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.

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.

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.

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.

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.

High-grade atrioventricular block in patients with acute myocardial infarction. Insights from a contemporary multi-center survey.

High-grade atrioventricular block (HAVB) is a frequent complication of acute myocardial infarction (AMI) and is associated with increased morbidity and mortality. We aimed to evaluate the incidence, predictors, and prognostic significance of HAVB in a contemporary cohort of patients with AMI, in the recent era of early reperfusion. Patients with acute coronary syndromes (n=11,487) during the years 2000-2010 were included. Patients were divided into two groups: with HAVB (n=308, 2.7%) and without HAVB (n=11,179, 97.3%). The incidence of HAVB decreased from 4.2% in 2000 to 2.1% in 2010 (p for trend<0.01). Patients with HAVB were more likely to develop in-hospital complications. Independent predictors of developing HAVB were older age, ST-elevation myocardial infarction (STEMI), smoking and Killip class≥2 on admission. 30-day and 1-year mortality rates were significantly higher in the HAVB as compared to the non-HAVB group (24% vs. 4.9%, p<0.01, 33.5% vs. 10%, p<0.01, respectively). Multivariable logistic regression analysis revealed that, HAVB was associated with increased 30-day (OR - 3.97; 95% CI - 1.96-8.04) and 1-year mortality risk (HR - 2.02; 95% CI - 1.3-3.1). Similar estimates were obtained for STEMI and non-STEMI (NSTEMI). In conclusion, although the incidence of HAVB decreased over the last decade, the associated morbidity and mortality are still high in these patients despite early reperfusion therapy.

Prolonged PR Interval at Birth Predicting the High Occurrence of Fatal Atrioventricular Block in Hypoplastic Left Heart Syndrome.

Infants with hypoplastic left heart syndrome (HLHS) are at high mortality especially when they are associated with bradyarrhythmias. However, the risk factor of developing high-grade atrioventricular block (HAVB) is still unclear. Seventy-three patients with HLHS in our institutions from 2002 to 2011 were enrolled. The survival rate was assessed by the anatomical types, treatments, occurrence of HAVB, severe tricuspid regurgitation (TR), and restrictive atrial septal defect (ASD) along with electrocardiogram findings at birth. There were 23 (32%) cardiogenic and 7 (10%) non-cardiogenic deaths. The occurrence rate of HAVB but not severe TR or restrictive ASD was higher in 30 deceased patients than in 43 survived patients [7 (23%) vs. 1 (2.3%), p = 0.0038]. The overall mortality rate was higher in patients with HAVB than in those without it (p = 0.0002). Of 7 deceased patients with HAVB, 6 HAVB occurred within 10 days post-surgery, and 3 HAVB led to the early death. The mortality rate of patients with prolonged PR (≥ 0.15 s) but not wide QRS (> 0.08 s) or prolonged QTc (> 0.43 s) at birth was higher than each without it (p = 0.0106). Multivariate analysis indicated that prolonged PR but no other variables was independently associated with the mortality (hazard ratio: 2.948, p = 0.0104). Prolonged PR at birth in HLHS infants predicts the development of fatal HAVB.

Atrioventricular block in coronary artery bypass surgery: perioperative predictors and impact on mortality.

INTRODUCTION: Disturbances of the cardiac conduction system are frequent in the postoperative period of coronary artery bypass surgery. They are mostly reversible and associated with some injury of the conduction tissue, caused by the ischemic heart disease itself or by perioperative factors. OBJECTIVE: Primary: investigate the association between perioperative factors and the emergence of atrioventricular block in the postoperative period of coronary artery bypass surgery. Secondary: determine the need for temporary pacing and of a permanent pacemaker in the postoperative period of coronary artery bypass surgery and the impact on hospital stay and hospital mortality. METHODS: Analysis of a retrospective cohort of patients submitted to coronary artery bypass surgery from the database of the Postoperative Heart Surgery Unit of the Sao Lucas Hospital of the Pontifical Catholic University of Rio Grande do Sul, using the logistic regression method. RESULTS: In the period from January 1996 to December 2012, 3532 coronary artery bypass surgery were carried out. Two hundred and eighty-eight (8.15% of the total sample) patients had atrioventricular block during the postoperative period of coronary artery bypass surgery, requiring temporary pacing. Eight of those who had atrioventricular block progressed to implantation of a permanent pacemaker (0.23% of the total sample). Multivariate analysis revealed a significant association of atrioventricular block with age above 60 years (OR=2.34; CI 95% 1.75-3.12; P<0.0001), female gender (OR=1.37; CI 95% 1.06-1.77; P=0.015), chronic kidney disease (OR=2.05; CI 95% 1.49-2.81; P<0.0001), atrial fibrillation (OR=2.06; CI 95% 1.16-3.66; P=0.014), functional class III and IV of the New York Heart Association (OR=1.43; CI 95% 1.03-1.98; P=0.031), perioperative acute myocardial infarction (OR=1.70; CI 95% 1.26-2.29; P<0.0001) and with the use of the intra-aortic balloon in the postoperative period of coronary artery bypass surgery (OR=1.92; CI 95% 1.21-3.05; P=0.006). The presence of atrioventricular block resulted in a significant increase in mortality (17.9% vs. 7.3% in those who did not develop atrioventricular block) (OR=2.09; CI 95% 1.46-2.99; P<0.0001) and a longer hospital stay (12.75 days x 10.53 days for those who didn't develop atrioventricular block) (OR=1.01; CI 95% 1.00-1.02; P=0.01). CONCLUSIONS: In most cases, atrioventricular block in the postoperative period of coronary artery bypass surgery is transient and associated with several perioperative factors: age above 60 years, female sex, chronic kidney disease, atrial fibrillation, New York Heart Association functional class III or IV, perioperative acute myocardial infarction and use of an intra-aortic balloon. Its occurrence prolongs hospitalization and, above all, doubles the risk of mortality.

Atrioventricular block in coronary artery bypass surgery: perioperative predictors and impact on mortality / Bloqueio atrioventricular pós-cirurgia de revascularização do miocárdio: fatores preditores perioperatórios e impacto na mortalidade

Abstract Introduction: Disturbances of the cardiac conduction system are frequent in the postoperative period of coronary artery bypass surgery. They are mostly reversible and associated with some injury of the conduction tissue, caused by the ischemic heart disease itself or by perioperative factors. Objective: Primary: investigate the association between perioperative factors and the emergence of atrioventricular block in the postoperative period of coronary artery bypass surgery. Secondary: determine the need for temporary pacing and of a permanent pacemaker in the postoperative period of coronary artery bypass surgery and the impact on hospital stay and hospital mortality. Methods: Analysis of a retrospective cohort of patients submitted to coronary artery bypass surgery from the database of the Postoperative Heart Surgery Unit of the Sao Lucas Hospital of the Pontifical Catholic University of Rio Grande do Sul, using the logistic regression method. Results: In the period from January 1996 to December 2012, 3532 coronary artery bypass surgery were carried out. Two hundred and eighty-eight (8.15% of the total sample) patients had atrioventricular block during the postoperative period of coronary artery bypass surgery, requiring temporary pacing. Eight of those who had atrioventricular block progressed to implantation of a permanent pacemaker (0.23% of the total sample). Multivariate analysis revealed a significant association of atrioventricular block with age above 60 years (OR=2.34; CI 95% 1.75-3.12; P<0.0001), female gender (OR=1.37; CI 95% 1.06-1.77; P=0.015), chronic kidney disease (OR=2.05; CI 95% 1.49-2.81; P<0.0001), atrial fibrillation (OR=2.06; CI 95% 1.16-3.66; P=0.014), functional class III and IV of the New York Heart Association (OR=1.43; CI 95% 1.03-1.98; P=0.031), perioperative acute myocardial infarction (OR=1.70; CI 95% 1.26-2.29; P<0.0001) and with the use of the intra-aortic balloon in the postoperative ...

Resumo Introdução: Os distúrbios do sistema de condução cardíaca são frequentes no pós-operatório de cirurgia de revascularização do miocárdio. Majoritariamente reversíveis, estão associados com alguma injúria do tecido de condução, causada pela própria cardiopatia isquêmica ou por fatores perioperatórios. Objetivo: Primário: investigar a associação entre fatores perioperatórios com o surgimento de bloqueio atrioventricular no pós-operatório de cirurgia de revascularização do miocárdio. Secundários: determinar a necessidade de estimulação cardíaca artificial temporária e de marca-passo definitivo no pós-operatório de cirurgia de revascularização do miocárdio e seu impacto na permanência e na mortalidade hospitalar. Métodos: Análise de Coorte retrospectiva de pacientes submetidos à cirurgia de revascularização do miocárdio, do banco de dados da unidade de Pós-Operatório de Cirurgia Cardíaca do Hospital São Lucas da Pontifícia Universidade Católica do Rio Grande do Sul, pelo método de regressão logística. Resultados: No período de janeiro de 1996 a dezembro de 2012, foram realizadas 3532 cirurgias de revascularização do miocárdio. Duzentos e oitenta e oito (8,15%) pacientes apresentaram bloqueio atrioventricular durante o pós-operatório de cirurgia de revascularização do miocárdio, necessitando de estimulação cardíaca artificial temporária. Oito dos que apresentaram bloqueio atrioventricular evoluíram para implante de marcapasso definitivo (0,23% do total da amostra). A análise multivariada evidenciou associação significativa de bloqueio atrioventricular com idade acima de 60 anos (OR=2,34; IC 95% 1,75-3,12; P<0,0001), sexo feminino (OR=1,37; IC 95% 1,06-1,77; P=0,015), doença renal crônica (OR=2,05; IC 95% 1,49-2,81; P<0,0001), fibrilação atrial (OR=2,06; IC 95% 1,16-3,66; P=0,014), classe funcional III e IV da New York Heart Association (OR=1,43; IC 95% 1,03-1,98; P=0,031), infarto agudo do miocárdio perioperatório (OR=1,70; IC ...

A novel HCN4 mutation, G1097W, is associated with atrioventricular block.

BACKGROUND: Loss-of-function mutations in the HCN4 gene have been shown to be associated with sinus dysfunction, but there are no reports on HCN4-mediated atrioventricular (AV) block. A novel missense HCN4 mutation G1097W was identified in a 69 year-old Japanese male with AV block, and we characterized the functional consequences of If-like channels reconstituted with the heterozygous HCN4 mutation. METHODS AND RESULTS: Wild-type (WT) HCN4 or/and HCN4-G1097W were expressed in a heterologous cell expression system. A functional assay using a whole-cell patch-clamp demonstrated that the mutant If-like currents were activated at more negative voltages compared to WT currents, while they retained the sensitivity to changes in intracellular cyclic adenosine monophosphate (cAMP) levels. Co-expression of G1097W with WT channels showed dominant-negative effects, including a reduction in peak currents and a negative voltage shifting on reconstituted currents. CONCLUSIONS: The HCN4-G1097W mutant channels displayed a loss-of-function type modulation on cardiac If channels and thus could predispose them to AV nodal dysfunction. These data provide a novel insight into the genetic basis for the AV block.

The role of cardiac resynchronization therapy for arterial switch operations complicated by complete heart block.

BACKGROUND: As mortality in patients with D-loop transposition of the great arteries (D-TGA) has decreased after the arterial switch operation (ASO), the focus has shifted to higher risk groups and outcomes that impact long-term morbidity and mortality, such as left ventricular (LV) dysfunction. We sought to examine the perioperative factors associated with LV dysfunction in patients with D-TGA and ventricular septal defects (VSD) after ASO. METHODS: A retrospective study was made of all patients with D-TGA/VSD who underwent ASO/VSD closure from 2001 to 2011. Patients with prematurity, L-looped ventricles, and straddling atrioventricular valves were excluded. The primary endpoint was moderate or severe LV dysfunction measured by echocardiogram 2 months or more after surgery. RESULTS: A total of 112 patients underwent ASO/VSD closure at a median age of 5 days. Median time of follow-up was 6.5 months, with no mortality noted. Six patients (8%) were noted to have at least moderate LV dysfunction. Risk factors were heart block requiring pacemaker placement (p<0.001) and length of intensive care unit admission (p=0.04). All 6 patients with heart block had an epicardial lead on the right ventricular free wall; 4 had moderate or severe LV dysfunction and underwent upgrade to cardiac resynchronization therapy (CRT); median time from initial pacemaker to CRT was 5 months. With a median follow-up of 5 months after CRT, LV function improved to normal (2 patients) or mild dysfunction (2 patients). CONCLUSIONS: Left ventricular dysfunction after surgical repair for D-TGA/VSD is low, with heart block and pacemaker insertion playing a significant role. The LV function improved after patients were upgraded to a CRT device.

Cardiac pacing in paediatric patients with congenital heart defects: transvenous or epicardial?

AIMS: Cardiac pacing is a difficult technique in children, particularly in patients with congenital heart defects (CHDs). Few studies to date have addressed this topic. METHODS AND RESULTS: We performed a retrospective analysis of the results of a single centre. Between 1982 and 2008, 287 patients with CHD, median age of 5 years (25-75%, 1-11) underwent cardiac pacing for sinus node dysfunction (SND) and atrioventricular block (AVB); 97% of patients underwent at least one heart surgery. Endocardial systems (Endo) were implanted in 117 patients, epicardial systems (Epi) in 170, with 595 leads (228 Endo, 367 Epi). Endocardial systems showed a significantly older age group with more frequent SND; Epi a younger age group, with more frequent AVB, greater number of surgical interventions. Perioperative complications were mortality 0.6% (Epi), pericardial effusion 0.6% (Epi), and haemothorax 3.4% (Endo). The median follow-up is 5 (2-10) years: the pacing system failed in 29% of patients, 13% Endo, and 40% Epi (P < 0.0001). Multivariate analysis showed a significantly higher risk of failure for Epi, a lower implant age, greater the number of leads implanted. The risk of malfunction of the leads increases significantly for Epi and the younger age when implanted. The steroid-eluting leads have a lower risk of malfunction (P = 0.05), steroid-eluting Endo leads provide significantly better outcomes than Epi. CONCLUSION: Cardiac pacing in paediatric patients with CHD shows satisfactory results in the long term. Endocardial systems show significantly better results than Epi systems. A younger age when implanted is a risk factor for complications at follow-up.

Clinical characteristics and long-term outcome of acute myocarditis in children.

The clinical course of acute myocarditis (AM) in children varies from being asymptomatic to causing sudden cardiac death. The aim of this study was to clarify the clinical characteristics and the long-term outcome of AM in children. We enrolled 24 children (aged from 0.1 to 14.6 years, median 8.4 years), who were diagnosed as AM between 1978 and 2010. The maximum follow-up period was 31 years (median 7 years). We retrospectively investigated their clinical course of AM. We also analyzed survival rate, persistence of decreased left ventricular ejection fraction (LVEF) by two-dimensional echocardiogram (2DE), and persistence of complete atrioventricular block (CAVB) by the Kaplan-Meier method. Furthermore, using univariate analysis we analyzed the factors that influenced the outcome. The survival rate was 86 % (95 % confidence interval (CI), 65-96) at 30 years. The persistence rate of LVEF less than 60 % at 1 month, 1 years, and 3 years was 44 % (95 % CI, 22-68), 36 % (95 % CI, 17-62) and 18 % (95 % CI, 3-59), respectively (n = 16), and the persistence of CAVB at 10 days was 36 % (95 % CI, 14-66, n = 11). In six patients with persistence of wide QRS (>100 ms), there were one acute death, two late deaths, and one orthotopic heart transplantation. The 30-year survival rate for six patients with wide QRS and 17 patients without wide QRS in the late phase was 50 % (95 % CI, 17-83) and 100 % (P = 0.0078), respectively. The factors in the acute phase influenced on the outcome were log creatine phosphokinase (CPK) 4.60 (95 % CI, 1.64-29.26, P = 0.001), appearance of ventricular tachycardia 19.71 (95 % CI, 2.50-399.9, P = 0.005), and LVEF 0.91 (95 % CI, 0.81-0.98, P = 0.015), respectively. The predictors of poor outcome in children with AM were high serum CPK, appearance of ventricular tachycardia and low LVEF in the acute phase, and persistence of wide QRS in the late phase. The long-term survival rate of children without these factors was fair.

Permanent pacemaker implantation after isolated aortic valve replacement: incidence, risk factors and surgical technical aspects.

OBJECTIVES: Conducting system defects are common in patients with aortic valve disease. Aortic valve replacement may result in further conduction abnormalities requiring permanent pacemaker implantation. The aim of our study was to identify the incidence and predictors for postoperative 30-day permanent pacemaker implantation in patients undergoing isolated aortic valve replacement, and the effect of an accurate surgical technique in order to prevent permanent pacemaker implantation. METHODS: Data from 261 consecutive patients (mean age 69 +/- 12 years, 136 men) undergoing isolated aortic valve replacement from January 2004 to January 2008 were analyzed retrospectively. Indications for aortic valve replacement were aortic valve stenosis (n = 156), stenoinsufficiency (n = 63), regurgitation (n = 42). Aortic bicuspid valve was present in 25% of cases (n = 64), redo operation was the indication in 7% (n = 18). Preoperative conducting system disease, defined as first-degree atrioventricular block, left or right bundle-branch block or left anterior hemiblock, was present in 25.6% (n = 67) of patients. An accurate surgical technique for debridement of calcific material was performed. RESULTS: In-hospital mortality was 0.8% (2 out of 261 patients). Postoperatively, 8 out of 261 patients (3%) required permanent pacemaker implantation, for second-degree (n = 1) or complete atrioventricular block (n = 7). Incidence of permanent pacemaker implantation was similar for patients either with or without preoperative conducting system disease (25 vs. 25.7%, P = NS). Independent predictors of permanent pacemaker implantation were greater preoperative end-systolic diameter (P = 0.026) and left ventricular septum hypertrophy (P = 0.041). CONCLUSIONS: Need of permanent pacemaker implantation after aortic valve replacement seems to be related more to preoperative advanced aortic valve disease rather than pre-existing conducting system abnormalities. An accurate surgical technique for aortic valve replacement probably helps to prevent further impairment of conducting system function requiring early postoperative permanent pacemaker implantation.

Cardiac arrhythmias in Thai Acute Coronary Syndrome Registry.

BACKGROUND: The incidence of arrhythmic complications in Thai patients with acute coronary syndromes (ACS) has not been previously reported. The present study results will serve as the local database for future studies. OBJECTIVE: To evaluate the incidence of arrhythmic complications in ASC in Thai patients and to identify factors that may affect arrhythmia complications in ACS patients. MATERIAL AND METHOD: Data collected from 9,373 patients from the Thai acute coronary syndrome registry (TACSR) were analyzed. This registry includes patients who presented with ACS including ST elevation myocardial infarction (STEMI), non-ST elevation myocardial infarction (NSTEMI) and unstable angina (UA), within 14 days from the symptoms onset. RESULTS: 395 (4.2%) patients with an ACS presented after cardiac arrest. These patients were noted to have significantly higher in-hospital mortality (50.1%). The incidence of serious cardiac arrhythmia complications in the TACSR was 16.6%. Among them, 62.7% were sustained VT/VE 31.5% had second or third degree AV block, and 5.8% has both VT/VF and AV Block. The incidence of VT was higher in the younger age group, while AV block and arrhythmic death were higher in the older aged patients. Arrhythmias complicating ACS were associated with increased mortality risk. Congestive heart failure (CHF) within the first 48 hours, current use of tobacco and cardiac troponin elevation were associated with significantly higher arrhythmic complications during hospitalization. CONCLUSION: Arrhythmias complicating ACS were associated with higher in hospital mortality. CHF within the first 48 hr, current tobacco use and cardiac troponin elevation were associated with significantly higher arrhythmic complications.