Cooled tip ablation of left ventricular outflow tract tachycardia through the aortic sinus of valsalva

BACKGROUND: Monomorphic tachycardia with an epicardial site of the arrhythmic focus in the left ventricular outflow tract (LVOT) usually cannot be ablated by an endocardial approach. We describe the use of cooled tip catheter ablation through the aortic sinus of valsalva to treat LVOT tachycardia. METHODS: In seven patients (four males, one with valvular cardiomyopathy, six patients without heart disease) with sustained and non-sustained ventricular tachycardia (VT) an epicardial focus of LVOT tachycardia could be identified by pace-mapping and earliest local activation within the aortic sinus of valsalva. Coronary angiography served to define the position of the coronary arteries with respect to the ablation catheter. High frequency current was delivered using a closed-loop cooled tip catheter system (Chilli Cool(R), Boston Scientific). ECG, Holter-ECG, echocardiography and transesophageal echocardiography were performed after the procedure and 3 months later. RESULTS: Foci were located in the left (two patients), in the right (three) and in the a coronary aortic sinus (two). Successful ablation could be achieved in six patients. No procedure-related complications could be observed during a mean follow-up of 4.2 months. CONCLUSION: Monomorphic VT with epicardial origin in the LVOT can be successfully treated by cooled tip ablation through the aortic sinus of valsalva. The use of a cooled tip ablation system may be favourable in several ways: 1) it allows the creation of deep lesions necessary to reach remote foci; 2) due to lower temperatures at the catheter/tissue interface surface tissue damage may be reduced; 3) lower catheter temperature may additionally reduce the risk of local clot formation which is crucial for all left-sided procedures and especially for ablation in the sinus of valsalva.     

Ventricular tachycardias mimicking those arising from the right ventricular outflow tract

INTRODUCTION: Ablation of ventricular tachycardia (VT) arising from the right ventricular outflow tract (RVOT) has proven highly successful, yet VTs with similar ECG features may originate outside the RVOT. METHODS AND RESULTS: We reviewed the clinical, echocardiographic, and ECG findings of 29 consecutive patients referred for ablation of monomorphic VT having a left bundle branch block pattern in lead V1 and tall monophasic R waves inferiorly. Nineteen patients (group A) had VTs ablated from the RVOT, and 10 patients (group B) had VTs that could not be ablated from the RVOT. The QRS morphology during VT or frequent ventricular premature complexes was the only variable that distinguished the two groups. During the target arrhythmia, ECGs of group B patients displayed earlier precordial transition zones (median V3 vs V5; P < 0.001), more rightward axes (90 +/- 4 vs 83 +/- 5; P = 0.002), taller R waves inferiorly (aVF: 1.9 +/- 1.0 vs 2.4 +/- 0.5; P = 0.020) and small R waves in lead V1 (10/10 vs 9/19; P = 0.011). Radiofrequency catheter ablation from the RVOT failed to eliminate VT in any group B patient, but ablation from the left ventricular outflow tract (LVOT) eliminated VT in 2 of 6 patients in whom left ventricular ablation was attempted. CONCLUSION: The absence of an R wave in lead V1 and a late precordial transition zone suggest an RVOT origin of VT, whereas an early precordial transition zone characterizes VTs that mimic an RVOT origin. The latter VTs occasionally can be ablated from the LVOT. Recognition of these ECG features may help the physician advise patients and direct one's approach to ablation.     

Nonsustained ventricular tachycardia arising from the right ventricular outflow tract

Characteristics of left bundle branch block morphology, inferiorly directed frontal plane QRS axis and repetitive nonsustained salvos were used to define a discrete subgroup of patients with ventricular tachycardia (VT). The origin of this tachycardia was thought to be the right ventricular outflow tract. Twenty-six patients with this definition (group 1) were compared with 29 consecutive patients with all other forms of VT (group 2). When compared with patients in group 2, group 1 patients were younger (average age 37 vs 51 years, p less than 0.005), had less structural heart disease (2 of 26 vs 25 of 29 patients, p less than 0.005) and had a better prognosis (no deaths) after an average follow-up time of 28 months in comparison with 5 deaths after an average follow-up of 35 months (p less than 0.05). Induction of VT was possible using isoproterenol infusion in 14 of 20 group 1 patients, but no VT could be induced in 9 group 2 patients (p less than 0.05). Exercise stress testing induced VT in 11 of 21 group 1 patients and 2 of 9 group 2 patients (p greater than 0.05). Programmed electrical stimulation failed to induce VT in 9 group 1 patients, but did induce it in 15 of 20 group 2 patients (p less than 0.005). Successful therapy in group 1 patients was achieved by beta blockers alone (7 patients), beta blockers plus type 1A antiarrhythmic drugs (9 patients), procainamide alone (2 patients), sotalol (3 patients) and amiodarone (2 patients). Three patients were not treated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Autonomic and pharmacological responses of idiopathic ventricular tachycardia arising from the left ventricular outflow tract

Background: It is well recognized that the mechanism of idiopathic ventricular tachycardia (VT) arising from the right ventricular outflow tract (RVOT) is mostly due to cyclic AMP-mediated triggered activity. The mechanism of VT arising from the left ventricular outflow tract (LVOT) has not been well clarified whether it is the same as VT of RVOT.
Methods: We studied autonomic modulations and pharmacological interventions on VT/premature ventricular contractions (PVCs) from LVOT to explore its possible mechanism in six patients (age: 49 ± 14, three males). None of them had structural heart diseases.
Results: Isoproterenol application easily induced VT and/or PVCs from LVOT. Valsalva maneuvers suppressed isoproterenol-induced VT in two and PVCs in two, and carotid sinus massage (CSM) suppressed PVCs in one patient. Adenosine triphosphate inhibited both VT and PVCs in all six patients. Propranolol, lidocaine, and procainamide eliminated VT/PVCs in four, three, and four patients, respectively. Verapamil terminated VT in one and PVCs in another one patient, but aggravated PVCs to VT in one patient.
Conclusion: The results suggest that the mechanism of VT from LVOT is mostly due to cAMP-mediated triggered activity as similar to that in VT from RVOT.     

Sustained monomorphic ventricular tachycardia ablation from the aortic sinus of valsalva

INTRODUCTION: The aim of this study was to delineate the electrophysiologic mechanisms of a novel type of ventricular tachycardia (VT) originating from the aortic sinus of Valsalva. METHODS AND RESULTS: Endocardial mapping was performed in four patients with symptomatic VT originating from the aortic sinus of Valsalva. Two patients suffered from dilative cardiomyopathy; the other two patients had no structural heart disease. Five VTs could be induced and terminated by programmed ventricular stimulation. Successful ablation was performed in the noncoronary sinus of Valsalva in three VTs and in the left aortic sinus in two. Abnormal (diastolic or presystolic) potentials were recorded during sinus rhythm (mean interval from the end of QRS complex to the potential 121+/-98 msec) and during VT (mean interval from the potential to QRS complex 64+/-45 msec) at effective sites in the aortic sinuses of Valsalva. Concealed entrainment was demonstrated at all successful sites. VT recurred in one patient after 1 month, whereas no recurrences were observed during follow-up of 8+/-6 months in the other three patients. CONCLUSION: Reentry constitutes one mechanism of VT originating from the aortic sinus of Valsalva. Entrainment mapping is useful to characterize the reentrant circuit of these VTs and to guide ablation.     

Anomalous left coronary artery arising from the right sinus of valsalva as a cause of ventricular tachycardia

This paper describes a rare case of a young patient with an anomalous left coronary artery (LCA) originating from the right sinus of Valsalva, passing between the aorta and the pulmonary artery. This rare case was discovered during coronary angiography for the evaluation of the patient, after restoration of symptomatic ventricular tachycardia.     

左心室流出道特发性室性心动过速

反复单形室性心动过速（repetitive monomorphic ventricular tachycardia, RMVT）在临床上很常见,表现为频发室性早搏（室早）,部分成对、成串,以及反复发作与室早相同形态的持续性或非持续性单形VT,这类心律失常多发生在无明确器质性心脏病证据的患者,常起源于右心室流出道,最近发现这种特征的VT部分也可起源于左心室流出道,具有和右心室流出道室性心动过速（right ventricle outflow tract ventricular tachycardia,RVOT-VT）不同的心电图和电生理特点,本文综述国内外关于左心室流出道室性心动过速（left ventricle outflow tract ventricular tachycardia,LVOT-VT）的研究进展.     

Coronary sinus mapping to differentiate left versus right ventricular outflow tract tachycardias.

Outflow tract ventricular tachycardia (OT-VT) can originate from several different segments of the outflow tract. Various ECG criteria have been proposed for localization of OT-VTs. We present two patients, one with left and one with right OT-VT. We used local ventricular electrograms in the coronary sinus to localize the focus of the OT-VT. Mapping of local ventricular electrograms in the coronary sinus may be a simple and effective method for differentiating right versus left ventricular outflow tract tachycardias. However, the diagnostic value and precision of this method should be evaluated in a series of patients before its implementation in the OT-VT ablation decision algorithm.     

特发性左心室流出道心外膜侧室性心动过速

目的报道9例经电生理检查证实的特发性左心室流出道心外膜侧室性心动过速(室速)的体表心电图及电生理检查特点.方法男性5例,女性4例,年龄15～58岁,6例为运动诱发的持续性室速,3例为运动诱发的非持续性室速.结果室速时,9例体表心电图QRS波全部呈现右束支阻滞图形(8例胸前导联V1-V6呈现高R波),Ⅱ、Ⅲ、aVF导联为高R波,Ⅰ、aVL导联为QS波.电生理检查,右心室和左心室心内膜标测未发现最早心室激动点,在较早心室心内膜激动处的心内电图多呈现起始部低幅电位,提示远场电位.心室内起搏标测未发现与室速体表心电图12导联QRS波形态相同的起搏点.8例通过心脏静脉系统标测发现最早的心室激动点[体表心电图最早QRS波前15～50ms,平均(32±12)ms]和完全或近乎完全的起搏标测位于心大静脉的远端1例、心前间隔静脉的近端7例.1例患者在左心室流出道消融成功,1例患者在心大静脉远端血管内消融成功.其他患者在右心室和/或左心室内消融失败.结论心脏静脉标测可以鉴别出特发性左心室流出道心外膜侧室速.     

Catheter ablation of ventricular tachycardia in the left ventricular outflow tract beyond the aortic valve

This case report describes successful catheter ablation of an ectopic focus in the left ventricular outflow tract just beyond the aortic valve. Extended pace-mapping revealed a focus about 1 cm beneath the origin of the left coronary artery--above the base of the left coronary cusp. During a follow-up of 1 year no further spontaneous episode of ventricular tachycardia was documented. This case report describes an unusual localization of an idiopathic ventricular tachycardia and it demonstrates that radiofrequency catheter ablation can be done even in a critical position.     

Coexistence of 2 types of atrial tachycardias and right ventricular outflow tract tachycardia

Double tachycardia is a relatively uncommon type of tachycardia. In this report, we discuss a 68-year-old woman with history of frequent palpitations. Electrophysiologic study revealed that narrow QRS tachycardias from 2 origins and 1 wide QRS tachycardia were induced and each of the tachycardias was induced by the other. We found that 2 focal atrial tachycardias and 1 ventricular tachycardia originated from right ventricular outflow tract. All of these tachycardias were successfully ablated during one session, and no recurrence appeared during 10 months of follow-up.     

射频导管消融特发性左心室流出道室性心动过速

目的 探讨特发性左心室流出道室性心动过速(室速)心电图特点及射频导管消融结果。方法 对5例未发现器质性心脏病的左心室流出道室速患者行12导联心电图、动态心电图、心内电生理检查及射频导管消融治疗。结果5例患者心电图Ⅱ、Ⅲ、aVF导联呈R波；Ⅰ导联呈rs或QS波，振幅大于0．5mV；V1导联呈rs或RS波，胸前导联R波移行发生于V2～V3；aVR和aVL导联呈QS波，3例患者的消融靶点在左冠状窦口内，2例位于主动脉瓣下，随访6个月，无1例复发。结论 左心室流出道室速有特殊心电图表现，射频导管消融是首选的治疗措施。