We analyzed the Rush conduction system pacing registry on LBBP to assess the success rates and complications associated with LBBP. All patients with an indication for permanent pacemaker or cardiac resynchronization therapy that underwent LBBP for various reasons from June 2018 to April 2020 were included in the analysis. A total of 57 of 59 patients underwent successful LBBP (success rate 97%). The average follow-up duration was 6.2±5 months. The implanted devices included 38 dual-chamber pacemakers, 17 cardiac resynchronization therapy defibrillators, and 2 cardiac resynchronization therapy pacing systems. The most common reason for performing LBBP was a high His-Bundle pacing threshold (n=23) at implant. The mean LBBP capture threshold at implant was 0.62±0.21 V at 0.4 ms which remained stable during follow-up at 0.65±0.68 V at 0.4ms. In 21 patients with cardiomyopathy, there was a significant improvement in left ventricle ejection fraction from 30±11% to 42±15%. A total of 7 lead-related complications (12.3%) were noted in the follow-up period. Three patients (5.3%) required lead revision during the follow-up period. Interventricular septal perforation occurred (as late sequela) after 2 weeks in one patient. LBBP can be achieved with a high success rate and low capture thresholds. Left ventricular dysfunction improved significantly during follow-up. Lead-related complications were relatively common occurring in 12.3% of initially successful implants. Lead revision was required in 3 (5%) of patients.

Delays in Temporary and Permanent Pacemakers: Causes and In-Hospital Outcomes.

BackgroundTemporary pacemakers frequently serve as a bridge to permanent pacemakers, but placement of the latter may be delayed. This study assessed the causes and in-hospital outcomes of patients with delayed placement of permanent pacemakers.MethodsThis retrospective study included all patients admitted to the Emergency Department who underwent temporary transvenous pacing in the Department of Cardiology, Lady Reading Hospital, Peshawar, Pakistan. The duration of hospitalization and the time from temporary to permanent placement were calculated in days. Asystole, infections, cardiac arrest, and death were recorded during the waiting period.ResultsOf the 260 patients who underwent temporary transvenous pacing, 136 (52.3%) were males and 124 (47.7%) were females, with an age range of 46-78 years. Coronary artery disease was prevalent in 34% of the patients. Only 5% of the patients were on arteriovenous (AV) nodal blocking agents, 44% had complete AV block, 22% had sinus node disease, and 14% had slow atrial fibrillation. The cause of high-degree AV block could not be determined in most patients. Most patients with ischemia- and hyperkalemia-induced AV block recovered. AV blocks induced by ischemia and with no known cause were not reversible, with most of these patients receiving permanent pacemakers. Of the 260 patients with high-degree AV block, 165 (63.5%) recovered. The mean waiting time for permanent pacemaker implantation was 8.7 ± 5.4 days. The waiting time was associated with increased infections and adverse hospital course.ConclusionA longer waiting period between permanent pacemaker indication and implantation is dangerous, as it is associated with an increased risk of adverse events such as infections, syncope, asystole, malignant arrhythmias, cardiac arrest, and death.

NOT ALL INFRA-HISIAN BLOCK REQUIRES PERMANENT PACING

Syncope in the setting of infra-hisian block (HVB) is an indication for permanent pacemaker (PPM). However, not all HVB uncovered during electrophysiologic study (EPS) requires a PPM. A 39 year old woman presented with non-prodromal loss of consciousness while driving resulting in an accident.

16-48: Does drug discontinuation in patients treated with temporary pacemaker reduce permanent pacemaker implantation?

Purpose: The presence of symptomatic third-degree or advanced second-degree atrioventricular (AV) block is a class I indication for permanent pacemaker (PPM) implantation. In patients with concomitant use of AV-blocking drugs, the need for PPM is generally based on the response to drug discontinuation. The objective of our study is to identify predictors for PPM implantation after AV-blocking drugs discontinuation in patients with temporary pacemaker (TPM). Methods: 187 consecutive patients who received a TPM between October 2011 and April 2014 were included retrospectively in our study. AV blocking drugs included digoxin and antiarrhythmic agents classes II-IV. In order to evaluate the impact of these drugs on AV block in each patient, the authors developed a score which included both the number of drugs used and its dose (the latter expressed as a percentage of its maximum recommended dose in clinical practice); the higher the score, the higher the impact of the drugs on AV block in each patient. Results: We included 50 patients with TPM in whom AV-blocking drugs were discontinued (median age of 81.5 [interquartile range 11.3] years, 50.0% males). Among patients discharged without PPM (n = 15, 30.0%), 2 required PPM on follow-up (632 [703] days). Patients who needed PPM on follow-up had lower score (27.8 [55.6] vs 167 [100], p = 0.042) and were under fewer AV-blocking drugs (1.0 [0] vs 2.0 [1.0], p = 0,001). Age (p = 0.566), QRS length (p = 0.866), previous syncope (p = 0.200) and the type of AV-blocking drug (amiodarone [p = 1.000], digoxin [p = 0.371], beta-blockers [p = 1.000] and calcium channel antagonists [p = 1.000]) were not associated with the need for PPM on follow-up. Conclusions: The majority of the patients with TPM had a persistent need for pacing despite AV blocking drugs cessation, which suggests that these drugs may expose a preexistent fragility of the conduction system. However, the lower the dose and number of these drugs, the higher the likelihood of the AV block being secondary to underlying weaknesses. Our score might help in decision making for PPM implantation in patients admitted for drug-induced AV block.

Long-term effect of cardiac pacing on sleep-disordered breathing in patients with conventional indications for a permanent pacemaker

BackgroundThe effect of cardiac pacing on sleep-disordered breathing is controversial. We investigated the long-term effect of cardiac pacing on sleep disordered breathing in patients with conventional indications for permanent pacemakers MethodsSubjects comprised 40 patients (29 men; mean age 69±9 years, mean left ventricle ejection fraction 69±8%, and body mass index 23.6±3.5kg/m2) who were diagnosed with indications for permanent pacemakers (sick sinus syndrome in 23 patients, atrioventricular block in 15, and brady atrial fibrillation in 2). All patients received polysomnographic evaluations before implantation of permanent pacemakers. After implantation of permanent pacemakers, all patients received polysomnographic evaluations during use of the pacemaker settings (AAI/DDD/VVI at 70 beats per minute). ResultsThe mean follow-up period was 35±13 months. Before implantation, the distribution of sleep-disordered breathing was as follows: 93% had apnea hypopnea index >5, 58% had apnea hypopnea index >15, and 20% had apnea hypopnea index >30. The mean apnea hypopnea index for all patients was 20±15, for those with obstructive type apnea was 4.9±5.3, and for those with central type apnea was 3.0±4.5. The mean Epworth Sleepiness Score was 5.9±4.0. No patient received continuous positive airway pressure therapy or any other therapy for sleep-disordered breathing during the follow up period. The mean apnea hypopnea index at 1 week after implantation of permanent pacemakers was 21±14 (P=0.8) and the mean apnea hypopnea index at end of follow-up was 11±7 (P<0.0001). ConclusionLong term cardiac pacing significantly reduces the number of episodes of sleep apnea in patients with conventional permanent pacemaker indications.

Bradycardia Pacing

Bradycardia Pacing

Reproducibility of tilt-table test result in patients with malignant neurocardiogenic syncope.

The indication for permanent pacemaker remains controversial in malignant neurocardiogenic syncope. A highly reproducible prolonged pause during a repeat head-up tilt-table testing may identify a subgroup of neurally mediated syncope with a prominent and consistent cardioinhibitory component. Seven patients (3 females) with a mean age of 30 years (23-44 years) were diagnosed to have malignant neurocardiogenic -syncope; all are classified according to the Vasovagal Syncope International Study as 2B type, with observed sinus pauses ranged from 3 s to 26 s of which only 1 demonstrated a reproducible sinus pause. No recurrence of syncope was clinically observed in patients during the follow-up period. Of 6 patients treated non--pharmacologically, one required a beta-blocker and none required a permanent pacemaker. Prolonged asystole manifest during head-up tilt-table testing is a poorly reproducible phenomenon and permanent pacemaker implantation in malignant neurocardiogenic syncope should not be a first line therapy.

Recannalisation of Venous occlusion, a new indication for permanent pacemaker lead extraction using a femoral approach Richard J. Schilling. Cardiology Department, St Mary's Hospital and Imperial College School of Medicine, London, United Kingdom

Recannalisation of Venous occlusion, a new indication for permanent pacemaker lead extraction using a femoral approach Richard J. Schilling. Cardiology Department, St Mary's Hospital and Imperial College School of Medicine, London, United Kingdom

Evolving indications for permanent pacing

Indications for permanent pacemakers have expanded in recent years. The American College of Cardiology (ACC) and American Heart Association (AHA) guidelines for implantation of cardiac pacemakers were recently updated and now include several of the newer indications. Greatest interest about newer applications of pacemaker therapy focuses on hypertrophic obstructive cardiomyopathy, dilated cardiomyopathy, and pacing for the prevention of atrial fibrillation. Pacing for neurocardiogenic syncope remains controversial despite emerging data. Pacing for long QT syndrome, pacing after cardiac transplantation, and pacing for hemodynamic improvement in the occasional patient with first-degree atrioventricular block and hemodynamic compromise also warrant attention. Available clinical data are discussed in the context of the recent ACC and AHA guidelines.

Effect of recent randomized trials on current pacing practice.

The most common indication for a permanent pacemaker is symptomatic bradycardia. An atrial-based pacemaker (dual-chamber or atrial) usually is preferred, except in patients with chronic atrial fibrillation. Several prospective, randomized trials recently have been completed to evaluate new indications for permanent pacemakers. A dual-chamber pacemaker with an optimal atrioventricular interval can reduce the left ventricular outflow tract gradient by >50% in patients with hypertrophic cardiomyopathy. This has been associated with symptomatic improvement in the majority of patients, but an important placebo effect appears likely. Pacing also has been evaluated in patients with medically refractory dilated cardiomyopathy. Despite encouraging initial studies, routine implantation of a permanent pacemaker in dilated cardiomyopathy is not indicated. In patients with cardioinhibitory or mixed vasovagal syncope and carotid sinus hypersensitivity, implantation of a pacemaker markedly decreases syncopal episodes. Pacemaker therapy is clearly indicated in patients with atrial fibrillation associated with symptomatic bradycardia, and exciting new data on the use of pacing to prevent atrial fibrillation appear promising. The best pacing modality for this indication may be dual-site atrial pacing. Finally, permanent pacemakers play an important role in the treatment of symptomatic long QT syndrome, usually in combination with beta-blockers.

Indications for Permanent Pacemakers in Young Adults

The sick sinus syndrome has become the most common indication for permanent pacemaker implantation. 1 In a recent review of 50 patients with the sick sinus syndrome treated with pacemaker insertion, the mean age of the group was 71 years. 2 There are occasional reports of the sick sinus syndrome in young adults. However, many of the reported cases involve postoperative congenital heart disease.3,4 Recently Kay and his group5reported a series of 18 cases of young adults who required pacemakers. Twelve had the sick sinus syndrome and served as the basis of their report. Electrophysiologic studies were performed in only 5 of their 12 cases, and the authors stressed that the corrected sinus node recovery time was normal in their 5 patients. We routinely perform electrophysiologic studies in all patients being considered for pacemaker implantations. We therefore reviewed our experience over 8 years with young adults who required permanent pacemaker insertions.

The significance of bundle branch block during acute myocardial infarction

Analysis of the course of 71 patients with acute myocardial infarction complicated by bundle branch block (BBB) confirms a high incidence of atrioventricular (A-V) block (42 per cent) and severe pump failure (35 per cent) in these patients. Hospital mortality was not correlated with BBB per se, but rather with the associated development of second or third degree A-V block (57 per cent with A-V block vs. 12 per cent without A-V block; p < .0005) or severe pump failure (35 per cent with vs. 11 per cent without severe pump failure; p < .001). However, late mortality was high and not significantly different among those surviving hospitalization whether transient A-V block was present or absent. Eight of 11 late deaths were sudden. Temporary pacing could not be shown to alter hospital survival statistically, but made the onset of complete heart block a hemodynamically smooth and clinically undetectable event in several patients who later survived. The place of permanent pacing in these patients cannot be clearly determined on the basis of this study or in the available literature. More data obtained either by pooling the experience of several centers or from a prospective randomized study are needed to determine the indications for permanent pacemakers.