Ventricular Tachycardia Group Research Articles

Efficacy and safety of focal pulsed-field ablation for ventricular arrhythmias: two-centre experience.

A pulsed electric field (PF) energy source is a novel potential option for catheter ablation of ventricular arrhythmias (VAs) as it can create deeper lesions, particularly in scarred tissue. However, very limited data exist on its efficacy and safety. This prospective observational study reports the initial experience with VA ablation using focal PF. The study population consisted of 44 patients (16 women, aged 61 ± 14years) with either frequent ventricular premature complexes (VPCs, 48%) or scar-related ventricular tachycardia (VT, 52%). Ablation was performed using an irrigated 4 mm tip catheter and a commercially available PF generator. On average, 16 ± 15 PF applications (25 A) were delivered per patient. Acute success was achieved in 84% of patients as assessed by elimination of VPC or reaching non-inducibility of VT. In three cases (7%), a transient conduction system block was observed during PF applications remotely from the septum. Root analysis revealed that this event was caused by current leakage from the proximal shaft electrodes in contact with the basal interventricular septum. Acute elimination of VPC was achieved in 81% patients and non-inducibility of VT in 83% patients. At the 3-month follow-up, persistent suppression of the VPC was confirmed on Holter monitoring in 81% patients. In the VT group, the mean follow-up was 116 ± 75 days and a total of 52% patients remained free of any VA. Pulsed electric field catheter ablation of a broad spectrum of VA is feasible with acute high efficacy; however, the short-term follow-up is less satisfactory for patients with scar-related VT.

Computed tomography as a predictive tool for ventricular tachycardia

Abstract Background Sudden cardiac death is the main cause of mortality worldwide. It is often linked with ventricular tachycardia (VT). To prevent VT, high-risk patients are typically equipped with intracardiac defibrillators (ICDs). Currently, left ventricular ejection fraction (LVEF) is the standard for determining a patient's risk level. Objective We hypothesized that the use of imaging software analyzing cardiac CT-scans could enhance the detection of patients with an increased risk of VT. Methods and Results In this study, 132 patients with ischemic cardiomyopathy (average age 66.2±11.4 years, with an average LVEF of 36.6±10.3%), all with implanted cardiac devices, underwent CT scans. We developed software to automatically analyze the heart's wall tissue thickness, cardiac fat, and calcification levels (Figure.1.A). A viable cardiac wall thickness of less than 3mm typically indicates a ventricular wall predominantly composed of scar tissue with minimal viable tissue remaining. In contrast, a viable wall thickness of less than 5mm includes regions with more viable tissue and therfore represents the total scar. Over an average follow-up of 6.6 years (79.8 ± 30.5 months) via live telemedicine, we observed that patients with VT had a significant difference in wall thickness ratio (3mm/5mm; no VT 0.31±0.18 vs, VT 0.44±0.18, p<0.01)) and higher calcification (0.10±0.38ml vs. 0.47±1.57ml, p=0.039). The amount of cardiac fat did not significantly differ between the no VT and VT groups (1.14±1.38ml vs.1.21±1.01ml, p=0.771). Logistic regression determined a critical cutoff for wall thickness at a ratio of 0.3 for 3mm and 5mm thickness. Kaplan Meyer analysis contrasted this wall thickness ratio of 0.3 (figure.1.B) against the established LVEF threshold of 35% (figure.1.C) for predicting VT-free survival, revealing a notable disparity favoring wall thickness ratio (p<0.01) over LVEF (p=0.77). Conclusions The findings suggest that a higher proportion of regions of thin viable tissue or dense scar in the total scar is a more effective predictor of VT-free survival than LVEF, potentially improving the identification of patients at risk for sudden cardiac death.Figure. 1

Intracardiac 3D navigation as a tool to improve the efficiency of ablation of idiopathic ventricular arrhythmias

Aim. Еvaluate the effect of 3D navigation on the effectiveness of ablation idiopathic ventricular arrhythmias. Materials and methods. The paper presents a retrospective postoperative analysis of 57 patients with idiopathic ventricular arrhythmias. Patients were divided into two groups. Group I included 30 (52.6 %) patients who used a 3D navigation system during mapping. Group II – 27 (47.4 %) patients in whom mapping was performed using classical methods. The effectiveness criteria were: frequency of acute suppression of arrhythmia, number of radiofrequency applications for suppression, and time of intervention. Results. Intraoperatively, complete suppression of the arrhythmia was successfully achieved in all cases in both groups. In group I average number of applications in patients with ventricular extrasystole was 5.5 (4.0; 8.0), while in group II – 6.5 (3,5; 9.0), without statistically significant difference (p = 0.414). A similar situation was observed with ventricular tachycardia. Іn group I number of applications was 3.2 (3.0; 4.3), and in group II – 5.0 (2.3; 11.0), which also had no statistically significant difference (р = 0.537). The duration of intervention for ventricular extrasystole in group I was 100.6 ± 26.6 min, while in group II – 136.4 ± 42.2 min, that has statistically significant difference (p = 0.007). During ablation of ventricular tachycardia in group I average duration was 89.3 ± 20.4 min, while in group II – 135.4 ± 55.5 min. The duration of intervention for ventricular tachycardia with the use of 3D navigation had a significantly shorter time compared to classical methods (p = 0.024). Conclusions. Based on the obtained data, we concluded that the use of 3D navigation significantly reduced the intervention time, regardless of the localization and type of arrhythmia. At the same time, no significant difference was found in the frequency of acute arrhythmia suppression and the number of applications to achieve the effect between the studied groups.

Worldwide Experience With an Irrigated Needle Catheter for Ablation of Refractory Ventricular Arrhythmias: Final Report

BackgroundWe previously reported feasibility of irrigated needle ablation (INA) with a retractable 27-G end-hole needle catheter to treat nonendocardial ventricular arrhythmia substrate, an important cause of ablation failure. ObjectivesThe purpose of this study was to report outcomes and complications in our entire INA-treated population. MethodsPatients with recurrent sustained monomorphic ventricular tachycardia (VT) or high-density premature ventricular contractions (PVCs) despite radiofrequency ablation were prospectively enrolled at 4 centers. Endpoints included a 70% decrease in VT frequency or PVC burden decrease to <5,000/24 h at 6 months. ResultsINA was performed in 111 patients (median: 2 failed prior ablations, 71% nonischemic heart disease, and left ventricular ejection fraction 36% ± 14%). INA acutely abolished targeted PVCs in 33 of 37 patients (89%), and PVCs were reduced to <5,000/day in 29 patients (78%). During 6-month follow-up, freedom from hospitalization was observed in 50 of 72 patients with VT (69%), and improvement or abolition of VT occurred in 47%. All patients received multiple INA applications, with more in the VT group than in the PVC group (median: 12 [IQR: 7-19] vs 7 [5-15]; P < 0.01). After INA, additional endocardial standard radiofrequency ablation was required in 23% of patients. Adverse events included 4 pericardial effusions (3.5%), 3 cases of (anticipated) atrioventricular block (2.6%), and 3 heart failure exacerbations (2.6%). During 6-month follow-up, 5 deaths occurred; none were procedure-related. ConclusionsINA achieves improved arrhythmia control in 78% of patients with PVCs and avoids hospitalization in 69% of patients with VT refractory to standard ablation at 6-month follow-up. Procedural risks are acceptable. (Intramural Needle Ablation for Ablation of Recurrent Ventricular Tachycardia, NCT01791543; Intramural Needle Ablation for the Treatment of Refractory Ventricular Arrhythmias, NCT03204981)

Dysrhythmic profile of drugs with a positive inotropic effect in patients with acute coronary syndrome

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Patients with acute coronary syndrome (ACS) may develop ventricular dysfunction and need to use drugs with a positive inotropic effect during the acute phase. Despite the hemodynamic benefit of the use of these drugs, positive inotropic drugs may have several side effects. Among these, ventricular arrhythmias and atrial fibrillation. Levosimendan is a drug that increases the sensitivity of the myocardium to calcium, producing a positive inotropic effect. Purpose This study aims to assess the frequency of occurrence of dysrhythmic complications with the use of positive inotropic drugs in patients hospitalized for ACS. Methods We performed a 6-year retrospective, observational, multicenter study. We included patients with ACS who used positive or not inotropic drugs during hospitalization, dividing the sample into two groups respectively (Group 1 and Group 2). Between the two groups we compared the occurrence of ventricular tachycardia and atrial fibrillation. In addition, we performed an analysis for the use of levosimendan. Results We analyzed a sample of 5860 patients. Of these, 70.3% were male. In Group 1 we included 377 patients and in Group 2 5329 patients. The occurrence of ventricular tachycardia in Group 1 was higher than in Group 2 (15.5% vs 1.6%; p&amp;lt;0.001; OR: 11.472; 95% CI [8.212;16.027]). The rate of occurrence of atrial fibrillation in Group 1 was higher than in Group 2 (19.3% vs 5.1%; p&amp;lt;0.001; OR:4.413; 95% CI [3.388;5.749]). Regarding the use of levosimendan, 50 patients were analyzed. Ventricular tachycardia was more frequent with the use of this drug than without it (18.0% vs 2.5%; p&amp;lt;0.001; OR: 8.576 95% CI [4.092;17.976]). Atrial fibrillation was more frequent with levosimendan use than with no use (34.0% vs 6.0%; p&amp;gt;0.001; OR: 8.137; 95% CI [4.487;14.754]). Conclusion Arrhythmic complications were much more frequent in the group that used positive inotropic drugs, namely ventricular tachycardia and atrial fibrillation. Levosimendan stands out, related to the increase in the occurrence of atrial fibrillation and the remaining inotropes with an increased risk of ventricular tachycardia. These arrhythmic complications pose a challenge in the management of these patients.

Evaluation of premature ventricular complexes during in-hospital ECG monitoring as a predictor of ventricular tachycardia in an intensive care unit cohort.

In-hospital electrocardiographic (ECG) monitors are typically configured to alarm for premature ventricular complexes (PVCs) due to the potential association of PVCs with ventricular tachycardia (VT). However, no contemporary hospital-based studies have examined the association of PVCs with VT. Hence, the benefit of PVC monitoring in hospitalized patients is largely unknown. This secondary analysis used a large PVC alarm data set to determine whether PVCs identified during continuous ECG monitoring were associated with VT, in-hospital cardiac arrest (IHCA), and/or death in a cohort of adult intensive care unit patients. Six PVC types were examined (i.e., isolated, bigeminy, trigeminy, couplets, R-on-T, and run PVCs) and were compared between patients with and without VT, IHCA, and/or death. Of 445 patients, 48 (10.8%) had VT; 11 (2.5%) had IHCA; and 49 (11%) died. Isolated and run PVC counts were higher in the VT group (p = 0.03 both), but group differences were not seen for the other four PVC types. The regression models showed no significant associations between any of the six PVC types and VT or death, although confidence intervals were wide. Due to thesmall number of cases, we were unable to test for associations between PVCs and IHCA. Our findings suggest that we should question the clinical relevance of activating PVC alarms as a forewarning of VT, and more work should be done with larger sample sizes. A more precise characterization of clinically relevant PVCs that might be associated with VT is warranted.

Ventricular arrhythmias in patients with prior aortic valve intervention: Characteristics, ablation and outcomes.

Data regarding ventricular tachycardia (VT) or premature ventricular complex (PVC) ablation in patients with aortic valve (AV) intervention (AVI) is limited. Catheter ablation (CA) can be challenging given perivalvular substrate in the setting of prosthetic valves. We sought to investigate the characteristics, safety, and outcomes of CA in patients with prior AVI and ventricular arrhythmias (VA). We identified consecutive patients with prior AVI (replacement or repair) who underwent CA for VT or PVC between 2013 and 2018. We investigated the mechanism of arrhythmia, ablation approach, perioperative complications, and outcomes. We included 34 patients (88% men, mean age 64 ± 10.4 years, left ventricular (LV) ejection fraction 35.2 ± 15.0%) with prior AVI who underwent CA (22 VT; 12 PVC). LV access was obtained through trans-septal approach in all patients except one patient who had percutaneous transapical access. One patient had combined retrograde aortic and trans-septal approach. Scar-related reentry was the dominant mechanism of induced VTs. Two patients had bundle branch reentry VTs. In the VT group, substrate mapping demonstrated heterogeneous scar that involved the peri-AV area in 95%. Despite that, the site of successful ablation included the periaortic region only in 6 (27%) patients. In the PVC group, signal abnormalities consistent with scar in the periaortic area were noted in 4 (33%) patients. In 8 (67%) patients, the successful site of ablation was unrelated to the periaortic area. No procedure-related complications occurred. The survival and recurrence-free survival rate at 1 year tended to be lower in VT group than in PVC group (p = .06 and p = .05, respectively) with a 1-year recurrence-free survival rate of 52.8% and 91.7%, respectively. No arrhythmia-related death was documented on long-term follow-up. CA of VAs can be performed safely and effectively in patients with prior AVI.

Modulation of post-pacing action potential duration and contractile responses on ventricular arrhythmogenesis in chloroquine-induced long QT syndrome

BackgroundExcitation-contraction (E-C) coupling, the interaction of action potential duration (APD) and contractility, plays an essential role in arrhythmogenesis. We aimed to investigate the arrhythmogenic role of E-C coupling in the right ventricular outflow tract (RVOT) in the chloroquine-induced long QT syndrome. MethodsConventional microelectrodes were used to record electrical and mechanical activity simultaneously under electrical pacing (cycle lengths from 1000–100 ms) in rabbit RVOT tissue preparations before and after chloroquine with and without azithromycin. KB-R7943 (a Na+-Ca2+ exchanger [NCX] inhibitor), ranolazine (a late sodium current inhibitor), or MgSO4 were used to assess their pharmacological responses in the chloroquine-induced long QT syndrome. ResultsSequential infusion of chloroquine and chloroquine plus azithromycin triggered ventricular tachycardia (VT) (33.7%) after rapid pacing compared to baseline (6.7%, p = 0.004). There were greater post-pacing increases of the first occurrence of contractility (ΔContractility) in the VT group (VT vs. non-VT: 521.2 ± 50.5% vs. 306.5 ± 26.8%, p < 0.001). There was no difference in the first occurrence of action potential at 90% repolarization (ΔAPD90) (VT vs. non-VT: 49.7 ± 7.4 ms vs. 51.8 ± 13.1 ms, p = 0.914). Pacing-induced VT could be suppressed to baseline levels by KB-R7943 or MgSO4. Ranolazine did not suppress pacing-induced VT in chloroquine-treated RVOT. ΔContractility was reduced by KB-R7943 and MgSO4, but not by ranolazine. ConclusionΔContractility (but not ΔAPD) played a crucial role in the genesis of pacing-induced VT in the long QT tissue model, which can be modulated by NCX (but not late sodium current) inhibition or MgSO4.

Rapid ventricular tachycardia in patients with tetralogy of Fallot and implantable cardioverter-defibrillator: Insights from the DAI-T4F nationwide registry

In repaired tetralogy of Fallot (TOF), little is known about characteristics of patients with rapid ventricular tachycardia (VT). Also, whether patients with a first episode of nonrapid VT may subsequently develop rapid VT or ventricular fibrillation (VF) has not been addressed. The objectives of this study were to compare patients with rapid VT/VF with those with nonrapid VT and to assess the evolution of VT cycle lengths (VTCLs) overtime. Data were analyzed from a nationwide registry including all patients with TOF and implantable cardioverter-defibrillator (ICD) since 2000. Patients with ≥1 VT episode with VTCL ≤250 ms (240 beats/min) formed the rapid VT/VF group. Of 144 patients (mean age 42.0 ± 12.7 years; 104 [72%] men), 61 (42%) had at least 1 VT/VF episode, including 28 patients with rapid VT/VF (46%), during a median follow-up of 6.3 years (interquartile range 2.2-10.3 years). Compared with patients in the nonrapid VT group, those in the rapid VT/VF group were significantly younger at ICD implantation (35.2 ± 12.6 years vs 41.5 ± 11.2 years; P = .04), had more frequently a history of cardiac arrest (8 [29%] vs 2 [6%]; P = .02), less frequently a history of atrial arrhythmia (11 [42%] vs 22 [69%]; P = .004), and higher right ventricularejection fraction (43.3% ± 10.3% vs 36.6% ± 11.2%; P = .04). The median VTCL of VT/VF episodes was 325 ms (interquartile range 235-429 ms). None of the patients with a first documented nonrapid VT episode had rapid VT/VF during follow-up. Patients with TOF and rapid VT/VF had distinct clinical characteristics. The relatively low variation of VTCL over time suggests a room for catheter ablation without a backup ICD in selected patients with well-tolerated VT.

Frequency of Arrhythmias and Postural Orthostatic Tachycardia Syndrome in Patients With Marfan Syndrome: A Nationwide Inpatient Study.

BackgroundMarfan syndrome (MFS) is an autosomal dominant connective tissue disorder affecting multiple systems, particularly the cardiovascular system. The leading causes of death in MFS are aortopathies and valvular disease. We wanted to identify the frequency of arrhythmia and postural orthostatic tachycardia syndrome, length of hospital stay, health care–associated costs (HAC), and in‐hospital mortality in patients with MFS.Methods and ResultsThe National Inpatient Sample database from 2005 to 2014 was queried using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD‐9‐CM) codes for MFS and arrhythmias. Patients were classified into subgroups: supraventricular tachycardia, ventricular tachycardia (VT), atrial fibrillation, atrial flutter, and without any type of arrhythmia. Data about length of stay, HAC, and in‐hospital mortality were also abstracted from National Inpatient Sample database. Adjusted HAC was calculated as multiplying HAC and cost‐to‐charge ratio; 12 079 MFS hospitalizations were identified; 1893 patients (15.7%) had an arrhythmia; and 4.9% of the patients had postural orthostatic tachycardia syndrome. Median values of length of stay and adjusted HAC in VT group were the highest among the groups (VT: 6 days, $18 975.8; supraventricular tachycardia: 4 days, $11 906.6; atrial flutter: 4 days, $11 274.5; atrial fibrillation: 5 days, $10431.4; without any type of arrhythmia: 4 days, $8336.6; both P=0.0001). VT group had highest in‐patient mortality (VT: 5.3%, atrial fibrillation: 4.1%, without any type of arrhythmia: 2.1%, atrial flutter: 1.7%, supraventricular tachycardia: 0%; P<0.0001) even after adjustment for potential confounders (without any type of arrhythmia versus VT; odds ratio [95% CI]: 3.18 [1.62–6.24], P=0.001).ConclusionsArrhythmias and postural orthostatic tachycardia syndrome in MFS were high and associated with increased length of stay, HAC, and in‐hospital mortality especially in patients with VT.

Coagulation Response and Prothrombotic Effect of Uninterrupted Oral Anticoagulant Administration AfterCatheter Ablation for VT.

Catheter ablation for ventricular tachycardia (VT) is associated with perioperative thromboembolic risk. However, the strategy for postprocedural management remains unknown. The aim of this study was to evaluate the prothrombotic response after VT ablation in various coagulation biomarkers in patients with and without the administration of oral anticoagulation (OAC). Data from 112 patients (58 with uninterrupted OAC and 54 without) with structural heart disease who underwent endocardial VT ablation were retrospectively analyzed. We also included 41 patients who underwent ablation for premature ventricular contraction from the right ventricle and 13 patients who underwent electrophysiology study (the control group). Blood samples of coagulation markers were collected before and 3days after the procedure in all patients. The percentage of D-dimer levels≤1.0μg/mL at baseline was lower in the VT ablation groups (76% and 50% in the OAC and non-OAC groups, respectively) than in the other groups (100%). After 3days, the percentage remained at 67% in the OAC group; however, the non-OAC VT group demonstrated a remarkable decrease of 20%. Similarly, fibrin monomer complex, thrombin antithrombin, and prothrombin fragment 1+2 levels were well suppressed in the control, premature ventricular contraction, and OAC groups. However, the non-OAC group demonstrated increased coagulation markers both before and after 3days. Multivariate analysis demonstrated that OAC administration and normal coagulation markers at baseline were independent predictors of stable coagulation status after ablation. The coagulation cascade was significantly activated in patients undergoing VT ablation. Uninterrupted OAC administration suppressed the coagulation response, which might be associated with a reduction in perioperative prothrombotic risk.

Abstract 155: Gender Differences In Patients With Ventricular Arrhythmias Undergoing Catheter Ablation

Significant differences in the clinical presentation and outcomes of cardiovascular diseases in men and woman have been described in the last few decades, including in management of cardiac arrhythmias. Recently, catheter ablation for ventricular arrhythmia (VA) has been shown to be highly effective at reducing ventricular tachycardia (VT) and premature ventricular contractions (PVC) burden, including reduction of VA episodes. Much of the published data has identified risk factors for VA recurrence, such as low LVEF, but have not included enough women for meaningful comparison of gender-based differences. The goal of this study was to examine gender differences in patients with ventricular arrhythmias who have undergone VA ablation. We conducted a retrospective analysis on a cohort of 115 patients receiving VA ablation at a tertiary hospital (54 pts for VT and 63 pts for PVC, 76 males and 39 females) to identify gender differences in patient characteristics at time of ablation. In the total group, there were 76 (66.1% males and 39 (33.9%) females, mean age - 59.6 +14.8 years; av. LVEF = 46.6% + 13.63%). Females were younger (52.2 vs 63.9 years) and had higher LVEF (53.7% vs 43.1%) as compared to men. History of pre-procedure ICD, ischemic heart disease and procedures, such as CABG or stent placement, were higher in men. Also, more males were diagnosed with hypertension and dyslipidemia. VT patients had lower LVEF and a higher proportion of males with worse pre-procedure characteristics than PVC patients. Hypertension and older age were observed among males in both PVC and VT groups. Overall, study results show female patients had less severe comorbidities, younger age and better LVEF. These findings can reflect differences in VA ablation outcomes as well as the selection of treatments for patients with VA.

Characteristics and outcomes of ventricular tachycardia and premature ventricular contractions ablation in patients with prior mitral valve surgery.

Data regarding ventricular tachycardia (VT) or premature ventricular complex (PVC) ablation following mitral valve surgery (MVS) is limited. Catheter ablation (CA) can be challenging given perivalvular substrate in the setting of mitral annuloplasty or prosthetic valves. To investigate the characteristics, safety, and outcomes of radiofrequency CA in patients with prior MVS and ventricular arrhythmias (VA). We identified consecutive patients with prior MVS who underwent CA for VT or PVC between January 2013 and December 2018. We investigated the mechanism of arrhythmia, ablation approach, peri-operative complications, and outcomes. In our cohort, 31 patients (77% men, mean age 62.3 ± 10.8 years, left ventricular ejection fraction 39.2 ± 13.9%) with prior MVS underwent CA (16 VT; 15 PVC). Access to the left ventricle was via transseptal approach in 17 patients, and a retrograde aortic approach was used in 13 patients. A combined transseptal and retrograde aortic approach was used in one patient, and a percutaneous epicardial approach was combined with trans-septal approach in one patient. Heterogenous scar regions were present in 94% of VT patients and scar-related reentry was the dominant mechanism of VT. Forty-seven percent of PVC patients had abnormal substrate at the site targeted for ablation. Clinical VA substrates involved the peri-mitral area in six patients with VT and five patients with PVC ablation. No procedure-related complications were reported. The overall recurrence-free rate at 1-year was 72.2%; 67% in the VT group and 78% in the PVC group. No arrhythmia-related death was documented on long-term follow-up. CA of VAs can be performed safely and effectively in patients with MVS.

Prediction of Serious Adverse Events of Patients with Hypertrophic Cardiomyopathy by Magnetic Resonance.

Although it is well known that patients with hypertrophic cardiomyopathy (HCM) have serious adverse events, such as life-threatening arrhythmia and heart failure, the prediction of such evens is still difficult. Recently, it has been reported that one of the causes of these serious adverse events is microvascular dysfunction, which can be noninvasively evaluated by employing cardiac magnetic resonance (CMR) imaging.We analyzed 32 consecutive HCM patients via CMR imaging and myocardial scintigraphy and divided them into two groups: ventricular tachycardia (VT) group and non-VT group. Myocardial perfusion studies were conducted quantitatively using the QMass® software, and each slice image was divided into six segments. The time-intensity curve derived from the perfusion image by CMR imaging was evaluated, and the time to 50% of the peak intensity (time 50% max) was automatically calculated for each segment.Although no difference was observed in various parameters of myocardial scintigraphy between the two groups, the VT group exhibited a higher mean of time 50% max and wider standard deviation (SD) of time 50% max in each segment than the non-VT group. The cutoff values were obtained by the receiver operating characteristic curves derived from the mean of time 50% max and SD of time 50% max. The two groups divided by the cutoff values exhibited significant differences in the occurrence of serious adverse events.CMR imaging may be useful for predicting serious adverse events of patients with HCM.

Clinical Presentation of Sustained Monomorphic Ventricular Tachycardia Without Cardiac Arrest.

Background“Palpitations” are one of the most common complaints prompting medical attention. Textbooks of medicine and cardiology as well as guideline documents and position papers describe palpitations as a common symptom of ventricular tachycardia (VT). However, data to support this description are lacking. The aim of our study was to evaluate the symptomatology of sustained monomorphic VT with emphasis on the prevalence of palpitations.Methods and ResultsConsecutive patients presenting to our center with a first event of a regular sustained monomorphic VT (n=59) or a regular supraventricular tachycardia (SVT; n=109) between January 2012 and September 2019 were interviewed regarding their symptoms during the arrhythmic event. We included only patients with a first arrhythmic event to avoid the influence of previous medical encounters on our patients’ terminology. As expected, patients with VT were older (age 68.8±13.6 versus 52.6±16.8 years; P<0.001), more often of male sex (94.9% versus 37.6%; P<0.001), had lower left ventricular ejection fraction (37±11% versus 59±2%, P<0.001) and more comorbidities (87.6% versus 40.5%; P<0.001) compared with patients with SVT. Importantly, even though the heart rate upon presentation did not differ between the 2 groups (165±26 beats/min during VT versus 171±32 beats/min during SVT; P=0.16), symptomatology differed significantly; specifically, palpitations were reported in only 8.8% of VT patients, compared with 90.7% of SVT patients (P<0.001). Common symptoms in the VT group included chest pain (64%), dyspnea (21%), and dizziness (26%).ConclusionsDespite similar heart rate, patients with VT rarely report having palpitations, whereas patients with SVT do so commonly. This finding may assist with decision making in patients reporting palpitations in whom an ECG tracing is not available.

Sustained ventricular tachycardia of left, right or both bundle branch block morphology in patients with Arrhythmogenic Cardiomyopathy

Abstract Aims In arrhythmogenic cardiomyopathy (ACM) sustained monomorphic ventricular tachycardia (VT) typically displays left bundle branch block (LBBB) morphology. Sustained VT with right bundle branch block (RBBB) morphology is very rare despite the frequent left ventricular involvement. The present study sought to assess the prevalence of spontaneous sustained LBBB-VT, RBBB-VT or both as well as clinical and genetic differences associated with these VT types. Methods and results Twenty-six centers from 11 European countries provided information on 952 patients with ACM and &amp;gt;1 episode of sustained VT observed during the patients' clinical course. VT was classified as: LBBB-VT; RBBB-VT or LBBB+RBBB-VT. Among 952 patients, 881 (92.5%) had LBBB-VT alone, 71 (7.5%) had RBBB-VT [alone in 42 (4.4%) patients or with LBBB-VT in 29 (3.0%) patients]. Male prevalence was 90.5%, 79.2% and 55.9% in the RBBB-VT, LBBB-VT and LBBB+RBBB-VT groups, respectively (P=0.001). Patients' age at first VT did not differ amongst the 3 VT groups. ICD implantation was more frequent for the RBBB-VT and the LBBB+RBBB groups (≈90% each) vs. 67.9% for the LBBB-VT group (P=0.001). Death incidence (9.5%–17.2%) was not significantly different between the 3 groups (P=0.425). Plakophylin-2 mutations predominated in the LBBB-VT and LBBB-VT+RBBB-VT groups (47.2% and 27.3%, respectively) and Desmoplakin mutations in the RBBB-VT group (36.7%). Conclusion This large European survey demonstrates: 1) Sustained RBBB-VT is documented in 7.5% patients with ACM; 2) Males markedly predominate in the RBBB-VT and LBBB-VT groups but not in the LBBB+RBBB VT group; 3) Distribution of desmosomal mutations appears to be different in the 3 VT groups. Funding Acknowledgement Type of funding source: None

Long-term results of irrigated bipolar radiofrequency ablation in patients with recurrent arrhythmia after failed unipolar ablation.

Introduction:The RF ablation of ventricular tachycardia (VT) or atrial flutter (AFl) can be unsuccessful due to lack of lesion transmurality. Bipolar ablation (BA) is more successful than unipolar ablation (UA). The purpose of our study was to investigate the long-term effect of BA ablation in patients after failed UA.Methods:Patients with septal VT (5) or AFL (2) after 2 to 5 unsuccessful UA were prospectively analysed after BA. All patients presented with heart failure or had ICD interventions.Results:BA was successful in 5 patients (1 failure each in the AFL and VT group). The follow-up duration was 10 to 26 months. In AFL group, BA was successful in 1 patient, unidirectional cavotricuspid block in was achieved in the other patient. All patients were asymptomatic for 12 months, but 1 had atrial fibrillation and the other had AFL reablation 19 months after BA. In VT group, all patients had several forms of septal VT. BA was successful in 4 patients. In 2 patients with high septal VT BA resulted in complete atrioventricular block. During follow-up, 1 patient had VT recurrence 26 months after BA and died after an unsuccessful reablation. Three patients had VT recurrences of different morphologies, which required reablation (UA in 2 and alcohol septal ablation in the other patient).Conclusion:BA was successful in patients with AFL and septal VT resistant to standard ablation. Relapses of clinical arrhythmia are rare; however, long-term follow-up is complicated by recurrences of different arrhythmias related to complex arrhythmogenic substrate

Islets of heterogeneous myocardium within the scar in cardiac magnetic resonance predict ventricular tachycardia after myocardial infarction

We assessed findings in cardiac magnetic resonance (CMR) as predictors of ventricular tachycardia (VT) after myocardial infarction (MI), which could allow for more precise identification of patients at risk of sudden cardiac death. Forty-eight patients after prior MI were enrolled and divided into twogroups: with (n = 24) and without (n = 24) VT. VT was confirmed by electrophysiological study and exit site was estimated based on 12-lead electrocardiogram. All patients underwent CMR with late gadolinium enhancement. The examined groups did not differ significantly in clinical and demographical parameters (including LV ejection fraction). There was a significant difference in the infarct age between the VT and non-VT group (15.8 ± 8.4 vs7.1 ± 6.7 years, respectively; P = .002), with the cut-off point at the level of 12 years. In the scar core, islets of heterogeneous myocardium were revealed. They were defined as areas of potentially viable myocardium within or adjacent to the core scar. The number of islets was the strongest independent predictor of VT (odds ratio [OR], 1.42; confidence interval [CI], 1.17-1.73), but total islet size and the largest islet area were also significantly higher in the VT group (OR, 1.04; CI, 1.02-1.07 and OR, 1.16; CI, 1.01-1.27, respectively). Myocardial segments with fibrosis forming 25%-75% of the ventricular wall were associated with a higher incidence of VT (7.5 ± 2.1 vs5.7 ± 2.6; P = .014). Three-dimension CMR reconstruction confirmed good correlation of the location of the islets/channels with VT exit site during electroanatomical mapping in five cases. The identification and quantification of islets of heterogeneous myocardium within the scar might be useful for predicting VT in patients after MI.

Tp-Te interval and Tp-Te/QT ratio may be predictive of idiopathic ventricular tachycardia in patients with frequent outflow tract premature ventricular complexes

Background The aim of present study is to evaluate the predictive value of QTc dispersion, Tp-Te interval and Tp-Te/QT ratio for idiopathic monomorphic outflow tract ventricular tachycardia (VT) occurrence in patients with frequent idiopathic outflow tract premature ventricular complexes (PVCs). Methods A total of 180 patients (49.2 ± 13.6 years, 74 male) who had undergone outflow tract PVC ablation between 01 January 2015 and 01 November 2018 constituted our study population. Patients with isolated outflow tract PVC without any VT recording on Holter recordings and without any inducible VT at EPS were classified as isolated PVC group. Patients with any episode of VT that has the same morphology with outflow tract PVC were classified as nonsustained or sustained VT groups based on the duration of VT episode. QTc dispersion, Tp-Te and Tp-Te/QT ratio values were calculated and compared between groups. Results There were 116 patients with isolated PVC, 35 patients with nonsustained VT and 29 patients with sustained VT. QTc dispersion, Tp-Te and Tp-Te/QT ratio values were significantly lower in patients with isolated PVC compared to patients with nonsustained or sustained VT episodes. Tpeak to Tend interval greater than 110.5 msec on derivation V6 predicted VT occurrence with 93.8% sensitivity and 82.8% specificity. Tpeak to Tend/QT interval greater than 0.27 on derivation V6 predicted VT occurrence with 93.8% sensitivity and 0.81% specificity. Conclusion Tp-Te interval and Tp-Te/QT ratio on derivation V6 may aid in prediction of presence of outflow tract VT in clinical practice.

QTc dispersion as a novel marker in identifying patients requiring an epicardial approach for ablation of scar mediated ventricular tachycardia

IntroductionEpicardial exit sites of ventricular tachycardia (VT) are frequently encountered during VT ablation requiring an epicardial ablation approach for successful elimination of VT. We sought to assess the utility of repolarization markers in identifying individuals requiring an epicardial ablation approach in addition to an endocardial approach. Methods32 patients who underwent successful ablation for scar mediated VT were included in the study. Fourteen patients who required a combined endocardial and epicardial VT ablation were defined as epicardial VT group (Epi) whereas 18 patients who were successfully ablated from the endocardium alone constituted the endocardial VT group (Endo). Repolarization markers during sinus rhythm were compared between the two groups. ResultsA higher QTc max and QTc dispersion were seen in the Epi group compared to Endo group (479 ± 34 vs 449 ± 20, p = 0.008 and 63 ± 13 vs 38 ± 8, p = 0.001, respectively). Ts-p and Ts-p/Tp-e were higher in the Epi group (166 ± 23 vs 143 ± 23, p = 0.008 and 1.55 ± 0.26 vs 1.3 ± 0.21, p < 0.005). On multivariate regression, QTc dispersion was an independent predictor of the need for an epicardial approach to ablation. A QTc dispersion more than 51.5 msec identified individuals requiring a combined epicardial and endocardial approach to ablation with a sensitivity of 92.9% and a specificity of 100%. ConclusionsPatients requiring an epicardial ablation have a higher QTc dispersion. A value greater than 51.5 msec reliably differentiates between the two groups with high sensitivity and specificity.