The Long-Term Change of Arrhythmias after Transcatheter Closure of Perimembranous Ventricular Septal Defects

Objectives. To observe and analyze the long-term change of different types of arrhythmias after transcatheter closure of perimembranous ventricular septal defect (pmVSD). Methods. We retrospectively collected the data of patients who underwent pmVSD closure in our institution from March 2002 to December 2010. Results. One hundred thirty-nine patients met the inclusion criteria, of which 265 (25.5%) had early arrhythmia. They were classified into two categories: conduction abnormality (191/1039; 18.4%) and origin abnormality (94/1039; 9.0%), including 20 patients with both types of arrhythmias. The median follow-up time was 84.5 months, and 103 patients (103/191; 53.9%) with early conduction block got permanent arrhythmias, while only three patients (3/94; 3.2%) with early anomalous origin arrhythmias still had an abnormal electrocardiogram. Serious arrhythmias (28/1039; 2.7%), including II° atrioventricular block (AVB), III° AVB, and complete left bundle branch block (CLBBB), can appear immediately in the early postoperative period (21 patients) or in the late outset (seven patients) after several months or even years (6 months to 8.3 years). Twenty patients (20/21; 95.2%) with serious arrhythmia in the early postoperative period improved after early treatment, but six patients relapsed or worsened during follow-up. At the endpoint, severe arrhythmia persisted in 13 patients, of which four patients got permanent pacemaker implanted, and one patient with recurrent CLBBB died from heart failure. Conclusions. The probability of delayed CAVB or bundle branch block after VSD closure is low but often occurs several years after surgery. Therefore, long-term ECG follow-up should last for several years or even decades. Serious arrhythmias that appear early after transcatheter pmVSD closure may impose a risk of recurrence although they have been cured already. Close attention should be paid to the changes of cardiac function in patients with CLBBB after VSD closure, and the severity of such arrhythmia should be taken seriously and reexamined.

Cardiac Involvement in Facioscapulohumeral Muscular Dystrophy (FSHD)

Background: Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common muscular dystrophies and predominantly affects facial and shoulder girdle muscles. Previous case reports and cohort studies identified minor cardiac abnormalities in FSHD patients, but their nature and frequency remain incompletely characterized.Methods: We reviewed cardiac, neurological and genetic findings of 104 patients with genetically confirmed FSHD.Results: The most common conduction abnormality was complete (7%) or incomplete (5%) right bundle branch block (RBBB). Bifascicular block, left anterior fascicular block, complete atrioventricular block, and 2:1 atrioventricular block each occurred in 1% of patients. Atrial fibrillation or flutter were seen in 5% of patients. Eight percent of patients had heart failure with reduced ejection fraction and 25% had valvular disease. The latter included aortic stenosis in 6% (severe in 4% and moderate in 2%) and moderate aortic regurgitation in 8%. Mitral valve prolapse (MVP) was present in 9% of patients without significant mitral regurgitation. There were no significant associations between structural or conduction abnormalities and age, degree of muscle weakness, or size of the 4q deletion.Conclusions: Both structural and conduction abnormalities can occur in FSHD. The most common abnormalities are benign (RBBB and MVP), but more significant cardiac involvement was also observed. The presence of cardiac abnormalities cannot be predicted from the severity of the neurological phenotype, nor from the genotype.

617 Electrocardiogram Abnormalities in Children Undergoing Polysomnography

Introduction Monitoring electrocardiogram (EKG) is an integral component of pediatric polysomnography (PSG). There is limited data regarding arrhythmia and conduction disturbances in the pediatric population undergoing a PSG. In this work we will present abnormal EKG findings during PSG in our sleep center. Methods A retrospective chart review from children at Seattle Children’s Hospital who underwent PSG read by a single Sleep Medicine physician (LD) in the last year was carried out. Data included age, sex, type of EKG abnormality, sleep diagnosis from PSG. Data from children with 1st or 2nd degree atrioventricular block (AVB) were compared to those from children with premature ventricular contractions (PVC). Results A total of 1,235 PSG were included. Twenty-four children (9 girls and 15 boys) aged 2–17 years (median 9 years) were identified with arrhythmias or conduction disturbances (1.9%). Nineteen out of 24 of these children (79.2%) had oAHI >1/hour; this frequency was not significantly different from that found in the whole group of 1,235 children (Chi-square test p=0.16). When comparing PSG parameters from children with AVB with those with PVC, we found no statistically significant difference. Seven out of nine children with AVB and seven out of ten with PVC had oAHI >1/hour (Fisher exact test p=0.56) while eight children with AVB out of nine and four out of ten with PVC were males, and this difference was the only statistically significant difference found (Fisher exact test p=0.04). None of the children were found to have a structural or conduction abnormality when referred to cardiology. Conclusion Our study found ECG abnormalities in 1.9 % of children undergoing PSG. None of the children were found to have abnormal findings after cardiology referral. Our study supports that EKG abnormalities are rare in PSGs of children and not associated with cardiac disease or sleep disorders, but appear more commonly in males. Support (if any):

EKG Findings Mimicking Pericarditis and STEMI in a patient with Ventricular Preexcitation: A Case Report

Wolff-Parkinson-White (WPW) syndrome is an electrical conduction abnormality of the heart in which atrial impulses are transmitted to the ventricle through an accessory pathway, leading to supraventricular tachycardia [1]. On EKG, WPW presents with shortened PR interval, widened QRS, and a characteristic delta wave. Here, we present the case of 44-year-old African American male with a history of preexcitation/WPW pattern and no known history of coronary artery disease who came to the hospital complaining of atypical chest pain. He had transient ST elevation in beats with delta waves, both in the ambulance and emergency room EKGs (Figure 1 and 2) . Five minutes later, a repeat EKG showed ST elevation along with PR depression mimicking pericarditis (Figure 4) . Cardiac enzymes remained normal. EKG stress test with myocardial perfusion imaging was negative for ischemia and echocardiogram was normal.

Camrelizumab-related lethal arrhythmias and myasthenic crisis in a patient with metastatic thymoma: a case report

Immune checkpoint inhibitors (ICIs) have emerged in recent years as a promising treatment option for several malignant tumors. However, ICI therapy has also been associated with various immune-related adverse events (irAEs), especially with pre-existing autoimmune status, which sometimes can be life-threatening. A 68-year-old woman diagnosed with metastatic thymoma was treated with camrelizumab as her initial anti-tumor protocol at a nearby hospital. On 11 days after the first dose of camrelizumab, the patient was admitted to our hospital with symptoms of dyspnea, fatigue, and poor appetite. Workup on admission indicated dramatically elevated transaminase, troponin I, creatine kinase, and creatine kinase MB and a new-onset conduction abnormality on electrocardiography. She had no other underlying disease prior to ICI treatment; therefore, ICI-related myocarditis, myositis and hepatitis were diagnosed, and intravenous methylprednisolone (80mg/day) and other supporting treatments were administered sequentially. Coronary angiography was performed on day 3 of hospitalization, but no abnormality was detected. On the same day, she lapsed into a coma with respiratory muscle failure, which was highly suspected of myasthenic crisis. Therefore, mechanical ventilation and higher dose of methylprednisolone (1 g/day) plus intravenous immunoglobulin (20g/day) were applied immediately. The third artrioventricular block occurred abruptly and an urgent temporary pacemaker was placed. Repeated ventricular tachycardia (VT) occurred, and even multiple antiarrhythmic drugs used in combination failed to alleviate the VT storm. On day 5 of hospitalization, she suffered from ventricular fibrillation and die of cardiac arrest. In conclusion, close follow-up should be conducted after ICI treatment, especially for patients already with or at high risk for autoimmune disorders. Once diagnosed with severe irAEs, prompt high dose of glucocorticoid alone or in combination with other immunomodulators if necessary should be administered. A multidisciplinary team approach is of importance for better management of patients with multiple organs involvement.

Recurrent syncope in patients with a pacemaker and bradyarrhythmia

Objectives To investigate the risk of recurrent syncope and all-cause mortality after implantation of a pacemaker in patients with bradyarrhythmia. Background A pacemaker is generally recommended when syncope is caused by bradyarrhythmias to prevent a new syncope. However, the occurrence and risk of recurrent syncope in patients with bradyarrhythmia after pacemakerimplantation are still unknown. Methods Patients with a prior syncope and an implantation of pacemaker were identified. Cumulative incidences of 5-years were estimated for the outcomes stratified into groups according to the type of bradyarrhythmia; and type of pacemaker. The risk of recurrent syncope and all-cause mortality were estimated using adjusted cox proportional hazard regressions. Results We identified 8,663 patients with a prior syncope and pacemaker implantation (median age of 78,1 years (SD 69,1–84,8) and 55,1% males). The 5-year cumulative incidence of recurrent syncope was 19,3% (95% confidence intervals (CI) 18,4–20,2). Factors associated with a significant increased risk of recurrent syncope were male sex, age 80 years and above, alcohol related disease, bleeding, chronic obstructive pulmonary disease, chronic kidney disease, stroke, and malignancy. Atrial fibrillation was associated with a significantly decreased risk of recurrent syncope. Patients with an advanced AV conduction abnormality had a lower associated risk of syncope compared to patients with sinus node dysfunction (HR 0,85, 95% CI 0,76–0,94, p=0,003). Conclusions One fifth of the cohort had a recurrence syncope after five years. Besides older age and male sex, several comorbidities were found to be associated with a higher risk of recurrence of syncope. Clinicians need to be attentive that a large proportion of patients with bradyarrhythmia suffer from syncope even when treated with a pacemaker. Funding Acknowledgement Type of funding source: None

Abnormal mitral flow, what is the cause?

Diastolic mitral regurgitation is a unique Doppler finding that can be missed if special attention is not paid to it. There are a few causes of such abnormal flow, ranging from a conduction abnormality to abnormal valvular and left ventricle function. Failure to recognize it might lead to unnecessary investigations and delay the primary diagnosis. We are presenting a teaching case and discuss the associated pathology.

Cardiac phenotype in ATP1A3-related syndromes

ObjectiveTo define the risks and consequences of cardiac abnormalities in ATP1A3-related syndromes.MethodsPatients meeting clinical diagnostic criteria for rapid-onset dystonia-parkinsonism (RDP), alternating hemiplegia of childhood (AHC), and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS) with ATP1A3 genetic analysis and at least 1 cardiac assessment were included. We evaluated the cardiac phenotype in an Atp1a3 knock-in mouse (Mashl+/−) to determine the sequence of events in seizure-related cardiac death.ResultsNinety-eight patients with AHC, 9 with RDP, and 3 with CAPOS (63 female, mean age 17 years) were included. Resting ECG abnormalities were found in 52 of 87 (60%) with AHC, 2 of 3 (67%) with CAPOS, and 6 of 9 (67%) with RDP. Serial ECGs showed dynamic changes in 10 of 18 patients with AHC. The first Holter ECG was abnormal in 24 of 65 (37%) cases with AHC and RDP with either repolarization or conduction abnormalities. Echocardiography was normal. Cardiac intervention was required in 3 of 98 (≈3%) patients with AHC. In the mouse model, resting ECGs showed intracardiac conduction delay; during induced seizures, heart block or complete sinus arrest led to death.ConclusionsWe found increased prevalence of ECG dynamic abnormalities in all ATP1A3-related syndromes, with a risk of life-threatening cardiac rhythm abnormalities equivalent to that in established cardiac channelopathies (≈3%). Sudden cardiac death due to conduction abnormality emerged as a seizure-related outcome in murine Atp1a3-related disease. ATP1A3-related syndromes are cardiac diseases and neurologic diseases. We provide guidance to identify patients potentially at higher risk of sudden cardiac death who may benefit from insertion of a pacemaker or implantable cardioverter-defibrillator.