Myocardial injury during radiofrequency catheter ablation: Comparison of focal and linear lesions

The aim of study was to investigate the extent of myocardial injury incurre d by creation of continuous RF current induced linear ablation lesions (LL; ablation of atrial fibrillation, right atrial procedure) in comparison to focal RF lesions (FL; AV node reentry tachycardia, WPW tachycardia). In 23 patients with LL (age 52.3 +/- 21.2 years, 18 men, 5 women) and in 16 patie nts with FL (age 53.9 +/- 5.1 years, 8 men-and 8 women), levels of creatine kinase (CK), myoglobin (MG), CI(MB mass (CKMB M), CKMB activity (CKMB A), and cardiac troponin T (cTnT) were determined before and 2, 4, 8, 24, and 4 8 hours after ablation. CKMB A was normal in 87% in LL and 100% in FL (< 6% of CK) with median maximum CK values of 214 (45-1583) U/L in LL and 36 (29 -212) U/L in FL. Peak values of all parameters were significantly higher in LL than in FL. The sensitivity of cTnT wets 50% in FL and 100% in LL. In F L MG, total CK, and CKMB M were abnormal in only 12.5% of cases while in LL MG and CKMB M were pathological in 100% and total CK was abnormal in 91.3% of patients. The amount of energy and number of RF applications correlated with cTnT, MG, and CKMB M (P = 0.01). In conclusion, (1) long linear RF cu rrent lesions for ablation of atrial fibrillation are associated with signi ficantly greater myocardial injury th an focal ablations. (2) In focal lesi ons only cTnT provided a sensitivity of 50% in the detection of myocardial injury while in linear lesions cTnT, CKMBM, and CKMB M seemed suitable for detection of RF current induced myocardial damage with 100% sensitivity. Al l biochemical parameters do not differentiate patients with coronary ischem ia up to 48 hours after an ablation. (3) Further investigations are necessa ry to determine if RF current linear lesions lead to impaired atrial contra ctility in cases of extensive tissue damage.