Myocardial Injury Resulting from Radiofrequency Catheter Ablation by Analysis of Troponin-T and Other Cardiac Enzymes

Although radiofrequency catheter ablation (RFA) has been used to eliminate tachyarrhythmias as a successful and safe method, there is no study that is demonstrating RFA induced tissue damage by using serum troponin-T (TnT). The aim of this study is to investigate myocardial injury resulting from RFA by analyzing TnT and other cardiac enzymes. The study population consisted of 22 (9 women and 13 men; mean age: 33.8+ 16.4 years) patients (pts) with symptomatic supraventricular or ventricular tachyarrhythmias and 23 healthy persons (3 women and 20 men; mean age: 29.1 +8.4 years) as a control group. There was WPW syndrome in 19 pts, automatic atrial tachycardia (AAT) in 2 pts and ventricular tachyardia (VT) in 1 pt. Twenty-nine RFA sessions were performed in 22 pts. Blood samples were taken before and after (6th, 1 6th hour and 4th day) the procedure from each pt. Complete cure was obtained in 16 of 19 pts (84%) with WPW syndrome. RFA was also successful in 2 pts with EAT and 1 pt with VT. Transient and mild complications occurred in 3 sessions. There was no difference between the mean basal TnT values of pts and the control group (0.01±0.01 ng/ml and 0.01+0.02 ng/ml respectively). The serum TnT level was increased above to normal values in 27 of 29 procedures (939) at the 6th hour (TnT-6); in 24 procedures (83%) at the 16th hour and in 8 procedures (27%) at the 4th day. Thus, in determining RFA tissue injury, sensitivity of and in 8 procedures (27%) at the 4th day. Thus, in determining RFA tissue injury, sensitivity of TnT was 93% and specificity was 100%. At 6th hour, 16th hour and 4th day of RFA, rates of increase above normal values of CK and CKMB were 34% and 41%; 28% and 28%; 3 and 3%, respectively. Therefore, the incidence of elevated TnT levels were significantly higher than CK and CKMB (p<0.0001, p<0.0001 and p<0.001 for 6th, 16th hour and 4th day, respectively). There was positive correlation between the serum TnT-6 level and the number of RF pulses (r:0.63), total pulse duration (r: 0.62), total energy (r: 0.65) and total power (r: 0.66), but there was no significant correlation between the levels of CK or CKMB and these parameters. The mean TnT values in subgroups comprising number of pulses>20, total pulse duration>500 second, total energy>l2000 joule and total power>600 Watt were significantly higher than subgroups comprising·the mean values less than these limits. The mean CK and CK MB values were not significantly different in these subgroups. There was no relation between enzyme levels and the rate of success or complications. It was concluded that TnT analysis is a very sensitive method in determining of degree of myocardial damage resulting from RFA, whereas CK and CKMB are less reliable.