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Trends in Cardiovascular Medicine Jul 2020Bradycardia is a commonly observed arrhythmia and a frequent occasion for cardiac consultation. Defined as a heart rate of less than 50-60 bpm, bradycardia can be... (Review)
Review
Bradycardia is a commonly observed arrhythmia and a frequent occasion for cardiac consultation. Defined as a heart rate of less than 50-60 bpm, bradycardia can be observed as a normal phenomenon in young athletic individuals, and in patients as part of normal aging or disease (Table 1). Pathology that produces bradycardia may occur within the sinus node, atrioventricular (AV) nodal tissue, and the specialized His-Purkinje conduction system. Given the overlap of heart rate ranges with non-pathologic changes, assessment of symptoms is a critical component in the evaluation and management of bradycardia. Treatment should rarely be prescribed solely on the basis of a heart rate lower than an arbitrary cutoff or a pause above certain duration. In the 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients with Bradycardia and Cardiac Conduction Delay (referred to hereafter as the 2018 Bradycardia Guideline), there was a significant shift in emphasis from prior guidelines that emphasized device-based implantation recommendations to a focus on evaluation and management of disease states [1,2]. In this review, we will highlight the changes in the new guideline as well as describe the key elements in evaluation and management of patients presenting with bradycardia.
Topics: Action Potentials; Atrioventricular Block; Bradycardia; Cardiac Pacing, Artificial; Clinical Decision-Making; Heart Conduction System; Heart Rate; Humans; Pacemaker, Artificial; Patient Selection; Sick Sinus Syndrome; Treatment Outcome
PubMed: 31311698
DOI: 10.1016/j.tcm.2019.07.001 -
Internal Medicine (Tokyo, Japan) Mar 2021
Topics: Atrioventricular Block; Electrocardiography; Heart Conduction System; Humans; Pacemaker, Artificial
PubMed: 33087679
DOI: 10.2169/internalmedicine.6150-20 -
Arquivos Brasileiros de Cardiologia Oct 2022
Topics: Humans; Atrioventricular Block; Electrocardiography
PubMed: 36287412
DOI: 10.36660/abc.20220643 -
European Journal of Pediatrics Sep 2016Atrioventricular block is classified as congenital if diagnosed in utero, at birth, or within the first month of life. The pathophysiological process is believed to be... (Review)
Review
UNLABELLED
Atrioventricular block is classified as congenital if diagnosed in utero, at birth, or within the first month of life. The pathophysiological process is believed to be due to immune-mediated injury of the conduction system, which occurs as a result of transplacental passage of maternal anti-SSA/Ro-SSB/La antibodies. Childhood atrioventricular block is therefore diagnosed between the first month and the 18th year of life. Genetic variants in multiple genes have been described to date in the pathogenesis of inherited progressive cardiac conduction disorders. Indications and techniques of cardiac pacing have also evolved to allow safe permanent cardiac pacing in almost all patients, including those with structural heart abnormalities.
CONCLUSION
Early diagnosis and appropriate management are critical in many cases in order to prevent sudden death, and this review critically assesses our current understanding of the pathogenetic mechanisms, clinical course, and optimal management of congenital and childhood AV block.
WHAT IS KNOWN
• Prevalence of congenital heart block of 1 per 15,000 to 20,000 live births. AV block is defined as congenital if diagnosed in utero, at birth, or within the first month of life, whereas childhood AV block is diagnosed between the first month and the 18th year of life. As a result of several different etiologies, congenital and childhood atrioventricular block may occur in an entirely structurally normal heart or in association with concomitant congenital heart disease. Cardiac pacing is indicated in symptomatic patients and has several prophylactic indications in asymptomatic patients to prevent sudden death. • Autoimmune, congenital AV block is associated with a high neonatal mortality rate and development of dilated cardiomyopathy in 5 to 30 % cases. What is New: • Several genes including SCN5A have been implicated in autosomal dominant forms of familial progressive cardiac conduction disorders. • Leadless pacemaker technology and gene therapy for biological pacing are promising research fields. In utero percutaneous pacing appears to be at high risk and needs further development before it can be adopted into routine clinical practice. Cardiac resynchronization therapy is of proven value in case of pacing-induced cardiomyopathy.
Topics: Age Factors; Atrioventricular Block; Cardiac Pacing, Artificial; Electrocardiography; Heart Diseases; Humans; Infant, Newborn; Prenatal Diagnosis
PubMed: 27351174
DOI: 10.1007/s00431-016-2748-0 -
Journal of the American Heart... Mar 2020
Topics: Atrioventricular Block; Cardiomyopathy, Hypertrophic; Humans; Prognosis
PubMed: 32146897
DOI: 10.1161/JAHA.120.015911 -
Cardiovascular Journal of Africa 2015Topical beta-blockers have a well-established role in the treatment of glaucoma. We aimed to investigate the outcome of patients who developed symptomatic...
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.
Topics: Administration, Ophthalmic; Adrenergic beta-Antagonists; Aged; Aged, 80 and over; Atrioventricular Block; Cardiac Pacing, Artificial; Electrocardiography; Female; Glaucoma; Heart Conduction System; Heart Rate; Hospitals, Teaching; Humans; Male; Middle Aged; Pacemaker, Artificial; Recurrence; Risk Factors; Time Factors; Treatment Outcome; Turkey
PubMed: 26659434
DOI: 10.5830/CVJA-2015-030 -
British Journal of Pharmacology Mar 2022Ventricular cardiac arrhythmia is a life threating condition arising from abnormal functioning of many factors in concert. Animal models mirroring human... (Review)
Review
Ventricular cardiac arrhythmia is a life threating condition arising from abnormal functioning of many factors in concert. Animal models mirroring human electrophysiology are essential to predict and understand the rare pro- and anti-arrhythmic effects of drugs. This is very well accomplished by the canine chronic atrioventricular block (CAVB) model. Here we summarize canine models for cardiovascular research, and describe the development of the CAVB model from its beginning. Understanding of the structural, contractile and electrical remodelling processes following atrioventricular (AV) block provides insight in the many factors contributing to drug-induced arrhythmia. We also review all safety pharmacology studies, efficacy and mechanistic studies on anti-arrhythmic drugs in CAVB dogs. Finally, we compare pros and cons with other in vivo preclinical animal models. In view of the tremendous amount of data obtained over the last 100 years from the CAVB dog model, it can be considered as man's best friend in preclinical drug research. LINKED ARTICLES: This article is part of a themed issue on Preclinical Models for Cardiovascular disease research (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.5/issuetoc.
Topics: Animals; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Atrioventricular Block; Dogs; Heart; Humans
PubMed: 33684961
DOI: 10.1111/bph.15436 -
CMAJ : Canadian Medical Association... May 2018
Topics: Anti-Bacterial Agents; Atrioventricular Block; Cardiac Pacing, Artificial; Humans; Lyme Disease; Myocarditis
PubMed: 29789287
DOI: 10.1503/cmaj.171452 -
JAMA Network Open Nov 2023Although a high body mass index (BMI) has been found to be associated with increased risk of cardiac conduction block (CCB) in older adults, no further studies have...
IMPORTANCE
Although a high body mass index (BMI) has been found to be associated with increased risk of cardiac conduction block (CCB) in older adults, no further studies have investigated the association between obesity and CCB in the general population.
OBJECTIVE
To investigate the association between obesity and CCB, including its subtypes.
DESIGN, SETTING, AND PARTICIPANTS
This cohort study used data from participants in the Kailuan Study in China (2006-2018) who had completed a physical examination in 2006 (baseline) and had not experienced CCB before baseline. Data analysis was conducted from March to September 2023.
EXPOSURES
Obesity status was defined by BMI in 3 groups: normal weight (18.5 to <24), overweight (24 to <28), and obesity (≥28).
MAIN OUTCOME AND MEASURES
The primary outcome was CCB, which was diagnosed from standard 12-lead electrocardiography. The primary end point included high-grade atrioventricular block (HAVB), complete right bundle branch block, complete left bundle branch block, left anterior fascicular block (LAFB), and left posterior fascicular block. First-degree atrioventricular block (FAVB), second-degree type 1 AVB, HAVB, complete and incomplete right and left bundle branch block, LAFB, and left posterior fascicular block were considered separately as secondary end points.
RESULTS
Among 86 635 participants (mean [SD] age, 50.8 [11.9] years; 68 205 males [78.7%]), there were 33 259 individuals with normal weight (38.4%), 37 069 individuals with overweight (42.8%), and 16 307 individuals with obesity (18.8%). The mean (SD) follow-up was 10.6 (3.07) years. In the multivariable Cox proportional hazards regression analysis, obesity was associated with an increased risk of incident CCB (hazard ratio [HR], 1.21; 95% CI, 1.04-1.42) vs normal BMI. In secondary analysis, obesity was associated with an increased risk of FAVB (HR, 1.44; 95% CI, 1.21-1.73), HAVB (HR, 1.99; 95% CI, 1.03-3.82), and LAFB (HR, 1.29; 95% CI, 1.03-1.62) vs normal BMI. There was no association between obesity and other CCB subtypes. Obesity was associated with a greater increase in risk of CCB vs normal BMI in older (aged ≥65 years; HR, 1.44; 95% CI, 1.05-1.96) vs younger (aged <65 years; HR, 1.13; 95% CI, 0.96-1.34) participants (P for interaction < .001) and those with diabetes (HR, 2.16; 95% CI, 1.24-3.76) vs without diabetes (HR, 1.19; 95% CI, 1.02-1.39) (P for interaction = .02).
CONCLUSIONS AND RELEVANCE
This study found that obesity was associated with an increased risk of CCB, with greater increases in risk for FAVB, HAVB, and LAFB. Individuals who were older and those who had diabetes had larger increases in risk.
Topics: Male; Humans; Aged; Middle Aged; Atrioventricular Block; Bundle-Branch Block; Overweight; Cohort Studies; Obesity; China; Diabetes Mellitus
PubMed: 37955899
DOI: 10.1001/jamanetworkopen.2023.42831 -
Circulation. Genomic and Precision... Apr 2023Complete atrioventricular block (CAVB) is a major reason for implantation of permanent pacemakers, but knowledge of CAVB inheritance is sparse. This nationwide study...
BACKGROUND
Complete atrioventricular block (CAVB) is a major reason for implantation of permanent pacemakers, but knowledge of CAVB inheritance is sparse. This nationwide study aimed to determine the occurrence of CAVB in first-, second-, and third-degree relatives (full siblings, half-siblings, and cousins).
METHODS
The Swedish multigeneration register was linked to the Swedish nationwide patient register for the period 1997 to 2012. All Swedish full sibling, half-sibling, and cousin pairs born to Swedish parents between 1932 and 2012 were included. Competing risks and time-to-event, subdistributional hazard ratios (SHRs) according to Fine and Gray and hazard ratios using Cox proportional hazards model were estimated using robust SEs and considering the relatedness of relatives (full siblings, half-siblings, cousins). Additionally, odds ratios (ORs) for CAVB were calculated for traditional cardiovascular comorbidities.
RESULTS
The study population (N=6 113 761) consisted of 5 382 928 full siblings, 1 266 391 half-siblings, and 3 750 913 cousins. In total, 6442 (0.11%) unique individuals were diagnosed with CAVB. Of these, 4200 (65.2%) were males. SHRs for CAVB were 2.91 for full siblings (95% CI, 2.43-3.49), 1.51 for half-siblings (0.56-4.10), and 3.54 for cousins (1.73-7.26) of affected individuals. Age-stratified analysis showed higher risk in young individuals born from 1947 to 1986: SHR, 5.30 (3.78-7.43) for full siblings, SHR, 3.30 (1.06-10.31) for half-siblings, and SHR, 3.15 (1.39-7.17) for cousins. Similar familial HRs according to Cox proportional hazard model and ORs were obtained without any major differences. Apart from familial relationship, CAVB was associated with hypertension (OR, 1.83), diabetes (OR, 1.41), coronary heart disease (OR, 2.08), heart failure (OR, 5.01), and structural heart disease (OR, 4.59).
CONCLUSIONS
Risk of CAVB among relatives of affected individuals depends on relationship degree, being strongest in young siblings. The familial association extending to third-degree relatives indicates presence of genetic components in the cause of CAVB.
Topics: Male; Humans; Female; Sweden; Atrioventricular Block; Family; Siblings; Parents
PubMed: 36802810
DOI: 10.1161/CIRCGEN.121.003654