Vnitr Lek 2005, 51(5):539-547

Catheter ablation of atrioventricular nodal reentry tachycardia - non invasive possibility of diagnostics, immediate and 1 year results following radiofrequency ablation and 1 year follow up of 40 patients treated in 2002

Y. Staňková^1,*, J. Müllerová¹, Z. Stárek¹, P. Vank², L. Zaoral¹, M. Novák¹

¹ I. interní kardio-angiologická klinika Lékařské fakulty MU a FN u sv. Anny, Brno, přednosta prof. MUDr. Jiří Vítovec, CSc., FESC

² Klinika funkční diagnostiky a rehabilitace Lékařské fakulty MU a FN u sv. Anny, Brno, přednosta prof. MUDr. Jarmila Siegelová, DrSc.

Introduction:
Catheter radiofrequency ablation (RFA) of atrioventricular nodal reentry tachycardia (AVNRT) is the method of first selection in patients with symptomatic tachycardia.

Aim:
Our target was to prove the yield of non-invasive investigative methods in the course of AVNRT diagnosis, to observe success of method and quality of life improvement after the RFA, X-rays stress, the number of RFA applications, time of skiascopy and effort time, complications of RFA and to compare exercise tolerance before and after the RFA.

Patients and methods:
40 patients with the diagnosis of AVNRT who underwent RFA from January 1, 2002 till December 31, 2002 in Faculty Hospital St. Ann, Brno, CZ, were evaluated. Before we°ve done EP study, we made clinical investigation, ECG, Holter monitoring, oesophageal atrial stimulation, bicycle ergometry, echocardiography. All investigation, were repeated after the RFA, except oesophageal atrial pacing.

Results:
Tachycardia was not found during bicycle ergometry in any patient. Tachycardia was recorded in 9 (24.3%) cases of 37 patients during 24hour Holter monitoring. Clinical tachycardia was recalled in 21 (65.6%) of 32 patients during oesophageal stimulation and in 37 (92.5%) of 40 patients during the EP study. Average number of radiofrequency energy applications to the patient was 11.1 ± 7.5 (1-38), skiascopic time was 12.5 ± 7.8 (3-43) minutes; average effort time was 145.9 ± 44.3 (90-260) minutes. Complications occurred in 2 cases (5.0%) - transient 1^st degree atrioventricular block once and pneumothorax on the left side once. After the RFA, the exercise tolerance increased of 0.5 W.kg^-1 in 16 of 36 patients tested (44.4%). Immediate success rate of RFA for AVNRT was 100%. From the group of 40 followed patients, relapse occurred in 3 (7.5%) patients during one year follow-up (successful reablation performed once, good effect of verapamil once, reablation refused once). So, without tachycardia in one year follow-up was 97.4% of patients in our group. One year after RFA, 38 from 39 (97.4%) living patients determine life quality improvement.

Conclusion:
For diagnosis and successful therapy of AVNRT is important recording of the arrhythmia. From non-invasive methods ECG and Holter monitoring are useful. Bicycle ergometry has not got practical importance. More important in diagnostic process is semi-invasive oesophageal atrial stimulation. The precious diagnosis and arrhythmia management is done by EP study with RFA. After the successful RFA, the efficiency grew in half of patients - we suppose removing psychical inhibition. Results of RFA at our workplace are comparable to the published results.

Keywords: catheter radiofrequency ablation; atrioventricular nodal reentry tachycardia; bicycle ergometry; Holter monitoring; oesophageal atrial stimulation

Received: November 13, 2003; Accepted: October 13, 2004; Published: May 1, 2005  Show citation