Non sinus focal atrial tachycardia (AT) is an uncommon arrhythmia. Electrocardiograms (ECGs) can be used to diagnose the condition. ECGs can also be used to pinpoint the origin of the focal AT; however, the precise location is ultimately confirmed by electrophysiology. Automaticity, triggered activity, and micro-reentry are possible underlying mechanisms for focal AT. Pharmacological therapy is recommended for symptomatic patients. Radiofrequency catheter ablation is a viable alternative, especially in patients intolerant to drugs, or patients with drug-refractory focal AT. This review describes the epidemiology, clinical features, diagnosis, and mechanisms of focal AT, as well as possible therapeutic approaches for this condition.
Arrhythmias, Cardiac ; Catheter Ablation ; Diagnosis ; Electrocardiography ; Electrophysiology ; Epidemiology ; Humans ; Tachycardia* ; Tachycardia, Ectopic Atrial

OBJECTIVEEctopic atrial tachycardia (EAT) is a common type of supraventricular tachycardia in pediatric population, and it can be resistant to antiarrhythmic drugs and lead to tachycardia induced cardiomyopathy (TIC) if not properly managed. This study assessed the clinical course and response to treatment of EAT in children.

METHODA retrospective review included 144 children at the First Hospital of Tsinghua University diagnosed with EAT from January 2009 to April 2014. The clinical detailed history, 12 lead ECG, 24-h Holter recording, echocardiography, response to therapy and follow-up were analyzed.

RESULTThe onset of EAT occurred at any age with a distribution with positive skewness, 57 children ≤1 years, 22 children > 1 - 3 years, 25 children > 3 - 6 years and 40 children ≥ 6 years of age. The percentages of the three tachycardia types were 36. 1% (n = 52) for incessant EAT, 52. 8% (n = 76) for paroxysmal EAT and 11. 1% (n = 16) for sporadic EAT, respectively. There were 115 patients received drug therapy in our hospital and in 72 cases the EAT was completely controlled. Antiarrhythmic therapy had been discontinued in 35 children with complete control. Normal sinus rhythm was observed by telemetry or Holter within 4 to 90 days and the mean duration of medical therapy was 310 days (range 15 to 608 days) in these children. The combination of sotalol and propafenone showed better effectiveness for control of children with EAT (54%, 41/76), compared with single sotalol (36%, 24/66) and the combination of amiodarone and metoprolol (30%, 7/23) (χ2 = 6. 296, P = 0. 043). Tachycardia type was able to predict the response to antiarrhythmic drugs for children with EAT, sporadic tachycardia had best control rate on pharmacological therapy compared with paroxysmal tachycardia and incessant tachycardia (94% (15/16) vs. 67% (42/63) vs. 42% (15/36), χ2 = 17. 925, P = 0. 000) . Acute success of radiofrequency ablation (RFA) in children who showed poor response to antiarrhythmic drugs was achieved in 45 of 49 (92%), ultimate success was achieved in 33 of 49 (67%). The incidence of TIC secondary to EAT was 18. 1% (n =26), and left ventricular ejection-fraction (LVEF) returned to normal in 23 children after successful control of EAT ((61 ± 4) % vs. (43 ± 5) %, t = - 10. 036, P = 0. 000). Side effects including abnormal thyroid function (in 3) and abnormal liver function (in 1) occurred in 4 (17%) of 23 children who received amiodarone and disappeared when amiodarone was discontinued.

CONCLUSIONEAT in children predominantly occurred in young infants and children. Incessant EAT comprised a great percentage. The combination of sotalol and propafenone provided the best results for control of children with EAT. RFA should be considered as a preferred treatment for older children who displayed poor response to medical therapy.

Amiodarone ; Anti-Arrhythmia Agents ; Cardiomyopathies ; Catheter Ablation ; Child ; Child, Preschool ; Echocardiography ; Electrocardiography ; Humans ; Infant ; Retrospective Studies ; Sotalol ; Tachycardia, Ectopic Atrial ; drug therapy ; physiopathology ; Tachycardia, Supraventricular ; drug therapy ; Ventricular Function, Left

Little is known about the long-term prognosis of or predictors for the different clinical types of atrial fibrillation (AF) in Korean populations. The aim of this study was to validate a risk stratification to assess the probability of AF progression from paroxysmal AF (PAF) to persistent AF (PeAF) or permanent AF. A total of 434 patients with PAF were consecutively enrolled (mean age; 71.7 +/- 10.7 yr, 60.6% male). PeAF was defined as episodes that are sustained > 7 days and not self-terminating, while permanent AF was defined as an ongoing long-term episode. Atrial arrhythmia during follow-up was defined as atrial premature complex, atrial tachycardia, and atrial flutter. During a mean follow-up of 72.7 +/- 58.3 months, 168 patients (38.7%) with PAF progressed to PeAF or permanent AF. The mean annual AF progression was 10.7% per year. In univariate analysis, age at diagnosis, body mass index, atrial arrhythmia during follow-up, left ventricular ejection fraction, concentric left ventricular hypertrophy, left atrial diameter (LAD), and severe mitral regurgitation (MR) were significantly associated with AF progression. In multivariate analysis, age at diagnosis (P = 0.009), atrial arrhythmia during follow-up (P = 0.015), LAD (P = 0.002) and MR grade (P = 0.026) were independent risk factors for AF progression. Patients with younger age at diagnosis, atrial arrhythmia during follow-up, larger left atrial chamber size, and severe MR grade are more likely to progress to PeAF or permanent AF, suggesting more intensive medical therapy with close clinical follow-up would be required in those patients.
Aged ; Atrial Fibrillation/epidemiology/mortality/*pathology ; Atrial Flutter/*epidemiology/mortality/pathology ; Atrial Premature Complexes/*epidemiology/mortality/pathology ; Disease Progression ; Echocardiography ; Female ; Heart Atria/pathology/ultrasonography ; Humans ; Male ; Middle Aged ; Republic of Korea/epidemiology ; Retrospective Studies ; Tachycardia, Ectopic Atrial/*epidemiology/mortality/pathology ; Tachycardia, Paroxysmal/*epidemiology/mortality/pathology ; Thromboembolism/epidemiology/mortality ; Treatment Outcome

Atrial Appendage ; physiopathology ; Catheter Ablation ; Child ; Child, Preschool ; Female ; Humans ; Male ; Tachycardia, Ectopic Atrial ; etiology ; surgery ; Tachycardia, Supraventricular ; etiology ; surgery

BACKGROUND AND OBJECTIVES: Prolonging of the corrected QT interval (QTc) has been reported after cardiac surgery in some studies. However, there have not been many studies on infant open cardiac surgery for ventricular septal defect (VSD) repair. This study was performed to define the changes in QTc and to find related post-surgery factors in this patient group. SUBJECTS AND METHODS: From 2008 to 2012, 154 infants underwent VSD repair at the Severance Cardiovascular Hospital. This study includes 105 of these cases. QTc was measured in these patients retrospectively. Demographic data and peri-procedural data, such as Aristotle score, cross-clamp time and bypass time, were analyzed. The exclusion criteria included multiple and small VSDs that underwent direct closure. RESULTS: Mean post-operative QTc was increased compared to the pre-operative measurements (from 413.6+/-2.3 to 444.9+/-2.5, p<0.001). In multiple linear regression, the comprehensive Aristotle score was associated with increasing QTc (p=0.047). The incidence of transient arrhythmia, such as atrial tachycardia, junctional ectopic tachycardia, premature atrial contraction, or premature ventricular contraction, was associated with QTc prolongation (p=0.005). Prolonged QTc was also associated with cross-clamp time (p=0.008) and low weight (p=0.042). Total length of stay at the intensive care unit and intubation time after surgery were not associated with QTc prolongation. CONCLUSION: Prolonged QTc could be seen after VSD repair in infants. This phenomenon was associated with peri-procedural factors such as the Aristotle score and cross-clamp time. Patients with QTc prolongation after cardiac surgery had an increased tendency towards arrhythmogenicity in the post-operative period.
Arrhythmias, Cardiac ; Atrial Premature Complexes ; Electrocardiography ; Heart Septal Defects, Ventricular* ; Humans ; Incidence ; Infant* ; Intensive Care Units ; Intubation ; Length of Stay ; Linear Models ; Retrospective Studies ; Tachycardia ; Tachycardia, Ectopic Junctional ; Thoracic Surgery ; Ventricular Premature Complexes

Adolescent ; Cardiomyopathies ; diagnosis ; etiology ; physiopathology ; Diagnosis, Differential ; Electrocardiography ; Female ; Humans ; Tachycardia, Ectopic Atrial ; complications

BACKGROUNDExtensive atrial fibrillation (AF) ablation is associated with an increased success rate of catheter ablation in chronic AF patients and an increased rate of atrial tachycardia (AT) during the procedure. The mechanism of these ATs varies in previous studies. Our study aimed to report the mechanism of organized AT occurring during the stepwise ablation procedure of chronic AF.

METHODSA prospective cohort of 86 consecutive patients who underwent an ablation procedure for chronic atrial fibrillation (CAF) was investigated. The stepwise procedure was performed in the following order: circumferential pulmonary vein ablation, complex fractionated atrial electrograms ablation, mapping and ablation of AT. The endpoint was noninducibility of AF/AT after sinus rhythm (SR) was restored or the procedure time was beyond 6 hours.

RESULTSSixty-nine (80%) of patients converted to SR via AT. A total of 179 sustained ATs were observed in 69 patients during the procedure. There were 81% (n = 145) macroreentrant ATs which included 65 perimitral circuits, 48 peritricuspid tachycardia and 32 roof dependent circuits, 12% (n = 21) localized reentrant and 7% (n = 13) focal ATs. Thirty (15%) patients experienced significant left atrium (LA) and LA appendage (LAA) conduction delay or dissociation in the procedure or during the follow-up period.

CONCLUSIONSMost CAF patients converted to SR via ablation of organized AT occurring during the stepwise procedure. The mechanism of most of these ATs was macro-reentry.

Aged ; Atrial Fibrillation ; surgery ; Catheter Ablation ; methods ; Electrophysiology ; Female ; Humans ; Male ; Middle Aged ; Prospective Studies ; Tachycardia, Ectopic Atrial ; surgery ; Treatment Outcome

Aged ; Diastole ; Female ; Humans ; Tachycardia, Ectopic Atrial ; physiopathology ; therapy

Adolescent ; Atrial Appendage ; Diagnostic Errors ; Female ; Humans ; Tachycardia, Ectopic Atrial ; diagnosis ; Tachycardia, Sinus ; diagnosis

We report a rare case of atrial tachycardia originating from the non-coronary aortic sinus. After failed radiofrequency (RF) energy applications at right His-bundle region, the complete elimination of atrial tachycardia was achieved with an RF energy application in the non-coronary aortic sinus. With the review of other papers, this report emphasizes the importance of mapping in the non-coronary aortic sinus in focal atrial tachycardia near the atrioventricular node or near the His-bundle.
Catheter Ablation/*methods ; Electrocardiography ; Female ; Humans ; Middle Aged ; Tachycardia, Ectopic Atrial/physiopathology/radiography/*therapy