Second degree heart block

OBJECTIVES: To uncover the clinical course of fetal isolated non-immune mediated second-degree AVB and determine the factors associated with the spontaneous recovery for fetal non-immune second-degree atrioventricular block (AVB). METHODS: A total of 20 fetuses with isolated, non-immune mediated second-degree AVB were prospectively recruited between 2014 and 2022. These fetuses were divided into the spontaneous recovery group (n=12) and the non-spontaneous recovery group (n=8)...

Long-term athletic training can result in structural and conduction changes within the heart, leading to Athlete's heart syndrome (AHS). This syndrome is characterized by increased left ventricle (LV) dimensions, thickness, and mass. Dynamic exercise significantly contributes to these alterations, with sinus bradycardia being a common conduction abnormality, often accompanied by first-degree atrioventricular (AV) block. However, higher degrees of AV conduction abnormalities, such as second- and third-degree blocks, though rare, might occur due to parasympathetic hypertonia...

BACKGROUND: Most trials that have shown a benefit of beta-blocker treatment after myocardial infarction included patients with large myocardial infarctions and were conducted in an era before modern biomarker-based diagnosis of myocardial infarction and treatment with percutaneous coronary intervention, antithrombotic agents, high-intensity statins, and renin-angiotensin-aldosterone system antagonists. METHODS: In a parallel-group, open-label trial performed at 45 centers in Sweden, Estonia, and New Zealand, we randomly assigned patients with an acute myocardial infarction who had undergone coronary angiography and had a left ventricular ejection fraction of at least 50% to receive either long-term treatment with a beta-blocker (metoprolol or bisoprolol) or no beta-blocker treatment...

Several anatomical, demographic, clinical, electrocardiographic, procedural, and valve-related variables can be used to predict the probability of developing conduction abnormalities after transcatheter aortic valve replacement (TAVR) that necessitate permanent pacemaker (PPM) implantation. These variables include calcifications around the device landing zone and in the mitral annulus; pre-existing electrocardiographic abnormalities such as left and right bundle branch blocks (BBB), first- and second-degree atrioventricular blocks, as well as bifascicular and trifascicular blocks; male sex; diabetes mellitus (DM); hypertension; history of atrial fibrillation; renal failure; dementia; and use of self-expanding valves...

Spontaneous intraoperative development of Mobitz II second-degree atrioventricular block is a rare event which requires decisive action on the part of anesthesiologists and anesthetists. Given that this arrhythmia can be fatal if not properly managed, it is imperative that every practitioner know how it should be managed. Currently, there is a lack of literature discussing what to expect when a patient develops this complication and what the best management strategies are. This case report describes the unexpected development of Mobitz II second-degree atrioventricular block in an elderly patient with no prior history of conduction abnormalities undergoing total hip arthroplasty and how it was managed during the perioperative period to avoid morbidity or mortality...

BACKGROUND: Refractory secondary hyperparathyroidism (SHPT) is a common complication observed in patients with end-stage renal disease and can result in ectopic calcification. Metastatic calcification involving the heart valves and the conduction system can easily lead to arrhythmias, including atrioventricular block. This case report describes a maintenance hemodialysis patient with refractory SHPT resulting in a complete atrioventricular block (CAVB), which was eventually reversed to a first-degree atrioventricular block...

An 81-year-old male with a history of coronary artery disease, hypertension, paroxysmal atrial fibrillation and chronic kidney disease presents with asymptomatic bradycardia. Examination was notable for an early diastolic heart sound. 12-lead electrocardiogram revealed sinus bradycardia with a markedly prolonged PR interval and second-degree atrioventricular block, type I Mobitz. We review the differential diagnosis of early diastolic heart sounds and present a case of Wenckebach associated with a variable early diastolic sound on physical exam...

The second generation of transcatheter pacing systems, called Micra AV, can provide atrio-ventricular (AV) synchronous pacing via a new pacing algorithm relying on sensing mechanical atrial contraction. Several novel programming parameters were introduced to enable AV synchronous pacing, including an A3 and A4 window as well as a conduction and an activity mode switch. In addition to several automated features, manual programming optimization of some of the novel parameters is key to improving AV synchrony...

BACKGROUND: The cardiovascular system is among the least systems affected by immune-related adverse events. We report a rare life-threatening case of pembrolizumab-induced myocarditis with complete atrioventricular block and concomitant myositis in a metastatic bladder cancer patient. CASE PRESENTATION: An 82-year-old Caucasian female with invasive urothelial carcinoma, started on first-line pembrolizumab, was admitted four days after receiving her second dose for severe asthenia, diffuse muscle aches, neck pain, and lethargy...

BACKGROUND: Screening for atrial fibrillation (AF) may reveal incidental arrhythmias of relevance. The aim of this study was to describe incidental arrhythmias detected during screening for AF in the STAR-FIB (Predicting SilenT AtRial FIBrillation in Patients at High Thrombembolic Risk) cohort study. METHODS AND RESULTS: In the STAR-FIB cohort study, we screened hospitalized patients for AF with 3 repeat 7-day Holter ECGs. We analyzed all Holter ECGs for the presence of the following incidental arrhythmias: (1) sinus node dysfunction, defined as sinus pause of ≥3 seconds' duration; (2) second-degree (including Wenckebach) or higher-degree atrioventricular block (AVB); (3) sustained supraventricular tachycardia of ≥30 seconds' duration; and (4) sustained ventricular tachycardia of ≥30 seconds' duration...

The year 2024 marks the centenary of Mobitz's description of type II second-degree atrioventricular block. Its definition remains valid to this day with only minor modification for the diagnosis of infranodal conduction block. Mobitz a century ago indicated that his type II atrioventricular block was associated with Stock-Adams attacks and a prolonged duration of the QRS complex before the eventual description of bundle branch block.

BACKGROUND: Data regarding permanent pacemaker (PPM) implantation following tricuspid valve surgery (TVS) are limited. We sought to evaluate its incidence, risk factors, and outcomes. METHODS AND RESULTS: Medicare beneficiaries who underwent TVS from 2013 to 2020 were identified. Patients who underwent TVS for endocarditis were excluded. The primary exposure of interest was new PPM after TVS. Outcomes included all-cause mortality and readmission with endocarditis or heart failure on follow-up...

Regadenoson (brand name Lexiscan) is a specific adenosine receptor agonist commonly used in pharmacologic stress testing due to its coronary vasodilatory effects. Despite it being generally well-tolerated, the American Society of Nuclear Cardiology established absolute and relative contraindications to the use of regadenoson in patients with certain co-morbidities such as uncontrolled hyper/hypotension, sinus node disease, and second-degree heart blocks. While cases of advanced heart block after the administration of regadenoson have been reported, they remain incidental...

BACKGROUND: Sinus bradycardia and first degree or second degree Mobitz type I atrioventricular (AV) block in an athlete are considered adaptive and reversible phenomena; however, some evidence suggests that they may persist after detraining and become pathological. The aim of the study was to investigate the characteristics of a group of former professional athletes who required pacemaker (PM) implantation for intrinsic (idiopathic) sinus node (SN) dysfunction or AV block in comparison to control groups of sedentary individuals...

BACKGROUND: Coronary pseudoaneurysm is a rare, potentially fatal, complication of coronary intervention. A challenging management case of a giant right coronary pseudoaneurysm is presented. CASE SUMMARY: A 56-year-old man presented with an atypical presentation for ST-elevation myocardial infarction. Initial angiogram showed a crescent-shaped ostial lesion with probable connection to the aorta, which disappeared after placing a drug-eluting stent. A few hours later, patient was found to have staph aureus bacteraemia and infective endocarditis for which he received a prolonged antibiotic course...

BACKGROUND: SwiftNINJA (Merit Medical Systems, USA) is a novel steerable microcatheter intended for coronary and peripheral vascular interventions. We evaluate and report the first use of SwiftNINJA in pediatric catheterization of congenital heart defects (CHDs). METHODS: We performed a retrospective clinical data review of children with CHDs in whom SwiftNINJA was used during cardiac catheterization between April 2022 and June 2023. Utility, application, and standard safety were described comprehensively...

AIM: Bradyarrhythmias result from inhibition of automaticity, prolonged repolarization, or slow conduction in the heart. The ERG channels mediate the repolarizing current IKr in the cardiac action potential, whereas T-type calcium channels (TTCC) are involved in the sinoatrial pacemaker and atrioventricular conduction in mammals. Zebrafish have become a valuable research model for human cardiac electrophysiology and disease. Here, we investigate the contribution of ERG channels and TTCCs to the pacemaker and atrioventricular conduction in zebrafish larvae and determine the mechanisms causing atrioventricular block...

INTRODUCTION: This study evaluated the feasibility of His bundle pacing (HBP) in consecutive, unselected patients with advanced atrioventricular block (AVB) over a medium-term follow-up period, comparing procedural characteristics between nodal and infranodal sites of the conduction block. MATERIALS AND METHODS: Seventy-five consecutive patients with second-degree or third-degree AVB in which HBP was attempted were prospectively included in this study. The clinical and procedural-related characteristics of the patients were recorded at baseline and over a mid-term follow-up...

BACKGROUND: Ebstein's anomaly occurs when there is an apical displacement of the tricuspid valve with septal and posterior valve leaflets tethering. This condition often occurs in association with other congenital, structural, or conduction system diseases, including intracardiac shunts, valvular lesions, arrhythmias, accessory conduction pathways, and first-degree atrioventricular (AV) block. We present for the first time a case of a patient with Ebstein's anomaly who presented with second-degree Mobitz II AV block and was successfully treated with conduction system pacing (CSP) due to her young age and the likelihood of a long-term high percentage of pacing...

BACKGROUND AND AIMS: Evaluating cardiovascular safety of sphingosine 1-phosphate (S1P) receptor modulators is warranted due to S1P receptor expression on cardiomyocytes and vascular endothelial cells. This analysis reports the cardiovascular safety of ozanimod, an S1P receptor modulator, in patients with moderately to severely active ulcerative colitis from the phase 3 True North (TN) and open-label extension (OLE). METHODS: All patients who received ozanimod in TN (n=796) and all eligible TN patients who entered the OLE (n=823) were included...