Catheter ablation of typical right atrial flutter in a 20-day-old neonate with tachycardiomyopathy.

Background: Fetal echocardiography can diagnose neonatal atrial flutter, which can cause heart failure in newborns. Little is known about catheter ablation in this population. Methods: Case report that aimed to review a successful ablation in a 20-day-old patient with refractory atrial flutter. Results: This is the first report of a successful neonatal atrial flutter ablation without any early recurrence after the procedure. Conclusions: Atrial flutter ablation performed on newborns is a reliable and long-lasting treatment option.

Prognosis of programmed ventricular stimulation in adult patients with syncope of unexplained origin: A historical cohort.

Background: Programmed ventricular stimulation (PVS) during electrophysiological study (EPS), is a globally accepted tool for risk stratification of sudden cardiac death (SCD) in some specific clinical situations. The aim of this study was to evaluate the prognosis of ventricular arrhythmia induction in a cohort of patients with syncope of undetermined origin (SUO). Methods: This is a historical cohort study in a population of patients with SUO referred for EPS between the years 2008-2021. In this interval, 575 patients underwent the procedure. Results: Patients with induced ventricular arrhythmias had a higher occurrence of structural heart disease (36.7% vs. 76.5%), ischemic heart disease (28.2 vs. 57.1%), heart failure (15.5% vs. 34.4%), and lower left ventricular ejection fraction (59.16% vs. 47.51%), when compared to the outcome with a negative study. PVS triggered ventricular arrhythmias in 98 patients, 62 monomorphic and 36 polymorphic. During a median follow-up of 37.6 months, 100 deaths occurred. Only the induction of sustained ventricular arrhythmias showed a significant association with the primary outcome (all-cause mortality) with a p value <.001. After the performance of EPS, 142 patients underwent cardioverter-defibrillator (ICD) implantation. At study follow-up, 30 patients had therapies by the device. Only the induction of sustained monomorphic ventricular arrhythmia showed statistically significant association with appropriate therapies by the device (p = .012). Conclusion: In patients with SUO, the induction of sustained monomorphic ventricular arrhythmia after programmed ventricular pacing is related to a worse prognosis, with a higher incidence of mortality and appropriate therapies by the ICD.

The First Brazilian Cardiovascular Registry of Atrial Fibrillation: Primary Results of the RECALL Study.

BACKGROUND: It is estimated that atrial fibrillation (AF) affects approximately 1.5 million people in Brazil; however, epidemiological data are limited. We sought to evaluate the characteristics, treatment patterns, and clinical outcomes in patients with AF in Brazil by creating the first nationwide prospective registry. METHODS: RECALL was a multicenter, prospective registry that included and followed for 1 year 4,585 patients with AF at 89 sites across Brazil from April 2012 to August 2019. Patient characteristics, concomitant medication use, and clinical outcomes were analyzed using descriptive statistics and multivariable models. RESULTS: Of 4,585 patients enrolled, the median age was 70 (61, 78) years, 46% were women, and 53.8% had permanent AF. Only 4.4% of patients had a history of previous AF ablation and 25.2% had a previous cardioversion. The mean (SD) CHA2DS2-VASc score was 3.2 (1.6); median HAS-BLED score was 2 (2, 3). At baseline, 22% were not on anticoagulants. Of those taking anticoagulants, 62.6% were taking vitamin K antagonists and 37.4% were taking direct oral anticoagulants. The primary reasons for not using an oral anticoagulant were physician judgment (24.6%) and difficulty in controlling (14.7%) or performing (9.9%) INR. Mean (SD) TTR for the study period was 49.5% (27.5). During follow-up, the use of anticoagulants and INR in the therapeutic range increased to 87.1% and 59.1%, respectively. The rates/100 patient-years of death, hospitalization due to AF, AF ablation, cardioversion, stroke, systemic embolism, and major bleeding were 5.76 (5.12-6.47), 15.8 (14.6-17.0), 5.0 (4.4-5.7), 1.8 (1.4-2.2), 2.77 (2.32-3.32), 1.01 (0.75-1.36), and 2.21 (1.81-2.70). Older age, permanent AF, New York Heart Association class III/IV, chronic kidney disease, peripheral arterial disease, stroke, chronic obstructive pulmonary disease, and dementia were independently associated with increased mortality while the use of anticoagulant was associated with lower risk of death. CONCLUSIONS: RECALL represents the largest prospective registry of patients with AF in Latin America. Our findings highlight important gaps in treatment, which can inform clinical practice and guide future interventions to improve the care of these patients.

Electrophysiological study as a predictor of mortality in unexplained syncope.

Background: Electrophysiological study can help in the diagnosis of arrhythmic syncope. According to the electrophysiological study finding, the prognosis of patients with syncope is still a matter of study. Objective: The aim of this study was to assess the survival of patients undergoing electrophysiological study according to their findings and to identify clinical and electrophysiological independent predictors of all-cause mortality. Methods: A retrospective cohort study included patients with syncope who underwent electrophysiological study from 2009 to 2018. A Cox logistic regression analysis was performed to identify independent prognostic factors for all-cause mortality. Results: We included 383 patients in our study. During a mean follow-up of 59 months, 84 (21.9%) patients died. The split His group had the worst survival compared with the control group, followed by sustained ventricular tachycardia and HV interval ≥ 70 ms, respectively (p = .001; p < .001; p = .03). The supraventricular tachycardia group showed no differences compared with the control group (p = .87). In the multivariate analysis, independent predictors of all-cause mortality were Age (OR 1.06; 1.03-1.07; p < .001); congestive heart failure (OR 1.82; 1.05-3.15; p = .033); split His (OR 3.7; 1.27-10.80; p = .016); and sustained ventricular tachycardia (OR 1.84; 1.02-3.32; p = .04). Conclusion: Split His, sustained ventricular tachycardia, and HV interval ≥ 70 ms groups had worse survivals when compared to the control group. Age, congestive heart failure, split His, and sustained ventricular tachycardia were independent predictors for all-cause mortality.

Brugada syndrome unmasked by left ventricle posteromedial papillary muscle ventricular tachycardia: Coincidence or consequence.

A 46-year-old man presented with left ventricle posteromedial papillary muscle ventricular tachycardia, presyncope, and a type-1 Brugada pattern on the post-electrical cardioversion electrocardiogram. There was a probability of a Brugada syndrome with the expression of its disease in the left ventricle; or a left monomorphic ventricular tachycardia as a part of Brugada phenocopy; or a Brugada syndrome with left monomorphic ventricular tachycardia as an epiphenomenon. Cardiac magnetic resonance, electrophysiological study, and ajmaline test were the key diagnostic tools employed.

Polymorphism of the Beta-1 Gly389Arg receptor in patients with dual atrioventricular nodal physiology.

INTRODUCTION: Gly389Arg ß1 adrenergic receptor polymorphisms seem to exert an influence on the modulation of the adrenergic effect in several types of patients. This study aimed to determine the prevalence of Gly389Arg polymorphisms among patients with evidence of double nodal pathway and to correlate the electrophysiological properties with the different genotypes of the respective polymorphisms. METHODS: A cross-sectional, descriptive and analytical study was designed to assess 49 patients, with evidence of double nodal pathway, submitted to electrophysiological study. Genomic DNA was extracted from peripheral blood leukocytes and the genotypes of the Arg389Gly polymorphisms were identified in all individuals by PCR/RFLP (polymerase chain reaction/restriction fragment length polymorphism). RESULTS: The majority of patients were female and had supraventricular tachycardia (75.5%). The prevalence of Arg389Arg genotype was found in 32 patients (65.3%), Arg389Gly genotype in 16 patients (32.7%) and Gly389Gly genotype in 1 patient (2%). With respect to the induction of nodal reentrant tachycardia, it was possible to induce non-isoproterenol tachycardia in 32 patients (65.3%), of whom 24 had the Arg389Arg genotype and 8 the Arg389Gly and Gly389Gly genotype (p = 0.05). The resting heart rate of patients of the Arg389Arg genotype was 81 ± 18 bpm and the Arg389Gly and Gly389Gly genotype of 71 ± 9 bpm (p = 0.044). Body mass index (BMI) among patients with genotype Arg389Gly and Gly389Gly was 29.8 ± 7.1 and patients with the Arg389Arg genotype was 26.2 ± 4.6 (p = 0.034). CONCLUSION: The Arg389Arg genotype was more easily related to triggering arrhythmia, higher resting heart rate and lower BMI.

Prognostic impact of atrial fibrillation and flutter temporal pattern on anticoagulation and return visits to the emergency department: A historic cohort of 1112 patients.

BACKGROUND: Emergency department (ED) visits due to atrial fibrillation and flutter (AFF) are common, and provide an opportunity to define stroke risk. The prognostic impact of AFF duration on return ED visits is unknown. We aimed to investigate both the prognostic impact of AFF classification on ED visits and the adherence to guideline recommendations on anticoagulation. METHODS: This single-center historic cohort of every patient treated for AFF in our ED during 2012. Follow-up data was obtained on May 2015 (median follow-up of 863 days). RESULTS: Among 1112 patients (495 Paroxysmal AF - parAF, 475 Persistent AF - persAF, and 142 flutter), those with parAF were less frequently under oral anticoagulation than persAF and flutter patients (15.8%, 39.4%, 40.1%, p < 0.01). Mean CHA2DS2-VASc scores of parAF were lower than persAF (2.2 vs. 3.12, p < 0.01), and did not differ from those with flutter. Return visits to the ED were highest among flutter patients and lowest among parAF (49.3% vs. 37.2%, p < 0.01). Heart failure, hypertension, female gender and atrial flutter were independent risk factors for repeated visits on multivariate regression. CONCLUSIONS: AFF duration provide prognostic information in the ED. ED return visits were common and particularly incident among flutter patients. Furthermore, stroke risk was high and anticoagulation rates were low across all groups. Patients with paroxysmal AF were less commonly anticoagulated even though their mean CHA2DS2-VASc scores were 2.2. These results reveal that guideline adherence is still lacking and should raise awareness to a stricter patient follow-up after ED visits.

Non-fluoroscopic catheter ablation: A randomized trial.

BACKGROUND: Catheter ablation provides curative treatment for tachyarrhythmias. Fluoroscopy, the method used for this, presents several risks. The electroanatomical mapping (MEA) presents a three-dimensional image without using X-rays, and may be adjunct to fluoroscopy. OBJECTIVES: We evaluated the possibility of performing catheter ablation with the exclusive use of electroanatomical mapping (MEA), dispensing with fluoroscopy. We compared the total time of procedure and success rates against the technique using fluoroscopy (RX) with emission of X-rays. METHODS: Randomized, unicentric, uni-blind study of patients referred for tachyarrhythmia ablation. RESULTS: Twelve patients were randomized to the XR group and 11 to the EAM group. The mean age was 48.5 (±12.6) vs 46.3 (±16.6) (P = ns). Success occurred in 11 patients (91.7%) in the RX group and 9 (81.8%) in the MEA group (P = 0.46). The procedure time in minutes was higher in the MEA group than in the RX group (79-47-125min vs 49-30-100min; P = 0.006). The mean fluoroscopy time was 11 ±â€¯9 min versus zero (RX vs MEA: P < 0.001). The mean radiofrequency applications were lower in the RX group against the MEA group (6 ±â€¯3.5 × 13.2 ±â€¯18.2 p < 0.019). There were no complications. CONCLUSION: MEA opened new therapeutic possibilities for patients with arrhythmias, reducing the risk of radiation. In this study, it was possible to demonstrate that it is feasible to perform ablation only with the use of MEA, with similar success with fluoroscopy, at the expense of a longer procedure time.

Coronary sinus cannulation predicts atrioventricular nodal reentry as mechanism of supraventricular tachycardia.

INTRODUCTION: Common clinical teaching, for invasive electrophysiology, is that if the first year fellow cannulates the coronary sinus (CS) in his first attempt, the arrhythmia is more likely to be atrioventricular nodal reentry tachycardia (AVNRT). This general perception has not yet been clinically tested. We evaluated this theory in prospective patients undergoing an electrophysiological study (EPS) for paroxysmal supraventricular tachycardia (PSVT). METHODS: Cohort study. CS ease of cannulation (CSCS) was graded as: 1) 1st year fellow cannulates in first attempt; 2) 1st year fellow needs more than one attempt or maneuver to cannulate the CS; 3) staff physician cannulates in first attempt after the fellow was unsuccessful; 4) staff physician requires more than one maneuver to cannulate the CS; 5) staff physician judges that the cannulation process was extremely difficult. RESULTS: Of the 1361 patients undergoing EPS in our institution, 165 were selected. Age was 49 ±â€¯15 years. AVNRT occurred in 77.6%, atrioventricular reentry tachycardia (AVRT) in 15.1% and atrial tachycardia (AT) in 7.3% of cases. The CSCS = 1 was more prevalent in AVNRT, 89% versus 68% AVRT and 58.3% of AT (P = 0.0005). Patients with CSCS = 1 have a higher chance of the PSVT being AVNRT (odds ratio: 4.41; 95CI: 1.84-10.56; P = 0.0009). CONCLUSION: The CSCS predicts the likelihood of the induced PSVT being AVNRT as compared to AVRT and AT. More studies are required to try to associate this finding to clinical patient characteristics to create a score for PSVT mechanism prediction.

Atrial flutter and embolic risk: The relationship between atrial flutter cycle length and left atrial appendage function.

BACKGROUND: The potential for thromboembolism in atrial flutter (AFL) is different from atrial fibrillation. AFL cycle length (AFL-CL) may be related to reduced left atrial appendage (LAA) function. Very rapid AFL-CL can lead to mechanical and electrophysiological disorders that contribute to lower LAA emptying velocity (LAEV). The aim of this study is to relate atrial flutter cycle length with LAEV and its role in thrombogenesis. METHODS: Cross-sectional study of patients with atrial flutter AFL who underwent transoesophageal echocardiography (TEE) before catheter ablation or electric cardioversion. AFL-CL in milliseconds was measured with a 12-lead EKG or in intracardiac records. RESULTS: We included 123 patients. There was correlation between AFL-CL and LAEV (r = 0.34; p = 0.003) in typical AFL. Cycle length, LA size and atypical flutter were predictors of low LAEV on multivariate analysis. An index multiplying atrial rate (bpm) during the arrhythmia versus left atrial size(mm) >11,728 was associated with spontaneous echogenic contrast and/or left atrial thrombus on TEE (C-statistic = 0.71; CI95%0.60-0.81). CONCLUSIONS: There was a significant relationship between the AFL-CL and LAEV. The LAEV was affected by the LA size, the type of atrial flutter and the AFL-CL. A new index, relating the atrial rate with the left atrial size, was able to identify a higher occurrence of spontaneous echogenic contrast and/or left atrial thrombus.

Simple risk stratification score for prognosis of syncope.

PURPOSE: The aim of this study is to describe a new simple score to predict the occurrence of severe adverse events in patients admitted for syncope to a tertiary cardiology referral center. METHODS: Three hundred ninety-three subjects with emergency department visits for syncope were identified and followed prospectively. The primary endpoint was death or unplanned hospital admission after the syncopal episode. The score consisted of sum of the following: previous syncope (2 points), an abnormal electrocardiogram (3 points), and history of heart disease (4 points). The accuracy of our score was compared to other scores available in the literature. RESULTS: Of the 393 subjects, 87 were diagnosed with syncope secondary to structural or electrical heart disease and 306 with noncardiac syncope. The primary endpoint occurred in 202 cases, including death occurring in 25 patients during the 12-month follow-up. The 30-day event rate for the primary endpoint was 26.5 %. The c-statistic for the new score was 0.76 (95 % CI 0.71-0.80) similar to other scores when applied to our sample. Patients with a score of 3 out of 9 had a hazard ratio of 3.46 (95 % CI 1.22-6.11) for death during the follow-up. CONCLUSIONS: In the study population, the new syncope score detected patients with an increased risk of death after discharge from a syncopal event. Our score predicted adverse events comparably to other scores reported in the literature. It has the advantage of being simple and easily obtained from the history and an inexpensive noninvasive test-the ECG.

CHA2 DS2 VASc Score as a Predictor of Cardiovascular Events in Ambulatory Patients without Atrial Fibrillation.

BACKGROUND: New evidence suggests that the CHA(2)DS(2)VASc (congestive heart failure, hypertension [HTN], age, diabetes, stroke, vascular disease, and female gender) score may be a reliable tool to predict the risk of thromboembolic events in patients without documented atrial fibrillation (AF). METHODS: We performed a prospective cohort study of outpatients without AF or flutter, who were not using oral anticoagulation. Clinical characteristics were assessed and patients were stratified according to the CHA(2)DS(2)VASc score. We evaluated the incidence of major adverse cardiac outcomes and its relation to the CHA(2)DS(2)VASc score during the follow-up. RESULTS: Four hundred sixty-eight patients without AF were enrolled with a mean follow-up of 12 ± 6 months. Age was 64.9 ± 11.3 years. The prevalence of HTN was 88.4%, diabetes 37.6%, heart failure 26.3%, and vascular disease 61.7%. Overall, CHA(2)DS(2)VASc score was 3.4 ± 1.4. There were 15 major adverse cardiac outcomes during 12.2 months of follow-up (overall incidence of 3.2 per 100 person-years). We found significant differences in relation to gender, age, previous stroke, and follow-up length in patients with and without adverse outcomes. The CHA(2)DS(2)VASc score was higher in those with adverse outcomes (4.2 ± 1.7 vs 3.4 ± 1.4; P = 0.035). Patients with a CHA(2)DS(2)VASc ≥6 had a relative risk for adverse outcomes of 4.2 (95% confidence interval: 1.27-13.90). CONCLUSIONS: In our population, CHA(2)DS(2)VASc score predicts major adverse cardiac outcomes, including stroke and death, in a cohort of patients without AF.

Longterm effects of cardiac mediastinal nerve cryoablation on neural inducibility of atrial fibrillation in canines.

In canines, excessive activation of select mediastinal nerve inputs to the intrinsic cardiac nervous system induces atrial fibrillation (AF). Since ablation of neural elements is proposed as an adjunct to circumferential pulmonary vein ablation for AF, we investigated the short and long-term effects of mediastinal nerve ablation on AF inducibility. Under general anesthesia, in 11 dogs several mediastinal nerve sites were identified on the superior vena cava that, when stimulated electrically during the atrial refractory period, reproducibly initiated AF. Cryoablation of one nerve site was then performed and inducibility retested early (1-2 months post Cryo; n=7) or late (4 months post Cryo; n=4). Four additional dogs that underwent a sham procedure were retested 1 to 2 months post-surgery. Stimulation induced AF at 91% of nerve sites tested in control versus 21% nerve sites early and 54% late post-ablation (both P<0.05). Fewer stimuli were required to induce AF in controls versus the Early Cryo group; this capacity returned to normal values in the Late Cryo group. AF episodes were longer in control versus the Early or Late Cryo groups. Heart rate responses to vagal or stellate ganglion stimulation, as well as to local nicotine infusion into the right coronary artery, were similar in all groups. In conclusion, focal damage to intrinsic cardiac neuronal inputs causes short-term stunning of neuronal inducibility of AF without major loss of overall adrenergic or cholinergic efferent neuronal control. That recovery of AF inducibility occurs rapidly post-surgery indicates the plasticity of intrathoracic neuronal elements to focal injury.

Effects of propofol on the cardiac conduction system.

BACKGROUND AND OBJECTIVES: Some studies have demonstrated that the use of propofol is occasionally associated with bradyarrhythmias or reversion of arrhythmias to sinus rhythm. This property of propofol suggests interference with the Cardiac Conduction System (CCS). CONTENTS: A review of the main contemporary articles on the use of propofol in the presence of cardiac arrhythmias was undertaken. The authors describe pathophysiological mechanisms of supraventricular tachyarrhythmias (SVT) and occasional interferences caused by propofol on the CCS. CONCLUSIONS: The studies undertaken so far seem to indicate that propofol probably interferes in automatic SVT (at least in children), but not in reentrant tachyarrhythmias.

Randomized study of surgery for patients with permanent atrial fibrillation as a result of mitral valve disease.

BACKGROUND: The Cox Maze procedure has been used to treat atrial fibrillation in patients with mitral valve disease. Recently, ectopic foci, originating in the pulmonary veins, were demonstrated in patients with atrial fibrillation, and the indication was that their arrhythmia could have a focal origin. In the light of this new evidence, a simplified surgical technique to isolate the pulmonary veins was developed to eliminate permanent atrial fibrillation in patients undergoing mitral valve surgery. This study compares three surgical procedures proposed to maintain sinus rhythm after mitral valve surgery. METHODS: A prospective clinical trial of 30 patients with mitral valve disease and permanent atrial fibrillation who had undergone mitral valve surgery were randomized in accordance with the type of surgery used on each: (1). associated en bloc isolation of pulmonary veins, (2). the Maze procedure, or (3). mitral valve correction alone. The preoperative clinical characteristics were similar in the three groups. RESULTS: The overall postoperative complications were similar in all three groups. The cardiopulmonary bypass time and the aortic cross-clamping time were shorter in the control group, but this factor bore no relation to increased morbidity in the intervention groups. The relative risk of atrial fibrillation after surgery was 0.08 in the group undergoing isolation of pulmonary veins (p = 0.010; 95% confidence interval, 0.01 to 0.71) and 0.20 in the Maze group (p = 0.044; 95% confidence interval, 0.04 to 1.02) compared with the control group. CONCLUSIONS: En bloc isolation of pulmonary veins associated with mitral valve surgery appears to be safe and just as effective as the Maze procedure in maintaining sinus rhythm in patients with permanent atrial fibrillation.