Heart Block Research Articles

Pacemaker Implantation for Low-Grade Conduction Abnormalities After Balloon-Expandable Transcatheter Aortic Valve Implantation.

A frequent complication after TAVI are postinterventional conduction abnormalities requiring permanent pacemaker implantation. In this study, we analyzed the characteristics of borderline conduction abnormalities leading to pacemaker implantation and the resulting ventricular pacing amounts. All patients who underwent balloon-expandable TAVI between 2014 and 2019 in our tertiary center were analyzed in a retrospective manner. One hundred and sixty-five patients of 1083 TAVI-patients developed postinterventional conduction abnormalities leading to pacemaker implantation. Of these 19 (11.5%) did not represent a clear indication for cardiac pacing according to current European guidelines. Patient characteristics, underlying conduction abnormalities, and the temporal change of ventricular pacing percentages at 24 h and 6 weeks after pacemaker implantation were analyzed. The dominating borderline conduction abnormalities leading to pacemaker implantation were new-onset persisting bundle-branch-blocks and new first-degree AV-blocks with progression of AV-delay. While pacemaker implantation was safe and without severe complications in all cases, only 6 of 19 patients had high pacing amounts (95%-100%) after 24 h while 11 patients had low to no pacing amounts (0%-5%). After 6 weeks, 8 patients showed decreasing pacing amounts, no patient had an increasing amount of ventricular pacing and all patients had an intrinsic ventricular rhythm > 30/min. In our cohort of 1038 TAVI patients, 19 patients underwent PMI for borderline CAs (11.5% of all PMI). Of these, only 2 patients had high pacing amounts after 6 weeks. The risk of complete persisting heart block in these patients is very low. Furthermore, algorithms to reduce ventricular pacing are highly effective to avoid ventricular pacing whenever reasonable.

Association of Risk Factors of Acute Myocardial Infarction and Heart Blockage Among non-diabetic Patients in a Tertiary Care Hospital – An Observational Study

Introduction: Cardiovascular diseases (CVDs) are a leading cause of death in the world. In 2015, an estimated 442.7 million prevalent cases of CVD were present worldwide. Cardiovascular diseases account for more than 17 million deaths globally each year. Previous studies identified diabetes mellitus, hypertension, hypercholesterolemia, smoking, alcohol consumption, obesity and sedentary lifestyle as risk factors. Aim of the study: The aim of this study was to determine the risk factors for acute myocardial infarction associated with heart blockage among non-diabetic patients. Methods: This was an observational study conducted in the Department of Cardiology of Jashore Medical College Sadar Hospital, Jashore, Bangladesh during the period from April, 2021 to March, 2022. In this study, we included 120 non-diabetic patients who were diagnosed with myocardial infarction. Result: Mean age was 53.03±11.3 years & most of our patients were male. Among all patients, majority (65%) patients had >60% blockage, followed by 30(25%) patients had 40%-60% artery blockage, and <40% blockage was found in 10% patients. Hypertension, dyslipidemia & dyslipidemia with hypertension, age ≥60 years, family history of CHD, smoking, diabetes & obesity were individual risk factors of CHD among non-diabetic patients. The most common risk factors for heart blockage were age >45 years, high blood pressure, high LDL, unhealthy diet, and stressful life. Conclusion: In our study, we found hypertension, history of CHD, dyslipidemia, dyslipidemia with hypertension, stress, age ≥60 years, and obesity were individual risk factors for CHD. These elements work as crucial risk factors for myocardial infarction in non-diabetic patients. Risk factors like age >45 years, high blood pressure, high LDL, unhealthy diet, and stressful life were responsible for the highest heart blockage in myocardial infarction patients. J Inv Clin Cardiol 2023; 5(2): 38-44

ECGWiz: a unified and generalizable AI model for comprehensive ECG diagnosis

Abstract Background Deep learning has demonstrated diagnostic performance in electrocardiogram (ECG) analysis comparable to that of clinicians. However, existing models primarily excel in diagnosing common conditions such as arrhythmias and heart blocks, which are easily identifiable using standard predictor variables. Conversely, models aiming to uncover novel insights, such as detecting structural changes or the presence of myocardial scar, often lack generalizability due to insufficient data, model architecture limitations, and other factors. Moreover, these models frequently encounter challenges, such as a decline in performance when applied to external datasets. To address these issues comprehensively, we propose the ECGWiz — a unified model capable of tackling diverse ECG-related problems with consistently high performance. Objective To develop a generalizable Foundation AI model for ECG diagnosis capable of detecting diverse cardiac abnormalities and diseases using few training samples. Methods We utilized publicly available datasets like PTB-XL, CPSC, etc. To build our model, totaling approximately 80,000 ECGs. These 12 lead ECGs are scaled and filtered before using them for training. The AI model is pretrained using Self Supervised Learning and Contrastive Learning strategies. Further, the model undergoes supervised training using a hierarchy of labels that increase in granularity, encompassing arrhythmias, heart blocks, other cardiac abnormalities, heart failure, sudden cardiac death and more. Lastly, the model is prepared for Few-Shot Learning — where the model learns from a minimal set of samples (5 to 10 ECGs) of the target disease. For testing the model, we are using unique datasets like PROSE which consists of non-ischemic cardiomyopathy patients with and without myocardial scaring detected using cardiac MRI imaging at the Johns Hopkins University. Results Our model, trained on a dataset of only 5 ECG recordings, demonstrated a 74% accuracy in identifying myocardial scarring as detected by LGE MRI, utilizing a standard 12-lead ECG. This performance is comparable to that of conventional deep learning methods, which necessitate datasets containing upwards of 120 ECG recordings. Conclusion Our model represents a promising stride in creating a unified and adaptable foundation AI model for comprehensive ECG-based diagnosis. Its capacity to learn from a minimal set of examples signifies a robust framework that can evolve and adapt to new challenges in ECG diagnosis. Ongoing improvements, particularly through dataset expansion, underscore its potential to enhance cardiovascular diagnostics, offering precise and efficient patient care.

Prediction of mortality, future arrhythmia and cardiovascular disease: an artificial intelligence-enhanced electrocardiography platform

Abstract Background Artificial intelligence-enhanced electrocardiography (AI-ECG) can be used to identify existing disease, but could additionally be used to predict occurrence of future disease and death. Purpose We developed an AI-ECG platform that predicts mortality and a wide spectrum of future arrhythmia and cardiovascular disease. Methods The AI-ECG risk estimation platform (AIRE) was developed in a dataset of 1,163,401 ECGs from 189,539 patients from a secondary care setting in the USA. Uniquely, AIRE uses deep learning with a residual convolutional neural network with a discrete-time survival loss function to output subject-specific survival curves (Fig 1A). AIRE was fine-tuned to additionally predict the endpoints described below. Results AIRE accurately predicts risk of all-cause mortality (C-index 0.775 (0.773-0.776) and can differentiate prognosis in high- and low-risk subjects, even when only cardiologist-defined normal ECGs are considered (Fig 2B). Additionally, in Cox regression analyses, AIRE was superior to conventional risk factors (Fig 1B). AIRE accurately predicted future ventricular arrhythmia (c-index 0.760 (0.756-0.763)), future complete heart block (CHB) (0.809 (0.805-0.814), future atrial fibrillation (0.753 (0.751-0.756), future atherosclerotic cardiovascular disease (0.696 (0.694-0.698)) and future heart failure (0.787 (0.785-0.789)) . AIRE was superior to left ventricular ejection fraction (LVEF) in predicting risk of future ventricular arrhythmias in subjects with LVEF <50% (C-index 0.649 (0.638 – 0.660) vs 0.615 (0.603 – 0.626) p < 0.0001 ). For CHB prediction, AIRE was able to further risk stratify subjects with bifascicular block and syncope into low (1.9% 5 year CHB), intermediate (8.8%), and high risk (20.7%) groups, and could guide treatment decisions. We externally validated our findings in four diverse, transnational cohorts from Brazil and the UK, including volunteers, primary care subjects and patients with Chagas disease, and found AIRE accurately predicted all-cause mortality in all four external cohorts (Fig 2). Non-mortality endpoints were successful externally validated in the UKB. In explainability analyses, we found features of QRS morphology, low QRS voltage, poor precordial R wave progression, inverted and biphasic T waves and ST segment changes were the most significant morphological features associated with high predicted mortality (Fig 1D). Through phenome- and genome-wide association studies (GWAS), we identified candidate biological pathways including changes in cardiac structure (LV mass, LV trabeculation and left atrial size). GWAS identified variants adjacent to VGLL2, KCNQ1, CCDC91 and TBX3 which have been described in association with QT interval, biological aging and metabolic syndrome (Fig 1E). Conclusion AIRE could be used worldwide across a range of clinical contexts for risk estimation of not only mortality but a wide spectrum of future arrhythmia and cardiovascular diseases.Figure 1Figure 2

Collision mapping enables accurate localization of the slow pathway in atrioventricular nodal reentrant tachycardia

Abstract Introduction Atrioventricular Node Reentry Tachycardia (AVNRT) is commonly treated with catheter ablation, with high success and low complication rates. However a small risk of complete AV block still remains. Recent studies could show that using collision map is a feasible approach in mapping the slow pathway. The aim of the current study is to show a reduction of the total ablation points needed to modify/ablate the slow pathway using the collision mapping compared to conventional 3D mapping guided slow pathway modulation/ablation and therefore minimize the risk of a complete heart block. Methods Patients diagnosed with AVNRT (n = 24) underwent collision mapping for slow pathway identification, compared to a historical cohort (n=76) using conventional mapping. For collision mapping a dynamic visualization of atrial propagation during sinus rhythm was condcted. Two propagation fronts were observed to collide at the triangle of Koch, one propagation through the slow and one through the fast pathway. The designated collision zone was considered ideal for catheter ablation (Figure 1). The endpoint after ablation in both groups was non-inducibility of AVNRTs. Results After propensity score matching the collision mapping group needed significantly fewer ablation impulses (2 (IQR 1 - 5) vs. 6 (IQR 2,5 - 11,5) p = 0.002) and shorter ablation time (p < 0.001) compared to the conventional group (Table 1). No significant differences were observed in procedure time (p = 0.209), fluoroscopy time (p = 0.296), or dose area product (p = 0.391). Conclusion Collision Mapping in AVNRT ablation showed a notable reduction in ablation points, suggesting enhanced procedural efficiency and safety.Figure 1Table1

Impact of dapagliflozin on supraventricular and ventricular arrhythmias, assessed by Holter ECG, in patients with heart failure with reduced ejection fraction

Abstract Background & Introduction Dapagliflozin has significantly reduced morbidity & mortality in patients with heart failure with reduced ejection fraction (HFrEF) (1). Some studies reported supraventricular & ventricular arrhythmia suppression, but Holter ECG was underused, hindering precise assessment of arrhythmia burden. Purpose We aim to assess the impact of dapagliflozin on reduction of arrhythmia in HFrEF at 1 year follow-up (FU) by Holter ECG. Methods This is a single center, prospective study. We have screened 219 HFrEF patients, but only 156 patients were enrolled with LVEF <40% in sinus rhythm from December 2021 to July 2023. All patients had dapagliflozin 10 mg once/day tablet with the standard HF therapy. Clinical evaluation, NYHA evaluation, 6-minute walking test (6MWT), echocardiogram, 24-hours Holter ECG and laboratory work-up were done at baseline, and FU at 6 months and 12 months. Results Males constituted 61.5% of study population; mean± SD participants’ age was 56.8 ± 8.6 years. The most common comorbidities were: ischemic etiology (63.3%), dilated cardiomyopathy (28.1%), hypertension (27.3%), smokers (14.7%), and type II diabetes (31.4%). LVEF was ≤ 35% in 85.9% of patients. We have reported (7.69%) deaths during 1-year FU, and 4 patients (2.56%) didn't complete 1-year FU. Main clinical and echocardiographic findings (baseline vs. 1-year FU): NYHA FC III& ambulant IV dropped from (42.9 to 32.9%), P value<0.05. Distance walked in 6MWT improved from 191.52 ± 75.37 to 219.35 ± 71.51 mean± SD meters, P value<0.05. E/e improved (9.4 to 8.3 cm/s, P value <0.01), LVEF improved (31.3 to 36.4%, P value<0.05). HF emergency: [HF visits dropped (23.7 to 19.2%) and HF hospitalization dropped (11.1 to 7.8%)], P value<0.05. Holter ECG (baseline vs. 1-year FU): Supraventricular Arrhythmia: [Paroxysmal AF reduced (56.2 to 47.6%), frequent PACs (≥ 10%) dropped (3.8 to 1.4%) & Intermittent 1st degree heart block dropped (12.5 to 7.3%)] P value <0.01. Ventricular Arrhythmia: [PVCs >5%-<10% dropped (16% to 9.3%), Frequent PVCs >10% dropped (3.2 to 1.4%), and NSVT dropped (7.8 to 3.1%)], P value <0.01. Stepwise logistic regression multivariable model aiming to predict the occurrence of ventricular and supraventricular arrhythmias has indicated a direct linear correlation with male gender, smoking, body mass index, left atrial volume, and a history of myocardial infarction. Conversely, there is an inverse relationship with systolic blood pressure, 6MWT distance, LVEF, and the administration of dapagliflozin (OR 0.72 [0.61 - 1.07], P value <0.01) concerning the likelihood of supraventricular and ventricular arrhythmias. Conclusions Dapagliflozin has demonstrated significant improvement in functional and echocardiographic parameters in HFrEF patients. Furthermore, it has effectively decreased the incidence of supraventricular and ventricular arrhythmias, identified through 24-hour Holter ECG monitoring during 1-year follow-up.

Can variants of genes associated with familial heart block predict conduction disease in the general population? A UK Biobank study.

Abstract Background Progressive familial heart block is a genetic disease that can present with worsening cardiac conduction disease (CCD) and risk of life-threatening bradycardia. The prevalence, penetrance, and expressivity of known rare pathogenic/likely pathogenic variants (P/LP) in the general population is unclear. In addition, the role of common genetic variation in this phenotypic expression is unknown. Understanding this is essential for patient management in clinic. Purpose 1). To investigate the prevalence of variants linked with early-onset CCD and phenotypic expression in a large biobank. 2). To investigate whether a PR interval polygenic risk score (PRS) improves risk prediction. Methods Early-onset conduction disease P/LP or variants of uncertain significance (VUS) were identified from ClinVar, genetic testing reports at a teaching hospital (6 variants), and the literature, mapping to 22 genes. From the full UK Biobank prospective cohort, 469,511 participants passed genetic quality control and were assigned to P/LP, VUS, or genotype negative (G-) groups, using whole exome sequencing analysed with bcftools. A PR-PRS was constructed using weights from a published meta-analysis excluding UKB data. The primary outcome was CCD (atrioventricular (AV) block, bundle branch block, pacemaker or ICD implantation) and secondary outcomes were high-grade AV block or pacemaker insertion, compared with lifetime risk Cox proportional hazards controlled for sex and age as a timescale. Results 55% of participants were female, 95% had European ancestry, and average age at censor was 71 years. There were 25 P/LP carriers, and 8,862 with a VUS, in 6 genes (MYH7, SCN5A, TNNI3K, TRPM4, TTN, and LMNA). Major demographic factors were the same between groups. CCD was significantly more prevalent in P/LP individuals (28% vs 5.8% in VUS vs 5.5% in G-; p<0.001) with a hazard ratio of HR 6.47 [95% CI=3.09-13.6] vs G-. This was driven by AV block and pacemaker implantation (HR 23.2 [95% CI=8.69-61.8] and 13.4 [95% CI=6.01-29.8], respectively). Results were similar in an unrelated subset and controlling for ischaemic heart disease and heart failure. The 7 P/LP individuals with conduction disease were mostly linked to a single LMNA variant (4 out of 6 carriers with penetrant disease). In the full cohort, the PR-PRS was predictive of CCD (HR=1.07 [95% CI=1.06-1.08]), AV block (HR=1.09 [95% CI=1.06-1.13]), and pacemaker implantation (HR=1.04 [95% CI=1.02-1.06]). When combined with P/LP status, both PR-PRS (HR=1.07 [95% CI=1.06-1.08]) and P/LP (HR=6.42 [95% CI=3.06-13.5]) were independent predictors of CCD. Conclusion(s) Rare variant carrier status predicts a 6.5-fold increased lifetime risk of CCD, a 23-fold increased risk of AV block and 13-fold risk for pacemaker requirement. However, phenotypic expression for some variants is highly variable. A PR-PRS captures risk independent of P/LP variants and warrants further investigation with updated PRS construction methods.

Sudden cardiac death in acute coronary occlusion: potential roles of sino-atrial nodal artery and conus artery

Abstract An estimated 80% of sudden cardiac death (SCD) is due to coronary artery disease1. Ventricular arrhythmia (VA) is most commonly associated with LAD infarctions, likely due to the larger extent of affected myocardium, but non-LAD territory infarctions also present with VA. We propose two potential contributors, the sinoatrial nodal artery (SANa) and conus artery (CA). We retrospectively analyzed 2 cohorts of patients presenting with STEMI complicated by SCD due to VA, and whether these arteries were compromised in non-LAD territory STEMI, compared with uncomplicated STEMI. In the first, cohort A, we compared 127 consecutive STEMI patients presenting with cardiac arrest, with 100 uncomplicated STEMI. SANa and CA involvement was assessed in patients presenting with non-LAD territory STEMI. In the second, cohort B, we looked at patients presenting with inferior STEMI involving the RCA only, 20 complicated by aborted SCD due to VA compared with 24 uncomplicated patients. Cohort A (see table) showed a preponderance of single vessel and proximal LAD culprits in the arrest group and a significant number of non-LAD culprits. The extent and complexity of coronary disease and amount of myocardium at risk, reflected in SYNTAX and modified Jeopardy scores, were not significantly different between arrest and non-arrest groups. In those with RCA or Circumflex culprits, 77% in the Arrest group had the SANa arising from the culprit vessel, with only 33% of patients in the Control group, p<0.005. In cohort B, 70% of arrest and 21% of non-arrest patients had SANa involvement, p<0.005. In this cohort, we also observed that 74% of the arrest patients had CA involvement, compared with only 21% of Control patients, p<0.005. There were no significant differences in heart rate nor incidence of complete heart block and atrial arrhythmia in either cohort. There was significantly more ST elevation in standard leads V1-V2, suggesting RVOT ischemia, in those with aborted SCD and RCA culprit in both cohorts (cohort B: Arrests 85% vs non-arrest 21%, p<0.005. The SANa arises from the proximal RCA in 60% of people, and 40% from the left system. Transient ischemia leading to sinus bradycardia may not result in as marked QT prolongation compared with AV block at comparable heart rates, but in the ischemic environment, with hypotension provoking sympathetic upregulation, may lead to enough repolarization heterogeneity to induce VA. The CA arises from the RCA in 50% or more, and otherwise from the right coronary sinus, supplying the RVOT, a region prone to arrhythmogenesis, even in structurally normal hearts, more so if ischemic. Recognizing the potential role of these arterial branches in the VA mechanism would alert operators into preserving their patency. Transient disturbances may not translate into long term adverse outcomes, but whereas permanent damage to the SAN is more readily remedied, further study is needed to assess any long-term sequelae of RVOT infarction.

Safety and efficacy of perventricular device closure of ventricular septal defects in children

Abstract Objectives To evaluate safety and efficacy of perventricular device closure techniques for the closure of ventricular septal defects (VSD) in children in United Arab Emirates. Methods In the year 2023-24, 13 children underwent per-ventricular device closures of VSD under the guidance of transesophageal echocardiography without cardiopulmonary bypass(CPB). The mean age at operation was 3.76 years (range 3 months-14 years). The ventricular septal defect sizes ranged from 2.7-6 mm. The device sizes ranged from 5-12mm. All patients except two required symmetrical device. Eight defects were peri membranous, 3 were sub-aortic and 2 were muscular. Ventricular septal defect occlusion device (Memoport, Beijing, China) were used through a 3-cm skin incision in the lower third of the sternum. Results All patients underwent VSD device closure successfully. The mean procedural duration was 42 minutes. None of the patients required CPB. The mean ventilation time and ICU stay was 3 hrs. and 24 hrs. respectively. None of the patients required inotropic support or blood transfusions. There were no residual shunt (except small shunt through the device), arrhythmias including heart block post operatively. At follow up, (3 months-7 months) there were no residual shunts, conduction disturbances, device dislodgement or major aortic or tricuspid valve complications. There was no mortality. Conclusions Perventricular device closure of VSD is highly successful, less invasive, safe and effective. It is associated with quick recovery, short length of stay and better cosmetic incision. Moreover, it avoids CPB.

Evaluation of Pharmaco-invasive PCI in Terms of in Hospital Clinical Outcome of Acute Anterior ST Segment Elevation Myocardial Infarction Patients Compared to Primary PCI

Background: The strategic reperfusion early after Myocardial Infarction trial and the French Registry of Acute Anterior ST segment elevation MI suggested that pharmaco-invasive strategy compares favorably with primary percutaneous coronary intervention (PPCI). Objectives: To evaluate in hospital clinical outcome of patients with acute anterior ST segment elevation myocardial infarction undergoing Primary PCI and pharmaco-invasive PCI. Methods: This cross sectional study was conducted in United Hospital, Dhaka. A total of 120 patients were studied. These patients were categorized into two groups. Those with acute anterior ST segment elevation MI who underwent primary PCI was denoted as group A (n= 55) and those with acute anterior ST segment elevation thrombolysed by streptokinase followed by PCI confined to pharmaco-invasive PCI was denoted as group B (n=65). Results: Acute LVF was more in pharmaco-invasive group than in primary PCI group and was statistically significant (p= 0.032). 02 patients (3.6%) died in primary PCI group: one of which was due to ventricular fibrillation followed by asystole 3 hours after procedure and the other died due to cardiac arrest 10 hours after the procedure. No major bleeding incidence was found in both groups. Conclusion: Acute anterior ST segment elevation myocardial infarction patients receiving pharmaco-invasive treatment compared with the Primary PCI had higher incidence of acute LVF and no significant discrepancy was observed regarding bleeding events, death, stent thrombosis, arrythymia, heart block and cardiac arrest. J Shaheed Suhrawardy Med Coll 2023; 15(1): 34-38

Neonatal lupus erythematosus successfully treated by exchange transfusion: a case report and literature review

IntroductionThere are few reports of severe hematological involvement in children with neonatal lupus erythematosus (NLE) treated with exchange transfusion. In this case report, we present a female patient with NLE admitted to the Children's Hospital of Soochow University. The main clinical manifestations were pancytopenia and congenital heart block (CHB). Her condition was serious and could not be improved by conventional treatment; however, she responded well to exchange transfusion therapy.Case presentationA female infant, aged 1 month and 3 days, was admitted to the Children's Hospital of Soochow University owing to the “discovery of thrombocytopenia over 1 month.” She tested positive for anti-SSA IgG, anti-Ro-52 IgG, and anti-mitochondrial M2 antibodies. In contrast, her mother tested positive for ANA (1:320) and anti-Ro/SSA antibodies. The patient was diagnosed with NLE and presented with pancytopenia and CHB. Her cardiac function was normal and no intervention was performed; however, her hematological involvement was more severe, without significant improvement after steroid, intravenous immunoglobulin, and transfusion treatments. After exchange transfusion therapy, the patient significantly improved, and the short-term follow-up prognosis was good.ConclusionFor patients with NLE presenting with hematological involvement that cannot be improved by conventional treatment or whose condition is serious, exchange transfusion therapy should be considered to reduce antibody titers and improve their condition.

Acute Quetiapine Intoxication: Relationship Between Ingested Dose, Serum Concentration and Clinical Presentation-Structured Literature Review and Analysis.

Over the past decade, quetiapine has become one of the most commonly used psychotropic drugs in acute intoxication events worldwide. A structured literature review and analysis were conducted to assess the relationship between the kinetic and dynamic profiles in acute quetiapine intoxication. The correlation between dose and peak serum concentration (cmax) was determined using Pearson's correlation coefficient. Binary logistic regression was used to evaluate dose and cmax as predictors of the most common clinical events, signs and symptoms. One hundred and thirty-four cases of acute quetiapine ingestion were included in the analysis, with a median ingested dose of 10 g and a median cmax of 4 mg/L. The typical half-life was estimated to be 16.5 h, significantly longer than at therapeutic doses. For the immediate-release formulation, a biphasic disposition could not be excluded. Dose and cmax demonstrated a weak but significant correlation (r = 0.256; N = 63; p = 0.043). Central nervous system depression and tachycardia were the most common clinical signs. Higher doses and concentrations increased the risk of severe intoxication and were good predictors of intubation, tachycardia, hypotension, QTc prolongation and seizures, but not QRS prolongation, arrhythmia, heart block, hypokalaemia or acidosis. The thresholds for dose and cmax that increased the risk for individual signs and symptoms varied widely. However, doses > 3 g or cmax > 2 mg/L can be considered as alert levels that represent a high risk for severe clinical course of acute quetiapine intoxication.

GIANT CELL MYOCARDITIS: AUTOPSY CONFIRMATION OF A DIAGNOSTIC DILEMMA - A RARE CASE REPORT

Abstract Introduction/Objective Giant cell myocarditis (GCM) is a rare and rapidly progressive form of myocarditis, commonly leading to fulminant heart failure (HF), refractory ventricular arrhythmias or conduction system abnormalities and carrying a high mortality rate without prompt treatment. Due to its rarity, there is limited data on its prevalence, although studies show an incidence of 0.007–0.053% among autopsied cases. This entity primarily affects the heart, exhibiting a rapid clinical course and a poor prognosis necessitating immunosuppressive therapy and, in most instances, heart transplantation to improve survival rates. Methods/Case Report We present a case of a 62-year-old male with a prior history of complete heart block status post permanent pacemaker placement, presenting with acute decompensated heart failure. Laboratory investigations revealed elevated cardiac troponin levels (>35000) with echocardiography showing a reduced ejection fraction of 25% and an initial diagnosis of non-ST elevation myocardial infarction (NSTEMI) was made. Endomyocardial biopsy revealed GCM. Despite aggressive management, including immunosuppressive therapy and mechanical circulatory support, his condition deteriorated rapidly, leading to multiorgan failure and eventual death. The diagnosis was confirmed on autopsy. The diagnostic challenge of GCM lies in its clinical or pathologic overlap with other myocardial disorders such as cardiac sarcoidosis, viral myocarditis, and cardiac amyloidosis. Endomyocardial biopsy (EMB) remains the gold standard for diagnosing this entity which is characterized by a widespread inflammatory cell infiltrate with multinucleated giant cells in association with myocyte damage. The etiology of GCM remains unclear, but it is believed to be immune-mediated, possibly triggered by an autoimmune response. Results (if a Case Study enter NA) NA Conclusion Pathologists should give importance to consider GCM in the differential diagnosis of patients presenting with acute heart failure refractory to standard therapy. Early recognition and prompt initiation of immunosuppressive therapy are crucial for improving outcomes in patients with GCM. Awareness of this entity is crucial to make a timely diagnosis.

Surgical Closure of Multiple Muscular Ventricular Septal Defects in Children Using 3D-Printed Models.

Multiple muscular ventricular septal defects (VSDs) are often difficult to visualize and access surgically. The main challenge is identifying all defects intraoperatively, without which residual defects are inevitable. Patient-specific three-dimensional (3D) printed models can help accurately demonstrate intracardiac anatomy. We present our experience using this technology to surgically close multiple muscular VSDs . Data of all patients with multiple VSDs in whom a 3D-printed model was used to aid surgical planning between September 2021 and July 2023 was collected retrospectively. Our approach involved generating a 3D model from a preoperative computerized tomography scan for each patient, which was then used to precisely identify the location of the multiple VSDs and plan surgical intervention. Six patients underwent closure of multiple VSDs using a 3D model. The mean age at surgery was 3.5 years (SD ± 2.8 years). Five (83.3%) patients had previously undergone pulmonary artery banding. The VSDs were approached through the right atrium in three (50%) and the right ventricle in three (50%) patients. Mean cardiopulmonary bypass and myocardial ischemia times were 185.2 min (SD ± 94.8 min) and 147.5 min (SD ± 86 min), respectively. There was no postoperative heart block or a hemodynamically significant residual VSD. All six patients had normal biventricular function at a median follow-up duration of 1.7 months (interquartile range: 1.2-7.4 months). 3D printing to aid closure of multiple VSDs is safe, reliable, and reproducible. We recommend adding 3D printing to surgeons' armamentarium when faced with the challenge of closing multiple muscular VSDs in children.

Impact of early detection and steroid treatment on fetal ventricular heart rate and pacemaker implantation in anti-Ro/SSA positive congenital heart block.

We investigated the effects of timing of detection and transplacental fluorinated steroid treatment on ventricular heart rate (HR) and age at pacemaker implantation in fetal third-degree atrioventricular block (AVB). Twenty-five of 31 fetuses diagnosed with Ro/SSA autoantibody-positive AVB II-III at our tertiary fetal cardiology center (2000-2020) and AVB III as final feto-neonatal outcome were reviewed. AVB was detected approximately 5 weeks earlier in pregnancy if followed in a surveillance program compared to cases referred from primary care for bradycardia (20.6 [2.3] [mean (SD)] vs. 25.4 [3.2] weeks, p = 0.001). AVB detected before 24 weeks had higher HR than those detected later in gestation (63.3 [6.9] vs. 57.2 [6.9] bpm, p = 0.042), with a larger proportion having HR >60 bpm (80% vs. 33%, p = 0.041). The 17/25 cases that received treatment with fluorinated steroid were diagnosed earlier in gestation, with higher HR at diagnosis (61.7 [7.1] vs. 54.7 [6.3] bpm, p = 0.026), 1-2 weeks after diagnosis/treatment start, and before birth (65.4 [12.4] vs. 54.9 [5.7] bpm, p = 0.030) than untreated cases. Overall, 11 cases were commenced on betamimetics: three at diagnosis and eight at or after the examination made 1-2 weeks after diagnosis/treatment start, without any HR improvement. Two of 24 surviving babies were born preterm, and 4/24 received a neonatal pacemaker. Age at pacemaker implantation correlated significantly with HR before birth (Spearman R 0.57, p = 0.004), and fetuses with HR >60 bpm had a higher rate of pacemaker-free survival at three (90% vs. 40%, p = 0.018) and 12 months of age (80% vs. 13%, p = 0.002). The same trend was observed in pacemaker-free survival at 3 months of age in fluorinated steroid-treated compared to untreated cases (71% vs. 38%, ns). Our data confirm that AVB III detected earlier in gestation have a higher HR, and suggest that this higher HR can be successfully maintained to the end of gestation in cases treated with fluorinated steroids. Fetuses with HR >60 bpm before birth had a lower rate of pacemaker implantation at 3 and 12 months of age.

7068 Paraganglioma in Cyanotic Congenital Heart Disease

Abstract Disclosure: R. Lis: None. V. Hamidi: None. Paragangliomas arise from the non-chromaffin cells of the parasympathetic nervous system, which are composed of glomus cells. These function as chemoreceptors in response to hypoxia. Carotid body paragangliomas have been linked to conditions with chronic hypoxia. This was first seen in residents of high altitude locations in a case report presented by Saldana et. al and regression of a paraganglioma with resolution of hypoxia was reported by Gruber et. al. There have been few additional case reports of Paraganglioma in other hypoxic states. We present a rare case of a functional Paraganglioma in a patient with Cyanotic Congenital Heart Disease (CCHD).This is a 19 year old female with a history of CCHD due to double inlet left ventricle and transposition of the great arteries. Soon after birth, she had a fontan procedure. She subsequently developed fontan associated liver disease as well as chronic kidney disease, hypertension, sinus node dysfunction, and complete heart block. Her baseline oxygen saturation was 78-85%. Her heart rate was 40-49 beats per minute with upcoming plans for pacemaker placement. Her blood pressure ranged 90/50 to 150/80 mmHg on Amlodipine 5 mg and Lisinopril 2.5 mg. She routinely received abdominal imaging to monitor her liver disease. A liver MRI incidentally revealed a retroperitoneal mass concerning for a paraganglioma. Serum Normetanephrines were found to be 26.60 nmol/L (reference range less than 0.89). 24 hr Urine Norepinephrine was 1,187 ug/d (reference range 14-20). Further imaging was negative for additional sites of disease. Given her complete heart block, she was started on alpha blockade only prior to pacemaker placement. After the pacemaker was placed, she was started on beta blockade and underwent surgical resection of her paraganglioma. The pathology confirmed paraganglioma and mutation testing was negative for germline mutations including SDH, VHL, RET, NF1 mutations. Paragangliomas in patients with CCHD have been scarcely described in the literature given the rarity of both of these conditions. However, there is a relatively increased incidence of paragangliomas in the CCHD population due to chronic hypoxia triggering the hypoxia pathway. EPAS1 mutated HIF2alpha is often found to be the culprit in these patients. In addition, case reports have often described these patients to either be asymptomatic or have potential symptoms masked by their cardiac disease. Therefore, CCHD patients are at increased risk for paragangliomas and warrant additional awareness and regular screening. Screening has been proposed to start after 10 years of hypoxia in a case review by Agarwal et. al. as paraganglioma incidence in CCHD populations has not been seen before age 11. Incidence of recurrence is not yet widely studied, but significant concern for recurrence is warranted if the etiology of hypoxia is not reversed. Presentation: 6/3/2024

Is concomitant tricuspid valve repair in patients undergoing robotic mitral valve repair safe and effective?

ObjectivesRobotic-assisted mitral valve repair (MVr) is a well-established procedure for management of degenerative mitral valve disease. Limited data regarding concomitant robotic-assisted tricuspid valve repair (TVr) is available. This review investigates prevalence and outcomes of concomitant robotic-assisted mitral and tricuspid valve repair. MethodsFrom 2014 to 2022, 839 patients underwent robotic-assisted MVr, including 76 patients with moderate or greater tricuspid regurgitation and/or tricuspid annular dilatation ≥40 mm. Among the 76 patients, 19 (25%) underwent isolated MVr and 57 (75%) had concomitant mitral and tricuspid valve repair. Outcome data between the 2 groups were analyzed. ResultsIn the MVr/TVr group, tricuspid regurgitation grades were mild in 4 (7%) patients, moderate in 44 (77%) and severe in 9 (15.7%). Significant tricuspid annular dilatation ≥40 mm was present in all patients. In the isolated MVr group, 3 (15.7%) patients had mild tricuspid regurgitation and 16 (84.2%) had moderate tricuspid regurgitation with significant tricuspid annular dilatation present in only 6 patients. Cardiopulmonary bypass and crossclamp time were 130.6 and 91 minutes versus 85 and 55.4 minutes for robotic MVr/TVr group versus MVr group, respectively (P < .05). The intensive care unit and hospital length of stay were similar: 27.7 versus 27.7 hours and 4.4 versus 4.2 days for MVr/TVr versus MVr (P = .24), respectively. There were no perioperative deaths or heart block in either group. Survival and freedom from reoperation with median follow-up of 16 and 46 months for MVr/TVr and MVr groups, respectively were 100%. ConclusionsConcomitant robotic-assisted tricuspid valve repair for functional regurgitation can be safely and effectively performed at the time of mitral valve repair with excellent short-term morbidity and mortality results.

Management of complete heart block detected during labor: A case report

Complete heart block in women of childbearing age is rare, and incidental diagnosis during pregnancy is more uncommon. Hence, there remain no well-established guidelines on the management of patients with complete heart block presenting in labor. Here, we present a 26-year-old full-term primigravida, with no known previous cardiac history, in active labor with asymptomatic bradycardia in the 30–40s unresponsive to atropine augmentation. After multidisciplinary consultation, the decision was to proceed with delivery as planned without indication for a temporary pacemaker. The patient successfully delivered a full-term infant via operative vaginal delivery, with an ensuing cardiac workup completed postpartum.

Failure of pacemaker therapy in a pediatric patient with neurally mediated complete heart block and syncope: A case report.

Neurally mediated syncope (NMS) is a well-known condition that can be subdivided into three subgroups: vasopressor type, cardioinhibitory type, and mixed type. While different degrees of sinus bradycardia occur at the time of syncope in all types, complete heart block is a rare event that can lead to pulselessness during syncope. We present a case of a 14-year-old girl with documented NMS before and after temporary pacemaker implantation, who had complete heart block during syncope. The patient's temporary pacemaker placement was ineffective in preventing syncope during a repeat head-up tilt test, indicating that permanent pacing may not be effective in this patient. Midodrine, an alpha-adrenergic agonist, was started, and the patient experienced complete control of syncope episodes without recurrence during a 2-month follow-up.

Paced QRS Duration as the Major Determinant of Pacing Induced Cardiomyopathy in Complete AV Block

Patients with complete heart block often develop pacing-induced cardiomyopathy (PICM) after placement of a permanent pacemaker. Objective: To establish paced QRS duration as determinant of pacing induced cardiomyopathy in complete Atrioventricular (AV) block. Methods: This descriptive study included 115 male and female patients that had a permanent pacemaker implanted for complete AV block, at the department of Cardiology, Hayatabad Medical Complex, Peshawar, during the period 1st November 2023 till 30th June 2024. Patients were evaluated for the presence of PICM and subsequently grouped as PICM and non-PICM. Paced QRS duration in both groups was compared. Results: PICM was confirmed in 63 patients (54.8%) and 52 (45.2%) were non-PICM. Mean age in PICM group was 71.2 ± 8.7 years and 66.8 ± 9.5 years in non-PICM group. The mean paced QRS duration in PICM group was 200.5 ± 22.3 milliseconds and 168.3 ± 15.7milliseconds in non-PICM group (p value &lt;0.001). Conclusion: Prolonged paced QRS duration was found as key indicator for predicting pacing induced cardiomyopathy in patients with permanent pacing for complete AV block.