Humans ; Child ; Tachycardia, Atrioventricular Nodal Reentry ; Radiofrequency Ablation ; Catheter Ablation ; Electrocardiography

PURPOSE: Atrioventricular nodal reentry tachycardia (AVNRT) is less common in pediatric patients than in adult patients. Thus, data for pediatric AVNRT patients are insufficient. Hence, we aimed to analyze the patient characteristics, treatment, and any recurrences in pediatric AVNRT patients. METHODS: We reviewed the records of 50 pediatric AVNRT patients who had undergone radiofrequency catheter ablation (RFCA) between January 1998 and December 2016 at a single regional center. The patients were aged ≤18 years. RESULTS: Among 190 pediatric patients who underwent RFCA for tachyarrhythmia, 50 (26.3%; mean age, 13.4±2.6 years) were diagnosed as having AVNRT by electrophysiological study. Twenty-five patients (25 of 50, 50%) were male. Twenty patients (20 of 50, 40%) used beta-blockers before RFCA. All patients had no structural heart disease except 1 patient with valvular aortic stenosis and coarctation of the aorta. RFCA was performed using the anatomic approach under fluoroscopic guidance. The most common successfully ablated region was the midseptal region (25 of 50, 50%). Slow pathway (SP) ablation and SP modulation were performed in 43 and 6 patients, respectively. Complication occurred in 1 patient with complete atrioventricular block. During follow-up, 6 patients had recurrence of supraventricular tachycardia, as confirmed by electrocardiography. Among them, 5 underwent successful ablation at the first procedure. In 1 patient, induction failed during the first procedure. CONCLUSION: RFCA is safe and effective in pediatric AVNRT patients. However, further research is needed for establishing the endpoints of ablation in pediatric AVNRT patients and for identifying risk factors by evaluating data on AVNRT recurrence after RFCA.
Adolescent* ; Adult ; Aortic Coarctation ; Aortic Valve Stenosis ; Atrioventricular Block ; Catheter Ablation* ; Child* ; Electrocardiography ; Follow-Up Studies ; Heart Diseases ; Humans ; Male ; Recurrence ; Risk Factors ; Tachycardia ; Tachycardia, Atrioventricular Nodal Reentry* ; Tachycardia, Supraventricular

Supraventricular tachycardia (SVT) refers to a heterogeneous group of arrhythmias localized within the upper part of the heart (the His bundle or above). In general, the term SVT does not include atrial fibrillation. Common forms of SVT include atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia, focal atrial tachycardia, and atrial flutter. Other, less common arrhythmias also fall under the category of SVT, including inappropriate sinus tachycardia and junctional reentrant/ectopic tachycardia. Paroxysmal supraventricular tachycardia refers to AVNRT and AVRT. SVTs can be identified and classified by clinical manifestation/physical examination, ECG, and/or electrophysiologic analysis.
Arrhythmias, Cardiac ; Atrial Fibrillation ; Atrial Flutter ; Bundle of His ; Diagnosis, Differential* ; Electrocardiography ; Heart ; Tachycardia ; Tachycardia, Atrioventricular Nodal Reentry ; Tachycardia, Sinus ; Tachycardia, Supraventricular*

Atrioventricular nodal reentrant tachycardia is the most common type of supraventricular tachycardia. The initiation and maintenance of tachycardia is caused by the characteristic anatomic and electrophysiologic properties of the atrioverntricular node. Acute management for the termination of tachycardia includes pharmacologic and non-pharmacologic management. There are several options for preventing recurrence of tachycardia, and radiofrequency ablation for modulation of tachycardia circuit can be considered as a primary strategy. A thorough understanding of the unique electrophysiologic features is very essential for optimal management and best possible outcome in cases of invasive management.
Catheter Ablation ; Recurrence ; Tachycardia ; Tachycardia, Atrioventricular Nodal Reentry* ; Tachycardia, Supraventricular

Among patients with Wolff-Parkinson-White syndrome, atrioventricular reciprocating tachycardia (AVRT) and atrioventricular nodal reentrant tachycardia (AVNRT) can coexist in a single patient. Direct transition of both tachycardias is rare; however, it can occur after premature atrial or ventricular activity if the cycle lengths of the two tachycardias are similar. Furthermore, persistent atrial activation by an accessory pathway (AP) located outside of the AV node during ongoing AVNRT is also rare. This article describes a case of uncommon atrial activation by an AP during AVNRT and gradual transition of the two supraventricular tachycardias without any preceding atrial or ventricular activity in a patient with preexcitation syndrome.
Atrioventricular Node ; Humans ; Pre-Excitation Syndromes ; Tachycardia* ; Tachycardia, Atrioventricular Nodal Reentry ; Tachycardia, Paroxysmal ; Tachycardia, Reciprocating ; Tachycardia, Supraventricular ; Wolff-Parkinson-White Syndrome*

INTRODUCTIONThe use of non-fluoroscopic systems (NFS) to guide radiofrequency catheter ablation (RFCA) for the treatment of supraventricular tachycardia (SVT) is associated with lower radiation exposure. This study aimed to determine if NFS reduces fluoroscopy time, radiation dose and procedure time.

METHODSWe prospectively enrolled patients undergoing RFCA for SVT. NFS included EnSiteTM NavXTM or CARTO® mapping. We compared procedure and fluoroscopy times, and radiation exposure between NFS and conventional fluoroscopy (CF) cohorts. Procedural success, complications and one-year success rates were reported.

RESULTSA total of 200 patients over 27 months were included and RFCA was guided by NFS for 79 patients; those with atrioventricular nodal reentrant tachycardia (AVNRT), left-sided atrioventricular reentrant tachycardia (AVRT) and right-sided AVRT were included (n = 101, 63 and 36, respectively). Fluoroscopy times were significantly lower with NFS than with CF (10.8 ± 11.1 minutes vs. 32.0 ± 27.5 minutes; p < 0.001). The mean fluoroscopic dose area product was also significantly reduced with NFS (NSF: 5,382 ± 5,768 mGy*cm2 vs. CF: 21,070 ± 23,311 mGy*cm2; p < 0.001); for all SVT subtypes. There was no significant reduction in procedure time, except for left-sided AVRT ablation (NFS: 79.2 minutes vs. CF: 116.4 minutes; p = 0.001). Procedural success rates were comparable (NFS: 97.5% vs. CF: 98.3%) and at one-year follow-up, there was no significant difference in the recurrence rates (NFS: 5.2% vs. CF: 4.2%). No clinically significant complications were observed in both groups.

CONCLUSIONThe use of NFS for RFCA for SVT is safe, with significantly reduced radiation dose and fluoroscopy time.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Catheter Ablation ; methods ; Child ; Female ; Fluoroscopy ; Humans ; Male ; Middle Aged ; Prospective Studies ; Radiation Dosage ; Radiation, Ionizing ; Tachycardia, Atrioventricular Nodal Reentry ; therapy ; Tachycardia, Supraventricular ; therapy ; Treatment Outcome ; Young Adult

The delivery of single His-refractory ventricular extra-stimulus during supraventricular tachycardia is useful to identify the mechanism of the tachycardia. We present the different responses based on the ventricular extra-stimulus site. Our findings demonstrate that the atrial activation via an accessory pathway was not advanced based on the ventricular pacing site. Therefore, atrioventricular tachycardia could masquerade as atrioventricular nodal reentrant tachycardia.
Tachycardia ; Tachycardia, Atrioventricular Nodal Reentry ; Tachycardia, Supraventricular*

We discuss two cases of incessant atrial tachycardia (AT), including the presentation and clinical course. It is important to differentiate AT from other causes of supraventricular tachycardia, such as atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT), as it would have implications on clinical management. Electrocardiographic features of AT, especially the presence of an AV Wenckebach phenomenon with 'grouped beating', are critical for differentiating AT from AVRT and AVNRT. It is also vital to identify the P waves and their relations to QRS on electrocardiography, as this would aid in the differentiation of various supraventricular tachycardias.
Aged ; Diagnosis, Differential ; Electrocardiography ; Electrophysiology ; Female ; Heart Conduction System ; abnormalities ; Hemodynamics ; Humans ; Male ; Respiration ; Tachycardia ; diagnosis ; Tachycardia, Atrioventricular Nodal Reentry ; diagnosis ; Tachycardia, Supraventricular ; diagnosis ; Tricuspid Valve ; physiopathology

A 41-year-old male was presented with drug-resistant supraventricular tachycardia. Electrophysiological study confirmed that the supraventricular tachycardia was caused by dual atrioventricular nodal pathways and a left lateral accessory pathway (AP). The left lateral AP was resistant to traditional endocardial ablation, but was successfully eliminated by radiofrequency ablation via the intracoronary sinus approach.
Accessory Atrioventricular Bundle ; Catheter Ablation ; Humans ; Male ; Tachycardia, Atrioventricular Nodal Reentry ; Tachycardia, Supraventricular

BACKGROUNDAtrioventricular nodal reentrant tachycardia (AVNRT) is one of the most common paroxysmal supraventricular tachyarrhythmias. The aim of the study was to prospectively compare the characteristics of radiofrequency catheter ablation of AVNRT guided by a magnetic navigation system with the conventional procedure.

METHODSPatients with AVNRT diagnosed by electrophysiological tests were randomized into two groups. In the conventional technique group (CMT), a common 4-mm-tip quadrapolar temperature-controlled ablation catheter was used. In the magnetic navigation system guidance group (MNS), a magnetic 4-mm-tip quadrapolar temperature-controlled ablation catheter was used. The following parameters were collected and compared between the two groups: ablation procedure time, patient fluoroscopy time, operator fluoroscopy time, energy delivery numbers, maximal energy per deployment, success rate, complication rate and operative cost.

RESULTSForty patients were enrolled and randomized into CMT and MNS groups. The age, gender, tachycardia history and basic cardiovascular diseases of the two groups were comparable (P > 0.05). All procedures were conducted successfully without complications. No tachycardia recurred during the follow-up period of (9.3 ± 2.6) months. In the MNS group, the patient and operator fluoroscopy times ((11.5 ± 4.3) min, (4.2 ± 1.5) min), energy delivery numbers (3.2 ± 0.9), and maximal energy per deployment ((16.9 ± 3.4) W) were shorter or lower than those of the CMT group ((14.3 ± 6.2) min, (13.6 ± 3.5) min, 6.3 ± 2.1, (23.7 ± 1.3) W, respectively) (P < 0.05). But the operative cost for the MNS group was higher than that of the CMT group (P < 0.01).

CONCLUSIONMagnetic navigation system guided radiofrequency catheter ablation of AVNRT has the advantages of shorter fluoroscopy time and lower energy delivery numbers and maximal energy per deployment compared to the present conventional ablation technique.

Catheter Ablation ; methods ; Humans ; Tachycardia, Atrioventricular Nodal Reentry ; surgery ; Treatment Outcome