Incidence Of Ventricular Arrhythmias Research Articles

Relationship between indexed surgery and postcardiotomy extracorporeal life support outcomes.

Veno-arterial extracorporeal life support (V-A ECLS) is increasingly being utilized for postcardiotomy shock (PCS), though data describing the relationship between type of indexed operation and outcomes are limited. This study compared V-A ECLS outcomes across four major cardiovascular surgical procedures. This was a single-center retrospective study of patients who required V-A ECLS for PCS between 2015 and 2022. Patients were stratified by the type of indexed operation, which included aortic surgery (AoS), coronary artery bypass grafting (CABG), valve surgery (Valve), and combined CABG and valve surgery (CABG + Valve). Factors associated with postoperative outcomes were assessed using logistic regression. Among 149 PCS patients who received V-A ECLS, there were 35 AoS patients (23.5%), 29 (19.5%) CABG patients, 59 (39.6%) Valve patients, and 26 (17.4%) CABG + Valve patients. Cardiopulmonary bypass times were longest in the AoS group (p < 0.01). Regarding causes of PCS, AoS patients had a greater incidence of ventricular failure, while the CABG group had a higher incidence of ventricular arrhythmia (p = 0.04). Left ventricular venting was most frequently utilized in the Valve group (p = 0.07). In-hospital mortality was worst among CABG + Valve patients (p < 0.01), and the incidence of acute kidney injury was highest in the AoS group (p = 0.03). In multivariable logistic regression, CABG + Valve surgery (odds ratio (OR) 4.20, 95% confidence interval 1.30-13.6, p = 0.02) and lactate level at ECLS initiation (OR, 1.17; 95% CI, 1.06-1.29; p < 0.01) were independently associated with mortality. We demonstrate that indications, management, and outcomes of V-A ECLS for PCS vary by type of indexed cardiovascular surgery.

Impact of Cardiac Resynchronization Therapy on Ventricular Arrhythmias and Survival After Durable Left Ventricular Assist Device Implantation.

The impact of cardiac resynchronization therapy (CRT) in patients receiving durable left ventricular assist device (LVAD) implantation remains unclear and there is no consensus regarding postoperative management. We sought to determine the impact of postoperative management of CRT on clinical outcomes following LVAD implantation. A total of 789 patients underwent LVAD implantation at our institution from 2007 to 2022 including 195 patients (24.7%) with preoperative CRT. Patients with preoperative CRT were significantly older and more frequently received an LVAD as destination therapy compared to patients without preoperative CRT. After LVAD implantation, 85 patients had CRT programmed "off" and 74 patients had CRT programmed "on." The risk of mortality was significantly increased amongst patients with preoperative CRT that was turned "on" following LVAD implantation compared to patients with preoperative CRT turned "off" following implant (subdistribution hazard ratio [sdHR] = 1.54; 1.06-2.37 95% confidence interval [CI]; p = 0.036). There was no significant difference between incidence of ventricular arrhythmias in patients with and without postoperative CRT "on" (35.1% vs. 48.2%; p = 0.095). Additional clinical trials are warranted to determine the best CRT programming strategy following LVAD implantation.

Association between COVID-19 vaccination and atrial arrhythmias in individuals with cardiac implantable electronic devices.

The impact of mRNA-based coronavirus disease-2019 (COVID-19) vaccines on atrial arrhythmias (AA) and ventricular arrhythmias incidence is unknown. BIOTRONIK Home Monitoring data and Medicare Claims data were utilized to identify individuals implanted with a cardiac implantable electronic device (CIED) between 2010 and 2020 who received one or more doses of COVID-19 vaccine in 2021. The burden of AA (%) in the 3 months postvaccination was compared to those noted in the preceding 3 months using the Wilcoxon signed rank test. Sub-analyses comparing the effects of the influenza vaccine against the COVID-19 vaccine were also evaluated for individuals who received the influenza vaccine in 2020. A 1:1 propensity score match comparison between COVID-19 vaccine and non-vaccinated patients was also performed. First and second doses of the COVID-19 vaccine were administered to 7757 and 6579 individuals with a CIED (age 76.2 ± 9.0 years, 49% males), respectively. While a small but statistically significant increase in the burden of AA was noted in the 3 months postvaccination compared to the preceding 3 months after the first dose of the COVID-19 vaccine (0.43 ± 9.04%, p = .028) a similar rise in AA was found following the influenza vaccine and for matched patients who did not receive the COVID-19 vaccine. No significant difference in device therapies was seen pre- and postvaccination. Though we report a small but significant increase in the number of CIED-detected AAs following vaccination for COVID-19 over a 3-month window, we believe these results correlate more with time and the progressive nature of AF rather than the vaccine itself. While these data should not dissuade from the use of these vaccines, increased vigilance and prompt treatment of AF is required for high-risk groups, specifically males over 70 years of age, following vaccination.

Ventricular unloading causes prolongation of the QT interval and induces ventricular arrhythmias in rat hearts.

Ventricular unloading during prolonged bed rest, mechanical circulatory support or microgravity has repeatedly been linked to potentially life-threatening arrhythmias. It is unresolved, whether this arrhythmic phenotype is caused by the reduction in cardiac workload or rather by underlying diseases or external stimuli. We hypothesized that the reduction in cardiac workload alone is sufficient to impair ventricular repolarization and to induce arrhythmias in hearts. Rat hearts were unloaded using the heterotopic heart transplantation. The ECG of unloaded and of control hearts were telemetrically recorded over 56 days resulting in >5 × 106 cardiac cycles in each heart. Long-term electrical remodeling was analyzed using a novel semi-automatic arrhythmia detection algorithm. 56 days of unloading reduced left ventricular weight by approximately 50%. While unloading did not affect average HRs, it markedly prolonged the QT interval by approximately 66% and induced a median tenfold increase in the incidence of ventricular arrhythmias in comparison to control hearts. The current study provides direct evidence that the previously reported hypertrophic phenotype of repolarization during cardiac unloading translates into an impaired ventricular repolarization and ventricular arrhythmias in vivo. This supports the concept that the reduction in cardiac workload is a causal driver of the development of arrhythmias during ventricular unloading.

Evaluation of the effect of empagliflozin on prevention of atrial fibrillation after coronary artery bypass grafting: a double-blind, randomized, placebo-controlled trial.

This study is aimed at evaluating the effect of empagliflozin in preventing atrial fibrillation after coronary artery bypass grafting (CABG). Eighty-two patients who fulfilled the inclusion criteria were allocated to the empagliflozin group (n = 43) or placebo group (n = 39). In two groups, patients received empagliflozin or placebo tablets 3days before surgery and on the first three postoperative days (for 6days) in addition to the standard regimen during hospitalization. During the first 3days after surgery, types of arrhythmias after cardiac surgery, including supraventricular arrhythmias, especially postoperative atrial fibrillation (POAF), ventricular arrhythmias, and heart blocks, were assessed by electrocardiogram monitoring. C-reactive protein (CRP) levels were evaluated pre-operatively and postoperative on the third day. The incidence of POAF in the treatment group was lower compared to the control group; however, this reduction was statistically non-significant (p = 0.09). The frequency of ventricular tachycardia was reduced significantly in the treatment group versus patients in the control (p = 0.02). Also, a significant reduction in the frequency of premature ventricular contractions (PVCs) was seen in the treatment group in comparison with the control group (p = 0.001). After the intervention, CRP levels were significantly less in the empagliflozin group compared to the control group in the third postoperative day (p = 0.04). The prophylactic use of empagliflozin effectively reduced the incidence of ventricular arrhythmia in patients undergoing CABG surgery.

Concomitant use of lansoprazole and ceftriaxone is associated with an increased risk of ventricular arrhythmias and cardiac arrest in a large Japanese hospital database

To determine whether concomitant use of ceftriaxone and oral or intravenous lansoprazole increases the risk of ventricular arrhythmia and cardiac arrest in the real-world setting in Japan. The data analyzed were obtained from the JMDC hospital-based administrative claims database for the period April 2014 to August 2022. Patients who received a proton pump inhibitor (PPI) while receiving ceftriaxone or sulbactam/ampicillin were identified. The frequency of ventricular arrhythmia and cardiac arrest was analyzed according to whether oral or intravenous PPI was concomitant with ceftriaxone or sulbactam/ampicillin. Estimates of the incidence of ventricular arrhythmia and cardiac arrest were then compared among the groups, using the Fine-Gray competing risk regression model. The results showed that the risk of ventricular arrhythmia and cardiac arrest was significantly higher with concomitant ceftriaxone and oral lansoprazole (hazard ratio 2.92, 95% confidence interval 1.99-4.29, P<0.01) or intravenous lansoprazole (hazard ratio 4.57, 95% confidence interval 1.24-16.80, P=0.02) than with concomitant sulbactam/ampicillin and oral or intravenous lansoprazole. Oral and intravenous lansoprazole may increase the risk of ventricular arrhythmia and cardiac arrest in patients who are receiving ceftriaxone.

Troponin T Assessment Allows for Identification of Mutation Carriers among Young Relatives of Patients with LMNA-Related Dilated Cardiomyopathy.

Background:LMNA-related dilated cardiomyopathy (LMNA-DCM) caused by mutations in the lamin A/C gene (LMNA) is one of the most common forms of hereditary DCM. Due to the high risk of mutation transmission to offspring and the high incidence of ventricular arrhythmia and sudden death even before the onset of heart failure symptoms, it is very important to identify LMNA-mutation carriers. However, many relatives of LMNA-DCM patients do not report to specialized centers for clinical or genetic screening. Therefore, an easily available tool to identify at-risk subjects is needed. Methods: We compared two cohorts of young, asymptomatic relatives of DCM patients who reported for screening: 29 LMNA mutation carriers and 43 individuals from the control group. Receiver operating characteristic (ROC) curves for potential indicators of mutation carriership status were analyzed. Results: PR interval, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and high-sensitivity cardiac troponin T (hscTnT) serum levels were higher in the LMNA mutation carrier cohort. Neither group differed significantly with regard to creatinine concentration or left ventricular ejection fraction. The best mutation carriership discriminator was hscTnT level with an optimal cut-off value at 5.5 ng/L, for which sensitivity and specificity were 86% and 93%, respectively. The median hscTnT level was 11.0 ng/L in LMNA mutation carriers vs. <3.0 ng/L in the control group, p < 0.001. Conclusions: Wherever access to genetic testing is limited, LMNA mutation carriership status can be assessed reliably using the hscTnT assay. Among young symptomless relatives of LMNA-DCM patients, a hscTnT level >5.5 ng/L strongly suggests mutation carriers.

Effects of Serum Potassium on Mortality in Patients With ST-Elevation Myocardial Infarction.

Disturbances in potassium levels can induce ventricular arrhythmias and heighten mortality in patients with ST-elevation myocardial infarction (STEMI). This study evaluates the influence of sK levels on seven-day mortality and incidence of ventricular arrhythmias in STEMI patients to further improve clinical guidelines and outcomes. This retrospective, propensity-matched study analyzed approximately 250,000 acute STEMI patients from 55 major academic medical centers/healthcare organizations (HCOs) in the US Collaborative Network of the TriNetX database. The sK levels recorded on the day of STEMI diagnosis were categorized into four cohorts: sK ≤ 3.4 (hypokalemia), 3.5 ≤ sK ≤ 4.5 (normal-control), 4.6 ≤ sK ≤ 5.0 (high-normal), and sK ≥ 5.1 (hyperkalemia). Patient cohorts were propensity-matched using linear and logistic regression for demographics. Outcomes of seven-day mortality, ventricular tachycardia (VT), and ventricular fibrillation (VF) were compared between these cohorts and the control group. The analysis showed hypokalemia was linked to significantly higher seven-day mortality (7.2% vs. 4.3%; RR 1.69; p<0.001), and increased rates of VT and VF. Similarly, hyperkalemia was associated with elevated mortality (12.7% vs. 4.6%; RR 2.76; p<0.001), VT, and VF rates. High-normal sK levels showed increased mortality (7.4% vs. 4.7%; RR 1.58; p<0.001), but unchanged VT or VF rates compared to the normal sK group. This comprehensive study highlights the correlation of sK levels with death in STEMI patients, revealing a nearly doubled risk of mortality with hypokalemia and almost triples with hyperkalemia. More notably, the mortality for STEMIs is higher for high-normal vs normal sK values. Additionally, hypokalemia and hyperkalemia were found to significantly elevate VT and VF risks.

Clinical impact of ICD implantation in octogenarians: a longitudinal cohort study

Abstract Background The implantation of defibrillators (ICDs) in patients over 80 years old is becoming increasingly common; however, evidence-based data regarding the actual clinical benefit in this population remain limited and contradictory. While age seems not to affect mortality and arrhythmia risk in octogenarians undergoing secondary prevention, the mortality reduction benefit given by ICD implantation for primary prevention appears to decrease with advancing age, likely due to the high number of non-arrhythmic deaths. Purpose This study aims to assess the long-term incidence of ventricular arrhythmias and mortality in a real-world cohort of octogenarian patients undergoing ICD implants. Methods This was an observational, retrospective, longitudinal cohort study. Demographic, clinical, and radiological data were collected for all patients undergoing ICD implantation between 2014 and 2021. Deaths from all causes and significant arrhythmic events (sustained ventricular tachycardias and ventricular fibrillation) detected during routine device controls and remote monitoring were recorded. Then was performed an univariate Kaplan-Meier analysis, stratifying the population by age in relation to the two study endpoints: ventricular arrhythmias and all-cause mortality. Results Out of a total of 700 patients, 512 underwent ICD implantation before the age of 80 (mean age at implantation 64±12), while 188 underwent ICD implantation after the age of 80 (mean age at implantation 82±3.2). No significant differences were found between these two groups in terms of gender (82% vs. 83% male; p 0.12), indication for implantation (74% vs. 75% primary prevention; p 0.79), and the presence of late gadolinium enhancement (LGE) on cardiac MRI (68% vs. 77%; p 0.14). Octogenarians were more frequently affected by ischemic heart disease (54% vs. 65%; p 0.01) and were more frequently treated with Amiodarone (17% vs. 24%; p 0.02). At the end of the average 8-year follow-up, octogenarians had significantly higher all-cause mortality than younger patients (HR=2.35 [1.88-3.16]; p&amp;lt;0.05), with survival curves diverging from 3 years after implantation. However, ventricular arrhythmic events were significantly reduced in octogenarian patients (HR=0.88 [0.87-0.89]; p&amp;lt;0.05). Conclusions In a real-world population of octogenarian patients, the clinical benefit of ICD implantation for primary prevention appears diminished, considering the trade-off between ventricular arrhythmias and mortality, in both ischemic and non-ischemic cardiomyopathy patients.

Atorvastatin, etanercept and the nephrogenic cardiac sympathetic remodeling in chronic renal failure rats.

Chronic renal failure (CRF) patients are predisposed to arrhythmias, while the detailed mechanisms are unclear. We hypothesized the chronic inflammatory state of CRF patients may lead to cardiac sympathetic remodeling, increasing the incidence of ventricular arrhythmia (VA) and sudden cardiac death. And explored the role of atorvastatin and etanercept in this process. A total of 48 rats were randomly divided into sham operation group (Sham group), CRF group, CRF + atorvastatin group (CRF + statin group), and CRF + etanercept group (CRF + rhTNFR-Fc group). Sympathetic nerve remodeling was assessed by immunofluorescence of growth-associated protein 43 (GAP-43) and tyrosine hydroxylase positive area fraction. Electrophysiological testing was performed to assess the incidence of VA by assessing the ventricular effective refractory period and ventricular fibrillation threshold. The levels of tumor necrosis factor-alpha (TNF-α) and interleukin-1beta were determined by Western blotting and enzyme-linked immunosorbent assay. Echocardiogram showed that compared with the Sham group, left ventricular end-systolic diameter and ventricular weight/body weight ratio were significantly higher in the CRF group. Hematoxylin-eosin and Masson staining indicated that myocardial fibers were broken, disordered, and fibrotic in the CRF group. Western blotting, enzyme-linked immunosorbent assay, immunofluorescence and electrophysiological examination suggested that compared with the Sham group, GAP-43 and TNF-α proteins were significantly upregulated, GAP-43 and tyrosine hydroxylase positive nerve fiber area was increased, and ventricular fibrillation threshold was significantly decreased in the CRF group. The above effects were inhibited in the CRF + statin group and the CRF + rhTNFR-Fc group. In CRF rats, TNF-α was upregulated, cardiac sympathetic remodeling was more severe, and the nephrogenic cardiac sympathetic remodeling existed. Atorvastatin and etanercept could downregulate the expression of TNF-α or inhibit its activity, thus inhibited the above effects, and reduced the occurrence of VA and sudden cardiac death.

Study of electrocardiographic indices of myocardial repolarization in patients with obstructive sleep apnea

Abstract Background Obstructive sleep apnea (OSA) is a sleep disorder manifested by airflow severe reduction or stoppage during breathing exertion. OSA cases had a higher incidence of ventricular arrhythmias, according to reports. Aim This research aimed to determine ventricular repolarization in OSA cases using the electrocardiographic indices of ventricular repolarization. Patients and methods This observational research involved 60 patients who underwent overnight polysomnography (PSG). 20 cases with normal PSG were employed as controls. Moderate or severe OSA cases were employed as study group. Tp-e, QTc intervals &amp; Tp-e/QTc ratios measurement was performed in all patients. Results Patients had significantly prolonged QTc intervals, Tp-e intervals &amp; Tp-e/QTc ratio compared to controls (446.4 ± 36.99 ms vs. 408.6 ± 25.23 ms, 86.12 ± 17.63 ms vs. 66.65 ± 15.49 ms &amp; 0.19 ± 0.04 vs. 0.16 ± 0.04 respectively, P&lt;0.001). There was a significant positive correlation between OSA degree and Tp-e/QTc ratio (r=0.374, P=0.017), Tp-e/QT ratio (r=0.448, P=0.004) &amp; Tp-e interval (r=0.377, P=0.016). There is also significant correlation between such repolarization indices and both lowest SpO2 and arousal index (P&lt;0.05). Conclusions We concluded a significant positive correlation between OSA degree and Tp-e/QTc, Tp-e/QT ratios &amp; Tp-e interval. OSA is associated with prolonged Tp-e/QTc &amp; Tp-e/QT ratios and a prolonged Tp-e interval.

Cardiovascular events reported in patients with B-cell malignancies treated with zanubrutinib

AbstractFirst-generation Bruton tyrosine kinase (BTK) inhibitor, ibrutinib, has been associated with an increased risk of cardiovascular toxicities. Zanubrutinib is a more selective, next-generation BTK inhibitor. In this analysis, incidence rates of atrial fibrillation, symptomatic (grade ≥2) ventricular arrhythmia, and hypertension were evaluated in a pooled analysis of 10 clinical studies with zanubrutinib monotherapy in patients (N = 1550) with B-cell malignancies and a pooled analysis of head-to-head studies comparing zanubrutinib with ibrutinib (ASPEN cohort 1; ALPINE). Among the 10 studies, most patients (median age, 67 years) were male (66.3%) and had CLL/SLL (60.5%). Overall incidence and exposure-adjusted incidence rates (EAIR) for atrial fibrillation, symptomatic ventricular arrhythmia, and hypertension were lower with zanubrutinib than ibrutinib. Despite a similar prevalence of preexisting cardiovascular events in ASPEN and ALPINE, atrial fibrillation/flutter incidence rates (6.1% vs 15.6%) and EAIR (0.2 vs 0.64 persons per 100 person-months; P < .0001) were lower with zanubrutinib than with ibrutinib. Symptomatic ventricular arrhythmia incidence was low for both zanubrutinib (0.7%) and ibrutinib (1.7%) with numerically lower EAIR (0.02 vs 0.06 persons per 100 person-months, respectively) for zanubrutinib. The hypertension EAIR was lower with zanubrutinib than ibrutinib in ASPEN but similar between treatment arms in ALPINE. The higher hypertension EAIR in ALPINE was inconsistent with other zanubrutinib studies. However, fewer discontinuations (1 vs 14) and deaths (0 vs 6) due to cardiac disorders occurred with zanubrutinib versus ibrutinib in ALPINE. These data support zanubrutinib as a treatment option with improved cardiovascular tolerability compared with ibrutinib for patients with B-cell malignancies in need of BTK inhibitors. These trials were registered at www.ClinicalTrials.gov as # NCT03053440, NCT03336333, NCT03734016, NCT04170283, NCT03206918, NCT03206970, NCT03332173, NCT03846427, NCT02343120, and NCT03189524.

Prior history of atrial fibrillation and arrhythmic outcomes: Data from the WEARIT-II prospective registry.

Wearable cardioverter defibrillator (WCD)is utilized in patients with assumed but not yet confirmed risk for sudden cardiac death (SCD).Many of these patients also present with atrial fibrillation (AF).However, the rate of WCD-detected ventricular or atrial arrhythmia events in this specific high-risk cohort is not well understood. In WEARIT-II,the cumulative probability of any sustained or nonsustained VT/VF(WCD-treatedand nontreated), and atrial/supraventricular arrhythmias during WCD use was assessed using the Kaplan-Meier method by prior AF, with comparisons by the log-rank test. The incidence of ventricular and atrial arrhythmia events were expressed as events per 100 patient-years, and were analyzed by prior AF using negative binomial regression. WEARIT-IIenrolled 2000 patients, 557 (28%) of whom had AF before enrollment. Cumulative probability of any sustained or nonsustained WCD-detected VT/VFduring WCD use was significantly higher among patients with a history of AF than without AF (6% vs. 3%, p = .001). Similarly, the recurrent rate of any sustained or nonsustained VT/VFwas significantly higher in patients with prior AF versus no prior AF (131.5 events per 100 patient-years vs. 22.7 events per 100 patient-years, p = .001). Patients with prior AF also had a significantly higher burden of any WCD-detected atrial arrhythmias/SVT/inappropriate arrhythmiastherapy (183.2 events per 100 patient-years vs. 74.8 events per 100 patient-years, p < .001). Our results demonstrate that patients with a history of AF wearing the WCD for risk assessment have a higher incidence of ventricular arrhythmias that may facilitate the decision making for ICD implantation.

Dual effect of cardiac FKBP12.6 overexpression on excitation-contraction coupling and the incidence of ventricular arrhythmia depending on its expression level

FKBP12.6, a binding protein to the immunosuppressant FK506, which also binds the ryanodine receptor (RyR2) in the heart, has been proposed to regulate RyR2 function and to have antiarrhythmic properties. However, the level of FKBP12.6 expression in normal hearts remains elusive and some controversies still persist regarding its effects, both in basal conditions and during β-adrenergic stimulation. We quantified FKBP12.6 in the left ventricles (LV) of WT (wild-type) mice and in two novel transgenic models expressing distinct levels of FKBP12.6, using a custom-made specific anti-FKBP12.6 antibody and a recombinant protein. FKBP12.6 level in WT LV was very low (0.16 ± 0.02 nmol/g of LV), indicating that <15% RyR2 monomers are bound to the protein. Mice with 14.1 ± 0.2 nmol of FKBP12.6 per g of LV (TG1) had mild cardiac hypertrophy and normal function and were protected against epinephrine/caffeine-evoked arrhythmias. The ventricular myocytes showed higher [Ca2+]i transient amplitudes than WT myocytes and normal SR-Ca2+ load, while fewer myocytes showed Ca2+ sparks. TG1 cardiomyocytes responded to 50 nM Isoproterenol increasing these [Ca2+]i parameters and producing RyR2-Ser2808 phosphorylation. Mice with more than twice the TG1 FKBP12.6 value (TG2) showed marked cardiac hypertrophy with calcineurin activation and more arrhythmias than WT mice during β-adrenergic stimulation, challenging the protective potential of high FKBP12.6. RyR2R420Q CPVT mice overexpressing FKBP12.6 showed fewer proarrhythmic events and decreased incidence and duration of stress-induced bidirectional ventricular tachycardia. Our study, therefore, quantifies for the first time endogenous FKBP12.6 in the mouse heart, questioning its physiological relevance, at least at rest due its low level. By contrast, our work demonstrates that with caution FKBP12.6 remains an interesting target for the development of new antiarrhythmic therapies.

Effects of Mitral Valve Surgery on Ventricular Arrhythmia in Mitral Valve Prolapse Patients: Five-Year Eollow-up.

Aim To evaluate the effect of mitral valve (MV) repair and replacement on the incidence of ventricular arrhythmias (VA) and to identify risk factors for the persistence of VA in patients with MV prolapse and severe mitral regurgitation (MR) during a mid-term follow-up.Material and methods A single-site observational, prospective study successively enrolled 30 patients (mean age, 55.2±9.9 years, 60% men) who underwent MV repair or replacement for severe MR due to MV prolapse or chordal avulsion. Transthoracic echocardiography and Holter monitoring were performed in all patients before and annually after surgery. A pathomorphological study of MV fragments excised during surgery was performed.Results During the five-year follow-up period (144 person-years), one case of sudden cardiac death outside a health care facility was recorded. MR severity progressed in three patients after MV repair. The total number of all VAs decreased during the follow-up period, with a significant decrease in the number of paroxysms of unstable ventricular tachycardia during the first two years after surgery. The presence of VA in the postoperative period was correlated with the severity of postoperative left ventricular (LV) remodeling: end-diastolic volume (EDV) (rs=0.69; p=0.005), LV ejection fraction (EF) (rs = -0.55; p=0.004) and severity of MV myxomatous alterations according to histological study data (rτ=0.58; p=0.045). The beta-blocker treatment did not influence the VA frequency and severity (rs= -0.18; p=0.69). According to a univariate regression analysis only EDV (p = 0.001), LVEF &lt;50% (p = 0.003), and myxomatous MV degeneration (p = 0.02) were risk factors for persistent ventricular tachycardia in the postoperative period.Conclusion Surgical intervention on MV in patients with MV prolapse and severe MR decreased the number of cases of malignant VAs and was correlated with the postoperative changes in LV volume and function, as well as the severity of MV myxomatous alterations.

Incidence of ventricular arrhythmias in patients with chronic total coronary occlusion: Results of the VACTOR study

BackgroundA chronic total coronary occlusion (CTO) is associated with ventricular arrhythmias (VA) in patients with an implantable cardioverter-defibrillator (ICD). Limited data is available on the incidence of VA in CTO patients without an ICD. ObjectivesTo investigate the incidence of sustained VA in CTO patients after successful CTO revascularization and in patients with untreated CTO or failed CTO revascularization. MethodsProspective, multicenter observational pilot study including CTO patients who were not eligible for an ICD and had a left ventricular ejection fraction >35 %. We enrolled patients with a successful CTO revascularization (group A) and patients with untreated CTO or failed CTO revascularization (group B). All patients received an implantable loop recorder with remote monitoring. The primary endpoint was sustained VA. ResultsNinety patients were enrolled (mean age 63 ± 10 years, 83.3 % man, mean LVEF 55 ± 8 %). Group A (n = 45) had a higher prevalence of CTO in the left anterior descending artery in comparison to group B (n = 45) (28.9 % versus 4.4 %, P = 0.002). Other baseline characteristics were similar. During a median follow-up time of 26 months (IQR, 19–35), five patients (5.6 %) had a sustained VA. There was no difference in the incidence of sustained VA between groups (3-year cumulative event rate: 8.8 % (group A) versus 4.5 % (Group B), log-rank P = 0.71). ConclusionPatients with an CTO, who do not qualify for an ICD, have a substantial risk of sustained VA. In our study the incidence was not different between patients with revascularized and those with untreated CTO.

Cardiac stereotactic radiation therapy for refractory ventricular arrhythmias in patients with left ventricular assist devices.

Left ventricular assist device (LVAD) implantation is an established treatment for patients with advanced heart failurerefractory to medical therapy. However, the incidence of ventricular arrhythmias (VAs) is high in this population, both in the acute and delayed phases after implantation. About one-third of patients implanted with anLVAD will experience sustained VAs, predisposing these patients to worse outcomes and complicating patient management. The combination of pre-existing myocardial substrate and complex electrical remodeling after LVAD implantation account for the high incidence of VAs observed in this population. LVAD patients presenting VAs refractory to antiarrhythmic therapy and catheter ablation procedures are not rare. In such patients, treatment options are extremely limited. Stereotactic body radiation therapy (SBRT) is a technique that delivers precise and high doses of radiation to highly defined targets, reducing exposure to adjacent normal tissue. Cardiac SBRT has recently emerged as a promising alternative with a growing number of case series reporting the effectiveness of the technique in reducing the VA burden in patients with arrhythmias refractory to conventional therapies. The safety profile of cardiac SBRT also appears favorable, even though the current clinical experience remains limited. The use of cardiac SBRT for the treatment of refractory VAs in patients implanted with anLVAD are even more scarce. This review summarizes the clinical experience of cardiac SBRT in LVAD patients and describes technical considerations related to the implementation of the SBRT procedure in the presence of anLVAD.

Myocardial scar characteristics by 3D-LGE cannot fully explain different arrhythmic event rates in primary and secondary prevention of sudden cardiac death

Abstract Background There is a noticeable difference in the incidence of ventricular arrhythmias among patients receiving defibrillator devices (ICD or CRT-D) for primary vs. secondary prevention of sudden cardiac death (SCD). The underlying reasons for this difference remain to be fully explained. Purpose To assess for differences in myocardial scar characteristics between patients who had defibrillator devices implanted in primary vs. secondary prevention scenarios, and their correlation with arrhythmic events. Methods In this single center retrospective study, patients who underwent late gadolinium enhancement (LGE) cardiac MRI for clinical purposes before the implantation of an ICD or CRT-D were included. Patients with channelopathies (n=2) or inappropriate imaging quality (n=7) were excluded. We used ADAS software to perform myocardial scar characterization in 3D-LGE datasets in all but 16 patients, in which 2D datasets were used. The primary endpoint was a composite of appropriate ICD therapy (appropriate shock or ATP), sustained ventricular tachycardia or SCD. Results A total of 116 patients (mean age 66±14 years, 81% male) were included, 40 (35%) with devices implanted in secondary prevention. During a median follow-up of 28 months (IQR 16-24), 23 events were identified (18 appropriate ICD therapy, 9 shocks and 9 ATP; 2 SCD; 3 sustained VT), 7 of which (30.4%) in the primary prevention group, and 16 (69.6%) in the secondary prevention group. The event rate was significantly higher in the secondary prevention setting (15.0 events per 100 persons-year [95% CI 7.7 – 22.4] vs. 4.1 events per 100 persons-year [95% CI 1.1 – 7.1]; p &amp;lt; 0.001). Despite a higher LVEF in the secondary prevention group (41 ± 14% vs. 30 ± 13%; p-value &amp;lt; 0.001), no statistically significant differences were found regarding scar tissue characteristics, namely scar and borderzone (BZ) mass, total channel mass, largest channel mass, number of channels and scar heterogeneity (BZ mass / scar mass ratio) – Table. Conclusion Despite the higher event rate in patients receiving defibrillator devices in secondary vs. prevention, no differences in myocardial scar characteristics were found between both groups. These findings suggest that arrhythmic risk is unlikely to be explained solely by the anatomical substrate, and support a greater role for the interplay between substrate and transient triggers.

Ventricular arrhythmia outcomes in hypertrophic cardiomyopathy from a high level myectomy centre

Abstract Background The presence of ≥15% late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (MRI) is used as a prognostic indicator for sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). [1] According to the European Society of Cardiology clinical practice guidelines (2014), septal myectomy is only indicated for symptomatic relief from left ventricular outflow tract obstruction (LVOTO) that is refractory to medical therapy, provided LVOTO gradient ≥ 50 mmHg. [2] At present, there is scarce data correlating the burden of ventricular arrhythmia and sudden cardiac death with LGE percentage or showing benefit of myectomy in reducing the burden of the same. Purpose We aimed to compare the burden of ventricular arrhythmia burden in patients with HCM who underwent septal myectomy compared with those who did not. Methods Adult patients with HCM followed in the advanced heart failure outpatient clinic at Allegheny General Hospital were included in this study. All included patients had cardiac MRI with LGE quantification and data related to cardiac events through devices placed for various indications (such as evaluation of reported palpitations, established supraventricular tachycardia, implantable cardioverter-defibrillator for primary or secondary prevention). Patients were divided into 2 groups: those undergoing myectomy (post myectomy group) and those that did not undergo myectomy (non-myectomy group). Chi square test was used to calculate incidence of premature ventricular contractions (PVCs), non-sustained ventricular tachycardia (NSVT) and sustained ventricular tachycardia (SVT) in the non-myectomy and post myectomy group. Results 76 patients with HCM (interventricular septal thickness ≥1.5 cm and LGE positive) longitudinally followed in the Allegheny General Hospital advanced heart failure outpatient clinic from 2016 to 2022 were included. 37 patients underwent septal myectomy. Baseline characteristics of post myectomy and non-myectomy group were matched and are listed in table 1. Left ventricular mass index was expectedly higher in patients undergoing myectomy. LGE was quantified on cardiac MRI prior to myectomy (mean 16.4% in myectomy group, 14.6% in non-myectomy group). Burden of ventricular arrhythmia (PVCs, NSVT and SVT) was found to be significantly lower in the post myectomy group (n=13, 44.83%) compared to the non-myectomy group (n=36, 92.31%). None of the patients included were noted to have ventricular fibrillation or sudden cardiac death. Conclusion Septal myectomy may reduce the incidence of ventricular arrhythmia and thus impact outcomes related to sudden cardiac death. This is likely a consequence of removal of arrhythmogenic scar tissue. Larger studies are required to further evaluate the burden and correlation of ventricular arrhythmia with scar tissue volume measured on cardiac MRI.

Arrhythmic risk stratification in patients with left ventricular ring-like scar

Abstract Background Myocardial fibrosis assessment with late gadolinium enhancement (LGE) at cardiac magnetic resonance (CMR) has recently emerged as an independent predictor of major adverse events in patients with non-ischemic cardiomyopathy. Several studies have examined different locations and extension degrees of LGE, and the so called "ring-like pattern" has been related with an increased incidence of ventricular arrhythmias, in patients with dilated cardiomyopathy (DCM), but also in patients with preserved systolic function. Purpose To describe clinical, electrocardiographic, echocardiographic, CMR and genetic features of the left ventricular (LV) ring-like scar phenotype and to evaluate which characteristics may be associated with the risk of sudden cardiac death (SCD). Methods Patients diagnosed with LV ring-like scar were identified at 6 referral Centres. Diagnosis was based on: 1) ring-like LGE LV pattern, defined as at least 3 contiguous segments with subepicardial/midwall LGE in the same slice with or without fatty infiltration; or 2) pathology examination of explanted hearts/autoptic cases suffering from sudden cardiac death (SCD). Moreover, patients must have an additional inclusion criterion: a positive genetic test, or ≥1 patient in the same family with an ascertained cardiomyopathy. Major adverse arrhythmic cardiac events (MAACE), defined as a composite of SCD, aborted SCD, and sustained ventricular tachycardia (SVT), were the primary study endpoint. Results The final cohort comprised 129 patients (male 59.7%, median age at diagnosis 44 years). During a median follow-up of 3.4 years (IQR 1.2 – 64.), MAACE occurred in 31 patients (24%). Nearly 70% of the patients had a likely pathogenic/pathogenic mutation, mostly in desmoplakin (DSP) and filamin-C (FLNC) genes (65% and 19%, respectively). Sex, QRS width, and LGE in LV anterior wall and/or apex, were the only independent predictors of the outcome events (HR: 0.329, 95% CI: 0.119-0.916, P = 0.033; HR: 1.036, 95% CI 1.019-1.053, P &amp;lt; 0.001; HR 4.270, 95% CI 1.337-13.630, P = 0.014, respectively). A significant interaction between sex and LGE in anterior wall/apex was observed, being this regions associated with MAACE only in male patients (p for interaction = 0.033). Although related to the arrhythmic endpoint at the Kaplan-Meier survival curves, neither DCM echocardiographic phenotype, nor LV ejection fraction ≤35% remained statistically associated to MAACE at the multivariate analysis. Age, genetic mutations, right ventricular involvement, proband status, LV-LGE extension (number of segments) were not statistically related to the study endpoint. Conclusions In this selected cohort of patients with LV ring-like scar and either a genetic test or family history, malignant arrhythmic events were predicted by male sex, QRS width and LGE in anterior wall and/or apex.Graphical Abstract