A Case of Transient Complete Heart Block During Left Heart Catheterization.

Iatrogenic complete heart blocks are rare but a reported complication of left heart catheterizations in patients with pre-existing right bundle branch blocks. We present the case of an 84-year-old male with a preexisting right bundle branch block who underwent a left heart catheterization for valve replacement evaluation. While attempting to engage the right coronary artery, the catheter instead crossed the aortic valve, causing the patient to become bradycardic to the 20s and hypotensive. The patient had a temporary transvenous pacer inserted and tolerated the rest of the procedure well. The cause of the complete heart block was thought to be due to the transient blockage of the left bundle branch due to ventricular septal irritation when the catheter crossed the aortic valve. When performing left heart angiograms in a patient with a right bundle branch block, operators should be prepared for a possible iatrogenic complete heart block.

Incidence of Coronary Artery Disease After Permanent Pacemaker Implantation: A Hospital-based Study from East India.

Bradyarrhythmias, characterized by heart rates of <60 bpm due to conduction issues, carry risks of sudden cardiac death and falls. Pacemaker implantation is a standard treatment, but the interplay between bradyarrhythmias, coronary artery disease (CAD), and patient attributes requires further exploration. This study was a retrospective hospital record-based study that analyzed data from 699 patients who underwent pacemaker implantation for symptomatic bradyarrhythmias between February 2019 and February 2022. Clinical parameters, coronary angiography (CAG) findings, ejection fraction, and indications for pacemaker implantation were documented. The relationship between CAD severity, specific bradyarrhythmias, and ejection fraction was explored. Statistical analysis included chi-squared tests and t tests. The mean age of the study population (n = 699) was 66.75 years (male:female ratio, 70:30), with 77.2% having type 2 diabetes and 61.6% being hypertensive. The majority of patients had minor or non-obstructive CAD (61.8%), followed by normal CAG findings (25.75%) and obstructive CAD (12.45%). Complete heart block (CHB) was the primary indication for pacemaker implantation (55.2%), followed by sick sinus syndrome (22.3%). The results did not show any association between ejection fraction and CAG findings. Patients who presented with CHB had a higher incidence of obstructive CAD, indicating greater severity. This study sheds light on the intricate interplay between severe bradyarrhythmias, CAD, and patient characteristics. Our analysis revealed no statistical significance between obstructive CAD and the need for a permanent pacemaker. This makes us question our practice of maintaining a low threshold for coronary angiography during pacemaker implantation. The observed low yield and anticoagulation protocol reassure us of the choice to delay this diagnostic intervention. These insights can guide tailored management strategies, enhancing clinical care approaches for patients with severe bradyarrhythmias necessitating pacemaker implantation.

High-Degree Atrioventricular Block and Torsades De Pointes in Severe Aortic Stenosis Treated With Transcatheter Aortic Valve Replacement.

Severe aortic stenosis (AS) significantly elevates cardiovascular risk, predisposing patients to high-degree atrioventricular (AV) block and life-threatening tachyarrhythmias, including torsades de pointes (TdP). This case report presents a patient with severe AS who developed high-degree AV block and, subsequently, TdP, highlighting the interplay between bradycardia and mechanisms that trigger ventricular tachycardias. The case underscores the importance of identifying and managing these risk factors to improve patient outcomes.

Myocardial Infarction and Complete Heart Block in a Patient With Anomalous Origin of the Left Coronary Artery From the Pulmonary Artery (ALCAPA).

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital malformation. We present a case of an elderly patient with ALCAPA presenting with complete heart block and non-ST-elevation myocardial infarction years after diagnosis and surgical correction. An 81-year-old female with a history of ALCAPA presented to the emergency department with chest pain and progressive mental deterioration. She was bradycardic and hypotensive. An electrocardiogram revealed a complete heart block. Troponin was 4.04 ng/mL. She received atropine and underwent transcutaneous pacing. Left heart catheterization revealed complete occlusion of the mid-left circumflex artery, which was intervened with balloon angioplasty and chronic total occlusion of the right coronary artery. She was supported with temporary transvenous pacing, did not require further pacing support, and was discharged home. Previous records unearthed that in 1988 she had presented with syncope and was diagnosed with ALCAPA, filling from right-to-left collaterals with large and ectatic coronaries. At the time, she underwent surgical correction with excision of the left coronary from the pulmonary artery and reimplantation in the left coronary cusp along the posterior aorta. She had remained asymptomatic after her surgery until this presentation. ALCAPA is extremely rare in adults. Insufficient collaterals to the left ventricle cause inadequate blood supply, leading to ischemia in adults, predisposing them to arrhythmias and risk of sudden death. Adults with ALCAPA remain at increased risk of adverse cardiac events later in life, requiring long-term monitoring.

Epicardial Pacing Outcomes in Infants with Heart Block: Lead and Device Complications from a Multicenter Experience.

BACKGROUND: Infants with complete heart block (CHB) require epicardial pacemaker (PM) insertion. Prior studies described epicardial pacing outcomes in infants and children though were limited by small and/or heterogeneous populations. OBJECTIVE: To explore patient and procedural-level associations with device complications in infants with CHB who received a permanent PM. METHODS: Multicenter, retrospective cohort study including infants receiving an epicardial PM between 2000-2021 for CHB. The primary outcome was time to device-related adverse event (DRAE): (1) lead failure requiring revision; (2) pocket infection; (3) exit block requiring increased pacing output; or (4) lead-related coronary artery compression. Time to event analysis was performed using the Kaplan-Meier method with a multivariable Cox proportional hazards model. RESULTS: 174 infants received an epicardial PM (282 bipolar, 39 unipolar leads) for CHB. Median age and weight at PM were 93.5 days and 4.5 kg, respectively. Pacing indication was postoperative CHB in 63% and congenital CHB in 37%. The median follow-up was 2.1 years. The primary outcome occurred in 26 infants at a median time to event of 0.6 years. Age ≤90 days at PM was the most significant risk factor for DRAE (HR 7.02, p<0.001), primarily driven by pocket infections. Lead failure occurred in 3% of leads with a 5- and 10-year freedom from failure of 93% and 83%, respectively. CONCLUSIONS: Device complications affect 15% of infants receiving a permanent PM for heart block. Age ≤90 days at PM implant is especially associated with infectious complications. Epicardial lead durability appears similar to previously reported pediatric experiences.

Sjogren's Antibodies and Neonatal Lupus: A Scoping Review.

Sjogren's syndrome (SS) is an autoimmune disease characterized by inflammation of exocrine glands. The disorder predominantly affects middle-aged women. Autoantibodies, including anti-SS-A/Ro and anti-SS-B/La antibodies, are present in most cases of SS. These antibodies can cross the placenta and likely play a role in pregnancy complications as well as the development of neonatal lupus, resulting in congenital heart block (CHB). It is essential to monitor the fetus for CHB during pregnancy. In particular, screening with echocardiography and monitoring heart rate at home are recommended practices. Regarding medical management, hydroxychloroquine and glucocorticoids have shown promise in reducing cardiac manifestations, but further research is needed to elucidate their longer term efficacy and safety. This scoping review analyzes literature from 2001 to 2024, focusing on pregnancy outcomes among women with SS, clinical manifestations of neonatal lupus, the role of anti-SS-A/Ro and anti-SS-B/La antibodies in the development of neonatal lupus and CHB, and emphasizes the need for future research efforts to refine treatment protocols and enhance clinical care strategies for pregnant women with SS.

A Rare Case of Complete Heart Block and Takotsubo Cardiomyopathy in an Elderly Patient: A Case Report.

Although Takotsubo cardiomyopathy (TC) is often linked to various tachyarrhythmias, the coexistence of Takotsubo cardiomyopathy and complete heart block is rare, and the cause-and-effect relationship remains unclear. We present the case of an 83-year-old female with a history of known second-degree atrioventricular (AV) block who presented with syncopal episodes and bradycardia. She was diagnosed with a complete heart block requiring a dual-chamber pacemaker. Upon case review, transthoracic echocardiography revealed severe apical hypokinesis, prompting coronary angiography, which showed normal coronary arteries, consistent with Takotsubo cardiomyopathy. This case explores the relationship between Takotsubo cardiomyopathy and complete heart block, as well as the potential pathophysiological mechanisms involved.

Complex Presentation of Congenital Heart Block and Coexisting Congenital Heart Disease in a One-Year-Old Girl: A Case Report.

Congenital complete heart block (CCHB) is a rare and potentially life-threatening condition, often associated with maternal autoantibodies. We present the case of a one-year-old girl with recurrent respiratory symptoms, ultimately diagnosed with CCHB and congenital heart disease. She exhibited bradycardia and signs of congestive heart failure. A diagnostic workup revealed significant cardiac abnormalities, including dilated chambers, ventricular septal defect, and patent ductus arteriosus. Serological tests for maternal autoantibodies were negative. The child's parents opted for discharge without surgical intervention. This case underscores the importance of comprehensive evaluation and management strategies in patients with congenital heart block, particularly in resource-limited settings.

Simultaneous Occurrence of Transient Complete Heart Block With Acute Lateral Medullary Infarct.

Lateral Medullary Syndrome (LMS) poses clinical challenges, often resulting from ischemic events in the medulla oblongata. We present a unique case of LMS in a woman in her 60s with a complex medical history. Alongside neurological deficits, she experienced a transient high-grade atrioventricular block (HgAVB), a rare cardiac manifestation linked to LMS. Given the rarity of simultaneous transient HgAVB with acute lateral medullary infarct, only a handful of case reports documenting similar findings are available in the existing literature. More research and case reporting are needed to better our understanding of this area. The patient's condition, marked by a sudden onset of severe headache and left-sided weakness, revealed an acute infarct in the medulla territory. Notably, her HgAVB spontaneously resolved after 72 hours. This case emphasises the crucial need for extended cardiac surveillance in LMS patients due to their susceptibility to life-threatening arrhythmias. The intricate interplay between the brainstem and cardiovascular system highlights autonomic dysregulation as a potential mechanism for cardiac abnormalities. The report advocates for a holistic approach to managing LMS cases, stressing interdisciplinary collaboration for timely diagnosis and intervention, ultimately improving patient outcomes and reducing the risk of fatal arrhythmias.

A systematic review of the clinical characteristics and course of atrioventricular blocks in hyperthyroidism.

BACKGROUND: Atrioventricular block (AVB) is rare in hyperthyroidism (HTH). Little is known about the true prevalence, clinical course, optimal management, and outcomes of different types of AVBs in patients with HTH. To address these uncertainties, we aimed to conduct a systematic review by combining the available literature to provide more meaningful data regarding AVBs in HTH. METHODS: We systematically searched PubMed, Scopus, Embase, and Google Scholar for articles reporting patients who developed AVB in the context of HTH. Data were analysed in STATA 16. The main outcomes included types of AVB, frequency of pacemaker insertion, and resolution of AVB. The systematic review is registered with the International Prospective Register of Systematic Reviews (PROSPERO) with the identification number CRD42022335598. RESULTS: A total of 56 studies (39 case reports, 12 case series, 3 conference abstracts, 1 retrospective study, and 1 prospective observational study) with 87 patients were included in the analysis, with a mean age of 39.1 ± 17.6 years. Females constituted 65.7% (n = 48) of the cohort. Complete heart block (CHB) was the most commonly reported AVB (N = 45, 51.7%), followed by first-degree AVB (16.1%) and second-degree AVB (14.9%). Overall, 21 patients underwent pacing. A permanent pacemaker was inserted in one patient with second-degree AVB and six patients with CHB. Mortality was reported in one patient with CHB. The clinical course and management of HTH and AVBs did not differ in patients with CHB or lower-degree blocks. Apart from lower rates of goitre and more use of carbimazole in those who underwent pacing, no differences were found when compared to the patients managed without pacing. CONCLUSION: Current data suggest that CHB is the most common type of AVB in patients with HTH. Most patients can be managed with anti-thyroid management alone. Additionally, whether pacemaker insertion alters the clinical outcomes needs further exploration.

Dengue Fever Culminating in Cardiac Arrest: A Case Report.

Infection from the dengue virus can manifest with a variety of clinical presentations. Cardiac involvement from dengue fever is a rarely reported phenomenon with significant morbidity and mortality. We illustrate the case of a 47-year-old male admitted to the hospital with fevers. The hospital course was complicated with cardiac arrest. Clinicians need to be weary of this rare occurrence particularly in areas with a known prevalence of dengue for prompt recognition and improved patient outcomes.

Incidental Finding of Transthyretin Cardiac Amyloidosis During Coronary Artery Bypass Grafting.

Transthyretin cardiac amyloidosis (ATTR-CA) is a condition characterized by extracellular deposition of misfolded transthyretin proteins in the myocardium and has been historically difficult to diagnose due to diverse clinical manifestations and nonspecific, variable electrocardiogram (ECG) and echocardiogram findings. Advancements in noninvasive cardiac imaging have led to significant increases in diagnoses of ATTR-CA. Once thought to be a rare condition, there is growing evidence to suggest that ATTR-CA is more prevalent than previously understood, prompting the need for early diagnosis and intervention. We outline the case of a 78-year-old male who presented to the emergency department with chest discomfort, shortness of breath, dizziness, and diaphoresis. He was found to have severe coronary artery disease (CAD) and intermittent complete heart block. Cardiac dysfunction was unable to be resolved by percutaneous coronary intervention (PCI) and thus the patient was referred for coronary artery bypass grafting (CABG). Intraoperatively, the patient's heart was found to be abnormally thickened and fibrosed. Biopsy of the cardiac tissue and evaluation using technetium-99m pyrophosphate scintigraphy, single-photon emission computed tomography, and liquid chromatography-tandem mass spectrometry revealed ATTR-CA. There is a need for fast and low-cost screening tools to allow for early identification of the disease. Diagnostic clues for cardiac amyloidosis include the presence of carpal tunnel syndrome, lumbar spinal stenosis, atrial fibrillation, treatment-resistant heart failure with preserved ejection fraction, and a thickened left ventricular wall. Given the presence of these red flag symptoms, clinicians should have a heightened index of suspicion for ATTR cardiac amyloidosis in elderly patients even when presenting in acute settings.

Complete Congenital Heart Block in the Offspring of an Asymptomatic Woman with Isolated High Titer Anti-Ro Antibody.

Among pregnant women, 1-2% are anti-Ro positive and while half of them have symptoms of connective tissue disease, the rest are asymptomatic. The presence of anti-Ro is of concern because of the risk of congenital heart block in the child. We report the case of an asymptomatic 27-year-old G2P1(1001) woman, who presented with persistent fetal bradycardia in her 21st week of gestation (AOG) and was found to have elevated titers for anti-Ro (>320 U/ml). Hydroxychloroquine 200 mg/day and prednisone 10 mg/day were given from the 33rd week of gestation up until the delivery. At 37 weeks AOG, she delivered a live male neonate with a complete heart block. On the 6th day of life, the infant remained bradycardic, hence a pacemaker was inserted and heart rate maintained at 100-120 bpm. On subsequent follow-ups, the mother and child did not develop any systemic manifestations and the infant was thriving well. While a diseased condition may not be apparent in a pregnant anti-Ro positive woman, the risk of neonatal lupus (NL) is demonstrated in this patient's case. This report illustrates how prenatal care of an asymptomatic woman led to the discovery of a fetal abnormality and served to prepare the family and the medical team to ably handle the birth and subsequent care of a neonate with NL.

Systemic Diseases and Heart Block.

Systemic diseases can cause heart block owing to the involvement of the myocardium and thereby the conduction system. Younger patients (<60) with heart block should be evaluated for an underlying systemic disease. These disorders are classified into infiltrative, rheumatologic, endocrine, and hereditary neuromuscular degenerative diseases. Cardiac amyloidosis owing to amyloid fibrils and cardiac sarcoidosis owing to noncaseating granulomas can infiltrate the conduction system leading to heart block. Accelerated atherosclerosis, vasculitis, myocarditis, and interstitial inflammation contribute to heart block in rheumatologic disorders. Myotonic, Becker, and Duchenne muscular dystrophies are neuromuscular diseases involving the myocardium skeletal muscles and can cause heart block.

Pacemaker-mediated reentrant arrhythmia facilitated by an atrial-tracking leadless pacemaker.

INTRODUCTION: Pacemaker-mediated tachycardia is a known arrhythmia in patients with dual chamber pacemakers and defibrillators and intact ventriculoatrial (VA) conduction. We report a case of pacemaker-mediated reentrant arrhythmia (PMRA) in a patient with an atrioventricular (AV) synchronous leadless pacemaker. METHODS AND RESULTS: A 91-year-old female presented with 2:1 AV conduction and received an AV synchronous leadless pacemaker. She had atrial mechanical sense-ventricular paced beats between heart rates of 80-100 bpm more than 80% of the time. She was found to have a new cardiomyopathy and was referred for placement of biventricular pacemaker. At the time of device implantation, her electrocardiogram showed ventricular pacing with a short RP interval and superiorly directed P waves. Changes in the ventricular pacing rate resulted in changes in the atrial rate. Following device placement, her heart rate decreased to the lower rate limit of her pacemaker. The atrial mechanical sense impulse most likely was generated by a retrograde conducted P wave resulting in near incessant PMRA. CONCLUSION: PMRA may occur in patients who receive an AV synchronous leadless pacemaker with intact VA conduction and sinoatrial node dysfunction. Due to the lower rates of PMRA, this arrhythmia may be underrecognized. Interventions for and implications of PMRA need further investigation.

Diagnosis and Management of Fetal Arrhythmias in the Current Era.

Diagnosis and management of fetal arrhythmias have changed over the past 40-50 years since propranolol was first used to treat fetal tachycardia in 1975 and when first attempts were made at in utero pacing for complete heart block in 1986. Ongoing clinical trials, including the FAST therapy trial for fetal tachycardia and the STOP-BLOQ trial for anti-Ro-mediated fetal heart block, are working to improve diagnosis and management of fetal arrhythmias for both mother and fetus. We are also learning more about how "silent arrhythmias", like long QT syndrome and other inherited channelopathies, may be identified by recognizing "subtle" abnormalities in fetal heart rate, and while echocardiography yet remains the primary tool for diagnosing fetal arrhythmias, research efforts continue to advance the clinical envelope for fetal electrocardiography and fetal magnetocardiography. Pharmacologic management of fetal arrhythmias remains one of the most successful achievements of fetal intervention. Patience, vigilance, and multidisciplinary collaboration are key to successful diagnosis and treatment.

Congenital Complete Heart Block-To Stimulate (When?) or Not to Stimulate?

This article presents the case of a 27-year-old female patient with idiopathic congenital complete heart block who does not consent to the implantation of a cardiac pacemaker but was referred by her primary care physician for cardiological evaluation. The conduction disturbance was recognized at the age of 6 and was asymptomatic. The professional disqualification from pacemaker implantation included a detailed history of a patient's symptoms, an echocardiographic assessment of the heart, exercise testing and ECG Holter monitoring. The aid of salbutamol administered orally was also useful.

Outcomes of surgical septal myectomy for obstructive hypertrophic cardiomyopathy after previous septal reduction therapy.

OBJECTIVE: To compare early and late outcomes of septal myectomy in patients with obstructive hypertrophic cardiomyopathy who presented with residual or recurrent left ventricular outflow tract (LVOT) obstruction after previous septal-reduction therapy (SRT). METHODS: From January 1989 to March 2022, 145 patients underwent reintervention by septal myectomy for residual LVOT obstruction after previous SRT; 72 patients had previous alcohol septal ablation (ASA) and 73 had previous surgical septal myectomy. Baseline patient characteristics, echocardiographic parameters, and surgical outcomes were compared between these 2 groups. RESULTS: Patients who had previous ASA were more likely to be male (50.0% vs 30.1%; P = .015), be older (median age 57.5 years vs 48.3 years; P < .001), and have a greater body mass index (32.7 kg/m2 vs 30.0 kg/m2; P = .011). After repeat SRT by septal myectomy, there was no significant difference in the incidence of postoperative complete heart block, necessitating permanent pacemaker, between the 2 groups (8.3% vs 2.7%; P = .151). One (0.7%) patient died within 30 days of surgery. Over a median follow-up of 7.5 years (interquartile range, 3.0-13.8), there were 20 deaths. Kaplan-Meier 5-, 10-, and 15-year survival rates were 100%, 91%, and 76% for the previous septal myectomy group, and 93%, 81%, and 64% for the previous ASA group (P = .207). CONCLUSIONS: Septal myectomy for residual or recurrent LVOT obstruction in patients who had previous ASA is safe, with an acceptably low rate of postoperative complete heart block. Surgical outcomes and late survival rates in patients with complete heart block ASA were satisfactory and comparable with patients who underwent repeat myectomy.

Contemporary trends of leadless pacemaker implantation in the United States.

INTRODUCTION: Leadless pacemakers (LPM) have established themselves as the important therapeutic modality in management of selected patients with symptomatic bradycardia. To determine real-world utilization and in-hospital outcomes of LPM implantation since its approval by the Food and Drug Administration in 2016. METHODS: For this retrospective cohort study, data were extracted from the National Inpatient Sample database from the years 2016-2020. The outcomes analyzed in our study included implantation trends of LPM over study years, mortality, major complications (defined as pericardial effusion requiring intervention, any vascular complication, or acute kidney injury), length of stay, and cost of hospitalization. Implantation trends of LPM were assessed using linear regression. Using years 2016-2017 as a reference, adjusted outcomes of mortality, major complications, prolonged length of stay (defined as >6 days), and increased hospitalization cost (defined as median cost >34 098$) were analyzed for subsequent years using a multivariable logistic regression model. RESULTS: There was a gradual increased trend of LPM implantation over our study years (3230 devices in years 2016-2017 to 11 815 devices in year 2020, p for trend <.01). The adjusted mortality improved significantly after LPM implantation in subsequent years compared to the reference years 2016-2017 (aOR for the year 2018: 0.61, 95% CI: 0.51-0.73; aOR for the year 2019: 0.49, 95% CI: 0.41-0.59; and aOR for the year 2020: 0.52, 95% CI: 0.44-0.62). No differences in adjusted rates of major complications were demonstrated over the subsequent years. The adjusted cost of hospitalization was higher for the years 2019 (aOR: 1.33, 95% CI: 1.22-1.46) and 2020 (aOR: 1.69, 95% CI: 1.55-1.84). CONCLUSION: The contemporary US practice has shown significantly increased implantation rates of LPM since its approval with reduced rates of inpatient mortality.