Recurrent Ventricular Arrhythmias Research Articles

Role of extensive diagnostic workup in young athletes and nonathletes with complex ventricular arrhythmias

Ventricular arrhythmias (VAs) are the most common cause of death in athletes. The differences in the electroanatomic substrate in athletes and nonathletes with complex VA are unknown. The purpose of this study was to compare the electroanatomic substrate of complex VA in athletes vs nonathletes. The study prospectively enrolled young athletes and nonathletes with VA. Patients underwent 2-dimensional echocardiography, cardiac magnetic resonance (CMR) imaging, coronary angiography, 3-dimensional electroanatomic mapping (3D-EAM), and 3D-EAM-guided endomyocardial biopsy (EMB). Follow-up included 24-hour electrocardiographic Holter or implantable cardioverter-defibrillator/loop recorder interrogation for VA recurrence. Thirty-three patients were enrolled: 18 competitive athletes (56%) and 15 nonathletes (44%). Left ventricular and right ventricular (RV) findings by echocardiography and CMR did not show structural disease. Nine athletes (50%) were asymptomatic compared to 1 nonathlete (7%; P <.05). Unifocal origin of VA was reported in 14 athletes (93%) and 17 nonathletes (94%). Athletes showed a larger RV unipolar than bipolar scar (18 ± 17 cm2 vs 3 ± 3.8 cm2; P = .04). Diagnostic yield of EMB was 50% in athletes and 40% in nonathletes. Among athletes, the final diagnosis was myocarditis in 2, arrhythmogenic ventricular right cardiomyopathy in 1, and focal replacement fibrosis in 1. Among nonathletes, EMB revealed focal replacement fibrosis in 4 cases. At median follow-up of 18.7 months, Kaplan-Meier curves showed lower VA recurrence in detrained athletes than nonathletes (53% vs 6%; P = .02). This study showed the need for extensive diagnostic workup in apparently healthy young patients with complex VA in order to characterize concealed cardiomyopathies.

Are Atrial High-Rate Episodes Associated With Increased Risk of Ventricular Arrhythmias and Mortality?

This study evaluated the temporal association between atrial high-rate episodes (AHREs) and sustained ventricular arrhythmias (VAs) in a remotely monitored cohort with implantable cardioverter-defibrillators (ICD) with and/or without cardiac resynchronization therapy with a defibrillator (CRT-D). Clinical relevance of AHREs in terms of VA rate and survival has not been outlined yet. This study analyzed data of patients with ICDs and CRT-Ds from the nationwide Home Monitoring Expert Alliance network. The cohort included 2,435 patients with a median follow-up of 25months (interquartile range: 13 to 42months) and age 70 years (range 61 to 77 years); 19.7% were women, 51.4% had coronary artery disease, and 45.2% had a CRT-D. There were 3,410 appropriate VA episodes; 498 (14.6%) were preceded by AHREs within 48 h; in 85.5% of this group, AHREs were still ongoing at episode onset. In a longitudinal analysis, the odds ratios (ORs) of experiencing any VA in a 30-day interval with AHREs versus intervals without AHREs were 2.35 (95% confidence interval [CI]: 1.86 to 2.97; p<0.001) for ventricular tachycardia (VT), 3.06 (95%CI: 2.35 to 3.99; p<0.001) for fast VT, 1.84 (95%CI: 1.36 to 2.48; p<0.001) for self-extinguishing ventricular fibrillation (VF), and 2.31 (95%CI: 1.17 to 4.57; p=0.01) for VF. ORs decreased with increasing AHRE burden. Patients with AHREs 48h before VAs were more likely to experience VA recurrences (adjusted hazard ratio [HR]: 1.78; 95%CI: 1.41 to 2.24; p<0.001) and had higher overall mortality (HR: 2.67; 95%CI: 1.68 to 4.23; p<0.001). AHREs were not uncommon 48h before VAs, which tended to be distributed around intervals with AHREs. Temporal connection between AHREs and VAs was a marker of increased risk of VA recurrence and a poorer prognosis.

J-Wave Elevation in the Inferior Leads Predicts Lethal Ventricular Arrhythmia Initiated by Premature Ventricular Contractions With Right Bundle Branch Block and Superior Axis.

Lethal ventricular arrhythmia (VA) can be initiated by idiopathic premature ventricular contractions (PVCs) originating from the left ventricular (LV) inferior wall. Furthermore, J-wave elevation in the inferior leads on ECG is sometimes associated with lethal VA. However, the relationship between these PVCs and J-wave elevation in patients with lethal VA is unclear, so we investigated it in the present study. We studied 32 consecutive patients who underwent radiofrequency (RF) ablation of idiopathic PVCs with right bundle branch block (RBBB) and superior axis. Thee PVCs were originating from the inferior wall of the LV. Lethal VA was defined as ventricular fibrillation (VF) or ventricular tachycardia (VT) with loss of consciousness (LOC). Among 32 patients, 3 had VF and 2 had VT with LOC. Other 27 had non-lethal VA. Baseline clinical characteristics were not significantly difference between lethal and non-lethal VA. The ratio of J-wave elevation in lethal VA was significantly higher as compared with non-lethal VA (100% vs. 11.1%, P<0.0001). Furthermore, no patients with J-wave elevation in the inferior leads had recurrence of lethal VA after RF ablation of the PVCs. We speculate that J-wave elevation in the inferior leads might be a predictor of lethal VA initiated by PVCs with RBBB and superior axis. RF ablation of these PVCs was a useful method of treating lethal VA.

Electrophysiologic effects and outcomes of sympatholysis in patients with recurrent ventricular arrhythmia and structural heart disease.

Autonomic modulation has been used as a therapy to control recurrent ventricular arrhythmia (VA). This study was to explore stellate ganglion block (SGB) effect on cardiac electrophysiologic properties and evaluate the long-term outcome of cardiac sympathetic denervation (CSD) for patients with recurrent VA and structural heart disease (SHD). Patients who had recurrent VA due to SHD were enrolled prospectively. Electrophysiologic study and ventricular tachycardia (VT) induction were performed before and after left and right SGB. VA burden and long-term outcomes were assessed for a separate patient group who underwent left or bilateral CSD for drug-refractory VA due to SHD. Electrophysiologic study of nine patients showed that baseline mean (SD) corrected sinus node recovery time (cSNRT) increased from 320.4 (73.3) ms to 402.9 (114.2) ms after left and 482.4 (95.7) ms after bilateral SGB (P = .03). SGB did not significantly change P-R, QRS, and Q-T intervals and ventricular effective refractory period, nor did the inducibility of VA. Nineteen patients underwent left (n = 14) or bilateral (n = 5) CSD. CSD reduced VA burden and appropriate ICD therapies from a median (interquartile range) of 2.5 (0.4-11.6) episodes weekly to 0.1 (0.0-2.4) episodes weekly at 6-month follow-up (P = .002). Three-year freedom from orthotopic heart transplant (OHT) and death was 52.6%. New York Heart Association functional class III/IV and VT rate less than 160 beats per minute were predictors of recurrent VA, OHT, and death. SGB increased cSNRT without changing heart rate. CSD was more beneficial for patients with mild-to-moderate heart failure and faster VA.

Idiopathic ventricular fibrillation – Long term prognosis in relation to clinical findings and ECG patterns in a Swedish cohort

BackgroundIdiopathic ventricular fibrillation (IVF) is a rare cause of sudden cardiac arrest which may pose therapeutic and prognostic challenges. To date, the only effective treatment for survivors of cardiac arrest is the insertion of an implantable cardioverter-defibrillator (ICD). We sought to review the long-term outcome of a Swedish cohort with IVF. Methods and resultsFifty patients with IVF diagnosis between 1988 and 2016 (mean age at index 34.3, 56% male), were followed for a median 13.8 years in this retrospective multicenter observational study. No cardiac mortality was reported. 32% (n = 16) of patients had recurrence of ventricular fibrillation or sustained ventricular tachycardia, requiring ICD therapy, at a median time of 1.9 years (range 0.1–20.3) from the index event. Annual incidence rate of ventricular tachyarrhythmia was 3.1%. Abnormal ECG at baseline did not predict appropriate ICD therapy (p = 0.56). During the follow-up period, 14% (n = 7) patients received a cardiac diagnosis. Follow-up genetic testing was low (26%), however did confirm pathogenic mutations in three cases. ConclusionIdiopathic VF is a rare diagnosis with a relatively good prognosis provided ICD therapy is initiated. Routine clinical follow-up is recommended due to potential late emerging cardiac pathology. ECG changes are common, but have no prognostic value in determining the risk of ventricular arrhythmias recurrence. Screening for genetic diseases has previously been low, and this calls for improvement, especially since cheaper and more comprehensive genetic panels are now readily available.

Cardiac sympathetic denervation for refractory ventricular arrhythmias in patients with structural heart disease: A systematic review

Cardiac sympathetic denervation (CSD) is an important adjunctive option for patients with refractory ventricular arrhythmias (VAs). Reports of efficacy of CSD in patients with structural heart disease (SHD) and refractory VA vary widely in literature. The purpose of this study was to conduct a systematic review of arrhythmic outcomes and complications in patients with SHD who underwent CSD due to recurrent VAs. Electronic databases (Google Scholar and PubMed) were searched to identify reports on CSD in SHD using appropriate medical subject terms. No sample size restriction was applied. All patients with known channelopathies were excluded. Baseline demographic and surgical data, arrhythmic outcomes, and procedural complications were evaluated. A total of 13 studies and 173 patients were included. Of the 173 patients (121 [70%] male); pooled mean age 54.6 [95% confidence interval 52.6-56.7] years), 48 (28%) had ischemic cardiomyopathy, and 141 (82%) underwent bilateral CSD. Overall freedom from events ranged from 58% to 100%. Complications were reported in 49 patients(28%). Transient hypotension (9%), pneumothorax (5%), neuropathic pain (skin sensitivity) (4%), Horner syndrome (3%), sweating pattern changes (3%), and hemothorax (2%) were the most common complications. No procedure-related deaths were reported. CSD reduced the number of VA events in patients with SHD, and the benefit from the intervention seemed to be independent of the underlying SHD. Although overall rate of postprocedural complications was high, most of the complications were temporary. Major postprocedural complications after CSD were infrequent.

Characterization of skin sympathetic nerve activity in patients with cardiomyopathy and ventricular arrhythmia

Heightened sympathetic nerve activity is associated with occurrence of ventricular arrhythmia (VA). To investigate the association of skin sympathetic nerve activity (SKNA) and VA occurrence. We prospectively enrolled 65 patients with severe cardiomyopathy. Of these, 39 had recent sustained VA episodes (VA-1 group), 11 had intractable VA undergoing sedation with general anesthesia (VA-2 group), and 15 had no known history of VA (VA-Ctrl group). All patients had simultaneous SKNA and electrocardiogram recording. SKNA was assessed using an average value (aSKNA), a variable value (vSKNA), and the number of bursts of SKNA (bSKNA). The VA-1 group had higher aSKNA and vSKNA compared with the VA-Ctrl group (aSKNA: 1.41 ± 0.53 μV vs 0.98 ± 0.41 μV, P = .003; vSKNA: 0.52 ± 0.22 μV vs 0.30 ± 0.16 μV, P<.001) and the VA-2 group (aSKNA: 0.83 ± 0.22 μV, P<.001; vSKNA: 0.23 ± 0.11 μV; P < .001). Although the VA-2 group had more VA episodes than the VA-1 group (median, 5 vs 2; P = .01), their SKNA was the lowest among the 3 groups. Multivariate Cox regression analysis showed that a higher aSKNA at baseline was an independent predictor of lower VA recurrence rate during a 417 ± 279-day follow-up (hazard ratio, 0.325; 95% confidence interval [CI], 0.119-0.883; P = .03). A >15% reduction in aSKNA after therapy was associated with a lower subsequent VA event rate (hazard ratio, 0.222; 95% CI, 0.057-0.864; P = .03). Patients with VA had increased SKNA as compared with control. Both SKNA and sustained VA could be suppressed by general anesthesia. The aSKNA at baseline was an independent predictor of VA recurrence.

Ranolazyna — nowy lek w nawracających opornych na leczenie arytmiach komorowych?

Introduction. The pharmacological treatment of ventricular arrhythmias (VA) has significant limitations. Ranolazine is a relatively new drug with documented antianginal and anti-ischaemic mechanisms and where preclinical data provides evidence of additional antiarrhythmic properties. The aim of this article was to evaluate the safety and efficacy of ranolazine in patients with recurrent antiarrhythmic therapy-refractory VA. Material and methods. This prospective evaluation included 30 patients (pts) (male/female: 26/4; mean age: 65 ± 10 years; coronary artery disease/dilated cardiomyopathy: 20/10; New York Heart Association class I/II/III/IV: 2/14/12/2, left ventricular ejection fraction: 27 ± 10%; implantable cardioverter-defibrillator (ICD): 15 pts, implantable cardioverter- -defibrillator with cardiac resynchronisation therapy (CRT-D): 14 pts with recurrent significant VA [ventricular fibrillation, sustained ventricular tachycardia (VT) and/or non-sustained VT, multiple ventricular premature complexes > 1,000/ /day, biventricular stimulation (BiV) i.e. pharmacotherapy, coronary revascularisation, and percutaneous ablation, had proved ineffective. The severity of the arrhythmia was assessed by 24-hour electrocardiographic (ECG) Holter monitoring and in ICD/CRT-D memory recording. The patients received, in addition to the standard pharmacotherapy (amiodarone: 18 pts, beta-blocker: 26 pts) ranolazine 375 mg twice daily for three months. Baseline data was compared to the data obtained after the three months of ranolazine treatment. Results. We observed a significant reduction of total ventricular extrasystoles determined by ECG Holter monitoring (median: 1,737 vs 1,260, p = 0.04). Similarly, significant VA in ICD/CRT-D memory recording was diminished (67.7 vs 35.5%, p = 0.03). The number of ICD interventions in terms of both antitachycardia pacing (9 pts vs 2 pts, p = 0.01), and shock delivery (8 pts vs 2 pts, p = 0.01), was lower after the three-month observation. The therapy was ineffective for nine (29%) patients — two were hospitalised during the three-month follow-up because of recurrent arrhythmia and in seven pts there was no noticeable reduction in the amount of VA. Adverse effects, in the form of gastrointestinal symptoms (diarrhoea: two, constipation: one), occurred in three (10%) patients. Conclusions. Authors observed no significant QT prolongation in any patient. There were no differences between the baseline and the post-ranolazine patient clinical characteristics. Ranolazine seems to be a safe and effective second- line therapy in the reduction of VA and ICD interventions in patients with recurrent antiarrhythmic therapy-refractory events.

Incidence and predictors of implantable cardioverter-defibrillator therapy and its complications in idiopathic ventricular fibrillation patients.

Idiopathic ventricular fibrillation (IVF) is a rare cause of sudden cardiac arrest. Implantable cardioverter-defibrillator (ICD) implantation is currently the only treatment option. Limited data are available on the prevalence and complications of ICD therapy in these patients. We sought to investigate ICD therapy and its complications in patients with IVF. Patients were selected from a national registry of IVF patients. Patients in whom no underlying diagnosis was found during follow-up were eligible for inclusion. Recurrence of ventricular arrhythmia (VA) was derived from medical and ICD records, electrogram records of ICD therapies were used to differentiate between appropriate or inappropriate interventions. Independent predictors for appropriate ICD shock were calculated using cox regression. In 217 IVF patients, recurrence of sustained VAs occurred in 66 patients (30%) during a median follow-up period of 6.1 years. Ten patients died (4.6%). Thirty-eight patients (17.5%) experienced inappropriate ICD therapy, and 32 patients (14.7%) had device-related complications. Symptoms before cardiac arrest [hazard ratio (HR): 2.51, 95% confidence interval (CI): 1.48-4.24], signs of conduction disease (HR: 2.27, 95% CI: 1.15-4.47), and carrier of the DPP6 risk haplotype (HR: 3.24, 1.70-6.17) were identified as independent predictors of appropriate shock occurrence. Implantable cardioverter-defibrillator therapy is an effective treatment in IVF, treating recurrences of potentially lethal VAs in approximately one-third of patients during long-term follow-up. However, device-related complications and inappropriate shocks were also frequent. We found significant predictors for appropriate ICD therapy. This may imply that these patients require additional management to prevent recurrent events.

Septal Coronary Venous Mapping to Guide Substrate Characterization andAblation of Intramural Septal Ventricular Arrhythmia.

This study describes the use of septal coronary venous mapping to facilitate substrate characterization and ablation of intramural septal ventricular arrhythmia (VA). Intramural septal VA represents a challenge for substrate definition and catheter ablation. Between 2015 and 2018, 12 patients with structural heart disease, recurrent VA, and suspected intramural septal substrate underwent a septal coronary venous procedure in which mapping was performed by advancement of a wire into the septal perforator branches of the anterior interventricular vein. A total of 5 patients with idiopathic VA were also included as control subjects to compare substrate characteristics. Patients were 63 ± 14 years of age, and 11 (92%) were men. Most patients with structural heart disease had nonischemic cardiomyopathy (83%). Six patients underwent ablation for premature ventricular contractions (PVC) and 6 for ventricular tachycardia. All patients had larger septal unipolar voltage abnormalities than bipolar voltage abnormalities (mean area 35.3 ± 16.8cm2 vs. 10.7 ± 8.4cm2, respectively; p= 0.01), Patients with idiopathic VA had normal voltage. Septal coronary venous mapping revealed low-voltage, fractionated, and multicomponent electrograms in sinus rhythm in all patients with substrate compared to that in patients with idiopathic VA (amplitude 0.9 ± 0.9mV vs. 4.4 ± 3.7mV, respectively; p= 0.007; and duration 147 ± 48ms vs. 92 ± 10ms, respectively; p= 0.03). Ablation targeted early activation, pace map match, and/or good entrainment sites from intraseptal recording. Over a mean follow-up of 339 ± 240days, the PVC and insertable cardioverter-defibrillator therapies burden were significantly reduced (from a mean of 22 ± 11% to 4 ± 8%; p= 0.005; and a mean 5 ± 2 to 1 ± 1; p= 0.001, respectively). Most patients (80%) with idiopathic VA remained arrhythmia free. In patients with suspected intramural septal VA, mapping of the septal coronary veins may be helpfulto characterize the arrhythmia substrate, identify ablation targets, and guide endocardial ablation.

Long-Term Follow-Up of Idiopathic Ventricular Fibrillation in a Pediatric Population: Clinical Characteristics, Management, and Complications.

BackgroundThe natural history and long‐term outcome in pediatric patients with idiopathic ventricular fibrillation (IVF) are poorly characterized. We sought to define the clinical characteristics and long‐term outcomes of a pediatric cohort with an initial diagnosis of IVF.Methods and ResultsPatients were included from an International Registry of IVF (consisting of 496 patients). Inclusion criteria were: (1) VF with no identifiable cause following comprehensive analysis for ischemic, electrical or structural heart disease and (2) age ≤16 years. These included 54 pediatric IVF cases (age 12.7±3.7 years, 59% male) among whom 28 (52%) had a previous history of syncope (median 2 syncopal episodes [interquartile range 1]). Thirty‐six (67%) had VF in situations associated with high adrenergic tone. During a median 109±12 months of follow‐up, 31 patients (57%) had recurrence of ventricular arrhythmias, mainly VF. Two patients developed phenotypic expression of an inherited arrhythmia syndrome during follow‐up (hypertrophic cardiomyopathy and long QT syndrome, respectively). A total of 15 patients had positive genetic testing for inherited arrhythmia syndromes. Ten patients (18%) experienced device‐related complications. Three patients (6%) died, 2 due to VF storm.ConclusionsIn pediatric patients with IVF, a minority develop a definite clinical phenotype during long‐term follow‐up. Recurrent VF is common in this patient group.

Ventricular Tachycardia Induced by Exercise Test as a Predictor of Coronary Artery Disease Development

A long-term clinical observation of the patient with ventricular tachycardia induced by exercise test but without myocardial ischemia and coronary artery atherosclerosis based on the results of angiography in the debut of the disease is described. However, arrhythmia reproducibility during stress tests, positive drug tests with nitroglycerin and beta-blocker, results of cardiac positron emission tomography with fatty acids revealed the ischemic genesis of arrhythmias, which was indirectly confirmed by a positive antiarrhythmic effect of the therapy with a metabolic drug (treatment with a beta-blocker was impossible because there was a sinus block). Coronary angiography was performed again after 7 years during the recurrence of ventricular arrhythmia with unstable angina. Stenosis of the left anterior descending artery was revealed. The antiarrhythmic effect of myocardial revascularization was continuously positive. Therefore, ventricular tachycardia induced by exercise test in patients with risk factors even in the absence of clinical and electrocardiographic criteria for myocardial ischemia could be an early debut of coronary artery disease.

Risk score for the exclusion of arrhythmic events in arrhythmogenic right ventricular cardiomyopathy at first presentation

AimsArrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetically determined heart muscle disorder associated with an increased risk of life-threatening arrhythmias in some patients. Risk stratification remains challenging. Therefore, we sought a non-invasive, easily applicable risk score to predict sustained ventricular arrhythmias in these patients. MethodsCohort of Patients who fulfilled the 2010 ARVC task force criteria were consecutively recruited. Detailed clinical data were collected at baseline and during follow up. The clinical endpoint was a composite of recurrent sustained ventricular arrhythmias and hospitalization due to ventricular arrhythmias. Multivariable logistic regression was used to develop models to predict the arrhythmic risk. A cohort including patients from other registries in UK, Canada and Switzerland was used as a validation population. ResultsOne hundred and thirty-five patients were included of whom 35 patients (31.9%) reached the endpoint. A model consisting of filtered QRS duration on signal-averaged ECG, non-sustained VT (NSVT) on 24 h-ECG, and absence of negative T waves in lead aVR on 12‑lead surface ECG was able to predict arrhythmic events with a sensitivity of 81.8%, specificity of 84.0% and a negative predictive value of 95.5% at the first presentation of the disease. This risk score was validated in international ARVC registry patients. ConclusionA risk score consisting of a filtered QRS duration ≥117 ms, presence of NSVT on 24 h-ECG and absence of negative T waves in lead aVR was able to predict arrhythmic events at first presentation of the disease.

Electrotherapy in acute cardiac conditions

Cardiac arrhythmia is one of the main reasons of admission to emergency units. Arrhythmia can be alone symptom, effect of compromise of stable disease or be caused by acute cardiac event. Temporary pacing according to current guidelines should be limited to advanced atrio-venricular block, life-threatening bradycardia related to cardiac procedures (ie. PCI). This method should not be used routinely but only when chronotro­pic drugs are ineffective. Likelihood of restoration of proper atrio-ventricular conduction, when block persists over 2 days is exiguous so decision of permanent system implantation should be taken earlier. Temporary pacing with stiff lead is related to increased risk of perforation and correlates with an increased risk of permanent device infection. Overdrive pacing should be considered in case of refractory to treatment recurrent ventricular arrhythmias. Immediate implantation of cardioverter-defibrillator should be performed in secondary prevention, when arrhythmia seems not to be related to potentially reversible cause. Frequently recurrent or persistent arrhythmias should be treated pharmacologically or with ablation before system implantation. In randomized trials it was not proved that implantation of ICD based on early risk stratification after myocardial infarction give any benefits. Experts point out the group of patients who could benefit from early (within 40 days after MI) implantation of an ICD. Cardiac resynchronization system implantation may be considered as a thera­py option to decrease congestion. Such treatment may allow the withdrawal of inotropic agents. Treatment of acute cardiac conditions with electrotherapy methods could be an effective therapy worth in selected group of patients.

Risks of age and sex on clinical outcomes post myocardial infarction

BackgroundHow sex and age influence post-myocardial infarction (post-MI) outcomes remains unclear. This study evaluated the influence of sex and age on drug therapy, echocardiographic parameters, and outcomes in post-MI patients undergoing percutaneous coronary intervention (PCI). MethodsWe retrospectively enrolled 643 patients with first acute MI who underwent successful PCI and two echocardiographic examinations within 1 year after MI. Clinical characteristics and 4-year follow-up outcomes were compared between sexes and age groups. Primary endpoints were cardiovascular mortality and hospitalization for heart failure (HF). ResultsCompared with males, female patients with MI, particularly older females, had more systemic diseases. Younger females received fewer guideline-directed therapies. Older patients presented with higher left ventricular volume and mass index but no significant differences in left ventricular ejection fraction. The Kaplan–Meier analysis revealed increased mortality in both younger and older females. Elderly patients, particularly older females, exhibited significantly higher post-MI HF incidence but no difference in recurrent MI, ventricular arrhythmia, or revascularization. ConclusionsIn MI patients receiving PCI, outcome differences between sexes are age-dependent. Age influences outcome more heavily in females than in males. Females are likely to exhibit worse overall survival, and older females are at higher risk of post-MI HF.

Infusion Needle Radiofrequency Ablation for Treatment of Refractory Ventricular Arrhythmias

BackgroundCatheter ablation is effective for eliminating most drug-refractory ventricular arrhythmias (VA). However, a major reason for procedural failure is arrhythmia originating deep within the myocardium where it is inaccessible to conventional endocardial or epicardial approaches. Affected patients have limited therapeutic options. ObjectivesThe objective of this study was to assess the safety and outcome of a novel radiofrequency ablation catheter that used an extendable/retractable 27-g needle capable of targeting deep arrhythmia (intramural) substrate. MethodsPatients who failed at least one prior catheter ablation procedure for sustained ventricular tachycardia (VT) or nonsustained VA with associated left ventricular dysfunction were enrolled at 3 centers. The target was sustained monomorphic VT in 26 patients, including 8 with recent VT storm or VT requiring intravenous medication, and 5 with incessant VA associated with ventricular dysfunction. ResultsNeedle ablation was performed in 31 patients (median of 2 failed prior ablation procedures; 71% nonischemic heart disease). After a median of 15 needle lesions/patient, ablation abolished at least 1 inducible VT in 19 of 26 VT patients (73%), and suppressed ambient arrhythmia in 4 of 5 nonsustained arrhythmia patients. At the 6-month follow-up, 48% of patients were free of recurrent arrhythmia and another 19% were improved. Procedure-related complications included a single pericardial effusion treated with percutaneous drainage and a left ventricular pacing lead dislodgement with no deaths. ConclusionsIn patients with recurrent ventricular arrhythmias refractory to medications and conventional catheter ablation, intramural needle radiofrequency ablation offers significant arrhythmia control with an acceptable procedural risk.

Management and outcomes in mitral valve prolapse with ventricular arrhythmias undergoing ablation and/or implantation of ICDs.

While there is an association between isolated mitral valve prolapse (MVP) and sudden cardiac arrest (SCA), the baseline characteristics and outcomes of patients with isolated MVP who experience ventricular arrhythmias (VAs) and then subsequently undergo catheter ablation and/or implantable cardioverter defibrillator (ICD) implantation are unknown. We performed a retrospective review of all patients at the Cleveland Clinic with isolated MVP between 1997 and 2016 who underwent VA catheter ablation or secondary prevention ICD implantation. Of 617 screened patients, we identified 43 patients with isolated MVP and significant VA who underwent ICD placement (n=13, 30%) or catheter ablation (n=30, 70%). Both leaflets were most commonly involved (n=22, 52%) with posterior MVP being next most common (n=15, 36%). The most common foci of VA origin was the left ventricular papillary muscle (n=9, 27%). Ablation was successful in the majority of cases (n=20, 65%). At a mean follow-up of 2.5 years, 11 patients (26%) had recurrent VT. Patients with isolated MVP and VA were more likely to have bileaflet prolapse and at least moderate mitral regurgitation. VA originated more commonly from left-sided foci. While ablation was acutely successful in the majority of cases, there was still a moderate rate of VA recurrence. There is still more study needed on factors that will predict malignant VAs and management of these VAs in the MVP population.

Characteristics and Outcomes in Patients With Electrical Storm

Electrical storm (ES) is a life-threatening condition with diverse clinical presentation, caused by recurrent malignant ventricular arrhythmia--≥3 episodes of ventricular tachycardia (VT) or ventricular fibrillation within 24hours and is associated with high mortality. The aim of this study was analysis of clinical profile, treatment, and prognosis of patients with ES admitted to a high-volume cardiovascular center. We present results of a single-center, retrospective, ongoing observational registry enrolling consecutive patients presenting with ES admitted between 2006 and 2017. Clinical history, results of diagnostic investigations, and treatment were collected for all patients. Follow-up data were collected from hospital documentation, outpatient clinic, remote monitoring systems, and from data gathered from national health services. Registry enrolled 101 consecutive patients admitted with ES. Two-thirds of patients had ischemic cardiomyopathy. Mean left ventricle ejection fraction was 26%. In 56.4% of the patients coronary angiogram was performed and in 20.8% cases percutaneous coronary intervention was needed. 18.8% of the patients underwent VT ablation. 12-month mortality from first ES in our population was 21.8%. NYHA class III and IV, raised N-terminal fragment of prohormone B-type Natriuretic Peptide and creatinine levels, and lower hemoglobin levels were independent predictors of death. In conclusion, most patients admitted with ES have ischemic cardiomyopathy. Over 1/3 of the population had significant narrowing of at least one coronary artery with ES masking ischemia and underwent percutaneous coronary intervention. Nearly 1/5 of the patients were treated with VT ablation. 12-month mortality was high and exceeded 1/4 of patients with ES.

Effect of Prophylactic Amiodarone Infusion on the Recurrence of Ventricular Arrhythmias in Out-of-Hospital Cardiac Arrest Survivors: A Propensity-Matched Analysis.

Amiodarone is recommended for shock-refractory ventricular arrhythmia during resuscitation; however, it is unknown whether amiodarone is effective for preventing ventricular arrhythmia recurrence in out-of-hospital cardiac arrest (OHCA) survivors treated with targeted temperature management (TTM). We investigated the effectiveness of prophylactic amiodarone in preventing ventricular arrhythmia recurrence in OHCA survivors. Data of consecutive adult non-traumatic OHCA survivors treated with TTM between 2010 and 2016 were extracted from prospective cardiac arrest registries of four tertiary care hospitals. The prophylactic amiodarone group was matched in a 1:1 ratio by using propensity scores. The primary outcome was ventricular arrhythmia recurrence requiring defibrillation during TTM. Among 295 patients with an initially shockable rhythm and 149 patients with initially non-shockable-turned-shockable rhythm, 124 patients (27.9%) received prophylactic amiodarone infusion. The incidence of ventricular arrhythmia recurrence was 11.26% (50/444). Multivariate analysis showed prophylactic amiodarone therapy to be the independent factor associated with ventricular arrhythmia recurrence (odds ratio 1.95, 95% CI 1.04–3.65, p = 0.04), however, no such association was observed (odds ratio 1.32, 95% CI 0.57–3.04, p = 0.51) after propensity score matching. In this propensity-score-matched study, prophylactic amiodarone infusion had no effect on preventing ventricular arrhythmia recurrence in OHCA survivors with shockable cardiac arrest. Prophylactic amiodarone administration must be considered carefully.

Global Longitudinal Strain as a Predictor of First and Subsequent Arrhythmic Events in Remotely Monitored ICD Patients With Structural Heart Disease

ObjectivesThis study sought to assess speckle-tracking–derived parameters as predictors of first and subsequent ventricular events in patients with structural heart disease and implantable cardioverter-defibrillators (ICD). BackgroundLeft ventricular ejection fraction (LVEF), the current primary parameter of risk stratification for ventricular arrhythmias (VAs) in structural heart diseases is burdened by many limitations. MethodsIn this retrospective, observational study, all consecutive patients with structural heart disease were admitted for ICD implantation. Patients not followed by a home-monitoring system were excluded. Two-dimensional (2D) speckle-tracking analysis was used to derive global longitudinal strain (GLS), mechanical dispersion (MD), and delta contraction duration (DCD) of all patients at enrollment. Home monitoring was checked weekly to detect all VAs and ICD therapies. A recurrent event statistical approach (Prentice, Williams, and Peterson model) was applied to evaluate subsequent events after the first ones. ResultsA total of 203 patients were consecutively enrolled and followed for a median of 2.2 years. Kaplan-Meier curves showed an increased risk of antitachycardia pacing or shock (log-rank p = 0.003) and VAs (log-rank p = 0.001) associated with lower quartiles of GLS. An impaired GLS was independently associated with an increased risk for the first ICD therapy (hazard ratio [HR]: 1.94; 95% confidence interval [CI]: 1.30 to 2.91; p = 0.001) and (HR: 1.42; 95% CI: 1.01 to 1.98; p = 0.04) for the first VA. GLS impairment was not significantly associated with an increased risk of recurrent ICD therapies or VAs. LVEF, MD, and DCD were not associated with an increased risk of first, second, and third ICD therapies or VA. ConclusionsImpaired GLS is associated with an increased risk of VAs and appropriate ICD therapies in a consecutive “real-world,” unselected population of remotely monitored patients with structural heart disease, although it does not seem reliable in predicting further arrhythmic events after the first one. MD and DCD do not predict first or subsequent arrhythmic events in ICD patients with structural heart disease.