Comparative Analysis Of Tilt Test Results Before And After Radiofrequency Catheter Ablation Of Supraventricular Tachycardia

Objective：Currently considered the Cardiac radiofrequency ablation can causecardiac autonomic nerve damage. This study investigated the patients of paroxysmalsupraventricular tachycardia (supraventricular tachycardia) in head-up tilt testingresults before and after treatment of radiofrequency ablation, in order to explore theaffect of cardiac autonomic function by radiofrequency ablation, to lay the foundationof radiofrequency ablation to treat the vasovagal syncope.Methods： The choice of22cases of paroxysmal supraventricular tachycardiapatients with a history of amaurosis or suspicious syncope. The supraventriculartachycardia onset of heart rate was140-217bpm (173.71±21.41) bpm. Excludestructural heart disease. The surface ECG showed paroxysmal supraventriculartachycardia, attentive electrophysiological examination confirmed the dualatrioventricular node pathways or atrioventricular bypasses. The day beforeradiofrequency ablation and postoperative day do tilt experiment. Tilt test wereperformed the basic tilt test (BHUT): patient supine on the tilt bed15-20min, record theECG and heart rate, and blood pressure. Tilt bed, start within5s patients were placed inthe first high-pin low, tilted70°. Maintain this posture ECG and heart rate, and bloodpressure were recorded every5minutes. A total of20minutes or terminated when thepatient can not tolerate.Results：Cardiac electrophysiology examination of22patients, of which9weredual atrioventricular node pathways;11cases of atrioventricular bypass,4of whichwere the right side of the bypass, six cases were the left side of the bypass, and1casewas the back intervals bypass.2patients with conventional electrophysiological examination and intravenous isoproterenol electrophysiological have failed to inducetachycardia, consider the possibility of atrial tachycardia， did not performradiofrequency ablation. Conventional radiofrequency ablation the patients ofatrioventricular nodal dual pathways and atrioventricular bypass. Actual ablation power20-40W, the ablation temperature was55°C, ablation time was90-180s in average of(128.18±23.8)s. Postoperative electrophysiological studies are not induced tachycardiaand no bypass and dual-path routing phenomenon legacy. The success rate of surgerywas100%. Tilt table test checks were performed on22patients preoperative andpostoperative after radiofrequency ablation.20cases of supraventricular tachycardia in all before and after ablation heart ratewere: supine position [(71.65±10.98) vs (73.05±10.24) bpm, P>0.05]; uprightposition [(80.85±10.54) vs (86.4±12.06) bpm, P <0.05]; upright position5min [(83±11.78) vs (87.75±10.93) bpm, P <0.05];10min [(84.25±11.01) vs (86.75±11.39)bpm, P <0.05];15min [(83±10.78) vs (86.5±12.55) bpm, P <0.05];20min [(81.8±11.03) vs (86.15±12.5) bpm, P <0.05). Before and after ablation systolic bloodpressure were: supine [(128.3±15.16) vs (122.1±20.65) mmHg, P <0.05]; uprightposition [(117.65±21.94) vs (110.7±16.61) mmHg, P <0.05]; upright for5min[(115.45±18.41) vs (116.55±17.75) mmHg, P>0.05];10min [(118.25±17.42) vs(113.85±14.10) mmHg, P>0.05];15min [(117.35±17.10) vs (116.25±17.63)mmHg, P>0.05];20min [(120.85±17.57) vs (117.3±16.38) mmHg, P>0.05].Before and after ablation diastolic blood pressure were: supine position [(77.65±12.26) vs (76±12.07) mmHg, P>0.05]; upright position [(75.85±13.30) vs (75.4±11.60) mmHg, P>0.05]; upright5min [(75.45±15.08) vs (76.4±13.95) mmHg, P>0.05];10min [(76.05±12.28) vs (76.65±12.33) mmHg, P>0.05];15min [(77.9±13.83) vs (76.35±13.97) mmHg, P>0.05];20min [(77.5±11.89) vs (78.05±14.15)mmHg, P>0.05];Degree of mean arterial pressure decreased before and after ablationwere (6.94±10.25) vs (6.22±5.49)%, P>0.05].9cases of dual atrioventricular node pathways in patients with heart rate beforeand after ablation were: supine position [(69.56±8.38) vs (72.56±7.02) bpm, P <0.05];upright position [(80.78±7.53) vs (89.11±12.35) bpm, P <0.05]; upright position5min [(83.33±10.79) vs (90.67±9.95) bpm, P <0.05];10min [(85.33±10.22) vs(87.11±11.35) bpm, P>0.05);15min [(83.44±10.65) vs (86.89±12.15) bpm, P>0.05);20min [(81.33±11.93) vs (85.89±11.72) bpm, P>0.05).Before and afterablation systolic blood pressure were as follows: the supine [(123.22±13.28) vs (115.44±17.95) mmHg, P>0.05); upright position [(109±16.66) vs (104.56±12.55)mmHg, P>0.05]; upright5min [(107.56±16.53) vs (105.33±9.85) mmHg, P>0.05];10min [(110.44±14.52) vs (107.78±10.62) mmHg, P>0.05];15min [(110.22±13.75) vs (107.56±15.17) mmHg, P>0.05];20min [(111.89±10.74) vs (110.44±14.37) mmHg, P>0.05].Before and after ablation diastolic blood pressure were: supineposition [(75.44±10.79) vs (71.89±10.49) mmHg, P>0.05]; upright position [(70.89±9.33) vs (67.11±7.17) mmHg, P>0.05]; upright for5min [(71.89±13.24) vs (68±8.19) mm Hg, P>0.05];10min [(70.78±7.51) vs (69.56±7.09) mmHg, P>0.05];15min [(72.67±10.71) vs (70.67±6.80) mmHg, P>0.05];20min [(74.22±8.63) vs(69.89±8.78) mmHg, P>0.05];Degree of mean arterial pressure before and afterablation [(10.42±7.94) vs (8.71±3.59)%, P>0.05].11cases of atrioventricular bypass patients, changes in heart rate before and afterablation were: supine position [(73.36±12.87) vs (73.45±12.63) bpm, P>0.05];upright position [(80.91±12.88) vs (84.18±11.92) bpm, P>0.05]; upright position5min [(82.73±13.04) vs (85.36±11.58) bpm, P>0.05];10min [(83.36±12.04) vs(86.45±11.96) bpm, P>0.05];15min [(82.64±11.40) vs (86.18±13.44) bpm, P>0.05];20min [(82.18±10.81) vs (86.36±13.68) bpm, P>0.05]. Before and afterablation systolic blood pressure: supine position [(132.45±15.91) vs (127.55±21.92)mmHg, P>0.05]; upright position [(124.73±23.87) vs (115.73±18.34) mmHg, P>0.05]; upright position for5min [(121.91±17.99) vs (125.73±17.74) mmHg, P>0.05];10min [(124.64±17.56) vs (118.82±15.08) mmHg, P>0.05];15min [(123.18±17.92) vs (123.36±16.81) mmHg, P>0.05];20min [(128.18±19.05) vs (123.27±16.1) mmHg, P>0.05]. Before and after ablation diastolic blood pressure were: supineposition [(79.45±13.57) vs (79.36±12.69) mmHg, P>0.05]; upright position [(79.91±15.03) vs (82.18±10.11) mmHg, P>0.05]; upright position5min [(78.36±16.46)vs (83.27±14.16) mmHg, P>0.05];10min [(80.36±14.00) vs (82.45±12.90) mmHg,P>0.05];15min [(82.18±15.06) vs (81±16.76) mmHg, P>0.05];20min [(80.18±13.84) vs (84.73±14.49) mmHg, P>0.05]; Before and after ablation, mean arterialpressure decreased [(4.09±11.37) vs (4.19±6.06)]%, P>0.05].Conclusions: Atrioventricular node slow pathway ablation selectively impairedcardiac autonomic nervous, mainly to the cardiac vagal nerve injury, resulting in theincrease of heart rate in the upright tilt test. Prompt the feasibility of denervationablation to treat vasovagal syncope.