Transient Complete Heart Block Research Articles

Palliative Right Ventricular Outflow Tract Stenting in Tetralogy of Fallot with Severe Cyanosis: Experience from a Single Center in Southern India

Background: This study conducted at an Indian tertiary care hospital aimed to characterize the clinical profile of tetralogy of Fallot (ToF) patients undergoing right ventricular outflow tract (RVOT) stenting and assess their immediate postprocedural outcomes until discharge. Methods: In this retrospective analysis, the clinical and procedural outcomes were analyzed for 20 patients who underwent palliative stenting in the RVOT for severe cyanosis associated with ToF during 2021–2023. Results: The median age for the patients was 2.3 years (range 3 months–21 years), two being adults (>18 years). Fourteen (70%) patients underwent elective RVOT stent and 30% underwent emergency stenting. The most common indication of RVOT stenting was hypoplastic branch pulmonary arteries (PAs) (n = 11, 78.6%) and cyanotic spell (n = 4, 66.7%) for elective and emergency surgeries, respectively. The average improvement in SpO2 was 27.2% (95% confidence interval 23.4–31.0, P < 0.001). Six (30%) patients had complications including reperfusion injury of lungs (n = 2, 33.4%) sepsis (n = 1, 16.7%), stent embolization (n = 1, 16.7%), re-stenting (n = 1, 16.7%), transient complete heart block (n = 1, 16.7%) during the procedure, and. One child went through RVOT stent postoperative due to severe residual stenosis and child developed severe tricuspid regurgitation and succumbed to death due to culture positive sepsis with multi-organ dysfunction. Rest (n = 19, 95%) were discharged with an average 6.7 days of hospital stay. Conclusion: ROVT stenting is a safe and effective palliative management in ToF enhancing oxygen saturation prior to definitive surgical repair.

Transient complete heart block as a presentation of acute (bacterial) meningitis: a case report

Transient complete heart block as a presentation of acute (bacterial) meningitis: a case report

Depth of implantation in relation to membranous septum as a predictor of conduction disturbances after transcatheter aortic valve implantation

BackgroundConduction disturbances remain one of the most common complications occurring post TAVI. We aim to determine the predictors of cardiac conduction disturbances after Transcatheter Aortic Valve Implantation (TAVI) and propose a relevant predictive model.We included 70 consecutive patients with severe symptomatic AS who underwent TAVI using the self-expanding valve Evolut R or the balloon expandable Sapien XT valve. All patients were subjected to electrocardiographic evaluation pre- and post-TAVI and at 30 days. Clinical, echocardiographic, CT-derived, and procedural parameters were collected and analyzed. ResultsConduction disturbances affected 28 patients (40%): 16 patients (22.9 %) developed Left Bundle Branch Block (LBBB), 7 patients (10%) experienced transient Complete Heart Block (CHB), and 5 patients (7.1%) experienced permanent CHB requiring Permanent Pacemaker Implantation (PPI). We classified predictors into preprocedural and procedural predictors. Multivariate logistic regression analysis of pre-procedural predictors showed that the presence of basal septal calcification is the most powerful independent predictor (OR: 28.63, 95% CI: 4.59–178.68, p < 0.001). Multivariate logistic regression analysis for pre and post procedural predictors showed that the relationship between depth of implantation at the septum and membranous septum expressed in percentage (sDIMS) with cut-off >70.42% is the most powerful independent procedural predictor (OR: 1.11, 95% CI: 1.03–1.2, p 0.006). ConclusionConduction disturbances remain a common complication of TAVI. Presence of basal septal calcification is a non-modifiable risk factor that increase patient propensity of development such complication after TAVI. A depth of implantation exceeding 70% of the membranous septal length has been found to strongly predict conduction disturbances post TAVI. sDIMS can be used in planning the depth of implantation to reduce incidence of conduction disturbances post TAVI.

Abstract 13737: Two Episodes of Intermittent Complete Heart Block Following Elective Procedures

Background: Iatrogenic bradycardia and complete heart block can occur with medications commonly administered during general anesthesia. Case: A 79-year-old male with past medical history of coronary artery disease, hypertension, paroxysmal atrial fibrillation and a left bundle branch block, underwent elective lithotripsy procedure, baseline ECG demonstrated in Figure A. Post-operatively, he developed asymptomatic complete heart block approximately 3 minutes after receiving sugammadex, a paralytic reversal agent (see Figure B). He was admitted for monitoring and spontaneously converted to sinus rhythm after 10 hours. The patient was discharged home with a 30-day event monitor; no pauses or high-grade atrioventricular block was noted during the monitoring period. Three months later, he underwent ureteroscopy stent exchange; during the induction with propofol he developed asystole followed by cardiac arrest. CPR was initiated and had return to spontaneous circulation after 3 minutes. The patient was transferred to the ICU, however, once again complete heart block was observed. Clinical decision-making: This case highlights recurrent episodes of transient complete heart block in the setting of an underlying left bundle branch and first-degree AV block that were exacerbated by medications during general anesthesia. Because of his underlying conduction disease and recurrent complete heart block and subsequent cardiac arrest, he ultimately underwent insertion of permanent dual chamber pacemaker. Conclusion: Iatrogenic transient complete heart block is a rare but potentially fatal complication. Prompt diagnosis and clinical suspicion of reversible causes are warranted. Significant underlying conduction disease should be considered to decide the ideal therapeutic option.

PO-05-038 CONDUCTION SYSTEM CONCERNS DURING PVC ABLATION AT THE POSTERIOR SUPERIOR PROCESS OF THE LEFT VENTRICLE: A SAFE APPROACH FROM ALL ANGLES

Ventricular arrhythmias (VA) originating from the posterior superior process (PSP) are infrequent and challenging to treat with catheter ablation due to their location in the highest portion of the inferior left ventricular (LV) septum , proximity to the conduction system and origin between LV and right atrium. The incidence of conduction system abnormality from ablation in this area is ill-defined. To describe procedural approach and outcome of PSP ablation including conduction system effect. We reviewed our institutional VA ablation database between 1/2019-11/2022 to identify patients (pts) who underwent PSP ablation. Incidence, procedural technique, and outcomes (including conduction abnormalities and procedural success) are evaluated. Among 556 pts who underwent VA ablation during this period, nine patients (1.6%) underwent PSP ablation. Sustained VT was present in 1 and the remainder had ablation for PVCs. Three patients (33%) were female, 3 pts had prior VA ablation. Mean LVEF was 50.6% +/-7 %, and two patients had structural heart disease with scar on cardiac MRI. The VA morphology had some variance but shared common characteristics including leftward axis, rs in II, negative (QS or rS) in III, and predominantly positive concordance in precordial leads, similar to previously reported series (Figure 1). During ablation, five pts (55.5%) had fast junctional rhythm, and one (11.1%) had transient complete heart block. No one had HV or QRS prolongation post procedure. Two (22.2%) patients had >30 msec AH prolongation, and four (44.4%) patients had >30 msec PR prolongation. Ablation from the right atrium (RA) in 2, coronary sinus (CS) in 3, and from the left ventricular (LV) septum in 8 patients. The patient who had transient complete heart block had full recovery and did not require pacemaker (PPM) implant, and one patient with post procedure AH and PR prolongation required PPM ten months after the procedure. During mean follow-up of 13.8 +/- 10.5 months, 83.3% patients had <3% PVC burden, and there were 92% absolute reduction in PVC burden (P<0.05). Ablation for VA originating from the PSP is associated with a risk of damage to the upper AV conduction, predominantly manifesting as AH prolongation. Care should be taken to monitor conduction during ablation to avoid permanent damage to the conduction system. Despite this, successful ablation can be achieved from the RA, CS or the LV septum.Tabled 1Table 1VA ablation at PSPN=9Age66.4 +/- 16.4Female3 (33%)LVEF (%)50.6 +/-7 %Prior VA ablation0.78 +/- 1.5Abnormal imaging with scar2 (22%)Conduction system disturbance during procedureFast junctional rhythm during ablation5 (55.5%)Transient heart block during ablation1 (11.1%)AH prolongation > 30msec post procedure2 (22.2%)HV prolongation > 30msec post procedure0PR prolongation > 30msec post procedure4 (44.4%)QRS prolongation > 10msec post procedure0Procedure detailAblation form the RA2 (22.2%)Ablation from the CS3 (33.3%)Ablation from the LV8 (88.8%)Ablation with RF energy9 (100%)Ablation with cryo energy0Procedure outcomeMean follow up (months)13.8 +/- 10.5Pre procedure PVC burden (%) *14.8+/- 11.5Post procedure PVC burden (%) **1.32 +/- 1.9VT recurrence ***0Required pacemaker implant1 (11.1%)* Seven patients had information on pre-procedure PVC burden. ** Six patients had information on post-procedure PVC burden. *** One patient had VT ablation. VA: Ventricular arrhythmia, PSP: posterior superior process, LVEF: left ventricular ejection fraction, RA: right atrium, CS: coronary sinus, LV: left ventricle, RF: radiofrequency. Open table in a new tab

Transient Complete Heart Block during Femoral Central Venous Catheter Placement in a Pediatric Patient: A Case Description and Literature Review

Highlights Abstract Femoral central venous catheter (CVC) placement is a common procedure performed in the pediatric intensive care unit. Femoral CVCs have a relatively low intraprocedural complication rate compared with other access sites. We describe a case of guidewire-induced transient complete heart block during femoral CVC insertion. This complication is rare in the pediatric population. The incidence of its occurrence and guidance to prevent this complication are discussed.

Gentle Giant: An Unusual Cause of Heart Block

<h3>Introduction</h3> Inflammatory cardiomyopathies can be a diagnostic dilemma. Early management can lead to reduced morbidity and mortality for patients. We describe a rare presentation of an unusual cardiomyopathy. <h3>Case Report</h3> A 58-year-old female presented with a 10-day prodrome of cough, NYHA class III dyspnea, and fatigue with minimal symptoms of orthopnea, paroxysmal nocturnal dyspnea or peripheral edema. She was previously healthy with no cardiac medications. Family history was significant for granulomatosis with polyangiitis. COVID-19 swab was negative. She was symptomatic with transient complete heart block and junctional escape of 20bpm. A temporary transvenous pacemaker was placed. Echocardiogram showed biventricular dysfunction with left ventricular ejection fraction < 30%. Troponin and brain-natriuretic peptide were elevated. Coronary angiogram showed no significant occlusions. CT excluded pulmonary embolism, pneumonia, or adenopathy. She was initiated on heart failure medications but beta blocker was not started given heart block. Six days into admission, her heart failure improved but she developed transient complete heart block without junctional escape. There was no ventricular ectopy. Evaluation for rheumatologic, infectious, and inflammatory causes showed elevated C-reactive protein and antineutrophil cytoplasmic antibodies. The remainder of the workup was negative. Leading diagnoses were idiopathic giant cell myocarditis or cardiac sarcoidosis. An endomyocardial biopsy revealed multinucleated giant cells and myocyte necrosis. She was diagnosed with giant cell myocarditis. Prior to discharge, she had defibrillator insertion and was initiated on prednisone and tacrolimus. Shortly after this time, she returned with critical cardiogenic shock despite intensification of immunosuppressive therapies and was listed for cardiac transplant. <h3>Summary</h3> Giant cell myocarditis (GCM) is a rare and often fatal autoimmune cause of heart failure. Patients frequently present with congestive heart failure, ventricular arrhythmia and a rapid progression of symptoms. In GCM, it is rare to present with atrioventricular conduction delays. Given the crossover in symptoms with sarcoidosis and GCM, diagnosis may be challenging. In this case of an acute presentation of heart failure and complete heart block, endomyocardial biopsy was central to the diagnosis and management of GCM.

2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients: Executive Summary.

2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients: Executive Summary.

Conduction abnormalities post alcohol septal ablation for hypertrophic cardiomyopathy – A single center experience

Conduction abnormalities are commonly noted after alcohol septal ablation (ASA). This was a retrospective, observational study where we studied the incidence of new onset conduction abnormalities post ASA. 23 patients, who underwent ASA over a period of 5 years, were included in the study. Baseline conduction abnormalities were noted in 26% patients (n = 6). Transient complete heart block (CHB) was noted in 21.7% (n = 5) whereas new onset right bundle branch block (RBBB) was seen in 60.8% (n = 14). Left bundle branch block was uncommon (4.3%,n = 1). Permanent pacemaker implantation was done in 4.3% (n = 1) for CHB. Conduction anomalies are frequent after ASA with RBBB being most common.

MANAGEMENT OF RECURRENT BRADYCARDIA WITH THEOPHYLLINE IN THE SETTING OF SPINAL CORD INJURY

TOPIC: Cardiovascular Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Cardiovascular complications are common in patients with cervical or high thoracic spinal cord injury (SCI) including autonomic dysreflexia and cardiac arrhythmias. Cardiac instability is a result of disruption of the descending sympathetic pathways and lack of compensation to parasympathetic responses via the vagus nerve for supraspinal control of the heart. We present a rare case of a 49-year-old male with recurrent episodes of bradycardia and subsequent complete heart block post SCI responding to theophylline. CASE PRESENTATION: 49-year-old male with a history significant for T5 fracture and spinal cord injury resulting in paraplegia was found to have brief episodes of bradycardia two months post accident during prolonged ventilator weaning. He was initially treated with and titrated off chronotropic agents (dopamine and isoproterenol). A month later, he began having recurrent episodes of transient complete heart block with the absence of ventricular activity for up to 30 seconds. After the period of heart block, he would progress to sinus bradycardia for about 30 seconds before transitioning to normal sinus rhythm. After specialty consultation, the patient was started on theophylline 100 mg three times daily with complete resolution of his symptoms for nine days. Then, during manual disimpaction, he had re-emergence of his transient complete heart block and had a brief cardiac arrest with pulseless electrical activity, which led to the implantation of a leadless pacemaker. DISCUSSION: This patient is unique in that cardiac dysrhythmias and cardiac arrest are more common in the acute phase of SCIs (2-6 weeks post injury), whereas this patient was 3 months post injury. Chronotropic and inotropic infusions are the primary treatment strategy for bradyarrhythmias. Dopamine and isoproterenol were trialed in the patient but stopped due to transient improvement in the symptoms. Minimizing vagal stimulation is important for the prevention of bradycardia associated with SCIs. Theophylline has been found to have anti-bradyarrhythmia effects and may be used for prevention of recurrent bradycardia. The mechanism is thought to be through antagonism of adenosine receptors, which is a crucial pathway in patients with high SCIs with unopposed vagal tone. In this case, initiation of oral theophylline prevented recurrent bradycardia and complete heart block for 9 days before a pacemaker was implanted. CONCLUSIONS: Routine use of theophylline to prevent cardiovascular complications in spinal cord injuries is not well known. Methylxanthine therapy may prevent recurrent bradyarrhythmias from occurring and avert or delay implantation of a pacemaker. REFERENCE #1: Furlan JC, Fehlings MG. Cardiovascular complications after acute spinal cord injury: pathophysiology, diagnosis, and management. Neurosurg Focus. 2008;25(5):E13. doi: 10.3171/FOC.2008.25.11.E13. REFERENCE #2: Alboni P, Rossi P, Ratto B, Pedroni P, Gatto E, Antonioli GE. Electrophysiologic effects of oral theophylline in sinus bradycardia. Am J Cardiol.1990; 65:1037-1039. REFERENCE #3: Whitman CB, Schroeder WS, Ploch PJ, Raghavendran K. Efficacy of aminophylline for treatment of recurrent symptomatic bradycardia after spinal cord injury. Pharmacotherapy. 2008 Jan;28(1):131-5. doi: 10.1592/phco.28.1.131. DISCLOSURES: No relevant relationships by Kirsten McGrew, source=Web Response No relevant relationships by Lindsay Saum, source=Web Response No relevant relationships by Adam Smalley, source=Web Response

Very large Atrial Septal Defect Device Closure: Feasibility and safety

Objectives: There is limited data regarding feasibility and safety of very large ASD devices deployment. Percutaneous closure of very large atrial septal defect (ASD) is a valid alternative to surgical approach. But complications like erosion, cardiac perforation, atrioventricular block, pericardial effusion, infective endocarditis, or cardiac arrhythmias may occur following ASD device closure.&#x0D; Methods: Forty four patients with very large ostium secundum ASD were studied in a tertiary medical centre. Adult patients with defect size of 38 mm or more and device size of 40 mm or more were selected for device closure. Patients having suitable anatomy, significant left to right shunt(&gt;1.5:1) ,right ventricular volume overload and without significant pulmonary arterial hypertension were chosen for device closure.&#x0D; Results : There were thirty six female patients and eight male patients in our study. Majority of our patients (twenty four) were in forty to fifty years age group. Device could be deployed successfully in forty two (95.5%). Twelve patients had device size of 46 mm (27%). Eight patients had 44 mm devices(18%). Forty two millimeter devices were used in sixteen patients (36%). Eight patients had device size of 40 mm(18%).Device embolization occurred in two patients. There were two cases of pericardial effusion and pericardiocentesis was needed in one patients. Transient complete heart block was seen in one patient. Four patients had suffered from transient and self terminating atrial arrhythmias. There was no mortality or erosion in our study.&#x0D; Conclusion: Percutaneous closure of very large ASD is feasible and associated with low complication rate

B-PO05-033 PACEMAKER IMPLANTATION AFTER SELECTIVE ALCOHOL SEPTAL ABLATION

Complete heart block (CHB) with permanent pacemaker (PPM) placement is a known risk of alcohol septal ablation (ASA) for hypertrophic cardiomyopathy. Historically, the incidence has been around 10% in all-comer populations. However, rates of 25% are reported in centers that selectively target older, higher risk patients (pts). Understanding predictors of CHB in this evolving cohort is important. Report baseline characteristics, associated factors (AF) of PPM placement, longer-term pacing need following ASA in a high-volume HCM center. 94 consecutive pts underwent ASA from 2/2017 to 12/2020. 25 were excluded due to prior septal reduction or device. Criteria for PPM included persistent post-ASA CHB >24 hours, recurrent pacing due to 2nd degree HB/ transient CHB >24 hours. 69 pts (mean age 65.7 ± 11 years, females 53.6%) were included. 19 (27.5%) required PPM prior to discharge, 6 (31.5%) of whom were prohibitive surgical risk for myectomy (20.3% PPM rate in pts not at prohibitive surgical risk). All had reduction in peak provoked gradient (pre-procedure mean 149.8 mm Hg vs. post-procedure mean 10.5 mmHg, p<0.01) and improved NYHA class. Comparison of baseline clinical, ECG, and procedural characteristics (e.g., peak troponin and gradient reduction) yielded no AF of PPM implantation, with exception of intraprocedural CHB (OR 12.4, 95% CI 3.4 - 45.3, p<0.0001). Post procedure PR prolongation >50 ms (OR 6.1, 95% CI 1.5 - 24.5, p = 0.01), first-degree AV block with RBBB and LAFB (OR 6.1, 95% CI 1.5 - 24.5, p = 0.01) and change in QRS axis >700 (OR 5.3, 95% CI 1.4 - 18.9, p= 0.01) was also associated with PPM. At 1 month, 16 pts (84.2%) required >1% RV pacing (mean 59.2%) suggesting appropriateness of PPM implantation. At 3 months 10 pts (52.6%) required pacing (mean 52.4%) indicating some late recovery. No procedural factors were associated with PPM following ASA with exception of intraprocedural CHB. Daily ECGs identified dynamic abnormalities associated with PPM. Short term follow up suggests PPM criteria are appropriate, with longer term follow up showing some recovery. As higher risk cohorts are targeted for ASA, PPM risk factors of long term pacing will be vital.

B-PO03-028 BIPOLAR PULSED ELECTRIC FIELD ABLATION OF THE INTERVENTRICULAR SEPTUM

Ablation of deep septal substrate with thermal energy sources conveys many challenges including inadequate lesion depth, inadvertent steam pops, and conduction system injury. Pulsed electric fields (PEF) were delivered across the interventricular septum as a preclinical proof-of-concept for transmural ablation through irreversible electroporation. In 8 healthy canine 4-week survival experiments, microsecond (n=2; 75-189J/animal) or nanosecond (n=6; 107-275J/animal) duration PEF were applied in a bipolar fashion between solid-tip ablation catheters positioned on either side of the septum in 2-5 separate locations. Radiofrequency (RF) control lesions were delivered for comparison at non-septal sites. Nanosecond PEF did not result in sustained ventricular tachyarrhythmias or skeletal muscle stimulation as opposed to microsecond PEF. Transient complete heart block was seen in 4 after delivery at the basal septum. Of these, bundle branch block persisted in 3 animals. Two animals died due to intractable VF during the initial experiment: 1 during microsecond delivery and another during an RF lesion. At 4 weeks of survival, 36 individual well-demarcated ablation lesions were demonstrated on both sides of the septum by cardiac MRI, necropsy, and histology. Lesion depth measured by histology was 2.62±2.06 mm with a maximum of 10.9 mm and transmurality in 1 animal. Bipolar irreversible electroporation of the interventricular septum is feasible and can result in transmural septal ablation lesions. Conduction system injury may occur at least transiently and further refinement is required to improve safety.

Reversibility of heart block after congenital heart surgeries in pediatrics, is it predictable?

Abstract Funding Acknowledgements Type of funding sources: None. Background AV block is a serious complication of congenital heart diseases(CHD) repair surgeries.it is associated with an increased mortality and morbidity. Purpose : Identifying the incidence of Complete Heart Block (CHB) after heart surgeries for CHD, analyzing the patients` specifications and procedural data to evaluate the potential correlations that contribute the HB postoperatively. Patients and methods : We enrolled all patients who underwent CHD surgeries from September 2014 till February 2020 and identified the patients who developed postoperative CHB, those patients were divided into two groups, (a group who developed transient CHB and those who developed permanent CHB which required implantation of permanent pacemaker (PPM). We defined the transient HB as the recovery from an advanced second or third degree HB after the surgery within 10days . And the presence of advanced second or third degree HB persisting for more than 10 days after cardiac surgery is considered a permanent HB and indicated for PPM implantation according to current guidelines . Results : Our cohort includes 2377 CHD surgeries, 46 % female patients, median weight was 12.06 kg at the time of the operation, median height was 85 cm. Mean age at the time of the operation was 2.7 years in the cohort with transient HB while it was 2.6 years in the cohort who received PPM. Incidence of HB following those surgeries was 3 %(72) patients, 1.8 %of the patients (43) had transient HB and 1.2% of the patients (21 ) received a PPM. Recovery from HB was within 7days in 35 patients (82%),Two out of the 43 patients who had transient HB ended up with late onset CHB requiring pacing representing 4.6 % of that cohort, one after one month of recovery and the other one after 11 years from the surgery despite they restored their sinus rhythm within 6 days and 10 days respectively. We found the highest incidence of postoperative HB associated with VSDs surgeries either isolated or with other complex CHD diseases followed by TOF with no significant difference between transient and permanent groups according to the type of surgery. The duration of preoperative PR interval suggested the incidence of permanent CHB postoperatively with a P value of 0.005 We found that gender, age, weight and height didn`t affect the outcome, preoperative heart rate and preoperative medications didn`t alter the prognosis, the duration of CBP time and the clamping time were of no statistical significance between the 2 groups with P value of ( 0.38 and 0.33 ). Conclusion : Incidence of CHB post CHD surgeries in our center is 3 %, only 1.2 % required PPM. Various clinical data , ECG criteria , procedural time and duration of the HB except for the preoperative PR interval failed to prove a significant correlation with the incidence of CHB necessitating further investigation to identify the specific risk factors for such complication. Abstract Figure. Incidence of CHB with various surgeries

Transient Third-degree Heart Block Secondary to Asymptomatic COVID-19 Infection

COVID-19 predominantly affects the lungs manifesting as respiratory illnesses including pneumonia and acute respiratory distress syndrome. Cardiac manifestations are also being increasingly reported such as pericardial disease, myocardial injury and dysfunction, arrhythmias and conduction abnormalities. A 70-year-old male with asymptomatic COVID-19 infection developed a transient episode of complete heart block just prior to his planned discharge from hospital. There are only few case reports purporting the development of a transient complete heart block in patients with moderate to severe COVID-19 infection. However, to date, this is the first report of incidentally detected, asymptomatic COVID-19 infection manifesting as third degree heart block.

Intra-procedural arrhythmia during cardiac catheterization: A systematic review of literature.

BACKGROUNDCardiac catheterization is among the most performed medical procedures in the modern era. There were sporadic reports indicating that cardiac arrhythmias are common during cardiac catheterization, and there are risks of developing serious and potentially life-threatening arrhythmias, such as sustained ventricular tachycardia (VT), ventricular fibrillation (VF) and high-grade conduction disturbances such as complete heart block (CHB), requiring immediate interventions. However, there is lack of systematic overview of these conditions.AIMTo systematically review existing literature and gain better understanding of the incidence of cardiac arrhythmias during cardiac catheterization, and their impact on outcomes, as well as potential approaches to minimize this risk.METHODSWe applied a combination of terms potentially used in reports describing various cardiac arrhythmias during common cardiac catheterization procedures to systematically search PubMed, EMBASE and Cochrane databases, as well as references of full-length articles.RESULTSDuring right heart catheterization (RHC), the incidence of atrial arrhythmias (premature atrial complexes, atrial fibrillation and flutter) was low (< 1%); these arrhythmias were usually transient and self-limited. RHC associated with the development of a new RBBB at a rate of 0.1%-0.3% in individuals with normal conduction system but up to 6.3% in individuals with pre-existing left bundle branch block. These patients may require temporary pacing due to transient CHB. Isolated premature ventricular complexes or non-sustained VT are common during RHC (up to 20% of cases). Sustained ventricular arrhythmias (VT and/or VF) requiring either withdrawal of catheter or cardioversion occurred infrequently (1%-1.3%). During left heart catheterizations (LHC), the incidence of ventricular arrhythmias has declined significantly over the last few decades, from 1.1% historically to 0.1% currently. The overall reported rate of VT/VF in diagnostic LHC and coronary angiography is 0.8%. The risk of VT/VF was higher during percutaneous coronary interventions for stable coronary artery disease (1.1%) and even higher for patients with acute myocardial infarctions (4.1%-4.3%). Intravenous adenosine and papaverine bolus for fractional flow reserve measurement, as well as intracoronary imaging using optical coherence tomography have been reported to induce VF. Although uncommon, LHC and coronary angiography were also reported to induce conduction disturbances including CHB.CONCLUSIONCardiac arrhythmias are common and potentially serious complications of cardiac catheterization procedures, and it demands constant vigilance and readiness to intervene during procedures.

Update on a no-cost epilepsy gene panel for seizure onset between 2 and 4 years of age: Results from 682 tests

A young child presented with severe ventricular dysfunction and troponin leak in the setting of coronavirus disease-2019. He developed intermittent, self-resolving, and hemodynamically insignificant episodes of complete heart block that were diagnosed on telemetry and managed conservatively. This report is the first description of coronavirus disease-2019–induced transient complete heart block in a child. (Level of Difficulty: Intermediate.)

Temporal Occurrence of Arrhythmic Complications After Alcohol Septal Ablation.

The temporal occurrence of arrhythmic complications after alcohol septal ablation (ASA) is unclear. As a result, the appropriate time to monitor patients after ASA is controversial. The purpose of this study is to determine the temporal occurrence of complete heart block (CHB) and ventricular tachyarrhythmia (VT) after ASA to better understand when patients can be safely discharged. Consecutive patients treated with ASA for hypertrophic cardiomyopathy from 2003 to 2019 at a tertiary referral center were reviewed retrospectively. The incidence and timing of CHB or sustained VT within 30 days post-ASA were assessed. A total of 243 patients were included in this study. Mean maximal septal thickness was 19.0±3.9 mm, and total volume of ethanol injected was 1.7±0.6 mL. CHB occurred in 59 (24.3%) patients, including transient CHB in 33 (13.6%) and permanent in 26 (10.7%). The initial episode of CHB occurred within 24 hours post-ASA in 51 (21.0%) patients, between 24 and 48 hours in 3 (1.2%), between 48 and 72 hours in 3 (1.2%), and after 72 hours in 2 (0.8%). New permanent pacemaker was placed in 46 (18.3%). Presence of baseline bundle branch block and age ≥70 were significantly associated with CHB but not CHB presenting after 24 hours. VT occurred in 3 (1.2%) patients, including 1 (0.4%) within 24 hours, 1 (0.4%) between 24 and 48 hours, and 1 (0.4%) after 72 hours. VT required cardioversion in 2 patients and new implantable cardioverter-defibrillator placement in 2. The incidence of CHB or VT presenting after 72 hours post-ASA was low. These findings suggest that timely discharge of patients without evidence of early conduction disturbances after ASA can be considered as a potentially safe management strategy, especially in patients without preexisting conduction abnormalities.

Myocardial Infarction Complicating Vasospastic Angina in a Female Patient—Case Report

Coronary artery vasospasm is an infrequent cause of acute coronary syndrome (ACS). A 50-year-old female developed persistent chest discomfort related to anterior STEMI. After an unsuccessful thrombolysis attempt, due to delay concern, the patient was then sent to the catheterization laboratory for rescue PCI. The coronary angiogram revealed a TIMI 3 flow proximal LAD significant stenosis with spastic appearance of the coronary arteries which has improved after intracoronary nitrates administration. Optical Coherence Tomography (OCT) excluded coronary artery dissection and haematoma also revealed thrombus on moderate atherosclerotic plaque. The patient was then pain-free; she was managed medically and discharged after few days of monitoring. Three weeks later, she developed transient chest pain with ST segment elevation while cycling during rehabilitation program. Provocation test by Ergonovine was positive with complete occlusion of proximal RCA (right coronary artery) complicated by transient complete heart block and shock. She was stabilized with 7 mg of intracoronary nitrates injection. She was discharged after close monitoring with calcium channel blocker and tobacco cessation. ACS may complicate prolonged coronary artery vasospasm making the diagnosis challenging. OCT may help understand ACS mechanism and exclude spontaneous coronary artery dissection. Provocation test is crucial for confirmation.

Percutaneous closure of symptomatic large tricuspid paravalvular regurgitation using two muscular VSD occluders

Paravalvular leaks are common following valve replacement surgery. Majority are benign and do not require any active intervention. However, occasionally severe paravalvular regurgitation can produce heart failure and/or hemolysis, needing closure of the defect. It is more commonly associated with aortic and mitral prosthesis, symptomatic tricuspid paravalvular regurgitation being a rare entity. In this report we present the successful percutaneous transcatheter closure of a large paravalvular tricuspid regurgitation in a 59-year old lady with history of multiple previous operations. The elongated crescent-shaped defect was closed using two muscular VSD devices without any residual leak and without hampering the bio-prosthetic tricuspid valve function. Patient had transient complete heart block during the procedure which recovered later. There was marked improvement in the symptomatic status of the patient at discharge (NYHA IV to NYHA II), which was sustained at follow-up.