Occurrence Of Atrial Tachyarrhythmias Research Articles

Acute atrial infarction: arelatively neglected and under-recognized entity in clinical practice.

Electrocardiograms (ECGs) and angiographic features indicative of acute atrial infarction (AAI) often go unnoticed and are under-recognized in clinical practice. In this retrospective observational study, we analyzed the data of 3981 out of 9803 patients (40.61%) who were referred to our hospital for angiography and/or percutaneous coronary intervention due to acute coronary syndrome (ACS). These patients were diagnosed with acute ST segment elevation myocardial infarction (AMI) affecting the inferior, posterior, and/or right ventricular regions. Of the 3981 patients, 270 (6.78%) had involvement of the main coronary atrial branch meeting the angiographic criteria for AAI. Among the 270 patients identified, the right coronary artery was diagnosed as the infarct-related artery (IRA) in 187 patients (groupR), while the left circumflex artery was the IRA in 83patients (groupL). The incidence of PR-segment deviation was similar between the two groups (65.2% in groupR vs.66.3% in groupL, p = 0.870), as was occurrence of atrial tachyarrhythmia (67.4% vs.55.4%, p = 0.059). The prevalence of P wave morphology abnormalities (29.9% vs.49.4%, p = 0.005) and sinus bradycardia or arrest (25.1% vs.66.3%, p < 0.001) was significantly lower in GroupR than in GroupL. Acute atrial infarction represents adistinct yet frequently overlooked clinical entity. Clinicians should consider the potential for atrial arrhythmias, thromboembolism, hemodynamic instability, and atrial rupture when diagnosing AAI.

Urinary isoxanthopterin as a novel predictor following catheter ablation for atrial fibrillation.

Oxidative stress is associated with atrial fibrillation recurrence following catheter ablation. Urinary isoxanthopterin (U-IXP) is one of the noninvasive markers which reflect the reactive oxygen species; however, its ability to predict atrial tachyarrhythmias (ATAs) occurrence following catheter ablation remains uncertain. Among the patients who received scheduled catheter ablation for atrial fibrillation, baseline U-IXP levels were measured just before the procedure. The prognostic impact of baseline U-IXP upon postprocedural ATAs occurrence was investigated. Among 107 patients (71 years old, 68% men), baseline U-IXP level was 0.33 nmol/gCr on the median. During a mean of 603 days of follow-up, 32 patients had ATAs. Baseline higher U-IXP was independently associated with the occurrence of ATAs following catheter ablation with a hazard ratio of 4.69 (95% confidence interval: 1.82-12.37, p =.001) adjusted for the left atrial diameter, a persistent type, and hypertension which were potential confounders, with a cutoff of 0.46 nmol/gCr, which stratified cumulative incidence of ATAs occurrence ( p < .001). U-IXP can be used as the noninvasive predictive biomarker for ATAs following catheter ablation for atrial fibrillation.

Pulmonary vein and left atrial posterior wall isolation for the treatment of atrial fibrillation: Comparable outcomes for adults with congenital heart disease.

Optimal treatment strategies for ACHD with AF are unknown. This study sought to assess outcomes of pulmonary vein isolation (PVI) ± left atrial (LA), posterior wall isolation (PWI) for adults with congenital heart disease (ACHD), and atrial fibrillation (AF). A retrospective review of all cryoballoon (CB) PVI ± PWI procedures at a single center over a 3-year period were performed. Clinical characteristics and outcomes for patients with and without ACHD were compared. The primary outcome was the occurrence of atrial tachyarrhythmia at 12-months postablation after a 90-day blanking period. Three-hundred and sixteen patients (mean: 63 ± 12 years, [63% male]) underwent CB PVI ± PWI during the study, including 31 (10%) ACHD (simple 35%, moderate 39%complex 26%; nonparoxysmal AF in 52%). ACHD was younger (51 vs. 64 years;p < .001) with a lower CHADS2 DS2 -VASc score (1.2 vs. 2.1;p = .001) but had a greater LA diameter (4.9 vs. 4.0 cm;p < .001) and a number of prior cardioversions (0.9 vs. 0.4;p < .001) versuscontrols. 12-month freedom from recurrent AF was similar for ACHD and controls (76% vs. 80%;p = .6) and remained nonsignificant in multivariate analysis (hazard ratio:1.8, 95% confidence interval:0.7-5.1; p = .22). At 12-months postablation, 75% of ACHD versus93% of control patients were off antiarrhythmic drug therapy (p = .07). This study demonstrates younger age and lower conventional stroke risk, yet clinically advanced AF for ACHD relative to controls. CB PVI ± PWI was an effective strategy for the treatment of AF among all forms of ACHD with similar 12-month outcomes as compared to controls.

Atrial tachyarrhythmias and heart failure events in patients with arrhythmogenic right ventricular cardiomyopathy.

BackgroundAtrial tachyarrhythmias (ATAs) are associated with an increased risk of incident heart failure (HF). The aim of this study was to evaluate the incidence of ATAs and time of ATA development during disease progression as well as the influence of ATAs on HF-related events in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC).MethodsWe retrospectively studied 90 ARVC patients who met the definitive diagnosis of the 2010 Task Force Criteria and were diagnosed with ARVC at our institutions between 1974 and 2012. The main outcomes were death due to HF and hospitalization due to worsening HF.ResultsEleven patients had a history of ATAs at the time of ARVC diagnosis. Of 79 patients without a prediagnosis history of ATAs, 21 (27%) newly experienced ATAs during a median follow-up period of 11.4 (range, 0.1–29.6) years. Among them, 15 patients experienced their first hospitalization due to worsening HF a median of 1.7 (range, 0.0–9.8) years after the occurrence of ATAs. Patients with ATAs were more likely to experience death due to HF and hospitalization due to worsening HF than patients without ATAs (odds ratio 19.2, 95% confidence interval 2.0–92.3, P < 0.01 and odds ratio 29.7, 95% confidence interval 8.4–104.8, P < 0.01, respectively). Multivariable analysis revealed that ATAs were associated with an increased risk of hospitalization due to worsening HF (hazard ratio 15.55, 95% confidence interval 4.82–50.17, P < 0.01).ConclusionsOur study suggests that the occurrence of ATAs is associated with an increased risk of HF-related events and worsens the prognosis of ARVC patients.

A multicenter study comparing the outcome of catheter ablation of atrial fibrillation between cryoballoon and radiofrequency ablation in patients with heart failure (CRABL-HF): Study design.

BackgroundCatheter ablation of atrial fibrillation (AF) is increasingly performed worldwide in patients with heart failure (HF). However, it has been recently emphasized that AF ablation in patients with HF is associated with increased risks of procedure‐related complications and mortality. There are little data about the differences in the efficacy and safety between cryoballoon (CB) and radiofrequency (RF) ablation of AF in patients with HF.MethodsThe CRABL‐HF study is designed as a prospective, multicenter, open‐label, controlled, and randomized clinical trial comparing the efficacy and safety of AF ablation between CB and RF ablation in patients with HF (LVEF ≤40%) (UMIN Clinical Trials Registry UMIN000032433). The CRABL‐HF study will consist of 110 patients at multicenter in Japan. The patients will be registered and randomly assigned to either the CB ablation or RF ablation group with a 1:1 allocation. The primary endpoint of this study is the occurrence of atrial tachyarrhythmias (ATs) at 1 year with a blanking period of 90 days after ablation. Key secondary endpoints are the success rate of the pulmonary vein isolation, total procedural time, left atrial dwelling time, total fluoroscopy time, radiation exposure, complication rate, composite of all‐cause mortality or HF hospitalizations, cardiovascular events, change in left ventricular ejection fraction, and change in quality of life.ResultsThe results of this study are currently under investigation.ConclusionThe CRABL‐HF study is being conducted to compare the efficacy and safety of catheter ablation of AF between CB and RF ablation in patients with HF.

Risk of cardiac tachyarrhythmia in patients with repaired tetralogy of Fallot: a multicenter cardiac MRI based study

Cardiac tachyarrhythmias are the leading cause of morbidity and mortality in patients with repaired tetralogy of Fallot (TOF). We evaluated risk factors for sustained ventricular tachyarrhythmia (VT) and atrial tachyarrhythmia (ATA) in these patients. Patients (n = 319) who underwent cardiac magnetic resonance (CMR) imaging at two tertiary centers between 2007 and 2016 were assessed. Potential risk markers, based on history, cardiac magnetic resonance imaging (CMR), electrocardiography (ECG) and echocardiography, were analyzed for prediction of the primary endpoint of VT, and the secondary endpoint of ATA. During a follow-up of 3.5 (0.9-6.1) years, 20 (6.3%) patients reached the primary endpoint, and 30 (9.4%) the secondary endpoint. Multivariable cox hazards regression identified right ventricular (RV) end-diastolic volume (Hazard ratio [HR] 2.03, per 10ml/m2 increase; p = 0.02), RV end-systolic volume (HR 3.04, per 10ml/m2 increase; p = 0.04), RV mass (HR 1.88, per 10g/m2 increase; p = 0.02), and RV ejection fraction (HR 6.06, per 10% decrease; p = 0.02) derived from CMR to be independent risk factors of VT. In addition, QRS-duration (HR 1.70, per 10ms increase; p = 0.001) and body mass index (BMI: HR 1.8, per 5kg/m2 increase; p = 0.02) were independent markers of VT. Older age at TOF repair (HR 1.33, per 2months increase; p = 0.03) and BMI (HR 1.76, per 5kg/m2 increase; p < 0.001) independently predicted ATA. RV systolic dysfunction, hypertrophy and dilatation on CMR, together with QRS prolongation, and obesity are predictive of VT in TOF patients. Older age at TOF repair and obesity were associated with the occurrence of ATA.

A multicenter study of the need of additional freezing for cryoballoon ablation in patients with atrial fibrillation: The AD-Balloon study

BackgroundPulmonary vein isolation (PVI) is a cornerstone of catheter ablation in patients with paroxysmal atrial fibrillation (PAF), and balloon-based ablation has been recently performed worldwide. Ablation using the second-generation cryoballoon (CB2) (Arctic Front AdvanceTM, Medtronic, MN, USA) is useful for PVI; however, there is some debate concerning the optimal freezing time and number of cycles after PVI is achieved. MethodsThe AD-Balloon study was designed as a prospective, multicenter, randomized clinical trial to evaluate the optimal strategy (freezing cycles) of CB2 ablation (UMIN Clinical Trials Registry UMIN000020130). The main objective of this study is to investigate the need for an additional freezing cycle after PVI in patients treated with CB2 ablation. Patients will be randomly assigned in a 1:1 ratio to treatment with additional freezing (AD group) or without additional freezing (non-AD group). In the AD group, 3min of additional freezing time will be applied in all pulmonary veins after PVI is confirmed at the previous freezing cycle. In the non-AD group, no additional freezing will be applied in all pulmonary veins after PVI is confirmed. The primary endpoint of this study is the occurrence of atrial tachyarrhythmias within a 1-year follow-up period. We will enroll 110 consecutive patients with PAF. We will also investigate the usefulness of delayed-enhancement magnetic resonance imaging to assess the ablation lesions caused by CB2 ablation. ResultsThe results of this study are currently under investigation. ConclusionThe AD-Balloon study would assess the need for an additional freezing cycle after PVI is achieved. Our findings may contribute to further improvement of the CB2 ablation procedure.

Incidence of atrial tachyarrhythmias in patients with early repolarization syndrome and Brugada syndrome: analysis of patients with implantable cardioverter defibrillators

Purpose: The electrocardiographic early repolarization syndrome (ERS) is associated with a risk of sudden cardiac death (SCD). It has not been known whether the arrhythmogenic substrate in patients with ERS is restricted to the ventricular level. The aim of this retrospective study was to evaluate the incidence of inappropriate shocks (IS) due to atrial tachyarrhythmias (ATAs) in patients with ERS as compared with Brugada syndrome (BrS). Methods: We analyzed data from 47 consecutive patients diagnosed with ERS and BrS who underwent implantable cardioverter defibrillator (ICD) implantation from May 1998 to December 2011. Three in patients with BrS had paroxysmal atrial fibrillation (AF). The clinical data were collected and analyzed for all events with shocks. Results: Seventeen patients with ERS (age 38.6±11.1, male=14) and 30 patients with BrS (43.6±11.3, male = 29) were enrolled. Twelve patients experienced AF after defibrillation for ventricular arrhythmia (6 in ERS vs. 6 in BrS, P = NS). During a mean follow-up of 5.3±4.5 years in the ERS and 4.4±4.0 years in the BrS, five patients received appropriate shock (3 in ERS vs. 2 in BrS, P = 0.25). There was no significant difference in the prevalence of ATAs in patients who diagnosed ERS compared with patients in BrS from pre- to post- ICD implantation (9 in ERS vs. 12 in BrS, P = 0.54). Three of 17 (17.6%) ERS and 6 of 30 (20.0%) BrS patients received IS due to ATAs during this periods (Figure, P = 0.72). ![Figure][1] Figure 1 Conclusions: ATA occurred not infrequently in patients with ERS and ICD implantation. There were no differences in the occurrence of ATA and IS in patients with ERS as compared to patients with BrS. [1]: pending:yes

Propafenone for the Prevention of Atrial Tachyarrhythmias After Cardiac Surgery: A Randomized, Double-blind Placebo-controlled Trial

We studied the efficacy of propafenone in preventing atrial tachyarrhythmias after cardiac surgery, and the possible relationships between CYP2D6 polymorphism and the efficacy, pharmacokinetics, and tolerability of propafenone. One hundred and sixty patients were randomized (double blind) to receive propafenone (n= 78) or placebo (n= 82) for 1 week after cardiac surgery. The patients who were assigned to the propafenone group received 1 mg/kg infused in 1 h, followed by a continuous infusion at a rate of 4 mg/kg/24 h until the following morning, and subsequently 450 mg/day orally until the sixth postoperative day. Thirty-seven patients completed the trial in the propafenone group and 45 in the placebo group. The frequency of occurrence of atrial tachyarrhythmia was lower in the propafenone group than in the placebo group (29.7% vs. 53.3%, P< 0.05; relative risk, 0.56). Plasma propafenone concentrations were markedly influenced by CYP2D6 genotype-derived phenotype.

Long term prognosis of patients who had a Fontan operation

Purpose : This study assessed the long term survival rate and long term complications of patients who had a modified Fontan operation for functionally univentricular cardiac anomaly. Methods : Between June 1986 and December 2000, 302 patients with a functional single ventricle underwent surgical interventions and were followed up until February 2006. The mean follow-up period was 8.3±5.3 years (range 3.5-18 years). Their median age was 2.4 years at the Fontan operation. The survival rate, the incidence and the risk factor of late complications were evaluated retrospectively. Results : The verall survival rate was 91 percent at 5 years and 87 percent at 10 years. In multivariate analysis, early calendar year of operation and significant regurgitation were risk factors of death. The surviving patients showed NYHA functional class I in 82 percent, class II in 15 percent, and class III in 3 percent. Redo Fontan operations were necessary in 8.8 percent of patients at average 12.8±3.6 years after initial Fontan operation. The most common cause of Fontan conversion was atrial arrhythmia. The incidence of thromboembolic events was 9.3% and these complications were associated with the occurrence of atrial tachyarrhythmia. Supraventricular tachycardia including atrial flutter or fibrillation were reported on the follow-up examination by 11.2 percent of survivors after 8.4±5.6 years. Atriopulmonary connection showed higher rates of late tachycardia than lateral tunnel operation. Conclusions : This study revealed that the recent survival rate of Fontan type operation was satisfactory, but the occurrence of late complications after a Fontan type operation increased with the longer survival. There is a need for strict follow up and early treatment of late complications in patients who had a Fontan operation.

676 Right ventricular pacing does not affect the occurrence of atrial tachyarrhythmias in dual chamber pacemaker patients

676 Right ventricular pacing does not affect the occurrence of atrial tachyarrhythmias in dual chamber pacemaker patients

676 Right ventricular pacing does not affect the occurrence of atrial tachyarrhythmias in dual chamber pacemaker patients

676 Right ventricular pacing does not affect the occurrence of atrial tachyarrhythmias in dual chamber pacemaker patients

Lack of evidence of areas of slow conduction early after radiofrequency current application at porcine atrial myocardium.

Electrophysiological sequelae after creation of atrial myocardial lesions by radiofrequency current (RFC) application have not been studied in vitro. During general anesthesia, a steerable 6 French electrode catheter, equipped with a thermistor at the 4-mm tip electrode, was positioned at the lateral atrial aspect of the tricuspid valve annulus in 5 piglets (German Landrace, mean body weight 12.5 kg). Temperature-guided (75 degrees C) RFC (500 kHz) was delivered over 30 seconds. Forty-eight hours later, the hearts were removed and placed in ice-cold Turner's solution. The right atria were dissected, and the RFC lesions with surrounding tissue were cut out and transferred to an organ bath according to Steiert. Preparations were superfused with Turner's solution at 37 degrees C. Pacing of the viable tissue at the border of the preparations was accomplished at a cycle length of 500 ms. Whole atrial preparations were impaled (76 to 150 impalements per specimen) with KCl capillary microelectrodes containing 3 MKCl. In the surrounding viable tissue of the five preparations, mean maximum diastolic transmembrane potential ranged from -61.3 to -63.7 mV, mean action potential duration at 90% repolarization ranged from 135.2 to 156.1 ms, and mean maximum upstroke velocity of phase 0 of the action potential was between 104.7 and 112.9 V/sec. Statistical analysis revealed no significant differences among all 3 variables. No intracellular action potential was recorded from the surface of all 5 lesions. The surrounding tissue was sharply demarcated, with unaltered transmembrane action potential characteristics in the vicinity of the lesions. Areas of slow conduction were not observed. Lack of evidence of areas of slow conduction after RFC application to the atrial myocardium may imply that this technique is safe regarding occurrence of atrial tachyarrhythmias.