Nicola Trevisi

Left Mitral Isthmus Ablation Associated with PV Isolation: Long-Term Results of a Prospective Randomized Study

Background: The deployment of an ablation line connecting the left inferior PV to the mitral annulus (mitral isthmus line [MIL]) enhances the efficacy of pulmonary vein disconnection (PVD) in preventing atrial fibrillation (AF) recurrences.

Electrophysiological characteristics and outcome in patients with idiopathic right ventricular arrhythmia compared with arrhythmogenic right ventricular dysplasia

Background: Idiopathic right ventricular arrhythmias (IRVA) are responsive to medical and ablative treatment and have a benign prognosis. Arrhythmias caused by right ventricular dysplasia (ARVD) are refractory to treatment and may cause sudden death. It is difficult to distinguish between these two types of arrhythmia. Objective: To differentiate patients with IRVA and ARVD by a conventional electrophysiological study. Methods: 56 patients with a right ventricular arrhythmia were studied. They had no history or signs of any cardiac disease other than right ventricular dysplasia. They were classified as having IRVA (n = 41) or ARVD (n = 15) on the basis of family history, ECG characteristics, and various imaging techniques. They were further investigated by standard diagnostic electrophysiology. Results: The two groups were clearly distinguished by the electrophysiological study in the following ways: inducibility of ventricular tachycardia by programmed electrical stimulation with ventricular extrastimuli (IRVA 3% v ARVD 93%, p < 0.0001); presence of more than one ECG morphology during tachycardia (IRVA 0% v ARVD 73%, p < 0.0001); and fragmented diastolic potentials during ventricular arrhythmia (IRVA 0% v ARVD 93%, p < 0.0001). Data from the clinical follow up in these patients supported the diagnosis derived from the electrophysiological study. Conclusions: Patients with IRVA or ARVD can be distinguished by specific electrophysiological criteria. A diagnosis of ARVD can be made reliably on the basis of clinical presentation, imaging techniques, and an electrophysiological study.

Percutaneous cardiopulmonary support for catheter ablation of unstable ventricular arrhythmias in high-risk patients.

Background and Purpose:In patients with severe cardiomyopathy, recurrent episodes of nontolerated ventricular tachycardia (VT) or electrical storm (ES) frequently cause acute heart failure and cardiac death; the suppression of the arrhythmia is therefore lifesaving, but feasibility of catheter ablation (CA) is precluded by the adverse hemodynamic conditions together with the characteristics of the arrhythmia that interdicts efficacious mapping. The use of the percutaneous cardiopulmonary support (CPS) for circulatory assistance may allow patient’s stabilization and enhance efficacy and safety of CA in this emergency setting.Patients and Methods:19 patients (19 males; mean age 61 ± 6 years; chronic ischemic cardiomyopathy, eleven patients; primary dilated cardiomyopathy, six patients; arrhythmogenic right ventricular dysplasia/ cardiomyopathy, two patients) with recurrent nontolerated VT episodes undergoing CPS-assisted CA were retrospectively evaluated. Twelve patients had acute hemodynamic failure refractory to inotropic agents and ventilatory assistance, seven patients had undergone a failing nonconventional CA procedure. 14 patients presented with ES, and in twelve the procedure was undertaken under emergency conditions within 24 h from admission. Patients were ventilated under general anesthesia and assisted by a multidisciplinary team. The CPS system consisted in a Medtronic Bio-Medicus centrifugal pump and in a Maxima Plus oxygenator, a 15-F arterial cannula, and a 17-F venous cannula.Results:Flows between 2 and 3 l/min were activated after induction of 56/62 forms of nontolerated VT, achieving hemodynamic stabilization in all patients. CA was mainly guided by conventional activation mapping and was effective in abolishing 45/56 supported VTs; in 10/19 patients all clinical VTs were suppressed by CA. Mean procedural time was 4 h and 20 min. Complete stabilization was achieved in 13 patients (68%) without VT recurrence during a 7-day in-hospital monitoring. A significant clinical improvement was observed in two patients (11%); one patient (5%) with persistent VT episodes acutely died after heart transplant. At a mean follow-up of 42 months (range 15–60 months), 5/18 patients (28%) were free from VT recurrence, 7/18 (39%) had a clear clinical improvement with reduced implantable cardioverter defibrillator interventions. 5/14 patients (36%) had ES recurrence; among them, three died because of acute heart failure. No serious CPS-related complications were observed.Conclusion:The CPS warrants acceptable hemodynamic stabilization and efficacious mapping in highrisk patients undergoing CA for unstable VT in the emergency setting. Safety and efficacy of this technique translate into significant clinical improvement in the majority of patients. Even if only relatively invasive, CPS should be reserved to patients with ES or intractable arrhythmia causing acute heart failure; moreover, the need for an experienced team of multidisciplinary operators implies that its use is restricted to selected high-competency institutions.ZusammenfassungHintergrund und Fragestellung:Bei Patienten mit schwerer Kardiomyopathie verursachen rezidivierende Episoden nicht tolerierter ventrikulärer Tachykardie (VT) oder eines elektrischen Sturms (ES) häufig akutes Herzversagen und plötzlichen Herztod; die Suppression der Arrhythmie ist daher lebensrettend, jedoch stehen der Durchführbarkeit der Katheterablation (KA) ungünstige hämodynamische Verhältnisse sowie die Charakteristika der Arrhythmie, die ein effizientes Mapping verhindert, entgegen. Der Einsatz des perkutanen kardiopulmonalen Supports (KPS) zur Kreislaufunterstützung kann zur Stabilisierung des Patienten beitragen und die Effizienz und Sicherheit der KA in diesem Notfallszenario erhöhen.Patienten und Methodik:19 Patienten (19 Männer; Durchschnittsalter 61 ± 6 Jahre; chronische ischämische Kardiomyopathie, elf Patienten; primäre dilatative Kardiomyopathie, sechs Patienten; arrhythmogene rechtsventrikuläre Dysplasie/Kardiomyopathie, zwei Patienten) mit rezidivierenden nicht tolerierten VT-Episoden, die einer KPS-unterstützten KA unterzogen wurden, wurden retrospektiv evaluiert. Zwölf Patienten hatten ein akutes, gegenüber inotropen Agenzien und assistierter Beatmung refraktäres hämodynamisches Versagen. Sieben Patienten hatten sich einem frustranen nichtkonventionellen KA-Verfahren unterzogen. 14 Patienten hatten ES, und bei zwölf wurde das Verfahren innerhalb von 24 h nach der Aufnahme unter Notfallbedingungen durchgeführt. Die Patienten wurden unter Vollnarkose beatmet und von einem multidisziplinären Team unterstützt. Das KPS-System bestand aus einer Medtronic-Bio-Medicus-Zentrifugalpumpe und einem Maxima-Plus-Oxygenator, einer arteriellen Kanüle (15 F) und einer venösen Kanüle (17 F).Ergebnisse:Nach der Induktion von 56/62 Formen nicht tolerierter VT wurden Flussraten zwischen 2 und 3 l/min eingestellt, so dass bei allen Patienten eine hämodynamische Stabilisierung erreicht wurde. Die KA wurde hauptsächlich durch konventionelles Aktivierungsmapping geführt, und sie war effizient bei der Beseitigung von 45/56 VT mit KPS; bei 10/19 Patienten wurden alle klinischen VT durch KA supprimiert. Die mittlere Eingriffszeit betrug 4 h und 20 min. Bei 13 Patienten (68%) wurde eine völlige Stabilisierung ohne rezidivierende VT während einer 7-tägigen stationären Überwachung erreicht. Bei zwei Patienten (11%) wurde eine erhebliche klinische Verbesserung beobachtet; ein Patient (5%) mit persistierenden VT-Episoden verstarb akut nach einer Herztransplantation. Nach einem mittleren Beobachtungszeitraum von 42 Monaten (Range 15–60 Monate) waren 5/18 Patienten (28%) in Bezug auf die VT rezidivfrei und 7/18 (39%) zeigten eine deutliche klinische Verbesserung mit weniger ICD-Interventionen (implantierbarer Kardioverter-Defibrillator). 5/14 Patienten (36%) hatten ES-Rezidive; davon starben drei aufgrund von akutem Herzversagen. Es wurden keine schweren, mit dem KPS im Zusammenhang stehenden Komplikationen beobachtet.Schlussfolgerung:Der KPS garantiert eine akzeptable hämodynamische Stabilisierung und effizientes Mapping bei Hochrisikopatienten, die sich notfallmäßig aufgrund einer instabilen VT einer KA unterziehen. Die Sicherheit und Effizienz dieser Technik führen bei der Mehrheit der Patienten zu einer erheblichen klinischen Verbesserung. Selbst wenn der KPS nur relativ invasiv ist, sollte er beschränkt sein auf Patienten mit ES oder hartnäckiger Arrhythmie, die akutes Herzversagen verursacht. Ferner impliziert die Notwendigkeit eines erfahrenen multidisziplinären Teams einen limitierten Einsatz in ausgewählten Einrichtungen mit hoher Fachkompetenz.

Imaging and epicardial substrate ablation of ventricular tachycardia in patients late after myocarditis

AIMSnWe present clinical, electroanatomical mapping (EAM), imaging, and catheter ablation (CA) strategies in patients with myocarditis-related ventricular tachycardia (VT).nnnMETHODS AND RESULTSnBetween January 2010 and July 2012, 26 consecutive patients underwent imaging-guided CA of myocarditis-related ventricular arrhythmias, 23 of 26 using a combined endo-epicardial approach. Segment per segment correspondence of late enhanced (LE) scar localization with EAM scar was assessed in all patients with available uni/bipolar maps (n = 19). Induced VTs were targeted prior to substrate modification. Late potentials (LPs) abolition constituted a procedural endpoint independently from VT inducibility. Clinical monomorphic VT was induced in 15 of 26 patients (57.7%) and was associated with epicardial LPs in 10 of 15, completely abolished in 7 of 10 patients. Of the 10 patients rendered non-inducible VTs were ablated epicardially in 7. Late potentials were also detected in 7 of 11 initially non-inducible patients and completely abolished in 4. After a median follow-up of 23 (15-31) months, 20 of 26 patients (76.9%) remained free from VT recurrence. Bipolar mapping revealed low-voltage scar (<1.5 mV) in 1 patient endocardially and in 14 of 19 epicardially. Unipolar mapping revealed low-voltage scar (<8 mV) in 12 of 19 patients endocardially and in 18 of 19 epicardially. Correspondence of LE scar localization with endocardial bipolar scar was 1%, with endocardial unipolar scar 23.7%, with epicardial bipolar scar 39.8%, and with epicardial unipolar scar 66.2%.nnnCONCLUSIONnPre-procedural scar imaging and EAM findings support the necessity of an epicardial approach in patients with prior myocarditis. Epicardial unipolar mapping (<8 mV) is superior in scar identification and CA based on substrate modification is safe and effective in this setting.

A novel algorithm for determining endocardial VT exit site from 12-lead surface ECG characteristics in human, infarct-related ventricular tachycardia.

Introduction: Characteristics of the 12‐lead ECG during VT are used to guide initial placement of mapping catheters in endocardial ventricular tachycardia (VT) ablation. Previously constructed algorithms for guidance in human infarct‐related VT are limited to patients known to have anterior or inferior infarcts only. We hypothesized that 12‐lead ECG characteristics could be used to determine VT exit site in patients with all types of infarction of unknown location.

Radiofrequency catheter ablation guided by noncontact mapping of ventricular tachycardia originating from an idiopathic left ventricular aneurysm

Idiopathic left ventricular aneurysm and diverticulum is known to be an arrhythmogenic substrate associated to ventricular tachyarrhythmias, generally based on a reentry mechanism. A case of a young woman affected by a monomorphic ventricular tachycardia, refractory to medical treatment, originating from an aneurysm of the membranous interventricular septum is reported. The left ventricular aneurysm was well characterized by multislice computed tomography and left ventricular angiography. Because of the nonsustained and poorly tolerated nature of the target arrhythmia, a noncontact mapping system was used to guide radiofrequency catheter ablation, allowing the elaboration of a three-dimensional activation map of the left ventricle on the basis of a ventricular tachycardia single beat. The procedure was acutely successful, and the patient remained free of ventricular tachycardia recurrences without antiarrhythmic drugs during a subsequent 6-month follow-up period. This is the first report of a successful radiofrequency catheter ablation guided by noncontact mapping system of a ventricular tachycardia originating from an idiopathic left ventricular aneurysm. This nonfluoroscopic mapping method allows a reliable reconstruction of the spatial relationships between the left ventricular main cavity and the aneurysm and can be safely and effectively used to map the ventricular tachycardia and guide the ablation procedure, particularly when conventional mapping is not indicated or not effective because of nonsustained or not-tolerated characters of ventricular tachycardia.

Characterization of the arrhythmogenic substrate in patients with arrhythmogenic right ventricular cardiomyopathy undergoing ventricular tachycardia ablation

AimsnArrhythmogenic right ventricular (RV) cardiomyopathy (ARVC) is associated with ventricular arrhythmias, even without RV structural disease. We aimed to characterize the RV substrate using electroanatomical mapping and to define outcomes following ventricular tachycardia (VT) ablation in patients with and without RV structural abnormalities.nnnMethods and resultsnTwenty-nine patients with definite or suspected ARVC undergoing VT ablation were classified as electrical and structural cardiomyopathy based on the absence or presence of major structural criteria. Right ventricular (RV) endocardial and epicardial mapping with assessment of bipolar and unipolar voltages, distribution of late potentials (LPs), and inducible VT morphologies were performed. The endpoints for VT ablation were VT non-inducibility and LP abolition. Fourteen patients were categorized as electrical RV cardiomyopathy and 15 were categorized as structural RV cardiomyopathy. In patients with electrical cardiomyopathy, scar was limited to the epicardial surface (epicardium 13 cm2vs. endocardium 1 cm2, P < 0.05), primarily in the outflow tract, whereas patients with structural disease had greater involvement of the endocardium. During a mean follow-up of 22 ± 11 months, the VT recurrence rate was 27%, with LP abolition being a predictor of VT-free survival (HR 0.075 (0.008-0.661), P = 0.020). There was a trend towards higher recurrence rates in structural RV cardiomyopathy (40%) compared with the electrical cardiomyopathy (15%, P = 0.17).nnnConclusionnThe development of RV structural disease in patients with ARVC is associated with extensive epicardial and endocardial scar. Conversely those patients without RV structural disease have identifiable epicardial scar limited to the RV outflow tract. Ventricular tachycardia (VT) ablation in both groups targeting LP abolition is effective in preventing VT recurrence.

Catheter ablation of atrial fibrillation guided by a 3D electroanatomical mapping system: a 2-year follow-up study from the Italian Registry On NavX Atrial Fibrillation ablation procedures (IRON-AF)

AimsClinical trials have established that atrial fibrillation (AF) catheter ablation improves symptoms in appropriately selected patients. Confirmation of these results by long-term prospective observational studies is needed. This registry was created to describe the experience of 16 Italian centers with a large cohort of AF patients treated with catheter ablation guided by the NavX 3D mapping system.MethodsFrom November 2006 to May 2008, 545 consecutive patients (age 60.4u2009±u20099.8, 67xa0% male) with paroxysmal (44xa0%), persistent (43xa0%), and long-standing persistent (13xa0%) AF referred for catheter ablation guided by the NavX system, were included in this registry. For this paper, follow-up was censored at 24xa0months; however, patients are being followed in the ongoing registry.ResultsBefore the ablation, 80xa0% of patients failed to respond to at least one antiarrhythmic drug aimed at rhythm control. Pulmonary vein (PV) isolation guided by a circular mapping catheter was performed in 70xa0% of patients whereas non potential-guided PV encircling was performed in 30xa0% of patients. In 67xa0% of patients, additional left atrial (LA) substrate modification was performed. Image integration was performed in 9.2xa0% of patients. Considering a 3-month blanking period, after a single-ablation procedure, the patients had 1- and 2-year freedom from AF recurrence of 67.4 and 57.0xa0% (36.1xa0% off antiarrhythmic drugs), respectively. Cox regression analysis showed that AF recurrences during blanking (HR 2.1), and previous AF ablation (HR 3.3) were independent predictors of AF recurrences. Major procedure-related complications occurred in 53 patients (9.7xa0%). In 35 patients (6.7xa0%), a repeat procedure was performed at a median of 5xa0months after the initial procedure.ConclusionsThis prospective, multicenter clinical experience provides significant insights into current ablation care of patients with AF. Despite favorable outcomes, real-world complication rates appear higher than previously recognized.

Management of Ventricular Tachycardia in the Setting of a Dedicated Unit for the Treatment of Complex Ventricular Arrhythmias

Background— We investigated the impact of catheter ablation on ventricular tachycardia (VT) recurrence and survival in a large number of patients with structural heart disease treated in the setting of a dedicated multiskilled unit. Methods and Results— Since January 2007, we have implemented a multidisciplinary model, aiming for a comprehensive management of VT patients. Programmed ventricular stimulation was used to assess acute outcome. Primary end points were VT recurrence and the occurrence of cardiac and sudden cardiac death. Overall, 528 patients were treated by ablation (634 procedures; 1–4 procedures per patient). Among 482 tested with programmed ventricular stimulation after the last procedure, a class A result (noninducibility of any VT) was obtained in 371 patients (77%), class B (inducibility of nondocumented VT) in 12.4%, and class C (inducibility of index VT) in 10.6%. After a median follow-up time of 26 months, VT recurred in 164 (34.1%) of 472 patients. VT recurrence was documented in 28.6% of patients with a class A result versus 39.6% of patients with class B and 66.7% with class C result (log-rank P<0.001). The incidence of cardiac mortality was lower in class A patients than in those with class B and class C (8.4% versus 18.5% versus 22%, respectively; log-rank P=0.002). On the basis of multivariate analysis, postprocedural inducibility of index VT was independently associated both with VT recurrence (hazard ratio, 4.030; P<0.001) and with cardiac mortality (hazard ratio, 2.099; P=0.04). Conclusions— Within a dedicated VT unit, catheter ablation prevents long-term VT recurrences, which may favorably affect survival in a large number of patients who have VT.

Management of Ventricular Tachycardia in the Setting of a Dedicated Unit for the Treatment of Complex Ventricular ArrhythmiasClinical Perspective

Background— We investigated the impact of catheter ablation on ventricular tachycardia (VT) recurrence and survival in a large number of patients with structural heart disease treated in the setting of a dedicated multiskilled unit. Methods and Results— Since January 2007, we have implemented a multidisciplinary model, aiming for a comprehensive management of VT patients. Programmed ventricular stimulation was used to assess acute outcome. Primary end points were VT recurrence and the occurrence of cardiac and sudden cardiac death. Overall, 528 patients were treated by ablation (634 procedures; 1–4 procedures per patient). Among 482 tested with programmed ventricular stimulation after the last procedure, a class A result (noninducibility of any VT) was obtained in 371 patients (77%), class B (inducibility of nondocumented VT) in 12.4%, and class C (inducibility of index VT) in 10.6%. After a median follow-up time of 26 months, VT recurred in 164 (34.1%) of 472 patients. VT recurrence was documented in 28.6% of patients with a class A result versus 39.6% of patients with class B and 66.7% with class C result (log-rank P<0.001). The incidence of cardiac mortality was lower in class A patients than in those with class B and class C (8.4% versus 18.5% versus 22%, respectively; log-rank P=0.002). On the basis of multivariate analysis, postprocedural inducibility of index VT was independently associated both with VT recurrence (hazard ratio, 4.030; P<0.001) and with cardiac mortality (hazard ratio, 2.099; P=0.04). Conclusions— Within a dedicated VT unit, catheter ablation prevents long-term VT recurrences, which may favorably affect survival in a large number of patients who have VT.