Radiofrequency Catheter Ablation of AV Nodal Reentry: The Anterior Approach

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75131/1/j.1540-8159.1993.tb01633.x.pd

Aortic Leaflet Perforation During Radiofrequency Ablation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73537/1/j.1540-8159.1991.tb02732.x.pd

Safety, feasibility and cost of outpatient radiofrequency catheter ablation of accessory atrioventricular connections

AbstractObjectives. The purpose of this study was to evaluate prospectively the safety, feasibility and cost of performing radiofrequency catheter ablation of accessory atrioventricular (AV) connections on an outpatient basis in 137 cases.Background. The efficacy and low complication rate of radiofrequency ablation as performed in the hospital suggested that it might be feasible to perform it on an outpatient basis.Methods. In 100 cases (73%) performed between September 1, 1991 and April 20, 1992, patients met criteria for treatment as outpatients. Reasons for exclusion were age <13 or >70 years (4), anteroseptal location of the accessory AV connection (5 patients), obesity (>30% of ideal body weight) (4 patients) or clinical indication for hospitalization (24 patients). Patients with only venous punctures had a recovery period of 3 h and those with arterial punctures had a recovery period of 6 h. There were 63 men and 32 women (5 patients underwent two ablation procedures >1 month apart), with a mean age ± SD of 36 ± 13 years. The pathway was left-sided in 67 cases and right-sided or posteroseptal in 33.Results. The procedure was successful in 97 of 100 cases, with a mean procedure duration of 99 ± 42 min. In 70 cases the patient was discharged the day of ablation, and in 30 cases the patient required a short (≤18-h) overnight stay because the procedure was completed too late in the day for recovery in the outpatient facility. The mean duration of observation was 4.8 ± 1.5 h for outpatients and 15 ± 1.4 h for patients who underwent overnight hospitalization. At follow-up study, two patients had a clinically significant complication; both had a femoral artery pseudoaneurysm detected ≥1 week after the procedure and both required surgical repair. Thirty consecutive patients (22 outpatients and 8 hospitalized overnight) undergoing catheter ablation after January 1, 1992 were chosen for a cost analysis. The mean cost of the procedure was $10,183 ±$1,082.Conclusions. The majority of patients undergoing radiofrequency catheter ablation of an accessory AV connection can be treated safely on an outpatient basis

Comparison of Fixed Burst Versus Decremental Burst Pacing for Termination of Ventricular Tachycardia

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72440/1/j.1540-8159.1993.tb01531.x.pd

Recurrence of conduction in accessory atrioventricular connections after initially successful radiofrequency catheter ablation

AbstractThe purpose of this study was to characterize the incidence and clinical features of accessory pathway recurrence after initially successful radiofrequency catheter ablation and to identify variables correlated with recurrence. Radiofrequency ablation was performed with a 7F deflectable tip catheter with a large (4 mm in length) distal electrode. Left-sided accessory patthways were approached through the left ventricle and right-sided pathways by way of the right atrium. Patients were included in the study if 1) they had an initially successful procedure, defined as the absence of accessory pathway conduction immediately after ablation, and 2) had undergone a 3-month follow-up electrophysiologic test or had documented recurrence of accessory pathway conduction.Accessory pathway conduction recurred after initially successful ablation in 16 (12%) of 130 patients. Almost half (7 of 16) of these recurrences were in the 1st 12 h after ablation, and the last occurred after 106 days. Return of delta waves on the electrocardiogram (ECG) or spontaneous paroxysmal supraventricular tachycardia was the initial indication of recurrence in 15 of the 16 patients. Two patients with manifest accessory pathways exhibited recurrence with exclusively concealed accessory pathway conduction.Accessory pathways ablated from the tricuspid anulus (right free wall or septal accessory pathways) had a much higher recurrence rate (24%) than did those on the mitral anulus (6%). Fourteen of 15 patients have had successful repeat accessory pathway ablation after the initial recurrence. After a mean follow-up period of 4 ± 3 months, there have been no repeat recurrences of any of these accessory pathways.It is concluded that accessory pathway recurrence is infrequent after successful radiofrequency catheter ablation. All but one episode of recurrence was diagnosed clinically, suggesting that routine follow-up electrophysiologic testing in asymptomatic patients is not warranted. Because manifest accessory pathways may recur with retrograde conduction only, patients with palpitation after ablation should have electrophysiologic testing even if no delta waves are seen on the ECG. The success rate of ablation after recurrence (93%) is comparable to that achieved at the initial session, suggesting that return of accessory pathway function should not be a contraindication to a repeat attempt

Noncapturing stimuli during the basic drive shorten ventricular refractoriness

Studies of ventricular programmed stimulation in animals1 and a recent study in humans1 showed that increasing the stimulation intensity of the basic drive train (S1) shortened the effective refractory period (ERP). This effect was independent of the intensity of the extrastimulus (S2). The mechanism of this shortening of refractoriness by high-current intensity is unknown. The effect disappears when the sites of pacing and extrastimulation are separated by &gt;2 cm,1 suggesting that high-current stimulation shortens refractoriness through changes in the sequence of local activation. Local sympathetic activation may also play a role, because autonomic blockade significantly attenuates the shortening in refractoriness that occurs with an increase in the strength of the current of the basic drive train.2 This study better defines the mechanism by which intense stimulation shortens refractoriness. High-current intensity stimuli were applied during the absolute refractory period of the basic drive train during measurement of ERP. This allowed evaluation of the effect of stimulation intensity on ventricular refractoriness independent of changes in local activation sequence.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29090/1/0000125.pd

Effect of operator experience on outcome of radiofrequency catheter ablation of accessory pathways

Radiofrequency catheter ablation of accessory pathways has been shown to be safe and effective, and is rapidly becoming the treatment of choice for patients with the Wolff-Parkinson-White syndrome or paroxysmal supraventricular tachycardia involving a concealed accessory pathway.1-6 Because radiofrequency catheter ablation requires skill in mapping and catheter manipulation, the outcome is at least in part operator-dependent. The purpose of this study was to determine the effect of operator experience on the outcome of radiofrequency catheter ablation of accessory pathways by analyzing the changes in efficacy and duration of the procedure as experience increased.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30824/1/0000486.pd

Relation between efficacy of radiofrequency catheter ablation and site of origin of idiopathic ventricular tachycardia

The results of radiofrequency catheter ablation of ventricular tachycardia (VT) in patients without structural heart disease are reported. Particular attention was focused on the relation between efficacy and the site of origin of the VT. Eighteen consecutive patients (5 women and 13 men; mean age 41 +/- 13 years) with idiopathic VT underwent catheter ablation using radiofrequency energy. Sites for radiofrequency energy delivery were selected on the basis of pace mapping. A follow-up electrophysiologic test was performed 1 to 3 months after the ablation procedure. Twenty VTs were induced. Radiofrequency catheter ablation was successful in eliminating all 10 VTs originating from the right ventricular outflow tract, and 5 of 10 from other sites in the left or right ventricle. There were no complications. The duration of ablation sessions was shorter, the frequency of identifying a site resulting in an identical pace map was higher, and the efficacy of catheter ablation was greater for VTs originating from the right ventricular outflow tract than for those from other locations. The results of this study demonstrate that radiofrequency catheter ablation of idiopathic VT is safe and effective. The efficacy of the procedure is dependent on the site of origin of the VT, with the efficacy being greater for VTs originating from the outflow tract of the right ventricle than for those from other locations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30894/1/0000563.pd

Magnitude of ST segment depression during paroxysmal supraventricular tachycardia

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29073/1/0000108.pd