Ablation Of Atrioventricular Reentrant Tachycardia Research Articles

Wide QRS Complexes Following Ablation for Reentrant Tachycardia

Scenario: A 25-year-old man was referred from a cardiology clinic for an acute exacerbation of supraventricular tachycardia (SVT) during an exercise stress echocardiogram. He has a history of dilated cardiomyopathy (50% left ventricular ejection fraction [LVEF]), wall motion abnormalities, and long QT syndrome. In the clinic before admission, an SVT event was captured during an electrocardiogram (ECG) recording and resolved with a carotid sinus massage. The patient was fully conscious during the event. A few days later, he underwent an electrophysiology (EP) study with radio frequency ablation for atrioventricular reentrant tachycardia (AVRT). He was transferred to the cardiac step-down unit after the EP procedure, and his blood pressure was 94/56 mm Hg, heart rate 87/min, respiratory rate 21/min (regular), oxygen saturation 94% via room air, and body temperature 37 °C (99 °F). The 12-lead ECG below was taken 6 hours after admission to the unit.Normal sinus rhythm, frequent premature ventricular complexes (PVCs) in a quadrigeminy pattern, prolonged QTc interval.Generally, wide QRS complexes (>120 milliseconds) represent electrical activity that originates from the ventricles. Exceptions are aberrantly conducted supraventricular beats, preexcitation associated with an accessory pathway, bundle branch block, and electrolyte imbalance. Given the AVRT diagnosis with recent ablation treatment, these PVCs may be mistaken for preexcitations associated with an accessory pathway, especially as the PVC QRSs appear slurred (ie, “pseudo” delta wave), a characteristic associated with an accessory pathway. However, some features support PVC as the cause. First, the wide QRS complexes are premature, albeit only slightly at first glance. However, if calipers are used, or even on careful visual inspection, one can appreciate that these beats are indeed premature. In this case, the P waves fall just before the PVC but should not be confused with a delta wave. Furthermore, there is a complete compensatory pause after the PVCs because the timing of the sinus node is not interrupted. In contrast, a supraventricular beat (eg, aberrancy, premature atrial complex) would typically have a P wave before the QRS complex, and one would see an incomplete pause because these beats usually enter the sinus node and reset its timing.PVCs can be monomorphic, as in this case, or polymorphic (multiple QRS morphologies). Interestingly, the morphology of the PVC can be used to determine the ventricle of origin (ie, left or right) by examining lead V1. In this example, the morphology resembles a left bundle branch block (ie, negative wide QRS complex). This pattern indicates that the ectopic impulse is moving away from lead V1 and travels toward the left ventricle (ie, deep S wave). The QRS complex is wide because the ventricular impulse travels slowly from the right ventricle, outside the normal conduction system, to the left ventricle, slowing depolarization.Premature beats, including PVCs, can trigger reentrant tachyarrhythmias when an accessory pathway is present. Although PVCs were not documented as the source of the AVRT events in this patient, they are a likely source. This patient’s history of cardiomyopathy may be contributing to the occurrence of PVCs, which may also need to be treated with ablation. Considering that this patient has a prolonged QTc and other significant risk factors (postablation, AVRT, cardiomyopathy, and reduced EF), medications that prolong the QT/QTc should be closely reviewed and adjusted if necessary to prevent torsades de pointes. This patient was discharged home and was followed up by outpatient cardiology.

Near zero vascular complications using echo-guided puncture during catheter ablation of arrhythmias: A retrospective study and literature review.

BackgroundCatheter ablation (CA) is routinely used for the treatment of arrhythmias. Vascular complications are the most common complications during these procedures. Previous data reported that ultrasound (US)‐guided puncture is a useful method to avoid vascular complications. We reported our experience using US‐guided puncture in patients undergoing CA for arrhythmias.MethodsA total of 273 patients (mean age 57 ± 17 years; 58% male) were referred to our center for CA of arrhythmias from January 2016 to December 2019. All procedures were performed by expert operators, and US‐guided vascular access was performed on all patients. Doppler sonography was performed the day after the procedure on all patients.ResultsEighty‐four patients (31%) underwent atrioventricular nodal reentrant tachycardia ablation, 49 patients (18%) atrioventricular reentrant tachycardia ablation, 14 patients (5%) atrial tachycardia ablation, 25 patients (9%) atrial flutter ablation, 63 patients (23%) atrial fibrillation ablation, and 38 patients (14%) ventricular tachycardia ablation. Vascular pseudo‐aneurysms and arteriovenous fistula were defined as major complications; furthermore, venous thrombosis and inguinal hematomas were as defined minor complications. The percentage of major vascular complications was 0.3% (1 arteriovenous fistula) and the percentage of minor vascular complications was 0.3% (1 venous thrombosis).DiscussionUltrasound‐guided vascular puncture in patients undergoing CA is useful to improve procedural success and reduce complications.

Open-window mapping of accessory pathways utilizing high-density mapping.

Accessory pathway (AP) mapping is currently based on point-by-point mapping and identifying if a local electrogram's origin is atrial, pathway, or ventricular, which is time-consuming and prone to insufficient mapping. We sought to determine the feasibility of automated and high-density mapping to define AP location using open-window mapping (OWM), which does not rely on defining the electrogram's origin but simply detects the sharpest local signal at each point. We enrolled 23 consecutive patients undergoing catheter ablation for atrioventricular reentrant tachycardia. High-density mapping was performed using OWM and ablation was performed. The successful site of ablation was determined by the loss of pathway function. OWM was 100% effective at identifying the successful site of ablation (average mapping time 7.3 ± 4.3min.) Permanent AP elimination was achieved using a mean radiofrequency energy time of 18.5 ± 24.5s/patient. Transiently successful ablations were 4.0 ± 1.8mm from permanently successful sites and had lower contact force (5.1 ± 2.5g vs. 11.7 ± 9.0g; P = 0.041). Unsuccessful sites had similar contact force to permanently successful sites (12.2 ± 9.2g vs. 11.7 ± 9.0g; P = 0.856) but were 6.4 ± 2.0mm away from successful sites. A novel technique of high-density, automated, and open-window mapping (OWM) effectively localizes APs without the need to differentiate the signal's site of origin. These findings suggest that OWM can be used to rapidly and successfully map and ablate APs. Both distances from the pathway and contact force were shown to be important for pathway ablation.

Incidence and Risk Factors for Atrial Fibrillation Recurrence after Ablation of Nodal and Atrioventricular Reentrant Tachycardia: A Meta-analysis.

IntroductionAtrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) are frequently associated with atrial fibrillation (AF). Targeting the slow or accessory pathways has been advocated as therapy for coexisting AF. But in practice, AF has frequently recurred after ablation, possibly because of various risk factors. The objective of this study is to investigate these risk factors and check for their significance in AF recurrence.Materials and methodsA systematic review of Medline, Cochrane, and ClinicalTrials.gov databases was conducted. Articles that studied AF recurrence after either AVNRT or AVRT ablation were reviewed. Publication bias was adequately assessed, and the random method was applied for all dichotomous values. Finally, the odds ratio (OR) and confidence intervals (CI) were calculated for each risk factor.ResultsFour studies were included, with a total of 1,308 participants. Only 218 participants had dual tachycardia (AF with either AVNRT or AVRT). The mean follow-up time was 29 +/- 3.3 months. The mean age was 56 +/- 15 years. Age constituted the only significant risk factor for AF recurrence (OR: 3.4, CI: 2.1-5.3, p<0.001). Atrial vulnerability did not significantly correlate with a higher risk of AF recurrence (OR: 4.8, CI: 0.7-29, p<0.008). Again, neither male gender (OR: 1.5, CI: 0.8-2.8, p<0.16) nor left atrial diameter (OR: 1.5, CI: 0.2-10, p<0.67) were significant risk factors for recurrence of AF.ConclusionOlder age was the only significant predictor of AF recurrence after ablation of AVNRT or AVRT. Further studies are needed to determine the age cut-off at which concomitant pulmonary vein isolation would be beneficial in patients undergoing ablation of AVNRT/AVRT.

Successful catheter ablation of atrioventricular reentrant tachycardia with left lateral bypass tract in a patient with unroofed coronary sinus atrial septal defect

Successful catheter ablation of atrioventricular reentrant tachycardia with left lateral bypass tract in a patient with unroofed coronary sinus atrial septal defect

Consequence of Use of Lower Dose Flat Plate Fluoroscopy in Pediatric Patients Undergoing Ablation for Supraventricular Tachycardia

Traditional imaging for ablation of supraventricular tachycardia has been fluoroscopy, although 3-dimensional electroanatomic mapping (3D) has been demonstrated to reduce radiation exposure. This study compares a technique for the reduction of radiation, low-dose fluoroscopy (LD), with standard-dose fluoroscopy (SD) and 3D with SD (3D-SD). This was a single institutional retrospective cohort study. All patients undergoing initial ablation for atrioventricular reentrant tachycardia (AVRT) or atrioventricular nodal reentrant tachycardia (AVNRT) from 2009 to 2012 were reviewed and divided into 3 groups: (1) SD, (2) 3D (CARTO or NavX) with SD, or (3) LD. LD uses the same equipment as SD but includes customized changes to the manufacturer's lowest settings by decreasing the requested dose to the detector. Primary outcomes were fluoroscopy time and dose area product exposure. One hundred eighty-one patients were included. The median age was 15.0 years (3.3-20.8); 59% had AVRT, 35% had AVNRT, and 6% had both AVRT and AVNRT. LD decreased the dose area product (DAP) compared with SD (637.0 vs 960.1 cGy*cm², p = 0.01) with no difference in fluoroscopy time. 3D-SD decreased fluoroscopy time compared with SD (9.9 vs 18.3 minutes, p <0.001) with DAP of 570.1.0 versus 960.1 cGy*cm² (p = 0.16). LD and 3D-SD had comparable DAP (637.0 vs 570.1 cGy*cm², p = 0.67), even though LD had significantly longer fluoroscopy time (19.9 vs 9.9 minutes, p <0.001). In conclusion, LD during catheter ablation of AVRT and AVNRT significantly reduced the DAP compared with SD and had similar radiation exposure compared with 3D with SD.

Risk factors of recurrence and complication in radiofrequency catheter ablation of atrioventricular reentrant tachycardia in children and adolescents – CORRIGENDUM

Risk factors of recurrence and complication in radiofrequency catheter ablation of atrioventricular reentrant tachycardia in children and adolescents – CORRIGENDUM

Risk factors of recurrence and complication in radiofrequency catheter ablation of atrioventricular reentrant tachycardia in children and adolescents

To compare potential risk factors for complications and recurrence after radiofrequency catheter ablation in symptomatic atrioventricular reentrant tachycardia in children and adolescents. We retrospectively reviewed the data of 213 consecutive patients with symptomatic atrioventricular reentrant tachycardia who underwent both electrophysiological study and radiofrequency catheter ablation, divided these patients into two groups, children (age < 12 years) and adolescents (12 < or = rage, 18 years), and compared the location of the accessory pathway, success rate, recurrence rate, complications, presence of congenital heart disease, presence of intermittent ventricular pre-excitation, and presence of Wolff–Parkinson–White syndrome in the two groups. The position of the accessory pathway was mostly right sided in children (61.3%) and left sided in adolescents (61.5%). Children had significantly more congenital heart disease than adolescents (6.4% versus 0.8%). Univariate analysis showed children or adolescents with right-sided accessory pathways to be 6.84 times and those with accessory pathways on both sides of the septum 25 times more likely to relapse than those with a single accessory pathway. Multivariate analysis indicated that children or adolescents with two accessory pathways were six times, and those with intermittent ventricular pre-excitation nine times more at risk of relapsing following radiofrequency ablation than those with single accessory pathways. All five complications occurred in children. The findings suggest that the position and number of accessory pathways and presence of intermittent ventricular pre-excitation are related to risks of recurrence of atrioventricular reentrant tachycardia in children and adolescents.

Transradial catheter ablation of left accessory pathway in patient with severe chest deformity

A 45-year-old woman with severe chest deformity and great vessel tortuosity successfully underwent left accessory pathway ablation of atrioventricular reentrant tachycardia via right transradial arterial access. Transradial catheter ablation of left accessory pathway was safe and efficacious without complications. When transfemoral or transseptal access was impossible, transradial access was a good alternative route.

Impact of Remote Magnetic Catheter Navigation on Ablation Fluoroscopy and Procedure Time

Remote magnetic catheter navigation (RCN) is gaining acceptance in clinical cardiac electrophysiology, but details regarding how RCN affects procedure execution are not well characterized. From January 1, 2005, to November 30, 2007, 721 cases were retrospectively analyzed and compared. Of these, 127 used RCN and 594 used manual catheter navigation (MCN). Data including procedure time, fluoroscopy time, ablation catheter, procedural success, and complications were extracted from our procedure database and compared between RCN and MCN. RCN use significantly decreased fluoroscopy time for atrial fibrillation (AF) ablation (-29 minutes, P < 0.001), atrioventricular nodal reentrant tachycardia ablation (-14 minutes, P < 0.001), and atrioventricular reentrant tachycardia ablation (-18 minutes, P = 0.045). While RCN significantly increased mean procedure time for AF (+36 minutes, P = 0.003) and atypical atrial flutter cases (+116 minutes, P = 0.016), RCN AF procedure time diminished with increasing number of cases performed. Two cases of tamponade occurred during AF ablation using MCN (2.2%, 2 of 91 cases). No tamponade occurred during all 75 AF ablations with RCN. RCN can reduce fluoroscopy time and may reduce complications during catheter ablation. While it may increase total procedure duration, procedure times decrease with increasing operator experience. (PACE 2008; 31:1399-1404).

Heart Rate Variability: Does it Change After RF Ablation of Reentrant Supraventricular Tachycardia?

Following RF ablation of reentrant supraventricular tachycardia, inappropriate sinus tachycardia may occur. Local parasympathetic denervation is a possible mechanism for these rhythm disturbances. The purpose of this study was to determine the incidence of sinus tachycardia and to determine the relation between endocardial lesions at different ablation sites and alterations in autonomic tone in several different groups of patients with supraventricular tachycardia, using techniques of heart rate variability analysis. The subjects of this study were 75 patients (48 women, 27 men) with a mean age of 39.99 (SD = 13.39). They underwent RF ablation of AV nodal slow pathways (40 cases), posteroseptal APs (23 cases), left lateral and right free wall APs (12 cases) because of symptomatic tachycardias. The mean sinus rate and time domain (standard deviation of RR intervals and root mean square of differences of adjacent RR intervals) and frequency domain (low frequency, high frequency and low frequency/high frequency ratio) analyses of heart rate variability were obtained by use of 24 hour Holter monitoring before and 1 month after ablation compared with pre-ablation values. Analysis of 24 hour ambulatory Holter-monitors, performed 1 month after RF ablation, showed no significant changes in time and frequency domain parameters of heart rate variability in different groups. A significant increase in mean heart rate was noted after RF ablation at AV nodal slow pathway group and left freewall/right free wall accessory pathways group. Patients undergoing RF ablation of right or left posteroseptal accessory pathways had no significant increase in the mean heart rate. In summary, an increase in sinus tachycardia may be initiated by RF ablation of atrioventricular reentrant tachycardia (AVNRT) and right free wall or left free wall accessory pathways. This finding shows that the modifications of heart rate are not directly related to the posteroseptal region or to the accessory pathways.

Catheter Ablation for a Right Anteroseptal Accessory Pathway in a Patient with an Endocardial Cushion Defect

We report a radiofrequency catheter ablation for atrioventricular reentrant tachycardia in a patient with a right anteroseptal accessory pathway complicating an endocardial cushion defect. His bundle potential was recorded 20 mm posterior to the accessory pathway. In the presence of associated congenital heart disease, it is very important to understand the anatomy of the conduction system prior to radiofrequency catheter ablation.

Two Cases of Catheter Ablation of Atrioventricular Reentrant Tachycardia by Right Septal Bypass Tract Mapped Using Multielectrode Basket Catheter

Two Cases of Catheter Ablation of Atrioventricular Reentrant Tachycardia by Right Septal Bypass Tract Mapped Using Multielectrode Basket Catheter