Cardiology in the Young 2014; Page 1 of 3
© Cambridge University Press, 2014
doi:10.1017/S1047951114001589
Brief Report Successful catheter ablation of a left anterior accessory pathway from the non-coronary cusp of the aortic valve Sérgio Laranjo,1 Mário Oliveira,2 Conceição Trigo1 1
Serviço de Cardiologia Pediátrica; 2Serviço de Cardiologia, Hospital de Santa Marta – CHLC, EPE, Lisboa, Portugal
Abstract Left anterior accessory pathways are considered to be rare findings. Catheter ablation of accessory pathways in this location remains a challenging target, and few reports about successful ablation of these accessory pathways are available. We describe our experience regarding a case of a manifest left anterior accessory pathway ablation using radiofrequency energy at the junction of the left coronary cusp with the non-coronary cusp. Keywords: Accessory pathway; non-coronary cusp; aortic root; catheter ablation; mapping system Received: 5 September 2014; Accepted: 24 July 2014
Case report A 17-year-old boy was referred because of recurrent episodes of paroxysmal tachycardia, despite antiarrhythmic drug treatment. He had a structurally normal heart. The electrocardiogram showed ventricular pre-excitation, with positive delta waves in leads II, III, and aVF, negative delta wave in leads aVR and aVL, and positive delta waves from V1 to V6, suggesting an accessory pathway location in the left anterolateral region. An electrophysiological study was conducted after written informed consent. Two quadripolar catheters were placed at the right ventricular apex and His bundle via the femoral vein, and a decapolar catheter was inserted in the coronary sinus via the right jugular vein. The electrophysiological study revealed a retrograde concentric conduction during right ventricular pacing, without decremental property, with a ventriculo-atrial refractory period of 300 ms. After intravenous 12-mg bolus injection of adenosine, ventriculo-atrial conduction was blocked for few seconds, and then remained unchanged, with the earliest atrial activation recorded at the His-bundle region. In addition, antegrade conduction over a left anterolateral accessory pathway was noted during atrial pacing manoeuvres. The atrial pacing protocol did not induce Correspondence to: S. Laranjo, MD, Serviço de Cardiologia Pediátrica, Hospital de Santa Marta, CHLC, Rua de Santa Marta, 1169-024 Lisboa, Portugal. Tel: + 351 213 594 332; Fax: + 351 217 99435; E-mail: [email protected]
any tachyarrhythmia, with or without isoproterenol. A standard (4 mm) 7-Fr radiofrequency catheter (Therapy; St Jude Medical, Sylmar, California, United States of America) was used to map the tricuspid annulus, through a femoral access, and the mitral annulus, via a transseptal approach, during sinus rhythm, by using a three-dimensional mapping system (Ensite NavX; St Jude Medical). The electrophysiological study and the three-dimensional propagation map showed the shortest atrioventricular interval with a QS pattern in the unipolar electrograms recorded on a left anterior position. However, radiofrequency applications at this location failed to eliminate the ventricular pre-excitation. Then, the ablating catheter was inserted through the right femoral artery and advanced retrogradely into the left ventricle. Electrophysiological and three-dimensional mapping was performed at the mitral annulus, to explore the ventricular insertion site, subvalvular mitroaortic curtain, and sinuses of Valsalva (above the cusps), respectively. An aortic root angiogram and coronarography were obtained to delineate the aortic root anatomy and origin of the coronary arteries. Heparin was administered to maintain activated clotting time above 250 seconds. The earliest site of ventricular activation during normal sinus rhythm was in the left sinus of Valsalva at the junction of the left coronary cusp with the non-coronary cusp (20 ms before the onset of delta wave), where a small sharp spike preceded ventricular electrogram (Figs 1 and 2).
2
Cardiology in the Young
2014
Figure 1. Three-dimensional propagation map (Ensite Navx; St Jude Medical) with shortest atrioventricular interval at the junction of the left coronary cusp with the non-coronary cusp.
Figure 2. Ablation site electrogram and normalisation of electrocardiogram after radiofrequency application.
Ablation at this site using 15 W, increasing to 3 W for 60 seconds, with a tip temperature
© Cambridge University Press, 2014
doi:10.1017/S1047951114001589
Brief Report Successful catheter ablation of a left anterior accessory pathway from the non-coronary cusp of the aortic valve Sérgio Laranjo,1 Mário Oliveira,2 Conceição Trigo1 1
Serviço de Cardiologia Pediátrica; 2Serviço de Cardiologia, Hospital de Santa Marta – CHLC, EPE, Lisboa, Portugal
Abstract Left anterior accessory pathways are considered to be rare findings. Catheter ablation of accessory pathways in this location remains a challenging target, and few reports about successful ablation of these accessory pathways are available. We describe our experience regarding a case of a manifest left anterior accessory pathway ablation using radiofrequency energy at the junction of the left coronary cusp with the non-coronary cusp. Keywords: Accessory pathway; non-coronary cusp; aortic root; catheter ablation; mapping system Received: 5 September 2014; Accepted: 24 July 2014
Case report A 17-year-old boy was referred because of recurrent episodes of paroxysmal tachycardia, despite antiarrhythmic drug treatment. He had a structurally normal heart. The electrocardiogram showed ventricular pre-excitation, with positive delta waves in leads II, III, and aVF, negative delta wave in leads aVR and aVL, and positive delta waves from V1 to V6, suggesting an accessory pathway location in the left anterolateral region. An electrophysiological study was conducted after written informed consent. Two quadripolar catheters were placed at the right ventricular apex and His bundle via the femoral vein, and a decapolar catheter was inserted in the coronary sinus via the right jugular vein. The electrophysiological study revealed a retrograde concentric conduction during right ventricular pacing, without decremental property, with a ventriculo-atrial refractory period of 300 ms. After intravenous 12-mg bolus injection of adenosine, ventriculo-atrial conduction was blocked for few seconds, and then remained unchanged, with the earliest atrial activation recorded at the His-bundle region. In addition, antegrade conduction over a left anterolateral accessory pathway was noted during atrial pacing manoeuvres. The atrial pacing protocol did not induce Correspondence to: S. Laranjo, MD, Serviço de Cardiologia Pediátrica, Hospital de Santa Marta, CHLC, Rua de Santa Marta, 1169-024 Lisboa, Portugal. Tel: + 351 213 594 332; Fax: + 351 217 99435; E-mail: [email protected]
any tachyarrhythmia, with or without isoproterenol. A standard (4 mm) 7-Fr radiofrequency catheter (Therapy; St Jude Medical, Sylmar, California, United States of America) was used to map the tricuspid annulus, through a femoral access, and the mitral annulus, via a transseptal approach, during sinus rhythm, by using a three-dimensional mapping system (Ensite NavX; St Jude Medical). The electrophysiological study and the three-dimensional propagation map showed the shortest atrioventricular interval with a QS pattern in the unipolar electrograms recorded on a left anterior position. However, radiofrequency applications at this location failed to eliminate the ventricular pre-excitation. Then, the ablating catheter was inserted through the right femoral artery and advanced retrogradely into the left ventricle. Electrophysiological and three-dimensional mapping was performed at the mitral annulus, to explore the ventricular insertion site, subvalvular mitroaortic curtain, and sinuses of Valsalva (above the cusps), respectively. An aortic root angiogram and coronarography were obtained to delineate the aortic root anatomy and origin of the coronary arteries. Heparin was administered to maintain activated clotting time above 250 seconds. The earliest site of ventricular activation during normal sinus rhythm was in the left sinus of Valsalva at the junction of the left coronary cusp with the non-coronary cusp (20 ms before the onset of delta wave), where a small sharp spike preceded ventricular electrogram (Figs 1 and 2).
2
Cardiology in the Young
2014
Figure 1. Three-dimensional propagation map (Ensite Navx; St Jude Medical) with shortest atrioventricular interval at the junction of the left coronary cusp with the non-coronary cusp.
Figure 2. Ablation site electrogram and normalisation of electrocardiogram after radiofrequency application.
Ablation at this site using 15 W, increasing to 3 W for 60 seconds, with a tip temperature
