Catheter Ablation ; Child ; Humans ; Male ; Tachycardia, Atrioventricular Nodal Reentry ; surgery

Abnormalities, Multiple ; surgery ; Adolescent ; Catheter Ablation ; Dextrocardia ; Humans ; Male ; Tachycardia, Atrioventricular Nodal Reentry ; surgery

Adolescent ; Catheter Ablation ; methods ; Humans ; Male ; Pre-Excitation, Mahaim-Type ; Tachycardia, Atrioventricular Nodal Reentry ; surgery

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

OBJECTIVEThe aim of this trial is to compare the efficacy and safety between national-made and imported ablation catheters for the treatment of atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT).

METHODA total of 1342 patients with AVNRT or AVRT were randomly treated with national-made ablation catheter (Group 1, n = 672) or imported ablation catheter (Group 2, n = 670).

RESULTSThe immediate ablation success rate was similar in Group 1 and Group 2 (97.9% vs. 99.1%, P > 0.05). There were also no significant differences in the procedure time [(68 +/- 36) min vs. (67 +/- 34) min], the fluoroscopic time [(14 +/- 14) min vs. (10 +/- 11) min], the number of energy delivery [(4.5 +/- 4.5) beats vs. (4.6 +/- 3.9) beats], the ablation time [(260 +/- 218) s vs. (257 +/- 207) s] and the score of ablation catheter performance evaluation [(4.4 +/- 0.5) vs. (4.5 +/- 0.4) ] between the two groups (all P > 0.05). Three patients developed pericardial effusion (1 in Group 1 and 2 in Group 2, P > 0.05). Incidence of recurrence of tachycardia during the 3 months follow up was similar between the 2 groups (14 in Group1 vs. 16 in Group 2, P > 0.05).

CONCLUSIONNational-made and imported radiofrequency ablation catheters have similar efficacy and safety for treatment of AVNRT and AVRT.

Adult ; Catheter Ablation ; Female ; Humans ; Male ; Middle Aged ; Tachycardia, Atrioventricular Nodal Reentry ; surgery ; Tachycardia, Reciprocating ; surgery ; Treatment Outcome

Catheter Ablation ; methods ; Coronary Sinus ; surgery ; Electrocardiography ; Female ; Humans ; Middle Aged ; Tachycardia, Atrioventricular Nodal Reentry ; pathology ; surgery

A multipoint and computerized intraoperative mapping system has been known to be of value in improving the results of surgery for cardiac arrhythmia. It shows great potential as a new tool in the surgical intervention of the more common and lethal types of supraventricular tachyarrhythmias such as atrial flutter and atrial fibrillation. In addition, it also enhances the ability of the investigators to map and ablate the sometimes fleeting automatic atrial tachycardia. The authors developed a 64 channel computerized cardiac mapping system using a microcomputer (Macintosh IIx) and this has been used for basic research in cardiac electrophysiology as well as in arrhythmia surgery. In this system, bipolar electrograms are obtained from 64 different cardiac sites simultaneously at a sampling rate of 1 Ksample/sec and with a continuous and total data storage of up to 30 seconds. When the reference electrode is selected, delay time from the reference point is displayed on a two dimensional diagram of the heart. This system was used in one patient who underwent a surgical ablation of a ventricular tachycardia in whom we observed a ventricular activation sequence involving a variety of rhythms over several minutes. The system design permits easy expansion to a simultaneous sampling from 256 sites. This 64-channel mapping appeared to have the potential to be of great help in our understanding of cardiac arrhythmia as well as in its diagnosis and surgical treatment.
Arrhythmia/*physiopathology/*surgery ; *Cardiac Surgical Procedures ; *Diagnosis, Computer-Assisted ; Electrophysiology/*methods ; Heart/*physiopathology ; Heart Septal Defects, Atrial/surgery ; Human ; Support, Non-U.S. Gov't ; Tachycardia, Atrioventricular Nodal Reentry/surgery

BACKGROUNDTypical accessory pathways (APs) of Wolf-Parkinson-White syndrome have been widely discussed in recent decades. However, the characteristics of the special AP, Mahaim fibre, are not so clear. It is known that these fibres have antegrade conduction only, long conduction time, decremental node-like conduction and automaticity properties. This study was to elucidate the automaticity of Mahaim fibre and its response to effective ablation.

METHODSThirteen patients with Mahaim fibre (ten atrioventricular and three atriofascicular accessory pathways) were subjected to electrophysiological study and radiofrequency ablation via catheter. The incidence and characteristics of anautomatic rhythm originating from Mahaim fibre were observed during the whole procedure, especially during radiofrequency current delivery.

RESULTSRepetitive and short-run automatic rhythm (rate: 65-72 beats per minute), with a QRS morphology similar to that of clinical pre-excited atrioventricular re-entrant tachycardia (AVRT), occurred in two patients during sinus rhythm. Conduction via Mahaim fibre was successfully eliminated by radiofrequency current. Fourteen applications of RF were associated with irregularly accelerated automatic tachycardia of Mahaim fibre (with a sensitivity of 78%), lasting for 1.2-14 seconds. However, such automatic tachycardia of Mahaim fibre did not occur during 54 failed applications of radiofrequency current.

CONCLUSIONSMahaim fibre has the function of automaticity. The accelerated automatic tachycardia of Mahaim fibre occur red during radiofrequency catheter ablation can be used as a predictor for successful procedure.

Adolescent ; Adult ; Catheter Ablation ; Child ; Female ; Humans ; Male ; Middle Aged ; Pre-Excitation, Mahaim-Type ; physiopathology ; surgery ; Tachycardia, Atrioventricular Nodal Reentry ; physiopathology ; surgery

OBJECTIVETo explore the feasibility and methodology of radiofrequency catheter ablation (RFCA) guided by 3D navigation system (Ensite-NavX) for right atrioventricular accessory pathway.

METHODThirty-three cases of right accessory pathway atrioventricular reentrant tachycardia including 16 cases in right free wall, 3 in right middle septum, 14 in right posterior septum; 23 cases of dominant accessory pathway and 10 cases of concealed were treated by RFCA guided by NavX navigation. NavX navigation modeling method or spatial localization method was exploited to locate target positioning.

RESULTAll patients were successfully ablated without serious complications. Among them, 25 cases were operated without exposure to X-ray, 7 patients were exposed for several seconds to verify catheter position, 1 case in right free wall was ablated under X-ray combined with Swartz sheath ablation.

CONCLUSIONNonfluoroscopy or less fluoroscopy RFCA for right atrioventricular accessory pathway with Ensite-NavX is safe and feasible, modeling or spatial orientation method are helpful to locate the ablation target positioning.

Adolescent ; Adult ; Aged ; Catheter Ablation ; methods ; Female ; Humans ; Imaging, Three-Dimensional ; Male ; Middle Aged ; Surgery, Computer-Assisted ; Tachycardia, Atrioventricular Nodal Reentry ; surgery ; Young Adult

OBJECTIVETo compare the efficacy and safety between cryoablation (Cryo) and radiofrequency (RF) ablation for treating patients with atrioventricular nodal reentrant tachycardia (AVNRT).

METHODSPatients with AVNRT (n = 304) were divided into Cryo group (n = 67) and RF group (n = 237). The procedure success rate, complete slow pathway block rate, atrioventricular block rate and relapse rate were compared between two groups.

RESULTSThere was no statistically difference between 2 groups in the success rate (Cryo group 98.5% vs RF group 97.0%, P = 0.820), complete slow pathway block rate (Cryo group 98.5% vs RF group 91.6%, P = 0.088), atrioventricular block rate (Cryo group 0 vs RF group 2.5%, P = 0.413), relapse rate (Cryo group 0 vs RF group 1.7%, P = 0.643). But Cryo group had more advantage than RF group.

CONCLUSIONEfficacy and safety were comparable between cryoablation and radiofrequency ablation for treating patients with AVNRT.

Adolescent ; Adult ; Aged ; Catheter Ablation ; methods ; Child ; Cryosurgery ; methods ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Tachycardia, Atrioventricular Nodal Reentry ; surgery ; Treatment Outcome ; Young Adult