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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 -
American Family Physician Aug 2021Sinus node dysfunction, previously known as sick sinus syndrome, describes disorders related to abnormal conduction and propagation of electrical impulses at the... (Review)
Review
Sinus node dysfunction, previously known as sick sinus syndrome, describes disorders related to abnormal conduction and propagation of electrical impulses at the sinoatrial node. An abnormal atrial rate may result in the inability to meet physiologic demands, especially during periods of stress or physical activity. Sinus node dysfunction may occur at any age, but is usually more common in older persons. The causes of sinus node dysfunction are intrinsic (e.g., degenerative idiopathic fibrosis, cardiac remodeling) or extrinsic (e.g., medications, metabolic abnormalities) to the sinoatrial node. Many extrinsic causes are reversible. Electrocardiography findings include sinus bradycardia, sinus pauses or arrest, sinoatrial exit block, chronotropic incompetence, or alternating bradycardia and tachycardia (i.e., bradycardia-tachycardia syndrome). Clinical symptoms result from the hypoperfusion of end organs. About 50% of patients present with cerebral hypoperfusion (e.g., syncope, presyncope, lightheadedness, cerebrovascular accident). Other symptoms include palpitations, decreased physical activity tolerance, angina, muscular fatigue, or oliguria. A diagnosis is made by directly correlating symptoms with a bradyarrhythmia and eliminating potentially reversible extrinsic causes. Heart rate monitoring using electrocardiography or ambulatory cardiac event monitoring is performed based on the frequency of symptoms. An exercise stress test should be performed when symptoms are associated with exertion. The patient's inability to reach a heart rate of at least 80% of their predicted maximum (220 beats per minute - age) may indicate chronotropic incompetence, which is present in 50% of patients with sinus node dysfunction. First-line treatment for patients with confirmed sinus node dysfunction is permanent pacemaker placement with atrial-based pacing and limited ventricular pacing when necessary.
Topics: Cardiac Pacing, Artificial; Electrocardiography; Heart Rate; Humans; Sick Sinus Syndrome; Sinoatrial Node
PubMed: 34383451
DOI: No ID Found -
Circulation Aug 2019
2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society.
Topics: Adrenergic beta-Antagonists; Arrhythmias, Cardiac; Bradycardia; Cardiac Conduction System Disease; Electrocardiography; Electrophysiological Phenomena; Epilepsy; Heart Diseases; Humans; Myocardial Infarction; Quality of Life
PubMed: 30586772
DOI: 10.1161/CIR.0000000000000628 -
Journal of the American College of... Aug 2019
2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society.
Topics: Bradycardia; Cardiac Conduction System Disease; Cardiac Pacing, Artificial; Disease Management; Humans; Sleep Apnea Syndromes
PubMed: 30412709
DOI: 10.1016/j.jacc.2018.10.044 -
Journal of the American College of... Aug 2019
2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm Society.
Topics: Advisory Committees; American Heart Association; Bradycardia; Cardiology; Humans; Societies; United States
PubMed: 30412710
DOI: 10.1016/j.jacc.2018.10.043 -
Cureus May 2021Steroids are one of the most commonly used drugs and known to be associated with several side effects. There have been case reports about the associated sinus...
Steroids are one of the most commonly used drugs and known to be associated with several side effects. There have been case reports about the associated sinus bradycardia with pulse dose corticosteroids administration both IV and oral. We present a case of asymptomatic sinus bradycardia associated with oral prednisone 40 mg. A 69-year-old male was admitted to the ICU for sepsis and subsequently was found to have gastrointestinal (GI) bleed. He developed an acute gout attack during hospitalization and was treated with prednisone 40 mg. Over the next 24 hours, the patient's heart rate dropped to 30s to 40s beats/minute while other vitals have remained stable. He was monitored on telemetry and review of the rhythm strips, as well as a 12-lead electrocardiogram (EKG), that showed sinus bradycardia; no pauses or atrio-ventricular (AV) nodal blocks were identified. The patient was not on any beta blocker or other therapies commonly associated with sinus bradycardia. His steroids were stopped while all other medications were continued. His heart rate slowly started to improve over the next 24 hours. He was not found to have any further episodes of bradycardia. Our case is unusual as we noted transient asymptomatic bradycardia with oral prednisone 40 mg dose. While bradycardia is reversible and may go unnoticed, it is important for the clinician to be aware of this adverse effect and include it in the list of potential differentials for bradycardia.
PubMed: 34141509
DOI: 10.7759/cureus.15065