TY - JOUR
T1 - Target temperatures of 48°C versus 60°C during slow pathway ablation
T2 - A randomized comparison
AU - Strickberger, S. Adam
AU - Tokano, Takasha
AU - Tse, Hung Fat
AU - Kim, Michael H.
AU - Oral, Hakan
AU - Flemming, Matthew
AU - Pelosi, Frank
AU - Michaud, Gregory F.
AU - Knight, Bradley P.
AU - Goyal, Rajiva
AU - Morady, Fred
PY - 1999
Y1 - 1999
N2 - Introduction: The relationship between temperature at the electrode- tissue interface and the loss of AV and ventriculoatrial (VA) conduction is not established, and the optimal target temperature for the slow pathway approach to radiofrequency ablation of AV nodal reentrant tachycardia (AVNRT) is unknown. Therefore, the purpose of this study was to compare target temperatures of 48°C and 60°C during the slow pathway approach to ablation of AVNRT. Methods and Results: The study included 138 patients undergoing ablation for AVNRT. Patients undergoing slow pathway ablation using closed- loop temperature monitoring were randomly assigned to a target temperature of either 48°C or 60°C. The primary success rates were 76% in the patients assigned to 48°C and 100% in the patients assigned to 60°C (P < 0.01). The ablation procedure duration (33 ± 31 min vs 26 ± 28 min; P = 0.2), fluoroscopic time (25 ± 15 min vs 24 ± 16 min; P = 0.5), and mean number of applications (9.3 ± 6.5 vs 7.8 ± 8.1; P = 0.3) were similar in patients assigned to 48°and 60°C, respectively. The mean temperature (46.1°± 24.8°C vs 48.7°± 3.2°C; P < 0.01), the temperature associated with junctional ectopy (48.1°± 2.0°C vs 53.5°± 3.5°C, P < 0.0001), and the frequency of VA block during junctional ectopy (24.6% vs 37.2%; P < 0.0001) were less in the patients assigned to 48°C compared to 60°C. The frequency of transient or permanent AV block was similar in each group (2.8% vs 3.6%; P = 0.2). In the 60°C group, only 12% of applications achieved an electrode temperature of 60°C. During follow-up of 9.9 ± 4.2 months, there was one recurrence of AVNRT in the 48°C group and none in the 60°C group. Conclusions: Compared to 48°C, a target temperature of 60°C during radiofrequency slow pathway ablation is associated with a higher primary success rate and a higher incidence of VA block during junctional ectopy induced by the radiofrequency energy. AV block is not more common with the higher target temperature, but only if VA conduction is aggressively monitored during applications of radiofrequency energy.
AB - Introduction: The relationship between temperature at the electrode- tissue interface and the loss of AV and ventriculoatrial (VA) conduction is not established, and the optimal target temperature for the slow pathway approach to radiofrequency ablation of AV nodal reentrant tachycardia (AVNRT) is unknown. Therefore, the purpose of this study was to compare target temperatures of 48°C and 60°C during the slow pathway approach to ablation of AVNRT. Methods and Results: The study included 138 patients undergoing ablation for AVNRT. Patients undergoing slow pathway ablation using closed- loop temperature monitoring were randomly assigned to a target temperature of either 48°C or 60°C. The primary success rates were 76% in the patients assigned to 48°C and 100% in the patients assigned to 60°C (P < 0.01). The ablation procedure duration (33 ± 31 min vs 26 ± 28 min; P = 0.2), fluoroscopic time (25 ± 15 min vs 24 ± 16 min; P = 0.5), and mean number of applications (9.3 ± 6.5 vs 7.8 ± 8.1; P = 0.3) were similar in patients assigned to 48°and 60°C, respectively. The mean temperature (46.1°± 24.8°C vs 48.7°± 3.2°C; P < 0.01), the temperature associated with junctional ectopy (48.1°± 2.0°C vs 53.5°± 3.5°C, P < 0.0001), and the frequency of VA block during junctional ectopy (24.6% vs 37.2%; P < 0.0001) were less in the patients assigned to 48°C compared to 60°C. The frequency of transient or permanent AV block was similar in each group (2.8% vs 3.6%; P = 0.2). In the 60°C group, only 12% of applications achieved an electrode temperature of 60°C. During follow-up of 9.9 ± 4.2 months, there was one recurrence of AVNRT in the 48°C group and none in the 60°C group. Conclusions: Compared to 48°C, a target temperature of 60°C during radiofrequency slow pathway ablation is associated with a higher primary success rate and a higher incidence of VA block during junctional ectopy induced by the radiofrequency energy. AV block is not more common with the higher target temperature, but only if VA conduction is aggressively monitored during applications of radiofrequency energy.
KW - Atrioventricular nodal reentrant tachycardia
KW - Paroxysmal supraventricular tachycardia
KW - Radiofrequency catheter ablation
KW - Temperature monitoring
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U2 - 10.1111/j.1540-8167.1999.tb00259.x
DO - 10.1111/j.1540-8167.1999.tb00259.x
M3 - Article
C2 - 10376916
AN - SCOPUS:0033032770
SN - 1045-3873
VL - 10
SP - 799
EP - 803
JO - Journal of cardiovascular electrophysiology
JF - Journal of cardiovascular electrophysiology
IS - 6
ER -