The Experts below are selected from a list of 1899 Experts worldwide ranked by ideXlab platform
Jeremy N Ruskin - One of the best experts on this subject based on the ideXlab platform.
-
Endocardial, Intramural, and Epicardial Activation Patterns During Sustained Monomorphic Ventricular Tachycardia
2016Co-Authors: In Late, Hasan Garan, Canine Myocardial Infarction, John T. Fallon, Simon Rosenthal, Jeremy N RuskinAbstract:Thirteen dogs in whom at least one morphologically distinct sustained Ventricular Tachycardia (VT) could be reproducibly initiated by programmed cardiac stimulation 18 ± 3 days following experimen-tal myocardial infarction were placed on total cardiopulmonary bypass for detailed study of the endocardial and epicardial activation during VT under hemodynamically stable conditions. Thirteen morphologically distinct Monomorphic VTs were investigated by simultaneous epicardial, endocar-dial, and intramural bipolar recordings. Local electrograms were used to generate computer-assisted isochronous-activation sequence maps. A complete reentry circuit could be mapped on the epicardial surface in 4 animals and on the endocardial surface in one other animal. In the remaining 8 animals, there was a gap period lasting 43-62 msec in the cardiac cycle during which no endocardial or epicardial activity was observed. In 6 of the 8 animals, bipolar intramural recordings from sites closely associated with regions of endocardial and epicardial conduction block showed intramural activity progressing slowly during the gap period. In these 6 animals, a reentry circuit could be completed by incorporating the local electrograms recorded from the intramural sites. VT could be reproducibly terminated by selectively rendering only these intramural sites refractory by critically timed extra-stimuli that failed to result in global Ventricular capture. VT could be terminated by epicardial coolin
-
amiodarone is poorly effective for the acute termination of Ventricular Tachycardia
Annals of Emergency Medicine, 2006Co-Authors: Keith A Marill, Ian S Desouza, Daniel K Nishijima, Thomas O Stair, Gary S Setnik, Jeremy N RuskinAbstract:Study objective It is hypothesized that intravenous (IV) amiodarone is poorly effective for the acute termination of sustained Monomorphic Ventricular Tachycardia because of the relatively slow onset of its Vaughn-Williams class III effect to prolong myocardial depolarization and the refractory period. This study is designed to determine the effectiveness and safety of IV amiodarone for the termination of sustained Monomorphic Ventricular Tachycardia. Methods A retrospective case series was collected at 4 urban university-affiliated hospitals from September 1996 to April 2005 after institutional review board approval with waiver of informed consent. Emergency department (ED) patients treated with IV amiodarone for Ventricular Tachycardia were identified by ED treatment and hospital pharmacy billing records, International Classification of Diseases, Ninth Revision discharge codes, and ECG characteristics. All consecutive patients who received at least 150 mg amiodarone in 15 minutes or less for spontaneous sustained Monomorphic Ventricular Tachycardia were eligible for inclusion. Sustained Monomorphic Ventricular Tachycardia was defined as a Tachycardia with uninterrupted duration or rapid recurrence despite automatic internal cardiac defibrillator therapy for at least 5 minutes before amiodarone treatment, Monomorphic morphology, rate greater than 120 beats/min, QRS duration greater than 120 ms, and subsequently determined to be Ventricular Tachycardia by ECG criteria (eg, atrioVentricular dissociation), implanted device interrogation, or formal electrophysiology study. Measured outcomes included sustained termination of Ventricular Tachycardia within 20 minutes of initiation of amiodarone infusion and any documented adverse effects. Rates of successful termination and adverse effects and their 95% confidence intervals (CIs) were calculated. The presence or average values of potentially confounding predictors in patients with and without Ventricular Tachycardia termination after amiodarone were also calculated and compared. Results Thirty-three patients were identified and included. Five patients received electrical therapy within 20 minutes of initiation of amiodarone infusion, and the response to amiodarone was unknown. Twenty-seven of the remaining 28 patients received 150 mg amiodarone, and the rate of successful Ventricular Tachycardia termination was 8 of 28, 29% (95% CI 13 to 49). Two of 33 patients, 6% (95% CI 1 to 20), required direct current cardioversion for presyncope or hypotension temporally associated with amiodarone treatment. Conclusion IV amiodarone, as currently administered, is relatively safe but ineffective for the acute termination of sustained Ventricular Tachycardia.
-
mechanism of sustained Monomorphic Ventricular Tachycardia in systemic sclerosis
American Journal of Cardiology, 1999Co-Authors: Andrew C Rankin, Brian A Mcgovern, Jeremy N Ruskin, Stefan Osswald, Hasan GaranAbstract:Three patients with advanced systemic sclerosis and recurrent or incessant Monomorphic Ventricular Tachycardia underwent cardiac electrophysiologic studies. BiVentricular transcatheter mapping showed findings most compatible with a reentrant mechanism, which was effectively treated with transcatheter ablation.
-
reproducible induction of atypical torsades de pointes by programmed electrical stimulation a novel form of sotalol induced proarrhythmia
Journal of Cardiovascular Electrophysiology, 1997Co-Authors: Subramaniam C Krishnan, Joseph M Galvin, Brian A Mcgovern, Hasan Garan, Jeremy N RuskinAbstract:Sotalol-Induced Polymorphic VT. We present a patient with sotalol-induced polymorphic Ventricular Tachycardia that was seen only with programmed Ventricular stimulation. Electrophysiologic studies performed prior to initiation of sotalol therapy revealed inducible Monomorphic Ventricular Tachycardia. Possible underlying electrophysiologic mechanisms are discussed.
-
mechanisms underlying different surface ecg morphologies of recurrent Monomorphic Ventricular Tachycardia and their modification by procainamide
Journal of Cardiovascular Electrophysiology, 1997Co-Authors: Stefan Osswald, Jeremy N Ruskin, David J Wilber, Jiunnlee Lin, Hartley B Holden, Hasan GaranAbstract:ECG Pleomorphism of Ventricular Tachycardia. Introduction: Distinct surface ECG morphologies (ECGMs), from one episode to the next, of recurrent Monomorphic Ventricular Tachycardia (VT) in the same patient complicate endocardial catheter mapping and the success of ablative therapy. This study investigates the incidence and mechanisms of multiple ECGMs during recurrent Monomorphic VTs in a canine model of experimental myocardial infarction (MI). Methods and Results: Computerized ECG analysis and simultaneous endocardial and epicardial activation mapping with a 64 bipolar electrode array were used to analyze the relation between site of VT origin, local activation sequence, and surface ECGM in 72 VT episodes induced in 9 of 17 dogs with experimental MI. Pairwise comparisons of all VTs induced in the same animal were done in drug-free state (47 VTs) and after intravenous procainamide (25 VTs). In drug-free state, VT pairs with similar surface ECGMs manifested endocardial hreak-through sites (BSs) within a distance < 10 mm in 46 (100%) of 46 VT pairs compared to 43 (45%) of 95 VT pairs with different surface ECGMs (P < 0.0001). Of all 89 VT pairs with endocardial BSs within < 10 mm, similar endocardial activation patterns were found in 34 (74%) of 46 pairs with similar ECGMs in contrast to 6 (14%) of 43 pairs with different ECGMs (P < 0.001). Similar comparisons of VT pairs induced after intravenous procainamide administration showed that the endocardial BSs were located within < 10 mm in 9 (75%) of 12 VT pairs with similar and in 17 (49%) of 95 with different surface ECGMs, respectively (P = NS). Conclusions: In the same heart, similar surface ECGMs of recurrent VT are highly predictive of closely spaced endocardial BSs in drug-free state, hut not after procainamide administration. Nearly half of the VTs with different surface ECGMs still originate from closely spaced endocardial BSs but commonly manifest a change in the endocardial activation spread from this site. Thus, assumptions about different mechanisms and sites of VT origin based on dilTerent surface ECGMs should be made with caution.
Hasan Garan - One of the best experts on this subject based on the ideXlab platform.
-
Endocardial, Intramural, and Epicardial Activation Patterns During Sustained Monomorphic Ventricular Tachycardia
2016Co-Authors: In Late, Hasan Garan, Canine Myocardial Infarction, John T. Fallon, Simon Rosenthal, Jeremy N RuskinAbstract:Thirteen dogs in whom at least one morphologically distinct sustained Ventricular Tachycardia (VT) could be reproducibly initiated by programmed cardiac stimulation 18 ± 3 days following experimen-tal myocardial infarction were placed on total cardiopulmonary bypass for detailed study of the endocardial and epicardial activation during VT under hemodynamically stable conditions. Thirteen morphologically distinct Monomorphic VTs were investigated by simultaneous epicardial, endocar-dial, and intramural bipolar recordings. Local electrograms were used to generate computer-assisted isochronous-activation sequence maps. A complete reentry circuit could be mapped on the epicardial surface in 4 animals and on the endocardial surface in one other animal. In the remaining 8 animals, there was a gap period lasting 43-62 msec in the cardiac cycle during which no endocardial or epicardial activity was observed. In 6 of the 8 animals, bipolar intramural recordings from sites closely associated with regions of endocardial and epicardial conduction block showed intramural activity progressing slowly during the gap period. In these 6 animals, a reentry circuit could be completed by incorporating the local electrograms recorded from the intramural sites. VT could be reproducibly terminated by selectively rendering only these intramural sites refractory by critically timed extra-stimuli that failed to result in global Ventricular capture. VT could be terminated by epicardial coolin
-
mechanism of sustained Monomorphic Ventricular Tachycardia in systemic sclerosis
American Journal of Cardiology, 1999Co-Authors: Andrew C Rankin, Brian A Mcgovern, Jeremy N Ruskin, Stefan Osswald, Hasan GaranAbstract:Three patients with advanced systemic sclerosis and recurrent or incessant Monomorphic Ventricular Tachycardia underwent cardiac electrophysiologic studies. BiVentricular transcatheter mapping showed findings most compatible with a reentrant mechanism, which was effectively treated with transcatheter ablation.
-
reproducible induction of atypical torsades de pointes by programmed electrical stimulation a novel form of sotalol induced proarrhythmia
Journal of Cardiovascular Electrophysiology, 1997Co-Authors: Subramaniam C Krishnan, Joseph M Galvin, Brian A Mcgovern, Hasan Garan, Jeremy N RuskinAbstract:Sotalol-Induced Polymorphic VT. We present a patient with sotalol-induced polymorphic Ventricular Tachycardia that was seen only with programmed Ventricular stimulation. Electrophysiologic studies performed prior to initiation of sotalol therapy revealed inducible Monomorphic Ventricular Tachycardia. Possible underlying electrophysiologic mechanisms are discussed.
-
mechanisms underlying different surface ecg morphologies of recurrent Monomorphic Ventricular Tachycardia and their modification by procainamide
Journal of Cardiovascular Electrophysiology, 1997Co-Authors: Stefan Osswald, Jeremy N Ruskin, David J Wilber, Jiunnlee Lin, Hartley B Holden, Hasan GaranAbstract:ECG Pleomorphism of Ventricular Tachycardia. Introduction: Distinct surface ECG morphologies (ECGMs), from one episode to the next, of recurrent Monomorphic Ventricular Tachycardia (VT) in the same patient complicate endocardial catheter mapping and the success of ablative therapy. This study investigates the incidence and mechanisms of multiple ECGMs during recurrent Monomorphic VTs in a canine model of experimental myocardial infarction (MI). Methods and Results: Computerized ECG analysis and simultaneous endocardial and epicardial activation mapping with a 64 bipolar electrode array were used to analyze the relation between site of VT origin, local activation sequence, and surface ECGM in 72 VT episodes induced in 9 of 17 dogs with experimental MI. Pairwise comparisons of all VTs induced in the same animal were done in drug-free state (47 VTs) and after intravenous procainamide (25 VTs). In drug-free state, VT pairs with similar surface ECGMs manifested endocardial hreak-through sites (BSs) within a distance < 10 mm in 46 (100%) of 46 VT pairs compared to 43 (45%) of 95 VT pairs with different surface ECGMs (P < 0.0001). Of all 89 VT pairs with endocardial BSs within < 10 mm, similar endocardial activation patterns were found in 34 (74%) of 46 pairs with similar ECGMs in contrast to 6 (14%) of 43 pairs with different ECGMs (P < 0.001). Similar comparisons of VT pairs induced after intravenous procainamide administration showed that the endocardial BSs were located within < 10 mm in 9 (75%) of 12 VT pairs with similar and in 17 (49%) of 95 with different surface ECGMs, respectively (P = NS). Conclusions: In the same heart, similar surface ECGMs of recurrent VT are highly predictive of closely spaced endocardial BSs in drug-free state, hut not after procainamide administration. Nearly half of the VTs with different surface ECGMs still originate from closely spaced endocardial BSs but commonly manifest a change in the endocardial activation spread from this site. Thus, assumptions about different mechanisms and sites of VT origin based on dilTerent surface ECGMs should be made with caution.
-
analysis of the initiation of spontaneous Monomorphic Ventricular Tachycardia by stored intracardiac electrograms
Journal of the American College of Cardiology, 1994Co-Authors: Marc Roelke, Brian A Mcgovern, Hasan Garan, Jeremy N RuskinAbstract:Abstract Objectives. This study was designed to analyze stored intracardiac electrograms generated during spontaneous Monomorphic Ventricular Tachycardia to examine the possible mechanisms responsible for the initiation of Ventricular Tachycardia in a group of postinfarction patients. Background. Implantable cardioverter-defibrillators capable of storing electrograms during an arrhythmic event provide an intracardiac electrogram analog to Holter ambulatory electrocardiographic monitoring. Such electrograms are of value in arrhythmia diagnosis and in determining the appropriateness of implantable cardioverter-defibrillator therapy and may aid in understanding the initiation of Ventricular arrhythmias. Methods. We studied 73 stored electrograms in 22 postinfarction patients with spontaneous Monomorphic Ventricular Tachycardia. Premature depolarizations before Tachycardia were classified by morphology and number. Electrogram morphology was compared with the morphology of the baseline rhythm and Ventricular Tachycardia. Prematurity was assessed by the coupling interval and a calculated prematurity ratio. Results. During baseline rhythm, ectopic activity was present in 30 (41%) of 73 stored episodes. Ventricular Tachycardia was preceded by a short-long-short sequence in 14% of episodes and by a rapid Ventricular rhythm in 5.5% of episodes. The onset of Ventricular Tachycardia was marked by single premature depolarizations in 33 episodes (45%), by pairs in 16 (22%) and by multiple complexes in 24 (33%). Morphology was similar to that of the ensuing Tachycardia in 35 episodes (48%). The mean coupling interval was 364 ms, and the mean prematurity ratio was 0.56. In all 10 episodes (14%) where the prematurity ratio was Conclusions. In this select group of postinfarction patients with recurrent sustained Monomorphic Ventricular Tachycardia treated with implanteble cardioverter-defbrillators, Ventricular Tachycardia was most often preceded by late-coupled premature depolarizations. Not infrequently, a short-long-short sequence occurred before Tachycardia. Premature depolarizations with a morphology different from that of the Tachycardia occurred earlier in the cardiac cycle than did those with a morphology similar to that of the Tachycardia. These indings may reflect different mechanisms of Ventricular Tachycardia initiation.
William G. Stevenson - One of the best experts on this subject based on the ideXlab platform.
-
long term outcomes of combined epicardial and endocardial ablation of Monomorphic Ventricular Tachycardia related to hypertrophic cardiomyopathy
Circulation-arrhythmia and Electrophysiology, 2011Co-Authors: Srinivas R Dukkipati, William G. Stevenson, Kyoko Soejima, Francis E Marchlinski, Keiichi Inada, Andre Davila, Rupa Bala, Sheldon M Singh, Vivek Y ReddyAbstract:Background— Monomorphic Ventricular Tachycardia (MMVT) is rare in patients with hypertrophic cardiomyopathy (HCM). There are limited data on the utility of catheter ablation for the treatment of MMVT in this population. This study details a series of case reports from multiple centers where combined epicardial-endocardial ablation was performed in a highly selected group of patients with HCM-related MMVT. Methods and Results— The cohort consisted of 10 patients with HCM-related MMVT. Pericardial access was achieved using the percutaneous subxyphoid approach. Epicardial and endocardial Ventricular 3D bipolar voltage maps were generated. Ablation sites were identified using a combination of entrainment, activation, late/fractionated potential, and pace mapping. Electrophysiological-identified epicardial scar was present in 8 (80%) patients, endocardial scar in 6 (60%), and no scar in 1 (10%). In the 5 patients with inducible, stable MMVT, 3 cases were successfully terminated with ablation from the epicardium and 1 from the endocardium. The case that failed catheter ablation required surgical cryoablation to abolish the incessant VT. In the remaining 5 patients, 4 underwent epicardial and endocardial ablation of sites with good pace maps and late/fractionated potentials. No ablation was performed in the remaining patient because of noninducibility and lack of identifiable scar. After 37±17 months (limits, 2 to 62 months; median, 37 months), the freedom from recurrent implantable cardioverter-defibrillator shocks was 78% (7/9 patients) in those who underwent ablation. Conclusions— In highly selected patients with HCM, combined epicardial and endocardial mapping and ablation is a feasible and reasonably efficacious option for MMVT if refractory to aggressive trials of antiarrhythmic drugs and antiTachycardia pacing.
-
substrate characterization and catheter ablation for Monomorphic Ventricular Tachycardia in patients with apical hypertrophic cardiomyopathy
Journal of Cardiovascular Electrophysiology, 2011Co-Authors: Keiichi Inada, William G. Stevenson, Kurt C Robertsthomson, Jens Seiler, Daniel Steven, Jonathan Rosman, Roy M John, Piotr Sobieszczyk, Usha B TedrowAbstract:VT Ablation in Apical Hypertrophic Cardiomyopathy. Introduction: Monomorphic Ventricular Tachycardia (VT) is uncommon in apical hypertrophic cardiomyopathy (HCM). The purpose of this study was to define the substrate and role of catheter ablation for VT in apical HCM. Methods: Four patients with apical HCM and frequent, drug refractory VT (mean age of 46 ± 10 years, left Ventricular [LV] ejection fraction; 54 ± 14%) underwent catheter ablation with the use of electroanatomic mapping. Endocardial mapping was performed in 4 patients and 3 patients underwent epicardial mapping. Results: In 3 patients, VT was related to areas of scar in the apical LV where maximal apical wall thickness ranged from 14.5 to 17.8 mm, and 2 patients had apical aneurysms. Endocardial and epicardial substrate mapping revealed low voltage (<1.5 mV) scar in both endocardial and epicardial LV in 2 and only in the epicardium in 1 patient. Inducible VT was abolished with a combination of endocardial and epicardial ablation in 2 patients, but was ineffective in the third patient who had intramural reentry that required transcoronary ethanol ablation of an obtuse marginal vessel for abolition. The fourth patient had focal nonsustained repetitive VT from right Ventricular outflow tract (RVOT), consistent with idiopathic RVOT-VT, that was successfully ablated. During follow-ups of 3-9 months, all patients remained free from VT. Conclusion: Monomorphic VT in apical HCM can be due to endocardial, epicardial or intramural reentry in areas of apical scar. Epicardial ablation or transcoronary alcohol ablation is required in some cases. (J Cardiovasc Electrophysiol, Vol. 22, pp. 41-48, January 2011)
-
Catheter ablation of Monomorphic Ventricular Tachycardia.
Current opinion in cardiology, 2005Co-Authors: William G. StevensonAbstract:PURPOSE OF REVIEW Patients with Ventricular Tachycardia are subject to frequent recurrences and antiarrhythmic drug therapy has been disappointing. Catheter ablation offers an alternative means of controlling Ventricular Tachycardia. RECENT FINDINGS The origin and pathophysiology of Ventricular Tachycardia are being defined for newly recognized types of Ventricular Tachycardia as well as scar-related Ventricular Tachycardias. The approach to mapping and ablation of Ventricular Tachycardia depends on the nature of the arrhythmia substrate, which is largely determined by the underlying heart disease. Focal origin Ventricular Tachycardias often occur in patients without structural heart disease. The right Ventricular and left Ventricular outflow tracts are common locations. Ablation is usually successful unless the focus is epicardial in location or in close proximity to the ostia of a coronary artery. The reentry path for idiopathic left Ventricular reentrant Ventricular Tachycardia is now defined. In patients with heart disease, most Ventricular Tachycardias are scar related, with areas of fibrous tissue forming the border for reentry paths. Substrate mapping defines areas of scar, abnormal conduction, and reentry circuit exits during sinus rhythm. Ablation of multiple Ventricular Tachycardias and unstable Ventricular Tachycardias performed largely during sinus rhythm is often possible. Ablation is usually adjunctive therapy to an ICD in these patients. Epicardial mapping and ablation are needed in some patients. SUMMARY Ablation is a reasonable alternative to antiarrhythmic drug therapy for controlling frequent Ventricular Tachycardia episodes in many patients. Further technological advances can be anticipated.
-
mapping and radiofrequency catheter ablation of the three types of sustained Monomorphic Ventricular Tachycardia in nonischemic heart disease
Journal of Cardiovascular Electrophysiology, 2000Co-Authors: Etienne Delacretaz, William G. Stevenson, Kristin E Ellison, William H Maisel, Peter L FriedmanAbstract:Ventricular Tachycardia Ablation, Introduction. Sustained Monomorphic Ventricular Tachycardia (VT) associated with nonischemic cardiomyopathy (CMP) is uncommon. Optimal approaches to catheter mapping and ablation are not well characterized, but they are likely to depend on the VT mechanism. The purpose of this study was to evaluate the mechanisms of sustained Monomorphic VT encountered in nonischemic CMP and to assess the feasibility, safety, and efficacy of catheter radiofrequency ablation for treatment. Methods and Results: Twenty-six consecutive patients with nonischemic CMP referred for management of recurrent VT were studied. In 16 (62%) patients, VT was related to a region of abnormal electrograms consistent with scar and the response to pacing suggested a reentrant mechanism. In 5(19%) patients, VT was due to bundle branch or interfascicular reentry. In 7(27%) patients, the VT mechanism was focal automaticity, 4 of whom had evidence of Tachycardia-induced CMP. After catheter ablation targeting parts of reentrant circuits, VT was not inducible in 8 (53%) of 15 patients with scar-related reentry, was modified in 5(33%) patients, and still was inducible in 2(13%) patients. Ablation was successful in 5 of 5 patients with bundle branch reentry and in 6 of 7 patients with a focal automaticity mechanism. Overall, catheter ablation abolished clinical recurrence of VT in 20 (77%) of 26 patients during a follow-up of 15 ± 12 months. Conclusion: Three different mechanisms of VT are encountered in patients with nonischemic CMP. The mapping and ablation approach varies with the type of VT. In this selected population, the overall efficacy was 77%.
-
catheter ablation for hemodynamically unstable Monomorphic Ventricular Tachycardia
Journal of Cardiovascular Electrophysiology, 2000Co-Authors: Kristin E Ellison, William G. Stevenson, Etienne Delacretaz, Michael O Sweeney, David C Leeroy, Peter L FriedmanAbstract:Ablation of Unstable Ventricular Tachycardia. Introduction: Hemodynamic collapse precludes extensive catheter mapping to identify focal target regions in many patients with Ventricular Tachycardia (VT) associated with heart disease. This study tested the feasibility of catheter ablation of poorly tolerated VTs by targeting a region identified during sinus rhythm. Methods and Results: Ablation was attempted in five patients, ages 44 to 59 years, with left Ventricular ejection fractions of 0.15 to 0.20 and poorly tolerated VT causing multiple implantable defibrillator therapies (6 to 30 episodes/month). VT was due to prior infarction in three patients and nonischemic cardiomyopathy in two. Target regions were sought that met the following criteria: (1) evidence of slow conduction from fractionated sinus rhythm electrograms and stimulus-QRS delays during pace mapping, and (2) evidence that the region contains the reentrant circuit exit from pace mapping. In 4 of 5 patients, a target region was identified and radiofrequency lesions applied. Ablation abolished all recurrences of VT in 3 of 4 patients during follow-up of 14 to 22 months. There were no complications. Conclusion: Ablation of poorly tolerated VT is feasible in some patients by mapping during sinus rhythm and performing ablation over a region of identifiable scar that contains abnormal conduction and a presumptive VT exit.
Peter L Friedman - One of the best experts on this subject based on the ideXlab platform.
-
mapping and radiofrequency catheter ablation of the three types of sustained Monomorphic Ventricular Tachycardia in nonischemic heart disease
Journal of Cardiovascular Electrophysiology, 2000Co-Authors: Etienne Delacretaz, William G. Stevenson, Kristin E Ellison, William H Maisel, Peter L FriedmanAbstract:Ventricular Tachycardia Ablation, Introduction. Sustained Monomorphic Ventricular Tachycardia (VT) associated with nonischemic cardiomyopathy (CMP) is uncommon. Optimal approaches to catheter mapping and ablation are not well characterized, but they are likely to depend on the VT mechanism. The purpose of this study was to evaluate the mechanisms of sustained Monomorphic VT encountered in nonischemic CMP and to assess the feasibility, safety, and efficacy of catheter radiofrequency ablation for treatment. Methods and Results: Twenty-six consecutive patients with nonischemic CMP referred for management of recurrent VT were studied. In 16 (62%) patients, VT was related to a region of abnormal electrograms consistent with scar and the response to pacing suggested a reentrant mechanism. In 5(19%) patients, VT was due to bundle branch or interfascicular reentry. In 7(27%) patients, the VT mechanism was focal automaticity, 4 of whom had evidence of Tachycardia-induced CMP. After catheter ablation targeting parts of reentrant circuits, VT was not inducible in 8 (53%) of 15 patients with scar-related reentry, was modified in 5(33%) patients, and still was inducible in 2(13%) patients. Ablation was successful in 5 of 5 patients with bundle branch reentry and in 6 of 7 patients with a focal automaticity mechanism. Overall, catheter ablation abolished clinical recurrence of VT in 20 (77%) of 26 patients during a follow-up of 15 ± 12 months. Conclusion: Three different mechanisms of VT are encountered in patients with nonischemic CMP. The mapping and ablation approach varies with the type of VT. In this selected population, the overall efficacy was 77%.
-
catheter ablation for hemodynamically unstable Monomorphic Ventricular Tachycardia
Journal of Cardiovascular Electrophysiology, 2000Co-Authors: Kristin E Ellison, William G. Stevenson, Etienne Delacretaz, Michael O Sweeney, David C Leeroy, Peter L FriedmanAbstract:Ablation of Unstable Ventricular Tachycardia. Introduction: Hemodynamic collapse precludes extensive catheter mapping to identify focal target regions in many patients with Ventricular Tachycardia (VT) associated with heart disease. This study tested the feasibility of catheter ablation of poorly tolerated VTs by targeting a region identified during sinus rhythm. Methods and Results: Ablation was attempted in five patients, ages 44 to 59 years, with left Ventricular ejection fractions of 0.15 to 0.20 and poorly tolerated VT causing multiple implantable defibrillator therapies (6 to 30 episodes/month). VT was due to prior infarction in three patients and nonischemic cardiomyopathy in two. Target regions were sought that met the following criteria: (1) evidence of slow conduction from fractionated sinus rhythm electrograms and stimulus-QRS delays during pace mapping, and (2) evidence that the region contains the reentrant circuit exit from pace mapping. In 4 of 5 patients, a target region was identified and radiofrequency lesions applied. Ablation abolished all recurrences of VT in 3 of 4 patients during follow-up of 14 to 22 months. There were no complications. Conclusion: Ablation of poorly tolerated VT is feasible in some patients by mapping during sinus rhythm and performing ablation over a region of identifiable scar that contains abnormal conduction and a presumptive VT exit.
Hein J J Wellens - One of the best experts on this subject based on the ideXlab platform.
-
comparison of procainamide and lidocaine in terminating sustained Monomorphic Ventricular Tachycardia
American Journal of Cardiology, 1996Co-Authors: Anton P M Gorgels, Adri Van Den Dool, Anton Hofs, Rob G A Mulleneers, Joep L R M Smeets, Marc A Vos, Hein J J WellensAbstract:Efficacy of procainamide and lidocaine in terminating spontaneous Monomorphic Ventricular Tachycardia (VT) was assessed in a randomized parallel study. Patients with acute myocardial infarction and those with poor hemodynamic tolerance of VT were excluded. Procainamide 10 mg/kg was given intravenously with an injection speed of 100 mg/min, and lidocaine was administered at an intravenous dose of 1.5 mg/kg in 2 minutes. Fourteen patients were randomized to lidocaine and 15 to procainamide. Termination occurred in 3 of 14 patients after lidocaine and in 12 of 15 patients after procainamide (p <0.01). Procainamide stopped 8 of 11 VTs not responding to lidocaine, and lidocaine stopped 1 of 1 not responding to procainamde. Of a total of 41 VT episodes, 4 of 15 responded to lidocaine and 20 of 26 to procainamide (p <0.01). Because of VT recurrences, 16 patients could be studied repeatedly with drugs given in the reversed order. This resulted in a total of 55 trials of 79 drug injections. Lidocaine terminated 6 of 31 VTs and procainamide 38 of 48 (p <0.001). The protocol was stopped in 4 cases because of adverse effects. A comparison of the QRS width and QT interval before and at the end of the injection revealed significant lengthening of these values after procainamide but no change after lidocaine. In conclusion, procainamide is superior to lidocaine in terminating spontaneously occurring Monomorphic VT.
-
the electrocardiographic clinical and electrophysiologic spectrum of idiopathic Monomorphic Ventricular Tachycardia
American Heart Journal, 1992Co-Authors: Lluis Mont, Joep L R M Smeets, Tamer Seixas, Pedro Brugada, Josep Brugada, Frank Simonis, Edward Kriek, Hein J J WellensAbstract:Ventricular Tachycardia (VT) can occur in the structurally normal heart [1–30]. In patients with VT the arrhythmia has been classified ‘idiopathic’ or ‘primary electrical disease’. Two main types of idiopathic Monomorphic VT have been described in the literature. One shows a right bundle branch configuration and a left or superior axis [10, 11, 15–29], and an-other shows a left bundle block configuration during Tachycardia with a normal or right axis [1–14]. Tachycardias with a right bundle branch configuration and left or superior axis can very often be terminated with intravenously administered verapamil and are easily inducible by programmed stimulation [16, 19, 20, 22, 24, 28]. On the other hand, the second group of Tachycardias are the most common and seem to originate in the right Ventricular outflow tract or superior part of the interVentricular septum. They may be difficult to induce by programmed electrical stimulation and do not respond to calcium channel blockers [4, 7, 12, 13, 30]. To our knowledge, no attempts have been made to compare the clinical and electrophysiologic characteristics of both groups and to define the features of patients who have other QRS configurations of Monomorphic VT (left bundle branch block with a left or superior axis and right bundle branch block with a normal or inferior axis). The purpose of this study was to compare the clinical and electrophysiologic characteristics of four groups of patients with Monomorphic idiopathic VT as defined according to the ECG configuration.