Effects of radiofrequency catheter ablation on regional myocardial blood flow. Possible mechanism for late electrophysiological outcome.

Nath, Sunil; Whayne, James G.; Kaul, Sanjiv; Goodman, Norman C.; Jayaweera, Ananda R.; Haines, David E.

doi:10.1161/01.cir.89.6.2667

Cited by 100 publications

(52 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The possibility that intramyocardial vasculature can alter RF lesion morphology through convective heat loss has not been explored previously. This concept differs from the work of Nath et al, 14 who demonstrated impaired circulation at the microscopic level immediately around RF lesions.…”

Section: Discussioncontrasting

confidence: 75%

Intramural Coronary Vasculature Prevents Transmural Radiofrequency Lesion Formation

Fuller

Wood

2003

Circulation

View full text Add to dashboard Cite

Background-Blood flow near a radiofrequency (RF) lesion can reduce lesion size by convective cooling. It is unknown whether blood flow through small vasculature within an RF lesion can prevent transmural lesion formation. Methods and Results-In 40 rabbit right ventricle preparations, 2 epicardial RF lesions were created straddling a selectively perfused (0 to 12 mL/min) marginal artery (diameter, 0.34Ϯ0.1 mm). RF lesions were created at either 60°C or 80°C and delivered either sequentially or simultaneously. Conduction through the lesion area was measured. The lesions were analyzed histologically. At a perfusion rate of 0 mL/min, all RF lesions were transmural and without conduction. As little as 1 mL of flow through the artery during RF delivery could prevent transmural lesion formation by preserving a cuff of tissue along the length of the vessel. High-energy delivery (45 W) and very high tissue temperatures (93°C) were needed to overcome the protective effect of vascular perfusion at 12 mL/min. The volume of preserved myocardium was related to arterial perfusion rate, artery diameter, and lesion temperature but not to the sequence of RF delivery (sequential versus simultaneous). Conduction persisted through the RF lesion in 20 experiments. Conduction through the lesion was related to the arterial perfusion rate and volume or cross-sectional area of preserved myocardium. Conclusions-Flow through even small intramyocardial vessels can prevent transmural lesion formation and preserve conduction through an RF lesion. These findings may represent an unrecognized obstacle to the creation of linear RF lesions in the clinical setting.

show abstract

Section: Discussioncontrasting

confidence: 75%

Intramural Coronary Vasculature Prevents Transmural Radiofrequency Lesion Formation

Fuller

Wood

2003

Circulation

View full text Add to dashboard Cite

show abstract

“…As previously reported and demonstrated in this study, although tip temperatures dropped instantaneously with termination of RF energy, tissue temperatures may continue to be elevated. 15,[23][24][25] Mechanistically, this is thought to result from 2 different heating processes. First, there is rapid resistive heating of a thin layer of tissue around the catheter tip during ablation.…”

Section: Discussionmentioning

confidence: 99%

Analysis of Catheter-Tip (8-mm) and Actual Tissue Temperatures Achieved During Radiofrequency Ablation at the Orifice of the Pulmonary Vein

et al. 2004

View full text Add to dashboard Cite

Background-Many ablative approaches in or near the orifice of the pulmonary vein (PV) have demonstrated success in eliminating atrial fibrillation. Despite current practice, there are no data regarding the in vivo efficacy and safety of an 8-mm catheter tip for ablation at the PV orifice. Methods and Results-Ten mongrel dogs were studied. Thermocouples were implanted in the atrial muscle of the PV orifice. Intracardiac echocardiography monitored catheter position, tip/tissue orientation, and microbubble formation. Ninety-four ablations were performed for 120 seconds. A temperature discrepancy Ͼ10°C between the catheter tip and tissue occurred during 47 (50%) of the ablations. Despite termination of energy delivery, the average tissue temperature remained within 1°C of the achieved steady state for 9 seconds. A temperature discrepancy Ͼ10°C was more common in the right superior PV, with oblique catheter positioning, when tissue temperatures were Ͼ60°C or 80°C, and with type 1 or type 2 microbubble formation. However, microbubbles were not present in 7 (13%, type 1) and 10 (40%, type 2) ablations with tissue temperatures Ͼ80°C. The maximum tissue temperature achieved with non-full-thickness lesions was 47.3Ϯ7.4°C vs 75.9Ϯ11.7°C (PϽ0.0001) for full-thickness lesions. Conclusions-Marked discrepancies between catheter-tip and tissue temperatures occurred with higher temperatures, prolonged ablation times, and unfavorable catheter thermistor-tissue contact. Also, these data suggest a conservative approach to atrial ablation, because full-thickness lesions were obtained when tissue temperatures reached 50°C to 60°C and the tissue retained high heat levels despite termination of radiofrequency energy. Finally, microbubbles are inconsistent markers of tissue overheating.

show abstract

“…In this regard, Nath et al demonstrated that tissues next to the site of RF ablation show thermal injury, which might progress to have late effects on AV conduction. 15 Another possible mechanism of AV block in the present case might be the result of the propafenon therapy; however, the patient took 150 mg of propafenone only once and her AV block persisted for 1 week. Considered together, we speculate that all these factors (pre-existing first-degree AV block, modulation of AV node by the ablation, and propafenone) may have contributed to the occurrence of a complete AV block.…”

Section: Discussionmentioning

confidence: 67%

Transient Complete Atrioventricular Block Occurring 1 Week After Radiofrequency Ablation for the Treatment of Atrioventricular Nodal Re-Entrant Tachycardia.

Takahashi¹,

Mitsuhashi²,

Hashimoto³

et al. 2002

Circ J

View full text Add to dashboard Cite

trioventricular (AV) block following radiofrequency ablation for the treatment of AV nodal re-entrant tachycardia (AVNRT) is a rare but serious complication of this procedure. [1][2][3] The AV block usually occurs during or immediately following the application of radiofrequency (RF) energy, and is transient. However, several rare cases have been reported in which the patient developed an AV block late after the procedure and subsequently required a permanent pacemaker implantation. 4,5 Here, we describe a 22-year-old woman with a first-degree AV block who developed a complete AV block 1 week after RF ablation for the treatment of the uncommon form of AVNRT (slow/slow). Her complete AV block persisted for another week, and she then recovered. Case ReportA 22-year-old woman was referred to the Jichi Medical Hospital (Tochigi, Japan) for consideration of RF ablation of supraventricular tachycardia. An electrocardiogram (ECG) showed that she had a first-degree AV block, which she had had from the age of 12 years. Since age 19, she had developed fast palpitations with dyspnea and her symptoms had increased. An ECG during sinus rhythm showed a first-degree AV block with a pulse rate interval of 0.28 s (Fig 1A). An ECG during symptoms showed a narrow QRS complex tachycardia with a deeply inverted P wave in II at 130 beats/min (Fig 1B). Results of her physical examination, laboratory analysis, chest X-ray, and echocardiography were normal, indicating that the patient has no other cardiovascular disease except for first-degree AV block. Circulation Journal Vol.66, November 2002An electrophysiologic study and RF ablation were performed under mild sedation after first obtaining the patient's informed consent. Catheters were positioned in the high right atrium, coronary sinus and right ventricular apex, and across the tricuspid valve to record the His bundle potential. At baseline (A -A interval: 825 ms), atrio-His (A-H) and His-ventricular (H-V) intervals were 225 ms and 30 ms, respectively. Using the extrastimulus technique, dual AV nodal physiology was demonstrated with a 140 ms jump in A-H intervals for a 10 ms decrease in coupling interval (S1-S1: 750 ms; S1-S2: 260 ms) (Fig 2A). At a pacing cycle length of 750 ms, the antegrade effective refractory period (ERP) of the AV node was 220 ms. The site of earliest atrial activation potential during ventricular pacing was the coronary sinus ostium (VA: 375 ms; Fig 2B] Atrioventricular (AV) block following radiofrequency (RF) ablation for the treatment of AV nodal re-entrant tachycardia (AVNRT) is a rare but serious complication of this procedure. Almost all such cases occur during or immediately after radiofrequencey (RF) energy application, followed by prompt recovery. The present report describes a 22-year-old woman with first-degree AV block on electrocardiography, who developed complete AV block 1 week after RF ablation for the treatment of the uncommon form of AVNRT (slow/slow). The patient's complete AV block persisted for another 1 week before she recovered. (Circ J ...

show abstract

Effects of radiofrequency catheter ablation on regional myocardial blood flow. Possible mechanism for late electrophysiological outcome.

Cited by 100 publications

References 18 publications

Intramural Coronary Vasculature Prevents Transmural Radiofrequency Lesion Formation

Intramural Coronary Vasculature Prevents Transmural Radiofrequency Lesion Formation

Analysis of Catheter-Tip (8-mm) and Actual Tissue Temperatures Achieved During Radiofrequency Ablation at the Orifice of the Pulmonary Vein

Transient Complete Atrioventricular Block Occurring 1 Week After Radiofrequency Ablation for the Treatment of Atrioventricular Nodal Re-Entrant Tachycardia.

Contact Info

Product

Resources

About