Atrioventricular conduction disorders in aortic valve infective endocarditis.

BACKGROUND: Aortic valve infective endocarditis may be complicated by high-degree atrioventricular block in up to 10-20% of cases. AIM: To assess high-degree atrioventricular block occurrence, contributing factors, prognosis and evolution in patients referred for aortic infective endocarditis. METHODS: Two hundred and five patients referred for aortic valve infective endocarditis between January 2018 and March 2021 were included in this study. A comprehensive assessment of clinical, electrocardiographic, biological, microbiological and imaging data was conducted, with a follow-up carried out over 1 year. RESULTS: High-degree atrioventricular block occurred in 22 (11%) patients. In univariate analysis, high-degree atrioventricular block was associated with first-degree heart block at admission (odds ratio 3.1; P=0.015), periannular complication on echocardiography (odds ratio 6.9; P<0.001) and severe biological inflammatory syndrome, notably C-reactive protein (127 vs 90mg/L; P=0.011). In-hospital mortality (12.7%) was higher in patients with high-degree atrioventricular block (odds ratio 4.0; P=0.011) in univariate analysis. Of the 16 patients implanted with a permanent pacemaker for high-degree atrioventricular block and interrogated, only four (25%) were dependent on the pacing function at 1-year follow-up. CONCLUSIONS: High-degree atrioventricular block is associated with high inflammation markers and periannular complications, especially if first-degree heart block is identified at admission. High-degree atrioventricular block is a marker of infectious severity, and tends to raise the in-hospital mortality rate. Systematic assessment of patients admitted for infective endocarditis suspicion, considering these contributing factors, could indicate intensive care unit monitoring or even temporary pacemaker implantation in those at highest risk.

International Cohort of Neonatal Timothy Syndrome.

INTRODUCTION: Timothy syndrome (TS) is an extremely rare, multisystem disorder classically associated with long QT, syndactyly, ventricular arrhythmias, and hypoglycaemia. A neonatal diagnosis allows maximal medical and device therapy to be implemented to avoid malignant arrhythmias and sudden cardiac death. METHODS: This was a retrospective case series study of type I TS (TS1) patients using data from the Timothy Syndrome Foundation's international registry, encompassing patients with a genetic diagnosis (CACNA1C variant G406R in exon 8A) recruited over a 28-year period. RESULTS: Forty-four cases of TS1 were included (26 male; 60%). Mean gestational age (GA) was 35.6 weeks (range 28 weeks - term), with 43% of patients born less than 37 weeks GA. In TS1 patients presenting with foetal bradycardia, mean GA was significantly lower (34.2 weeks, p < 0.05). Foetal bradycardia secondary to atrioventricular block was present in 20 patients (45%), resulting in premature delivery in 14 patients (32%). Fifteen patients (34%) were diagnosed with TS1 as neonates. Long QT at birth helped secure a diagnosis in 25 patients (57%). Syndactyly was seen in most patients (n = 40, 91%). Twenty patients died, with an average age of death of 2.3 years (range 1 month-6 years). Of the 7 patients who died before the first year of life (16%), the average age of death was 2.5 months. CONCLUSION: TS is associated with high early mortality. TS should be considered in paediatric patients presenting with long QT and syndactyly. Recognition of TS in the neonatal period allows for early intervention to prevent life-threatening arrhythmias.

Factors associated with temporary pacing insertion in patients with inferior ST-segment elevation myocardial infarction.

BACKGROUND: High-degree atrioventricular block (HAVB) is a prognostic factor for survival in patients with inferior ST-segment elevation myocardial infarction (STEMI). However, there is little information about factors associated with temporary pacing (TP). The aim of this study was to find factors associated with TP in patients with inferior STEMI. METHODS: We included 232 inferior STEMI patients, and divided those into the TP group (n = 46) and the non-TP group (n = 186). Factors associated with TP were retrospectively investigated using multivariate logistic regression model. RESULTS: The incidence of right ventricular (RV) infarction was significantly higher in the TP group (19.6%) than in the non-TP group (7.5%) (p = 0.024), but the incidence of in-hospital death was similar between the 2 groups (4.3% vs. 4.8%, p = 1.000). Long-term major adverse cardiovascular events (MACE), which were defined as a composite of all-cause death, non-fatal myocardial infarction (MI), target vessel revascularization (TVR) and readmission for heart failure, were not different between the 2 groups (p = 0.100). In the multivariate logistic regression analysis, statin at admission [odds ratio (OR) 0.230, 95% confidence interval (CI) 0.062-0.860, p = 0.029], HAVB at admission (OR 9.950, 95% CI 4.099-24.152, p<0.001), and TIMI-thrombus grade ≥3 (OR 10.762, 95% CI 1.385-83.635, p = 0.023) were significantly associated with TP. CONCLUSION: Statin at admission, HAVB at admission, and TIMI-thrombus grade ≥3 were associated with TP in patients with inferior STEMI. Although the patients with TP had the higher incidence of RV infarction, the incidence of in-hospital death and long-term MACE was not different between patients with TP and those without.

Long-term prognosis of patients with permanent cardiac pacemaker indication in three referral cardiac centers in Cameroon: Insights from the National pacemaker registry.

BACKGROUND: There is evidence that cardiac pacemakers improve symptoms and quality of life in patients with severe bradycardia. Globally, the number of pacemaker implantations is on the rise. However, the associated high-cost limits pacemaker's accessibility in low resource settings. This study aimed to investigate access to pacemakers and the long-term outcome of patients requiring a pacemaker. METHOD: We conducted a cohort study in 03 health care structures in Cameroon. Participants aged at least 18 years with indication for a permanent pacemaker between January 2010 and May 2016 were included. Clinical profile, electrocardiography, pacemaker implantation parameters were recorded. Long-term survival was studied by event-free analysis using the Kaplan-Meier method. RESULTS: In total, 147 participants (mean age 67.7±13.7 years, female 58.5%) were included. Fatigue (78.7%), dyspnoea (77.2%), dizziness (47.1%) and palpitations (40.4%) were the main symptoms while syncope was present in 35.7% of patients. The main indication for cardiac pacemaker was atrioventricular block (85.3%). Forty (27.2%) could not be implanted with 34 (85%) of participants highlighting cost of intervention as main reason. VVIR was the main mode of stimulation (70.5%). Of 125 patients in which follow-up was ascertained, 17(13.5%) died after a median survival time of 2.8 years post diagnosis [IQR: 1.8-4.2]. The survival curve was better in participants with a pacemaker with a Hazard ratio of 2.7 [CI: 1.0-7.3, P=0.045]. CONCLUSION: Our patients with severe heart blocks presented late and more than a quarter did not have access to pacemaker but its implantation multiplied the survival rate by 2.7 times at approximately 3 years post diagnosis. Improving early detection of heart blocks and access to cardiac pacing to reduce mortality shall be a key future priority.

Long-term outcomes of arrhythmia and distinct electrophysiological features in congenitally corrected transposition of the great arteries in an Asian cohort.

Congenitally corrected transposition of the great arteries (ccTGA) is associated with various types of arrhythmia, including supraventricular tachycardia (SVT) and complete atrioventricular block (cAVB). Our study aims to characterize the arrhythmia burden, associated risk factors, arrhythmia mechanisms, and the long-term follow-up results in patients with ccTGA in a large Asian cohort. METHODS: We enrolled 104 patients (43 women and 61 men) diagnosed with ccTGA at our institution. The mean age at last follow-up was 20.8 years. RESULTS: For 40 patients (38%) with tachyarrhythmia, paroxysmal SVT (PSVT) and atrial arrhythmia were observed in 17 (16%) and 27 (26%) patients, respectively, with 4 patients (4%) having both types of SVT. The 20-year and 30-year SVT-free survival rates were 68% and 54%, respectively. Seven patients (7%) developed cAVB: 2 (2%) developed spontaneously, and the other 5 (5%) was surgically complicated (surgical risk of cAVB: 7%, all associated with ventricular septal defect repair surgery). PSVT was mostly associated with accessory pathways (5/9) but also related to twin atrioventricular nodal reentry tachycardia (3/9) and atrioventricular nodal reentry tachycardia (1/9). Most of the accessory pathways were located at tricuspid valve (9/10). Catheter ablation successfully eliminated all PSVT substrates (10/10) and most of the atrial arrhythmia substrates (3/5), with low recurrence rate. CONCLUSIONS: The arrhythmia burden in patients with ccTGA is high and increases over time. However, cAVB incidence was relatively low and kept stationary in this Asian cohort. The mechanisms of SVT are complicated and can be controlled through catheter ablation.

Network meta-analysis of His bundle, biventricular, or right ventricular pacing as a primary strategy for advanced atrioventricular conduction disease with normal or mildly reduced ejection fraction.

INTRODUCTION: Although right ventricular pacing (RVP) may impair ventricular function, it is commonly used for advanced atrioventricular block (AVB) and normal or mildly reduced ejection fraction (EF). We aimed to compare His bundle pacing (HBP), biventricular pacing (BiVP), and RVP for advanced AVB in patients with normal or mildly reduced EF. METHODS AND RESULTS: MEDLINE, Embase, Cochrane CENTRAL, ClinicalTrials.gov, Scopus, and Web of Science were searched. Outcomes were all-cause death, heart failure hospitalizations (HFH), EF, left ventricular volumes, 6-minute walk test, and QRS duration. HBP or BiVP was compared with RVP. Subsequently, network meta-analysis compared the three pacing options. Our protocol was registered in PROSPERO (CRD42018094132). Six studies compared BiVP and RVP (704 vs 614 patients) and four compared HBP and RVP (463 vs 568 patients). Follow-up was 6 months to 5 years. There was significantly lower mortality and HFH with HBP or BiVP as compared with RVP (odds ratio [OR], 0.66, [0.51-0.85], P = .002; OR, 0.61 [0.45-0.82], P < .001, respectively]. HBP or BiVP also showed significant increase in EF and decrease in QRS duration (mean difference [MD], 5.27 [3.86-6.69], P < .001; MD -42.2 [-51.2 to -33.3], P < .001, respectively). In network meta-analysis, HBP and BiVP were associated with significantly improved survival compared to RVP, with surface under the cumulative ranking curve (SUCRA) probability of 79.4%, 69.4%, and 1.2% for HBP, BiVP, and RVP, respectively. For HFH, SUCRA probability was 91.5%, 57.2%, and 1.3%, respectively. CONCLUSION: HBP or BiVP were the superior strategies to reduce all-cause death and HFH for advanced AVB with normal or mildly reduced EF, with no significant difference between BiVP and HBP.

Prognostic Implication of First-Degree Atrioventricular Block in Patients With Hypertrophic Cardiomyopathy.

Background The association between first-degree atrioventricular block (AVB) and life-threatening cardiac events in patients with hypertrophic cardiomyopathy (HCM) remains unclear. This study sought to investigate whether presence of first-degree AVB was associated with HCM-related death in patients with HCM. Methods and Results We included 414 patients with HCM (mean age, 51±16 years; 64.5% men). The P-R interval was measured at the time of the initial evaluation and patients were classified into those with and without first-degree AVB, which was defined as a P-R interval ≥200 ms. HCM-related death was defined as a combined end point of sudden death or potentially lethal arrhythmic events, heart failure-related death, and stroke-related death. First-degree AVB was noted in 96 patients (23.2%) at time of enrollment. Over a median (interquartile range) follow-up period of 8.8 (4.9-12.9) years, a total of 56 patients (13.5%) experienced HCM-related deaths, including 47 (11.4%) with a combined end point of sudden death or potentially lethal arrhythmic events. In a multivariable analysis that included first-degree AVB and risk factors for life-threatening events, first-degree AVB was independently associated with an HCM-related death (adjusted hazard ratio, 2.41; 95% CI, 1.27-4.58; P=0.007), and this trend also persisted for the combined end point of sudden death or potentially lethal arrhythmic events (adjusted hazard ratio, 2.60; 95% CI, 1.28-5.27; P=0.008). Conclusions In this cohort of patients with HCM, first-degree AVB may be associated with HCM-related death, including the combined end point of sudden death or potentially lethal arrhythmic events.

Pacing therapy in children with isolated complete atrioventricular block: a retrospective study of pacing system survival and pacing-related complications in a national cohort.

AIMS: To evaluate pacing system survival and complications to pacemaker (PM) therapy in children with isolated complete atrioventricular block (CAVB). METHODS AND RESULTS: We performed a nationwide retrospective study of children diagnosed before 15 years of age with isolated CAVB and PM treatment. Between 1983 and 2012, 127 patients underwent PM-implantations at 3.2 (0-17) [median (range)] years and were followed for 11 (0.6-19) years. An endocardial or epicardial PM system was implanted in 72 and 55 patients, respectively. A total of 306 pacing leads (76% steroid-eluting) were implanted. Pacing system survival was significantly affected by age, with a higher risk of a new intervention for children aged <1 month at first implantation. Lead survival of the steroid-eluting leads at 5 and 10 years was 90 and 81%, respectively, with no difference between epicardial and endocardial systems. Complications leading to revision of the pacing system occurred in 24% of the patients. Patients aged <1 month at first PM implantation had a five-fold increased risk for a complication to occur. Dividing the cohort according to year of first procedure showed that those who had their first implantation ≥2002 had fewer complications and also lead- and pacing system survival was better in the later cohort. CONCLUSION: Pacing system survival and complications to PM therapy in young patients with isolated CAVB were significantly affected by age, with low age at PM implantation constituting a risk factor. Endocardial and epicardial pacing systems showed no significant differences in performance.

Morbimortalidad cardiovascular y variación del grado funcional en pacientes ancianos portadores de marcapasos / Medium-long term mortality and change in functional status in elderly patients with pacemaker

Resumen Antecedentes: Aproximadamente un 49% de los implantes se efectúan a individuos mayores de 80 años; sin embargo, la evidencia científica sobre mortalidad y cambio en la situación funcional de estos pacientes es muy pobre. Objetivo: Diseñamos un estudio prospectivo para analizar la morbimortalidad cardiovascular y la variación de su grado funcional a medio plazo en pacientes ancianos con electroestimulación permanente. Método: Estudio observacional prospectivo, que incluye 308 pacientes ancianos sometidos a implante de marcapasos en un hospital terciario entre 2012 y 2014. Como variables principales se evaluaron eventos cardiovasculares, mortalidad y grado funcional, con una media de seguimiento de 3.5 años. Resultados: El 60% de los pacientes incluidos en nuestro estudio tenían una edad superior a 80 años, y la indicación más frecuente fue el bloqueo auriculoventricular completo (44.3%), seguido de la fibrilación auricular lenta o bloqueada (16.7%). El modo de estimulación más frecuente en la muestra general fue el DDD (38.6%) (VVI en pacientes octogenarios, 38.7%). En el seguimiento, la mortalidad a largo plazo fue mayor en dispositivos ventriculares, especialmente en octogenarios (p = 0.001). El modo de estimulación ventricular (VVI) fue predictor independiente de mortalidad. A largo plazo, no se observó mejoría del índice de Barthel ni del grado funcional tras el implante del marcapasos. Conclusiones: La morbimortalidad cardiovascular en pacientes octogenarios portadores de marcapasos resulta superior a la de la población general, especialmente en dispositivos monocamerales. La electroestimulación permanente no se asocia con mejoría del grado funcional a medio-largo plazo en estos pacientes.

Abstract Background: Nowadays, 49% of patients with pacemakers are older than 80 years old. Nevertheless, mortality and change in functional status after pacemaker implantation are not well documented in elderly patients. Objective: We designed a prospective study to analyze cardiovascular mortality and change in functional status of elderly patients, medium-long term after pacemaker implantation. Methods: Observational study including pacemaker implants in individual older than 70 years old in a single center university hospital between 2012 and 2014. Analysis testing for an association between pacemaker system, medium-long term mortality and functional status after implantation were undertaken. Results: 60% of patients were older than 80 years old. Third-degree atrio-ventricular block (44.3%) and slow ventricular response atrial fibrillation (16.7%) were the most frequent electrocardiogram abnormalities, while bicameral DDD was the sort of pacing our department used the most (38.6%) (VVI in octogenarian patients, 38.7%). Long-term mortality was significantly higher in ventricular devices, especially in octogenarian patients (p = 0.001 respectively). Single-chamber VVI pacing acted as independent predictors of all-cause mortality in these individuals (p = 0.001). We found no significant improvement in Barthel index and functional status in this subgroup of patients, 3 years after pacing. Conclusion: Long-term mortality in individuals older than 80 years old with pacemaker implantation, was significantly higher comparing with general population, especially in ventricular devices. No significant improvement in functional status was detected in this subgroup of patients.

Regional abnormalities on cardiac magnetic resonance imaging and arrhythmic events in patients with cardiac sarcoidosis.

BACKGROUND: Patients with cardiac sarcoidosis (CS) may present with arrhythmic events (AE): atrioventricular block (AVB) and/ or ventricular arrhythmias (VA). We sought to: (a) use regional analysis of cardiac magnetic resonance imaging (CMR) to describe anatomic and functional phenotypes of patients with CS and AE; (b) Assess the association of regional CMR abnormalities with the combined endpoint of death, heart transplantation (HT) and AE; and (c) use machine learning (ML) to predict the combined endpoint based on CMR features. METHODS: we included 76 patients with CS and CMR. We analyzed cine images to determine regional longitudinal (LS) and radial strain (RS); and late gadolinium enhancement imaging to determine regional scar burden (%scar). RESULTS: Patients with AVB (n = 7), compared with those without, had higher %scar in the anterior (21.8 ± 27.4 vs 5.1 ± 8.9; P = 0.0005) and anteroseptal (19.3 ± 24.5 vs 3.5 ± 5.5; P < .0001) walls. Patients with VA (n = 12), compared with those without, had higher %scar in the basal inferoseptum (20.4 ± 30.8 vs 8.3 ± 13.4; P = .03). During mean follow-up of 4.4 ± 3.3 years, four patients died or underwent HT; eight had VA; and zero developed AVB. Multiple regional abnormalities were associated with the combined endpoint, including scar in the anteroseptal wall (HR 1.06 [1.02-1.09] per 1%scar increase, P = .002). The ML algorithm predicted the combined endpoint with a C-statistic of 0.91. CONCLUSION: Regional CMR abnormalities are associated with AE in patients with CS.

A rat model of complete atrioventricular block recapitulates clinical indices of bradycardia and provides a platform to test disease-modifying therapies.

Complete atrioventricular block (CAVB) is a life-threatening arrhythmia. A small animal model of chronic CAVB that properly reflects clinical indices of bradycardia would accelerate the understanding of disease progression and pathophysiology, and the development of therapeutic strategies. We sought to develop a surgical model of CAVB in adult rats, which could recapitulate structural remodeling and arrhythmogenicity expected in chronic CAVB. Upon right thoracotomy, we delivered electrosurgical energy subepicardially via a thin needle into the atrioventricular node (AVN) region of adult rats to create complete AV block. The chronic CAVB animals developed dilated and hypertrophied ventricles with preserved systolic functions due to compensatory hemodynamic remodeling. Ventricular tachyarrhythmias, which are difficult to induce in the healthy rodent heart, could be induced upon programmed electrical stimulation in chronic CAVB rats and worsened when combined with ß-adrenergic stimulation. Focal somatic gene transfer of TBX18 to the left ventricular apex in the CAVB rats resulted in ectopic ventricular beats within days, achieving a de novo ventricular rate faster than the slow atrioventricular (AV) junctional escape rhythm observed in control CAVB animals. The model offers new opportunities to test therapeutic approaches to treat chronic and severe CAVB which have previously only been testable in large animal models.

Maternal steroid therapy for fetuses with immune-mediated complete atrioventricular block: a systematic review and meta-analysis.

INTRODUCTION: To explore the effect of maternal fluorinated steroid therapy on fetuses affected by immune-mediated complete atrio-ventricular block (CAVB) in utero. MATERIAL AND METHODS: Pubmed, Embase, Cinahl, and ClinicalTrials.gov databases were searched. Only studies reporting the outcome of fetuses with immune CAVB diagnosed on prenatal ultrasound without any cardiac malformations and treated with fluorinated steroids compared to those not treated were included. The primary outcome observed was the regression of CAVB; secondary outcomes were need for pacemaker insertion, overall mortality, defined as the occurrence of either intrauterine (IUD) or neonatal (NND) death, IUD, NND, termination of pregnancy (TOP). Furthermore, we assessed the occurrence of all these outcomes in hydropic fetuses compared to those without hydrops at diagnosis. Meta-analyses of proportions using random effect model and meta-analyses using individual data random-effect logistic regression were used to combine data. RESULTS: Eight studies (162 fetuses) were included. The rate of regression was 3.0% (95%CI 0.2-9.1) in fetuses treated and 4.3% (95%CI 0.4-11.8) in those not treated, with no difference between the two groups (odds ratio (OR): 0.9, 95%CI 0.1-15.1). Pacemaker at birth was required in 71.5% (95%CI 56.0-84.7) of fetuses-treated and 57.8% (95%CI 40.3-74.3) of those not treated (OR: 9, 95%CI 0.4-3.4). There was no difference in the overall mortality rate (OR: 0.5, 95%CI 0.9-2.7) between the two groups; in hydropic fetuses, mortality occurred in 76.2% (95%CI 48.0-95.5) of the treated and in 23.8% (95%CI 1.2-62.3) of the untreated group, while in those without hydrops the corresponding figures were 8.9% (95%CI 2.0-20.3) and 12% (95%CI 8.7-42.2), respectively. Improvement or resolution of hydrops during pregnancy occurred in 76.2% (95%CI 48.0-95.5) of cases treated and in 23.3% (95%CI 1.2-62.3) of those nontreated with fluorinated steroids. CONCLUSIONS: The findings from this systematic review do not suggest a potential positive contribution of antenatal steroid therapy in improving the outcome of fetuses with immune CAVB.

Medium-long-term mortality and change in functional status in elderly patients with pacemaker.

Background: Nowadays, 49% of patients with pacemakers are older than 80 years old. Nevertheless, mortality and change in functional status after pacemaker implantation are not well documented in elderly patients. Objective: We designed a prospective study to analyze the cardiovascular mortality and change in functional status of elderly patients, medium-long term after pacemaker implantation. Methods: An observational study including pacemaker implants in individual older than 70 years old in a single-center university hospital between 2012 and 2014. Analysis testing for an association between pacemaker system, medium-long-term mortality, and functional status after implantation was undertaken. Results: About 60% of patients were older than 80 years old. The third-degree atrioventricular blockage (44.3%) and slow ventricular response atrial fibrillation (16.7%) were the most frequent electrocardiogram abnormalities, while bicameral DDD was the sort of pacing our department used the most (38.6%) (VVI in octogenarian patients, 38.7%). Long-term mortality was significantly higher in ventricular devices, especially in octogenarian patients (p = 0.001). Single-chamber VVI pacing acted as independent predictors of all-cause mortality in these individuals (p = 0.001). We found no significant improvement in Barthel Index and functional status in this subgroup of patients, 3 years after pacing. Conclusions: Long-term mortality in individuals older than 80 years old with pacemaker implantation was significantly higher comparing with general population, especially in ventricular devices. No significant improvement in functional status was detected in this subgroup of patients.

Objetivo: Aproximadamente un 49% de los implantes se efectúan a individuos mayores de 80 años; sin embargo, la evidencia científica sobre mortalidad y cambio en la situación funcional de estos pacientes es muy pobre. Diseñamos un estudio prospectivo para analizar la morbimortalidad cardiovascular y la variación de su grado funcional a medio plazo en pacientes ancianos con electroestimulación permanente. Método: Estudio observacional prospectivo, que incluye 308 pacientes ancianos sometidos a implante de marcapasos en un hospital terciario entre 2012 y 2014. Como variables principales se evaluaron eventos cardiovasculares, mortalidad y grado funcional, con una media de seguimiento de 3.5 años. Resultados: El 60% de los pacientes incluidos en nuestro estudio tenían una edad superior a 80 años, y la indicación más frecuente fue el bloqueo auriculoventricular completo (44.3%), seguido de la fibrilación auricular lenta o bloqueada (16.7%). El modo de estimulación más frecuente fue el DDD (38.6%). En el seguimiento, la mortalidad a largo plazo fue mayor en dispositivos ventriculares, especialmente en octogenarios (p = 0.001). El modo de estimulación VVI fue predictor independiente de mortalidad. A largo plazo, no se observó mejoría del grado funcional tras el implante del marcapasos. Conclusiones: La morbimortalidad cardiovascular en pacientes octogenarios portadores de marcapasos resulta superior a la de la población general, especialmente en dispositivos monocamerales. La electroestimulación permanente no se asocia con mejoría del grado funcional a medio-largo plazo en estos pacientes.

First-degree atrioventricular block on basal electrocardiogram predicts future arrhythmic events in patients with Brugada syndrome: a long-term follow-up study from the Veneto region of Northeastern Italy.

AIMS: This study was designed to assess the prognostic value of clinical and electrocardiographic parameters in Brugada syndrome (BrS). METHODS AND RESULTS: The study population included 272 consecutive patients (82% males; mean age 43 ± 12 years), with either a spontaneous (n = 137, 50%) or drug-induced (n = 135, 50%) Type 1 Brugada electrocardiogram (ECG) pattern. The study combined endpoint included sudden cardiac death (SCD), cardiac arrest, and appropriate intervention of implantable cardioverter-defibrillator (ICD). A first-degree atrioventricular (AV) block (PR = 219 ± 17 ms) was documented at basal ECG in 45 patients (16.5%); 27 of these underwent an electrophysiological study with recording in 21 (78%) of an HV interval ≥55 ms (mean 61 ± 3 ms). Patients with first-degree AV block had a wider QRS complex (median 110 ms vs. 95 ms; P = 0.04) and more often showed a left anterior hemiblock pattern (n = 13, 29% vs. n = 35, 16%; P = 0.056). During a mean follow-up of 85 ± 55 months, 17 patients (6.3%) experienced ≥1 major arrhythmic events (appropriate ICD intervention, n = 13 and SCD, n = 4). At univariate analysis, the occurrence of major arrhythmic events was significantly associated with a history of syncope or cardiac arrest (P < 0.001), Type 1 ECG pattern (P = 0.04), and first-degree AV block (P < 0.001). Univariate and multivariable predictors of events included a history of syncope or cardiac arrest [hazard ratio (HR) 5.8, 95% confidence interval (95% CI) 2.04-16.5; P < 0.001; and HR 6.68, 95% CI 2.34-19.1; P < 0.001; respectively], a spontaneous Type 1 ECG pattern (HR 1.56, 95% CI 1.03-4.24; P = 0.033; and HR 1.84, 95% CI 1.01-4.29; P = 0.044; respectively) and a first-degree AV block at baseline ECG (HR 3.84, 95% CI 1.47-9.99; P = 0.006; and HR 4.65, 95% CI 2.34-19.1; P = 0.002; respectively). CONCLUSION: Besides a history of cardiac arrest or syncope, first-degree AV block on basal ECG is an independent predictor of malignant arrhythmic events and a stronger marker of arrhythmic risk than a spontaneous 'coved-type' ECG pattern in patients with BrS.

Prognostic Implications of QRS Duration in Third-Degree Atrioventricular Block Patients with Heart Failure Treated with Cardiac Resynchronization Therapy.

Cardiac resynchronization therapy (CRT) improves heart function and prognosis in third-degree atrioventricular block (AVB) patients with heart failure (HF). However, it is still unclear how to screen for appropriate patients before implantation. This study aimed to evaluate the value of using QRS duration to predict CRT efficacy.This study enrolled a total of 72 third-degree AVB patients with HF who received CRT implantation. The patients were divided into Groups A (QRS duration < 120 ms, 33 cases), B (120 ms ≤ QRS duration < 150 ms, 22 cases), and C (QRS duration ≥ 150 ms, 17 cases) according to their baseline QRS duration. The effects of different QRS durations on CRT efficacy were analyzed.The CRT response rate were 30.3%, 50.0%, and 76.5% in Groups A, B, and C, respectively (P = 0.008). The patients in the 3 groups showed significant changes in left ventricular (LV) end-diastolic volume, LV end-systolic volume, and LV ejection fraction over the baseline values at 12 months after the implantation (P < 0.05), with the greatest change observed in Group C. Survival analysis indicated statistically significant differences among Groups A, B, and C (P = 0.024). Multivariate logistic regression analysis suggested that QRS duration was an independent prognostic factor for CRT efficacy. Baseline QRS duration was associated with improved myocardial remodeling and reductions in the incidence rates of primary endpoint events.QRS ≥ 150 ms is an effective predictor of postoperative outcome in patients with third-degree AVB and HF treated with CRT.

Outcome of Cardiac Sarcoidosis Presenting With High-Grade Atrioventricular Block.

BACKGROUND: Symptomatic high-grade atrioventricular block (AVB) is the most common and often the only presenting manifestation (lone AVB) of cardiac sarcoidosis. Implantation of an intracardiac cardioverter defibrillator instead of a pacemaker is recommended, but the true risk of fatal arrhythmia, one incident to lone AVB in particular, remains poorly known. METHODS: We used Myocardial Inflammatory Diseases in Finland Study Group Registry to analyze the presentations, left ventricular (LV) function, pacemaker therapy, and ventricular arrhythmias in cardiac sarcoidosis. From year 1988 to 2015, altogether 325 cases of cardiac sarcoidosis were diagnosed in Finland. Of them, 143 patients (112 women, mean age 52 years) presented with Mobitz II second degree or third degree AVB in the absence of other explanatory cardiac disease. RESULTS: Concomitant with AVB at presentation, 20 patients had either ventricular tachycardia or severe LV dysfunction with ejection fraction <35% and 29 patients had nonsevere LV dysfunction (ejection fraction, 35%-50%) while 90 patients presented with AVB alone. During a median of 2.8 years' follow-up, 23 sudden cardiac deaths (fatal or aborted) and 19 ventricular tachycardias were recorded as arrhythmic end point events. Their composite 5-year incidence (95% confidence interval) was 56% (36%-88%) in the AVB subgroup with ventricular tachycardia or severe LV dysfunction versus 24% (12%-49%) in the subgroup with nonsevere LV dysfunction and 24% (15%-38%) with lone AVB ( P=0.019). The 5-year incidence of sudden cardiac death was 34% (16%-71%), 14% (6%-35%), and 9% (4%-22%) in the respective subgroups ( P=0.060). CONCLUSIONS: The risk of sudden cardiac death is significant in cardiac sarcoidosis presenting with high-grade AVB with or without ventricular tachycardia or LV dysfunction. The consensus recommendation to implant an intracardiac cardioverter defibrillator whenever permanent pacing is needed seems well-founded.

Frequency of Complete Atrioventricular Block Complicating ST-Elevation Myocardial Infarction in Patients Undergoing Primary Percutaneous Coronary Intervention.

OBJECTIVES: ST-segment elevation myocardial infarction (STEMI) can be associated with many conduction disturbances including complete atrioventricular block (CAVB). CAVB complicating STEMI resulted in an increased mortality before the modern era of primary percutaneous coronary intervention (PCI). The aim of this study was to ascertain the rate and risk factors for CAVB in STEMI patients undergoing rapid reperfusion with PCI. METHODS: We analyzed 223 patients presenting with STEMI. Patient characteristics, procedural characteristics, and in-hospital data were compared between patients with and without CAVB. RESULTS: Out of 223 patients, 174 underwent PCI; the majority (87%) was African-American. CAVB was present in 8 patients (4.6%), and 6 of them had RCA occlusion. Independent predictors of CAVB included diabetes mellitus, female gender, lower systolic and diastolic blood pressure, and inferior-lateral/lateral STEMI. Ten patients (5.7%) required temporary pacing at presentation; only 1 patient required permanent pacing before discharge. No patient with anterior STEMI developed CAVB. CONCLUSIONS: The incidence and in-hospital mortality rate of CAVB in patients with STEMI who underwent primary PCI was reduced when compared to data from the thrombolytic era. This may be due to faster flow recovery in the infarct-related artery achieved with PCI.

Atrioventricular and intraventricular block after transcatheter aortic valve implantation.

Aortic stenosis is the most common valvular heart disease in industrialized countries and the most common cause of left ventricular outflow tract (LVOT) obstruction. Transcatheter aortic valve replacement (TAVR) is an alternative to surgical aortic valve replacement for intermediate to high-risk surgical candidates with symptomatic severe aortic stenosis. Conduction system abnormalities, including atrioventricular (AV) and intraventricular (IV) block, are the most common complication of TAVR. In this review, we aim to explore the anatomical issues relevant to atrioventricular block, the relevant clinical and procedural aspects, and the management and long-term implications of AV and IV block.

Association of cardiac implantable electronic devices with survival in bifascicular block and prolonged PR interval on electrocardiogram.

PURPOSE: Bifascicular block and prolonged PR interval on the electrocardiogram (ECG) have been associated with complete heart block and sudden cardiac death. We sought to determine if cardiac implantable electronic devices (CIED) improve survival in these patients. METHODS: We assessed survival in relation to CIED status among 636 consecutive patients with bifascicular block and prolonged PR interval on the ECG. In survival analyses, CIED was considered as a time-varying covariate. RESULTS: Average age was 76 ± 9 years, and 99% of the patients were men. A total of 167 (26%) underwent CIED (127 pacemaker only) implantation at baseline (n = 23) or during follow-up (n = 144). During 5.4 ± 3.8 years of follow-up, 83 (13%) patients developed complete or high-degree atrioventricular block and 375 (59%) died. Patients with a CIED had a longer survival compared to those without a CIED in the traditional, static analysis (log-rank p < 0.0001) but not when CIED was considered as a time-varying covariate (log-rank p = 0.76). In the multivariable model, patients with a CIED had a 34% lower risk of death (hazard ratio 0.66, 95% confidence interval 0.52-0.83; p = 0.001) than those without CIED in the traditional analysis but not in the time-varying covariate analysis (hazard ratio 1.05, 95% confidence interval 0.79-1.38; p = 0.76). Results did not change in the subgroup with a pacemaker only. CONCLUSIONS: Bifascicular block and prolonged PR interval on ECG are associated with a high incidence of complete atrioventricular block and mortality. However, CIED implantation does not have a significant influence on survival when time-varying nature of CIED implantation is considered.

Prognostic Value of Electrocardiography in Patients With Fulminant Myocarditis Supported by Percutaneous Venoarterial Extracorporeal Membrane Oxygenation　- Analysis From the CHANGE PUMP Study.

BACKGROUND: Fulminant myocarditis (FM) presents various abnormal findings on ECG, the prognostic impact of which has not been not fully elucidated. The aim of this study was therefore to clarify the prognostic value of ECG data in FM patients supported by venoarterial extracorporeal membrane oxygenation (VA-ECMO).Methods and Results:In this multicenter chart review, we investigated 99 patients with FM supported by VA-ECMO. The final cohort consisted of 87 patients (mean age, 52±16 years; female, 42%) after 12 patients who required conversion to other forms of mechanical circulatory support were excluded. The median LVEF was 14.5%. At the time of VA-ECMO initiation, 38 patients (44%) had arrhythmias including atrial fibrillation (6%), complete atrioventricular block (CAVB; 17%), and ventricular tachycardia or fibrillation (VT/VF; 15%). Of the 49 patients with sinus rhythm (SR), 26 had QRS duration ≥120 ms (wide QRS). On logistic regression analysis, wide QRS predicted in-hospital death in patients with SR (OR, 3.6; 95% CI: 1.07-13.61, P=0.04). Compared with SR with narrow QRS (QRS duration <120 ms), CAVB and VT/VF had a higher risk of in-hospital death (CAVB: OR, 7.20; 95% CI: 1.78-34.15, P=0.005; VT/VF: OR, 8.10; 95% CI: 1.86-42.31, P=0.005). CONCLUSIONS: In patients with FM, CAVB and VT/VF carried a higher risk of in-hospital death. Wide QRS also predicted a higher risk of in-hospital death in patients with SR.