Verapamil-sensitive Idiopathic Left Ventricular Tachycardia Research Articles

Verapamil-sensitive idiopathic left ventricular tachycardia and concomitant atrioventricular nodal reentrant tachycardia

We describe the case of a young patient with runs of repetitive monomorphic left ventricular tachycardia. He was diagnosed with verapamil-sensitive, idiopathic left ventricular tachycardia (ILVT) and underwent an electrophysiological study, in which dual atrioventricular (AV) nodal physiology was evident, with an AV nodal reentrant tachycardia (AVNRT) being easily and reproducibly induced. Both the AVNRT and the ILVT were successfully ablated using high-density electroanatomical mapping and an open-irrigation catheter. In conclusion, verapamil-sensitive ILVT might coexist with AVNRT. In case of invasive therapy, a thorough electrophysiological evaluation is mandatory to exclude or treat other co-existing reentrant supraventricular arrhythmias.

The change of cardiac axis deviation in catheter ablation of verapamil-sensitive idiopathic left ventricular tachycardia.

The underlying mechanism of verapamil-sensitive idiopathic left ventricular tachycardia (ILVT) has been postulated to be reentrant activation in the Purkinje fiber network of the left posterior fascicle or the left anterior fascicle (LAF). However, changing of cardiac axis deviation in sinus rhythm (SR) or during ILVT after radiofrequency catheter ablation (RFCA) has been rarely analyzed. Of the 232 patients with sustained ILVT induced and surface electrocardiogram (ECG) in SR recorded before and after RFCA, the changes of ECG morphology in SR and during ILVT were analyzed. The surface ECG in SR changed in 114 (49.1%) patients after RFCA. ILVT could still be induced in 27 (23.7%) patients. In comparison with the original ILVT, three forms of ECG morphology were observed. In eight patients, the ILVT morphology was unchanged. In the 13 patients with ILVT axis deviation conversion after ablation, the successful target was more proximal. In the six patients with ILVT morphology change but without axis deviation conversion after ablation, the successful ablation site was more distal. Among 15 patients with recurrent ILVT during follow-up, seven patients had previous axis deviation changes in SR after RFCA, the changes maintained in four patients and recovered in three patients. The morphology changes on surface ECG in SR after RFCA would not be a necessary prerequisite or a good endpoint for ILVT ablation. To analyze ILVT morphology changes after ablation would help to further clarify an appropriate approach for catheter ablation of ILVT.

Change in QRS morphology as a marker of spontaneous elimination in verapamil-sensitive idiopathic left ventricular tachycardia.

Verapamil-sensitive idiopathic left ventricular tachycardia (verapamil-ILVT) is thought to be due to a reentry within the LV fascicular system. Radiofrequency catheter ablation (RFCA) is effective for elimination of the VT; however, a long-term prognosis of patients with verapamil-ILVT is still unclear. Eighty consecutive verapamil-ILVT patients (62 men, 31±12 years of age, LVEF: 65±4%) were enrolled. Seventy-six (95%) cases of VT involved right bundle branch block and left axis deviation. We retrospectively analyzed changes in the QRS duration (ΔQRS-d) and QRS axis (ΔQRS-axis) during follow-up and compared them with recurrence of VT. During a mean follow-up period of 10years (2-32years), no sudden death or heart failure occurred. Fifty-one (64%) patients underwent RFCA, and 46 (90%) of them had no VT without any medication after RFCA. The ΔQRS-d (16±2 vs. 8±1ms, P=0.24) and ΔQRS-axis (20±4 vs. 4±3 degrees, P=0.23) were not different in patients with no VT (VT[-]) and those with recurrence of VT (VT[+]). However, in the remaining 29 patients without RFCA, VT was spontaneously eliminated in 16 patients. The ΔQRS-d (30±6 vs. 6±1ms, P=0.002) and ΔQRS-axis (23±4 vs. 5±2degrees, P=0.001) were significantly larger in VT(-) patients compared to VT(+) patients during follow-up. Some verapamil-ILVT patients who show QRS morphology changes over the follow-up period may become free from VT without any invasive or pharmacological treatments, suggesting that further altered LV fascicular conduction might eliminate the reentry of verapamil-ILVT.

Electrophysiological and anatomical background of the fusion configuration of diastolic and presystolic Purkinje potentials in patients with verapamil-sensitive idiopathic left ventricular tachycardia

BackgroundIt is unclear whether false tendons (FTs) are a substantial part of the reentry circuit of verapamil-sensitive idiopathic left ventricular tachycardia (ILVT). This study aimed to prove the association between FTs and the slow conduction zone by evaluating the electro-anatomical relationship between the so-called diastolic Purkinje (Pd) potentials and FTs using an electro-anatomical mapping (EAM) system (CARTO). MethodsThe 1st protocol evaluated the spatial distribution of Pd and presystolic Purkinje (Pp) potentials in 6 IVLT patients using a conventional CARTO system. In the remaining 2 patients (2nd protocol), the electro-anatomical relationship between the Pd–Pp fusion potential and the septal connection of the FT was evaluated using an EAM system incorporating an intra-cardiac echo (CARTO-Sound). ResultsPd potentials were observed in the posterior–posteroseptal region of the LV and had a slow conduction property, whereas Pp potentials were widely distributed in the interventricular (IV) septum. At the intersection of the 2 regions, which was located in the mid-posteroseptal area, both Pd and Pp potentials were closely spaced and often had a fused configuration. In the latter 2 patients (2nd protocol), it was confirmed that the intra-cardiac points at which the Pd–Pp fusion potential was recorded were located in the vicinity of the attachment site of the FT to the IV septum. In all patients, ILVTs were successfully eliminated by the application of radiofrequency at those points. ConclusionFTs may at least partly contribute to the formation of the Pd potential, and thus form a critical part of the reentry circuit of ILVT.

Variations of electroanatomic substrates and markers of successful ablation in idiopathic left ventricular tachycardia: role of electroanatomic substrates and potential mechanism of tachycardia.

The variation of the substrates of verapamil-sensitive idiopathic left ventricular tachycardia (ILVT) was not understood. The purpose of this study was to investigate the variation of electroanatomic substrate [slow conduction zone (SCZ) and left ventricular conduction system (LVCS)] in ILVT and control individuals and markers of successful ablation. Electroanatomical mapping was performed during sinus rhythm in 20 ILVT patients and 26 control individuals with paroxysmal supraventricular tachycardia. LVCS and SCZ were tagged in geometry and the anatomic aspects were investigated. According to the distribution of Purkinje potential, LVCS was distinguished into three types: left bundle branch (LBB) was divided into two discrete fascicles without interconnections; divided into three separate fascicles; and fanlike structure distribution over septum broadly. The length of LBB and its fascicles in patients with ILVT were slightly longer than those of controls (P > 0.05). In the ILVT group, the SCZ was located at the inferoposterior septum in 17, inferior apical septum in one and two SCZs were located at the posterior and mid-septal in the other two patients, which were greater in size and longer in length than those of six controls (P < 0.05). At the crossover junction area with diastolic potential and Purkinje potential, with the size of 1.5 ± 0.4 cm(2), concealed entertainment and ablation were obtained successfully in all patients with ILVT. The anatomy of the LVCS and SCZ is highly variable in patients with ILVT, and the crossover junction area with diastolic potential and Purkinje potential might be a marker of ablation.

ASSA13-02-21 Variations of Left Ventricular Conduction System and Markers of Successful Ablation in Patients with Verapamil–Sensitive Idiopathic Left Ventricular Tachycardia

Objective The substrates of verapamil-sensitive idiopathic left ventricular tachycardia (ILVT) had been shown involving a slow conduction zone (SCZ) and posterior Purkinje network. However, the variation of these was not understood. The purpose was to investigate the variation of the left ventricular conduction system (LVCS) and markers of successful ablation. Methods Electroanatomical mapping was performed during sinus rhythm in 20 patients with ILVT and 20 control subjects with paroxysmal supraventricular tachycardia. LVCS and SCZ were tagged and the anatomic aspects of them were investigated. Results According to the distribution of Purkinje potential, LVCS was distinguished into 3 types: 1: left bundle branch was divided into two discrete fascicles without interconnections; 2: was divided into three separate fascicles; 3: fanlike structure distribution over septum broadly. The length of left bundle branch and its fascicles in ILVT patients were slight longer than those of controls (P > 0.05). SCZ was located at inferoposterior septum in 17 patients with ILVT and 4 controls. The size of SCZ in the ILVT group was remarkably greater (P = 0.007) than those of the control group. Two SCZs were located at posterior and mid-septal in 2 patients, and inferior apical septum in 1 patient. At the crossover junction area with diastolic potential and Purkinje potential, with the size of 1.5 ± 0.4cm 2 , concealed entertainment and/or ablation were obtained successfully in all patients with patients. Conclusions The anatomy of LVCS and SCZ is variable in human subjects in particular those with ILVT. These variabilities suggest that the electrophysiological mechanism of ILVT is complex. While exact mechanism of reentry of ILVT was not confirmed because of the lack of the activation electroanatomic mapping, the crossover junction area with Purkinje potential and diastolic potential might be a marker of radiofrequency ablation of ILVT.

The main trunk of the left bundle branch is not part of the re-entry circuit of verapamil-sensitive idiopathic left ventricular tachycardia

We report the case of a 19-year-old man with verapamil-sensitive idiopathic left ventricular tachycardia (ILVT), who had paroxysmal palpitations for 3 years. Programmed right atrial and ventricular stimulation easily induced ventricular tachycardia (VT) with QRS duration of 125ms, right bundle branch block pattern, and right inferior axis, which are characteristics of ILVT. Left ventricular endocardial mapping accidentally produced a complete left bundle branch block and provoked prolongation of the QRS duration of VT, which was 143ms. However, no changes occurred in the cycle length, inducibility, or maintenance of VT. The VT was eliminated successfully by catheter ablation at the pre-Purkinje potential (PP) recording site. These findings suggest that the main trunk of the left bundle branch is not a critical component of the re-entry circuit of ILVT.

Negative Participation of the Left Posterior Fascicle in the Reentry Circuit of Verapamil‐Sensitive Idiopathic Left Ventricular Tachycardia

Left posterior fascicle and idiopathic Left VT. The left posterior fascicle may be a bystander of the circuit of verapamil-sensitive idiopathic left ventricular tachycardia. During ventricular tachycardia (VT), 3 sequences of potentials were seen at the left posterior septum: diastolic Purkinje potentials propagating from base to apex and presystolic left posterior fascicular potentials and systolic left ventricular (LV) myocardial potentials propagating in the reverse direction. Selective capture of the left posterior fascicle by the sinus beat did not affect the VT cycle length. Entrainment pacing revealed that the retrograde limb of the circuit was not the left posterior fascicle, but the LV myocardium.

Characteristics of systolic and diastolic potentials recorded in the left interventricular septum in verapamil-sensitive left ventricular tachycardia

We studied the electrophysiological characteristics of systolic (SP) and diastolic (DP) potentials recorded during sinus rhythm (SR) in the left interventricular septum of a 27 year-old woman presenting with verapamil-sensitive idiopathic left ventricular tachycardia (VT). During SR, and during VT, SP was activated from ventricular base-to-apex, and DP from apex-to-base. SP and DP were both detected at the site of successful ablation during SR, whereas during VT, DP was detected away from the earliest activation site. Thus, SP apparently reflected a critical component of the reentrant circuit, while DP reflected the activation of a bystander pathway.

The characteristics of verapamil-sensitive idiopathic left ventricular tachycardia combined with a left accessory pathway and the effect of radiofrequency catheter ablation

Verapamil-sensitive idiopathic left ventricular tachycardia (ILVT) combined with a left accessory pathway (AP) is a relatively rare condition. This study examines the characteristics of patients with this condition and the effect of radiofrequency catheter ablation (RFCA). Catheter ablation was performed on 140 ILVT patients at a single centre from January 2004 to December 2009. A concealed left AP was found in seven patients (5%), all of whom were male, with an average age of 21 ± 9 years. Sustained ILVT and orthodromic atrioventricular reentrant tachycardia (AVRT) were induced in all seven patients. Retrograde activation through a bystander AP occurred concomitantly with ILVT, with an average tachycardia length of 346 ± 29 ms (range 310-400 ms). The location of the APs in four patients was left posterior, two of which showed a slow and decremental property, while in three it was left lateral. Ablation via a retrograde transaortic approach was performed in the seven patients. The left AP was ablated first in six patients, but ILVT was no longer induced in one and became non-sustained in another. In the seventh patient, ILVT was ablated first and this proved successful. Among patients with IVLT, 5% had a concomitant left AP, most of who were young men. The location of the left AP was mainly posterior and lateral, with 30% showing a slow and decremental property. Idiopathic left ventricular tachycardia and AP should be ablated simultaneously.

Ventricular Fibrillation Triggered during Radiofrequency Energy Delivery for Verapamil-Sensitive Idiopathic Left Ventricular Tachycardia

Verapamil-sensitive idiopathic left ventricular tachycardia (VT) can be suppressed by radiofrequency ablation (RF) on the Purkinje network. RF delivered on the Purkinje fibers triggers premature ventricular contractions or repetitive ventricular response and disappear after cessation of RF. We present a case with idiopathic left VT who represented ventricular fibrillation (VF) during RF on the Purkinje network. Case: A 15-year-old male admitted our hospital because of recurrent sustained VT with QRS morphology of right bundle branch block and left axis deviation. Intravenous verapamil terminated VT. However, electrophysiologic study could not induce VT even if isoproterenol infusion. We delivered RF energy at the distal left posterior fascicular region where Purkinje potentials were recorded during sinus rhythm with pace-mapping QRS morphology mimicking VT-QRS. Shortly after RF delivery, polymorphic VT induced and degenerated into VF. RF deliveries around the VF site induced similar responses. Then, we created RF lesions on the Purkinje fibers more proximal to the VF-induced sites. No VT was documented 3 years after ablation. Conclusion: Purkinje network appears to have potential role for VF induction. RF ablations at the proximal site of the critical Purkinje network can prevent VT/VF occurrence in such case.

Hormone Sensitive Idiopathic Ventricular Tachycardia Associated With Pregnancy: Successful Induction With Progesterone and Radiofrequency Ablation

Successful Induction With Progesterone and Radiofrequency Ablation. Verapamil-sensitive idiopathic left ventricular tachycardia in pregnancy is a rare diagnosis. We report a case of a primigravida female with new onset fascicular ventricular tachycardia that was managed with oral verapamil. Post pregnancy, the tachycardia was not inducible in the electrophysioplogy lab. Progesterone, a hormone associated with pregnant state, was used to successfully induce the tachycardia, which was ablated. This is the first reported case of an idiopathic ventricular tachycardia associated with pregnancy that could be induced later by recreating the hormonal milieu associated with pregnant state.

Electrophysiological behavior of systolic and diastolic potentials recorded during sinus rhythm in the left interventricular septum in a patient with verapamil-sensitive idiopathic left ventricular tachycardia

Electrophysiological behavior of systolic and diastolic potentials recorded during sinus rhythm in the left interventricular septum in a patient with verapamil-sensitive idiopathic left ventricular tachycardia

Left posterior fascicular block

Verapamil-sensitive, idiopathic left ventricular tachycardia (ILVT) with right bundle branch block configuration and left-axis deviation is known to be due to re-entry mechanism but the exact nature of reentrant circuit in ILVT is not fully elucidated. Radiofrequency (RF) ablation was applied during ventricular tachycardia (VT) and termination of the VT or abolishing the inducibility of the tachycardia was used as an endpoint for successful RF. In this study, the left posterior fascicular block in surface electrocardiogram (ECG) was used as a new endpoint of ablation to cure ILVT. Electrophysiological studies and radiofrequency ablation were performed in 39 consecutive patients [30 men, 9 women; age ranging from 10 to 64 years, mean (29 +/- 16) years] with verapamil-sensitive ILVT and structurally normal hearts. VT could be terminated by the intravenous administration of verapamil in all patients. The target site was the midseptum of LV where the earliest Purkinje potentials were recorded during VT. RF current was applied to the target site with or without late diastolic potential (LDP) during sinus rhythm in 37 patients and during VT in 2 patients to meet the ablation endpoint: the left posterior fascicular block in the surface ECG. Thirty-seven patients with ILVT had been treated by RF ablation during sinus rhythm and two had been treated during VT. All of them met the endpoint of the left posterior fascicular block. Thirty-eight cases were symptom-free without medications during the follow-up period (range from 3 to 95 months, median 17 months). One patient developed a clinical recurrence and the left posterior fascicular block in surface ECG disappeared. The patient received another treatment. The endpoint was met and the procedure was successful. The left posterior fascicular block in surface ECG used as an endpoint of RF ablation to treat ILVT is effective. It is important especially in those patients whose VT can not be induced or the inducible condition is unstable. The effective endpoint implied that the left posterior fascicle might be a critical part of the re-entrant circuit.

The mechanism of the cycle length and QRS alternans during verapamil-sensitive idiopathic left ventricular tachycardia

The mechanism of the cycle length and QRS alternans during verapamil-sensitive idiopathic left ventricular tachycardia

Resolution of Tachycardia-Induced Cardiomyopathy Following Ablation of Verapamil-Sensitive Idiopathic Left Ventricular Tachycardia

Few reports have described tachycardia-induced cardiomyopathy secondary to ventricular tachycardia. We present a 12-year-old boy with dilated cardiomyopathy and incessant verapamil-sensitive idiopathic left ventricular tachycardia. Twelve-lead electrocardiogram showed right bundle branch block QRS morphology with superior axis during tachycardia. Electrophysiology study confirmed the diagnosis, and radiofrequency ablation was done and successfully terminated and prevented induction of ventricular tachycardia. During the follow-up period of 18 months, the patient remained free of symptoms and arrhythmia. Three months after ablation, left ventricular ejection fraction improved and cardiac silhouette became normal on chest x-ray.

A case of verapamil-sensitive idiopathic left ventricular tachycardia with ventricular fibrillation induced by radiofrequency energy

A case of verapamil-sensitive idiopathic left ventricular tachycardia with ventricular fibrillation induced by radiofrequency energy

Verapamil-sensitive idiopathic left ventricular tachycardia in pregnancy

Verapamil-sensitive idiopathic left ventricular tachycardia is a rare diagnosis. A 31-year-old multiparous woman presented with shortness of breath, palpitations and new-onset, wide complex tachycardiaat approximately 28 weeks' gestation. Multiple antiarrhythmic agents were administered without resolution of the arrhythmia. Verapamil-sensitive idiopathic left ventricular tachycardia was diagnosed onthe basis of a fusion beat with a right bundle branch pattern, a pathognomonic finding, which was noted on an electrocardiogram. Verapamil resulted in conversion to normal sinus rhythm. The patient deliveredat term uneventfully. To our knowledge, this is the first description of verapamil-sensitive idiopathic left ventricular tachycardia in pregnancy. The case illustrates that the origin of wide complex tachyarrhythmiasshould be identified to provide the proper treatment expeditiously.

The Mechanisms of Tachyarrhythmias in Infants with Structurally Normal Heart

Background and Objectives:The mechanisms of supraventricular tachycardia (SVT in children are known to have age-dependent distributions. However, the distribution of the mechanisms of tachyarrhythmia, as a whole, is not known in infants and children. The aim of this study was to evaluate the mechanisms of tachyarrhythmia in infants with a structurally normal heart. Subjects and Methods:We retrospectively reviewed the mechanisms of tachycardia in 56 children with structurally normal hearts, who had had a tachyarrhythmia in infancy. The mechanisms of tachycardia were confirmed in surface electrocardiogram and by transesophageal, or trans- venous, electrophysiological study. Results:The majority of tachycardia during infancy were SVT, in 50 of the 56 (89%. In the infants with SVT, 29 (58% had atrioventricular reentrant tachycardia using an accessory pathway, With a manifested accessory pathway were in 13 of the 29. Primary atrial tachycardia was found in 19 (38%:a chaotic atrial tachycardia in 10, an atrial flutter in 5 and an atrial ectopic tachycardia in 4. 6 (11% had a ventricular tachycardia, and of these 5 had a verapamil-sensitive idiopathic left ventricular tachycardia. The most infrequent tachycardia during infancy was an atrioventricular nodal reentrant tachycardia, which occurred in only 2 (4%. 39% of the tachycardia during infancy occurred in the neonatal period. Atrioventricular nodal reentrant and ventricular tachycardia were not found during the neonatal period. Conclusion:The most frequent mechanism of tachycardia during infancy was SVT related, with an accessory pathway. Primary atrial and ventricular tachycardia were also found in nearly half the infants, and these were sometimes difficult to manage without understanding their precise mechanism. ( ( ( (Korean Circulation J 2002;32(12 :1085-1090

Effects of verapamil and lidocaine on two components of the re-entry circuit of verapamil-sensitive idiopathic left ventricular tachycardia

OBJECTIVESWe characterized pharmacologically the slow conduction zone of verapamil-sensitive idiopathic left ventricular tachycardia (ILVT) with regard to the late diastolic potential (LDP).BACKGROUNDWe showed that the slow conduction zone of ILVT could be divided into two components by LDP; that is, the distal component with a tachycardia-dependent conduction delay property and the proximal one without it.METHODSElectrophysiologic studies were performed in eight consecutive patients. The LDP was recorded during left ventricular (LV) mapping during ILVT. Entrainment was performed from the right ventricular outflow tract while recording LDP. The effects of lidocaine (1 mg/kg body weight) and verapamil (0.5 or 1.0 mg) were examined during entrainment.RESULTSThe LDPs preceding the Purkinje potential (PP) were serially recorded from the upper third to the middle of the LV septum along the narrow longitudinal line. The ventricular tachycardia (VT) cycle length increased after lidocaine (p < 0.05), and further after verapamil (p < 0.05). The increments in the VT cycle length after administration of the drugs strongly correlated with those in LDP-PP (r > 0.9 for both drugs). The interval from the ventricular potential to LDP was unchanged after administration of the drugs. In one patient, verapamil terminated VT by local conduction block between LDP and PP. The LDP-PP measured during entrainment increased after lidocaine, and further after verapamil, whereas the interval from the stimulus to LDP remained unchanged.CONCLUSIONSThe component distal to LDP is mainly calcium channel-dependent and partly depressed sodium channel-dependent. The proximal component is considered to be sodium channel-dependent (normal).