Management of patients with drug-induced atrioventricular block

Incidence and predictors of pacemaker implantation at follow-up after reversible high-degree sinus node dysfunction or atrioventricular block

BACKGROUND

A pacemaker implantation is not indicated in cases of reversible high-degree symptomatic sinus node dysfunction (SND) and atrioventricular block (AVB). However, it remains uncertain whether these reversible automaticity/conduction disorders may recur in some patients at follow-up, in the absence of reversible cause. This retrospective study aimed to determine the incidence and predictive factors of permanent pacemaker (PPM) implantation at follow-up and after reversible high-degree SND/AVB.

METHODS

Based on medical electronic files codes, we identified patients who were hospitalized in our cardiac intensive care unit between January 2003 and December 2020 due to reversible high-degree SND/AVB and who were discharged from the hospital alive and without PPM implantation. Acute myocardial infarction and post-cardiac surgery patients were excluded. We categorized the patients according to the need for PPM at follow-up due to non-reversible high-degree SND/AVB.

RESULTS

Of the 93 patients included, 26 patients (28%) were readmitted for PPM implantation at follow-up after hospital discharge. Among baseline characteristics, compared with patients who did not have high-degree SND/AVB recurrence, those who had subsequent PPM implantation had less frequent previous hypertension (70% vs. 46%, p = .031). Regarding the initial causes of reversible SND/AVB, isolated hyperkalemia was found more often in the patients readmitted for PPM (19% vs. 3% vs. p = .017). Moreover, recurrence of high-degree SND/AVB was significantly associated with the presence of intraventricular conduction disorders (either bundle branch block or left bundle branch hemiblock) on ECG at discharge (36% in patients without PPM vs. 68% in PPM patients, p = .012).

CONCLUSION

Almost one third of the patients discharged alive from the hospital after a reversible high-degree SND/AVB needed a pacemaker implantation at follow-up. Complete bundle branch block or left bundle branch hemiblock on discharge ECG after recovery of atrioventricular conduction and/or sinus automaticity was associated with a greater risk of recurrence leading to pacemaker implantation.

Reversible Causes of Atrioventricular Block

Atrioventricular blocks may be caused by a variety of potentially reversible conditions, such as ischemic heart disease, electrolyte imbalances, medications, and infectious diseases. Such causes must be always ruled out to avoid unnecessary pacemaker implantation. Patient management and reversibility rates depend on the underlying cause. Careful patient history taking, monitoring of vital signs, electrocardiogram, and arterial blood gas analysis are crucial elements of the diagnostic workflow during the acute phase. Atrioventricular block recurrence after the reversal of the underlying cause may pose an indication for pacemaker implantation, because reversible conditions may actually unmask a preexistent conduction disorder.

Long-term follow-up of patients with drug-related atrioventricular block without a need of permanent pacemaker during index hospitalization

Background

Most of the patients hospitalized due to drug-related atrioventricular (AV) block do not require permanent pacemaker implantation (PPI) since AV block regresses following cessation of the responsible drug. However, AV block requiring PPI may relapse in long-term follow-up. In this study, we retrospectively evaluated the factors predicting the need for a PPI in the long-term follow-up in patients admitted to our hospital with drug-related AV block but did not require PPI in index hospitalization.

Results

We evaluated 177 patients who had been hospitalized with drug-related AV block between January 2012 and July 2020 and who had not required PPI during hospital follow-up. The patients were divided into two groups according to whether PPI was performed or not. The independent predictors of long-term PPI were evaluated and the effect of glomerular filtration rate (GFR) of the patients during the index hospitalization on the long-term outcome was compared. A GFR above 60 ml/min is an independent significant risk factor in predicting long-term permanent pacemaker implantation in drug-related AV blocks. It is found that the need for PPI was 2.64 times higher without adjusted and 1.9 times higher with adjusted for all covariates in patients with GFR above 60 ml/min during hospitalization compared to those with GFR below 30 ml/min.

Conclusions

GFR may be considered as an indicator of the PPI need in patients with drug-related atrioventricular AV block.

Bedside Temporary Transvenous Pacemaker Insertion in the Emergency Department: A Single-Center Experience

Objectives

Insertion of a temporary transvenous pacemaker (TTPM) is one of the life-saving interventions performed in the emergency department (ED). The aim of the study was to determine demographic, clinical characteristics, and in-hospital outcomes of patients who underwent TTPM insertion due to hemodynamically unstable bradyarrhythmia in the ED.

Methods

In our study, 234 consecutive patients who underwent TTPM insertion at the bedside in the ED between January 2014 and October 2019 were included in the study. Etiological characteristics, electrocardiographic (ECG) findings, requirements for permanent pacemaker (PPM), and in-hospital mortality of the patients were analyzed retrospectively.

Results

Extrinsic causes were the most common etiology of unstable bradyarrhythmia (57.6%). Most extrinsic causes were drug therapy-related factors (60.7%). Bradyarrhythmia persisted in 60% of patients after extrinsic causes were eliminated. The most common ECG finding was a high-degree atrioventricular block (62%). PPM was implanted in 44% of patients. In-hospital mortality rate was 19.7%. In the multivariate regression analysis, the left ventricular ejection fraction (LVEF) and diastolic blood pressure (DBP) measured at admission (p<0.001 and p<0.001, respectively) were determined to be independent predictors for in-hospital mortality.

Conclusion

First diagnosis and intervention in the ED are of great importance for patients with unstable bradyarrhythmia. The fastest possible TTPM insertion in the ED can reduce mortality by reducing the exposure time to hypoperfusion of vital organs, especially in patients with reduced LVEF and low DBP. Furthermore, it should be kept in mind that an underlying latent conduction system disease can also be present in bradyarrhythmias thought to occur potentially due to extrinsic factors.

Reversible Causes of Atrioventricular Block

Atrioventricular blocks may be caused by a variety of potentially reversible conditions, such as ischemic heart disease, electrolyte imbalances, medications, and infectious diseases. Such causes must be always ruled out to avoid unnecessary pacemaker implantation. Patient management and reversibility rates depend on the underlying cause. Careful patient history taking, monitoring of vital signs, electrocardiogram, and arterial blood gas analysis are crucial elements of the diagnostic workflow during the acute phase. Atrioventricular block recurrence after the reversal of the underlying cause may pose an indication for pacemaker implantation, because reversible conditions may actually unmask a preexistent conduction disorder.

Systemic immune-inflammation index as a tool for predicting the need for a permanent pacemaker in patients with drug-induced atrioventricular block

BACKGROUND

Drug-induced atrioventricular block (AVB) is generally considered reversible and does not require a permanent pacemaker implantation (PPM). However, some studies have demonstrated a failure of AVB cessation even when the inducing agent has been discontinued. This study has investigated the use of systemic immune-inflammation index (SII) to predict irreversible drug-induced AVB after drug discontinuation.

METHOD

Files of patients with high-degree AVB that required a temporary pacemaker (TPM) were retrospectively analyzed. Sixty-three patients in which AVB was drug-induced were included in the study. The patients were divided into the following two groups: (1) those whose AVB reversed after discontinuation of the related drug, and (2) those in which AVB did not reverse.

RESULTS

AVB reversed in 24 patients (38%) after the inducing agent was discontinued while in the remaining 39 patients (62%) PPM was required. The most common drugs to induce AVB were beta-blockers (n = 46, 73%). Follow-up time with TPM was significantly longer in the irreversible group (2.91 ± 1.05 days vs. 4.94 ± 2.15 days, p < .001). Multivariate logistic regression analysis showed that SII (odds ratio [OR] = 1.002; 95% confidence interval [CI] = 1.000-1.003; p = .01) was an independent predictor of the requirement for a PPM. An SII > 752.05 was found to be a predictor of irreversible AVB requiring PPM with a sensitivity of 64% and specificity of 75% (receiving-operating characteristics [ROC] area under the ROC curve [AUC]: 0.704, 95% CI = 0.570-0.838, p = .007).

CONCLUSION

Approximately 2/3 of drug-induced high-degree AVBs are irreversible. SII is an easily available and cheap inflammatory biomarker that can be used to predict irreversible AVB.

Neurologic complications of brady-arrhythmias

Brady-arrhythmias are responsible for both overt as well as subtle neurologic signs and symptoms, from the seemingly benign and nonspecific symptoms associated with presyncope, to sudden focal neurologic deficits. A brief background on nodal and infra-nodal brady-arrhythmias is provided, followed by extensive discussion regarding neurologic complications of brady-arrhythmias. The multiple mechanisms of and associations between Brady-arrhythmias and transient ischemic attacks and ischemic stroke are discussed. Controversial associations between brady-arrhythmias and neurologic disease are discussed as well, such as potential roles of brady-arrhythmias in cognitive impairment and sequelae of chronotropic incompetence; and the contribution of brady-arrhythmias to syncope and associated injuries to the nervous system. The chapter is written to stand on its own, with guidance toward other pertinent sections of this text where appropriate for further reading.

Use of Disproportionality Analysis to Identify Previously Unknown Drug-Associated Causes of Cardiac Arrhythmias Using the Food and Drug Administration Adverse Event Reporting System (FAERS) Database

INTRODUCTION

Drug-induced QT_c-prolongation is a well-known adverse drug reaction (ADR), however there is limited knowledge of other drug-induced arrhythmias.

PURPOSE

The objective of this study is to determine the drugs reported to be associated with arrhythmias other than QT_c-prolongation using the FAERS database, possibly identifying potential drug causes that have not been reported previously.

METHODS

FAERS reports from 2004 quarter 1 through 2019 quarter 1 were combined to create a dataset of approximately 11.6 million reports. Search terms for arrhythmias of interest were selected from the Standardized MedDRA Queries (SMQ) Version 12.0. Frequency of the cardiac arrhythmias were determined for atrial fibrillation, atrioventricular block, bradyarrhythmia, bundle branch block, supraventricular tachycardia, and ventricular fibrillation and linked to the reported causal medications. Reports were further categorized by prior evidence associations using package inserts and established drug databases. A reporting odds ratio (ROR) and confidence interval (CI) were calculated for the ADRs for each drug and each of the 6 cardiac arrhythmias.

RESULTS

Of the 11.6 million reports in the FAERS database, 68,989 were specific to cardiac arrhythmias of interest. There were 61 identified medication-reported arrhythmia pairs for the 6 arrhythmia groups with 33 found to have an unknown reported association. Rosiglitazone was the most frequently medication reported across all arrhythmias [ROR 6.02 (CI: 5.82-6.22)]. Other medications with significant findings included: rofecoxib, digoxin, alendronate, lenalidomide, dronedarone, zoledronic acid, adalimumab, dabigatran, and interferon beta-1b.

CONCLUSION

Upon retrospective analysis of the FAERS database, the majority of drug-associated arrhythmias reported were unknown suggesting new potential drug causes. Cardiac arrhythmias other than QTc prolongation are a new area of focus for pharmacovigilance and medication safety. Consideration of future studies should be given to using the FAERS database as a timely pharmacovigilance tool to identify unknown adverse events of medications.

Permanent pacemaker implantation and its predictors in patients admitted for complete atrioventricular block: a report from the Tokyo Cardiovascular Care Unit Network multi-center registry

Little is known about the permanent pacemaker implantation rate and predictors of permanent pacemaker implantation in patients admitted for complete atrioventricular block (cAVB). The present study was a retrospective analysis based on a multicenter cohort of 797 patients with cAVB (mean age: 79.6 ± 10.7 years; males: 48.4%) registered with the Tokyo Cardiovascular Care Unit Network multicenter registry between 2013 and 2016. Secondary cAVB due to acute coronary syndrome was excluded. The permanent pacemaker implantation rate was 82.9%. Multivariable logistic regression analysis revealed that systolic blood pressure (SBP) > 140 mmHg [odds ratio (OR) 2.10; 95% confidence interval (CI) 1.38-3.22; P < 0.001], male gender (OR 1.63; 95% CI 1.07-2.49; P = 0.023), and left ventricular ejection fraction (LVEF) ≥ 50% (OR 2.19; 95% CI 1.16-2.06; P = 0.016) were predictors of permanent pacemaker implantation while pre-admission β-blocker use (OR 0.28; 95% CI 0.17-0.47; P < 0.001) was associated with a lower risk of permanent pacemaker implantation. Reversible cAVB was not rare in patients admitted for cAVB. Data on SBP on admission, gender, LVEF, and pre-admission β-blocker use may be important for assessing the requirement for permanent pacemaker implantation in the emergency care setting.

Incidence and predictors of complete atrioventricular conduction recovery among patients with heart block

Aim: In this study, our aim was to determine clinical factors related to the recovery of the conduction system in patients presenting with atrioventricular (AV) block. Materials & methods: A total of 178 patients who were hospitalized at a tertiary center due to second- or third-degree AV block were retrospectively analyzed. Results: During hospital follow-up, 19.1% of patients had fully recovered from AV block. According to a logistic regression analysis; younger age (odds ratio [OR]: 0.950; 95% CI: 0.932-0.967; p < 0.001), presenting with acute coronary syndrome (OR: 18.863; 95% CI: 3.776-94.222; p < 0.001), β-blocker usage (OR: 12.081; 95% CI: 3.498-41.726; p < 0.001), high serum creatinine levels (OR: 4.338; 95% CI: 2.110-8.918; p < 0.001) and no calcification at the aortic valve (OR: 0.189; 95% CI: 0.050-0.679; p = 0.011) were found to be related to resolution of AV block. Conclusion: It is crucial to know the reversible causes of AV block to prevent unnecessary permanent pacemaker implantation.

Atrioventricular block in patients undergoing treatment with bradycardic drugs. Predictors of pacemaker requirement

INTRODUCTION AND OBJECTIVES

Atrioventricular block (AVB) in the presence of bradycardic drugs (BD) can be reversible, and pacemaker implantation is controversial. Our objective was to analyze the pacemaker implantation rate in the mid-term, after BD suspension, and to identify predictive factors.

METHODS

We performed a cohort study that included patients attending the emergency department with high-grade AVB in the context of BD. We studied the persistence of AVB after BD discontinuation, recurrence in patients with AVB resolution, and the predictive variables associated with pacemaker requirement at 3 years.

RESULTS

Of 127 patients included (age, 79 [71-83] years), BAV resolved in 60 (47.2%); among these patients, recurrence occurred during the 24-month median follow-up in 40 (66.6%). Pacemaker implantation was required in 107 patients (84.3%), despite BD discontinuation. On multivariable analysis, the variables associated with pacemaker need at 3 years were heart rate <35 bpm (OR, 8.12; 95%CI, 1.82-36.17), symptoms other than syncope (OR, 4.09; 95%CI, 1.18-14.13), and wide QRS (OR, 5.65; 95%CI, 1.77-18.04). Concomitant antiarrhythmic treatment was associated with AVB resolution (OR, 0.12; 95%CI, 0.02-0.66).

CONCLUSIONS

More than 80% of patients with AVB secondary to BD require pacemaker implantation despite drug discontinuation. Predictive variables were wide QRS, heart rate <35 bpm, and clinical presentation other than syncope.

Complications and Outcomes of Temporary Transvenous Pacing: An Analysis of > 360,000 Patients From the National Inpatient Sample

BACKGROUND

The incidence of complications and the outcomes of temporary transvenous pacemaker (TTP) placement in the modern era are not well established.

METHODS

To determine the current incidence of pericardial complications and the outcomes of patients undergoing TTP, we performed an analysis using the National Inpatient Sample (NIS), which is a US national database of hospital admissions. All patients who underwent TTP were identified by using International Classification of Diseases, Ninth Revision, Clinical Modification codes. A multivariate logistic regression model was constructed for a primary outcome of pericardial tamponade and another for a primary outcome of in-hospital mortality.

RESULTS

A total of 360,223 patients underwent TTP placement in the United States between 2004 and 2014. In-hospital mortality was 14.1%, and 37.9% later underwent permanent pacemaker implantation. Potential procedural complications included pericardial tamponade in 0.6% of patients, pneumothorax in 0.9% of patients, and non-pericardial bleeding in 2.4% of patients. In adjusted models, female sex (OR, 1.33 [95% CI, 1.09-1.64]; P = .005), in-hospital cardiac arrest (OR, 3.52 [95% CI, 2.76-4.48]; P < .001), teaching hospital status (OR, 1.91 [95% CI, 1.53-2.40]; P < .001), and previous coronary artery bypass grafting (OR, 0.26 [95% CI, 0.14-0.49]; P < .001) were associated with tamponade. Following multivariate adjustment, pericardial tamponade complicating TTP insertion was associated with a fivefold increase in risk for in-hospital death (OR, 5.00 [95% CI, 2.51-9.96]; P < .001).

CONCLUSIONS

TTP placement is generally safe with low pericardial complication rates. Clinicians should be mindful of infrequent but serious complications of TTP, and strategies to mitigate pericardial tamponade and other complications should be sought and implemented.

Electrocardiographic assessments and cardiac events after fingolimod first dose - a comprehensive monitoring study

Background

First dose observation for cardiac effects is required for fingolimod, but recommendations on the extent vary. This study aims to assess cardiac safety of fingolimod first dose. Individual bradyarrhythmic episodes were evaluated to assess the relevance of continuous electrocardiogram (ECG) monitoring.

Methods

START is an ongoing open-label, multi-center study. At the time of analysis 3951 patients were enrolled. The primary endpoints are the incidence of bradycardia (heart rate < 45 bpm) and second-/third-degree AV blocks during treatment initiation. The relevance of Holter was assessed by matching ECG findings with the occurrence of clinical symptoms as well as by rigorous analysis of AV blocks with regard to the duration of pauses and the minimal heart rate recorded during AV block.

Results

Thirty-one patients (0.8%) developed bradycardia (<45 bpm), 62 patients (1.6%) had second-degree Mobitz I and/or 2:1 AV blocks with a lowest reading (i.e. mean of ten consecutive beats) of 35 bpm and the longest pause lasting for 2.6 s. No Mobitz II or third-degree AV blocks were observed. Only one patient complained about mild chest discomfort and fatigue. After 1 week, there was no second-/third-degree AV block.

Conclusions

Continuous Holter ECG monitoring in this large real-life cohort revealed that bradycardia and AV conduction abnormalities were rare, transient and benign. No further unexpected abnormalities were detected. The data presented here give an indication that continuous Holter ECG monitoring does not add clinically relevant value to patients’ safety.

Trial registration

NCT01585298; registered April 23, 2012.

Management and outcome of topical beta-blocker-induced atrioventricular block

BACKGROUND

Topical beta-blockers have a well-established role in the treatment of glaucoma. We aimed to investigate the outcome of patients who developed symptomatic atrioventricular (AV) block induced by topical beta-blockers.

METHODS

All patients admitted or discharged from our institution, the Siyami Ersek Training and Research Hospital, between January 2009 and January 2013 with a diagnosis of AV block were included in the study. Subjects using ophthalmic beta-blockers were recruited and followed for permanent pacemaker requirement during hospitalisation and for three months after discontinuation of the drug. A permanent pacemaker was implanted in patients in whom AV block persisted beyond 72 hours or recurred during the follow-up period.

RESULTS

A total of 1 122 patients were hospitalised with a diagnosis of AV block and a permanent pacemaker was implanted in 946 cases (84.3%) during the study period. Thirteen patients using ophthalmic beta-blockers for the treatment of glaucoma and no other rate-limiting drugs were included in the study. On electrocardiography, eight patients had complete AV block and five had high-degree AV block. The ophthalmic beta-blockers used were timolol in seven patients (55%), betaxolol in four (30%), and cartelol in two cases (15%). The mean duration of ophthalmic beta-blocker treatment was 30.1 ± 15.9 months. After drug discontinuation, in 10 patients the block persisted and a permanent pacemaker was implanted. During follow up, one more patient required pacemaker implantation. Therefore in total, pacemakers were implanted in 11 out of 13 patients (84.6%). The pacemaker implantation rate did not differ according to the type of topical beta-blocker used (p = 0.37). The presence of infra-nodal block on electrocardiography was associated with higher rates of pacemaker implantation.

CONCLUSION

Our results indicate that topical beta-blockers for the treatment of glaucoma may cause severe conduction abnormalities and when AV block occurs, pacemaker implantation is required in a high percentage of the patients.

Reversibility of High-Grade Atrioventricular Block with Revascularization in Coronary Artery Disease without Infarction: A Literature Review

Complete atrioventricular (AV) block is known to be reversible in some cases of acute inferior wall myocardial infarction (MI). The reversibility of high-grade AV block in non-MI coronary artery disease (CAD), however, is rarely described in the literature. Herein we perform a literature review to assess what is known about the reversibility of high-grade AV block after right coronary artery revascularization in CAD patients who present without an acute MI. To illustrate this phenomenon we describe a case of 2 : 1 AV block associated with unstable angina, in which revascularization resulted in immediate and durable restoration of 1 : 1 AV conduction, thereby obviating the need for permanent pacemaker implantation. The literature review suggests two possible explanations: a vagally mediated response or a mechanism dependent on conduction system ischemia. Due to the limited understanding of AV block reversibility following revascularization in non-acute MI presentations, it remains difficult to reliably predict which patients presenting with high-grade AV block in the absence of MI may have the potential to avoid permanent pacemaker implantation via coronary revascularization. We thus offer this review as a potential starting point for the approach to such patients.