Sustained Ventricular Tachyarrhythmias Research Articles

Risk Factors of Cardiac Complications in Pregnant Women with Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a common inherited genetic cardiac disease during pregnancy. Studies of risk factors are of great significance for maternal and fetal outcomes. The aim of the study was to identify predictive risk factors for cardiac complications in pregnant women with HCM. One hundred patients with HCM who delivered at the Shanghai obstetrical cardiology intensive care center between January 2000 and December 2022 were retrospectively reviewed. A logistic regression model was used to identify independent risk factors for cardiac complications. Twenty-one cases were obstructive HCM (21%), 16 with cardiac function grade I and 5 with grade II; 79 cases were non-obstructive HCM (79%), 67 with cardiac function grade I, 11 with grade II, and 1 with grade III. Ninety-one cases had abnormal electrocardiogram (ECG) (91%), mainly with ST-T changes (77%). The average interventricular septum was 19.39 ± 6.13 mm by echocardiography (21.75 ± 5.86 mm for obstructive HCM and 18.73 ± 6.08 mm for non-obstructive HCM). The main cardiac complications were maternal death (n = 2, 2%), heart failure (n = 7, 7%), and sustained ventricular tachyarrhythmia (n = 1, 1%). Cardiac complications occur commonly during the third trimester and postpartum period. Three independent risk factors to predict cardiac complications in pregnant women with HCM were obstructive HCM (P = 0.036), New York Heart Association (NYHA) class ≥II (P = 0.022), and previous history of syncope (P = 0.037). HCM increases the risk of maternal death, heart failure, and malignant arrhythmia. More attention should be given to risk assessment and pregnancy management. Early detection of risk factors can reduce the incidence of maternal mortality and cardiac complications.

Therapy duration and improvement of ventricular function in de novo heart failure: the Heart Failure Optimization study.

In patients with de novo heart failure with reduced ejection fraction (HFrEF), improvement of left ventricular ejection fraction (LVEF) is expected to occur when started on guideline-recommended medical therapy. However, improvement may not be completed within 90 days. Patients with HFrEF and LVEF ≤ 35% prescribed a wearable cardioverter-defibrillator between 2017 and 2022 from 68 sites were enrolled, starting with a registry phase for 3 months and followed by a study phase up to 1 year. The primary endpoints were LVEF improvement > 35% between Days 90 and 180 following guideline-recommended medical therapy initiation and the percentage of target dose reached at Days 90 and 180. A total of 598 patients with de novo HFrEF [59 years (interquartile range 51-68), 27% female] entered the study phase. During the first 180 days, a significant increase in dosage of beta-blockers, renin-angiotensin system inhibitors, and mineralocorticoid receptor antagonists was observed (P < .001). At Day 90, 46% [95% confidence interval (CI) 41%-50%] of study phase patients had LVEF improvement > 35%; 46% (95% CI 40%-52%) of those with persistently low LVEF at Day 90 had LVEF improvement > 35% by Day 180, increasing the total rate of improvement > 35% to 68% (95% CI 63%-72%). In 392 patients followed for 360 days, improvement > 35% was observed in 77% (95% CI 72%-81%) of the patients. Until Day 90, sustained ventricular tachyarrhythmias were observed in 24 wearable cardioverter-defibrillator carriers (1.8%). After 90 days, no sustained ventricular tachyarrhythmia occurred in wearable cardioverter-defibrillator carriers. Continuous optimization of guideline-recommended medical therapy for at least 180 days in HFrEF is associated with additional LVEF improvement > 35%, allowing for better decision-making regarding preventive implantable cardioverter-defibrillator therapy.

Chronic inflammatory cardiomyopathy and its overlap with arrhythmogenic cardiomyopathy: long-term follow-up of a prospective single-centre cohort study

Abstract Background Chronic Inflammatory Cardiomyopathy (infl-CMP) may overlap with Arrhythmogenic Cardiomyopathy (ACM), a group of conditions with similar ventricular arrhythmic phenotypes and key imaging, electrocardiographic, histopathological, and genetic features. Purpose This single-centre cohort study aimed to assess the role of pathogenic genetic variants of ACM in long-term follow-up of patients with infl-CMP and ventricular arrhythmic phenotype. Methods In this prospective, single-centre study, 24 consecutive patients with suspected infl-CMP and ventricular arrhythmic phenotype were enrolled at our tertiary referral hospital between 2017 and 2022. Baseline demographic and clinical characteristics of the patients were collected. All patients underwent extensive workup, including electrocardiography, echocardiography, cardiac magnetic resonance, and genetic counselling and testing. Endomyocardial biopsy was performed if a definite diagnosis had not been reached after non-invasive diagnostic workup. Patients were classified according to phenotype as ACM (either definite or borderline), as indicated by the 2010 Padua Criteria, and genetically classified as genotype-positive or genotype-negative according to the presence of pathogenic variants for ACM. Long-term follow-up was performed to assess cardiovascular morbidity and mortality. The primary outcome was the occurrence of in-hospital admission for sustained ventricular tachyarrhythmias. Results At admission, 5 (21%) patients presented with syncope, 19 (79%) with high ventricular burden (&amp;gt;25% premature ventricular contractions) or with sustained ventricular tachyarrhythmias. After complete diagnostic work-up, 17 patients (71%) received a diagnosis of either definite or borderline ACM, while the remaining 7 patients (29%) received a diagnosis of infl-CMP. In 18 patients (75.0%), an endomyocardial biopsy was required as part of the diagnostic workup. In our population, the frequency of pathogenic ACM variants was 41% (8 variants in ACM patients and 2 variants in infl-CMP); in particular, pathogenic genetic variants coexisted in 2 patients (1 in the ACM group: PKP2 and KCNE1 mutations; 1 in the infl-CMP group: DSG2 and TMEM43 mutations). At a mean follow-up of 4.37 (SD ±1.77) years, the primary outcome occurred in 8 patients (33%), all identified as borderline or definite ACM (X²=4.94, p=0.026). Notably, sustained ventricular tachyarrhythmias occurred in 25% of genotype-negative and 50% of genotype-positive patients (X²=1.50, p=0.220). Conclusions Criteria-driven diagnosis of ACM was significantly associated with the occurrence of sustained ventricular tachyarrhythmias at long-term follow up. The presence of pathogenic genetic variants of ACM did not clearly stratify the ventricular arrhythmic risk as a single factor in our cohort of patients with ventricular arrhythmic phenotype.

Clinical findings and outcomes of Brugada syndrome in women

Abstract Introduction Brugada syndrome (BrS) is a genetic disorder characterized by typical ECG changes and association with spontaneous ventricular tachyarrhythmia (VTA) and sudden death in young patients. BrS has been widely established to be particularly prevalent in men, however less information exists regarding female patients and their long-term risk. Objectives The purpose of this study was to investigate the clinical characteristics and long-term prognosis of women with BrS. Methods This study includes a retrospective analysis of a single-center cohort of patients followed and observed for relevant clinical outcomes. The data collected included demographic data, severity of symptoms (e.g. syncope, VTA), cardioverter-defibrillator logs and occurrence of sudden cardiac death. Results 317 patients were diagnosed with BrS between 1998 and 2023. Among those, 112 (36%) were female. At presentation, 5 patients (4%) were symptomatic with history of survived cardiac arrest and/or documented VTA. 29 (26%) had history of unexplained syncope and 78 (70%) were asymptomatic. The average age at diagnosis was 42.1±15.1 yrs. as opposed to 40.1±14.2 yrs. in men. Females presented less frequently with a type 1 ECG pattern (5% vs 21%; p&amp;lt;0.01), had a trend to a higher rate of family history of sudden cardiac death (31% vs 25%; p=n.s.), and had less sustained VTA during programmed ventricular stimulation (4% vs 19%; p&amp;lt;0.01). Genetic testing was performed in 89 females (79% of the sample) and pathogenic variants were present in 36 (40%) women. An implantable cardioverter defibrillator was inserted in 24 (31%) females for primary prevention. During mean follow-up of 138±72 months, 11 women had cardiovascular events (syncope, VT/VF or death). Syncope was most common and occurred in 8 cases. No VTA were documented in any female patient. In the group of ICD patients, 8 shocks have occurred. None of these were deemed appropriate by medical controls. There were 3 deaths. Two were considered non-arrhythmic due to pulmonary embolism and breast carcinoma. One ICD patient died suddenly during sleep. Unfortunately, no device interrogation data was available. Conclusion Women typically present less symptomatic and demonstrate a reduced incidence of life-threatening arrhythmias during follow-up , often experiencing a frequent occurrence of inappropriate implantable defibrillator therapy. The less frequent prevalence of the BrS ECG pattern in women adds complexity to the diagnostic process. Further studies are still needed to elucidate gender differences for risk stratification of BrS.

Prognostic Value of [99mTc]Tc-DPD Quantitative SPECT/CT in Patients with Suspected and Confirmed Amyloid Transthyretin-Related Cardiomyopathy and Preserved Left Ventricular Function.

Quantitative 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid ([99mTc]Tc-DPD) SPECT may be used for risk-stratifying patients with amyloid transthyretin-related cardiomyopathy (ATTR-CM). We aimed to analyze the predictive value of quantitative [99mTc]Tc-DPD SPECT/CT in suspected and confirmed ATTR-CM according to different disease stages. Methods: The study enrolled consecutive patients with suspected ATTR-CM who were referred to a single tertiary center and underwent quantitative [99mTc]Tc-DPD SPECT/CT allowing SUVmax and SUVpeak analysis. Patients were divided into 2 groups according to left ventricular ejection fraction (LVEF) at baseline (i.e., ≥50% and <50%). Clinical, laboratory, and echocardiographic parameters and major adverse cardiac events (i.e., all-cause death, sustained ventricular tachyarrhythmia, hospitalization for heart failure, implantation of a cardioverter defibrillator) were investigated for any correlation with quantitative uptake values. Results: In total, 144 patients with suspected ATTR-CM were included in the study (98 with LVEF ≥ 50% and 46 with LVEF < 50%), of whom 99 were diagnosed with ATTR-CM (68.8%; 69 with LVEF ≥ 50% and 30 with LVEF < 50%). A myocardial SUVmax of at least 7 was predictive of major adverse cardiac events at 21.9 ± 13.0 mo of follow-up (hazard ratio, 2.875; 95% CI, 1.23-6.71; P = 0.015) in patients with suspected or confirmed ATTR-CM (global χ2 = 6.892, P = 0.02) and an LVEF of at least 50%. SUVmax was not predictive in patients with an LVEF of less than 50% and suspected or confirmed ATTR-CM. Conclusion: In patients with suspected or confirmed ATTR-CM and preserved LVEF, representing an early disease stage, quantitative [99mTc]Tc-DPD SPECT should be considered to improve early-stage risk stratification.

Characteristics Associated with Ventricular Tachyarrhythmias and Their Prognostic Impact in Heart Failure with Mildly Reduced Ejection Fraction.

Background: The occurrence of ventricular tachyarrhythmias represents an established risk factor of mortality in heart failure (HF). However, data concerning their prognostic impact in heart failure with mildly reduced ejection fraction (HFmrEF) is limited. Therefore, the present study aims to investigate patient characteristics associated with ventricular tachyarrhythmias and their prognostic impact in patients with HFmrEF. Methods: Consecutive patients hospitalized with HFmrEF (i.e., left ventricular ejection fraction 41-49% and signs and/or symptoms of HF) were retrospectively included at one institution from 2016 to 2022. The prognosis of patients with HFmrEF and different types of ventricular tachyarrhythmias (i.e., non-sustained ventricular tachycardia (nsVT), sustained VT (sVT), and ventricular fibrillation (VF) was investigated for the primary endpoint of long-term all-cause mortality at 30 months. Secondary endpoints included in-hospital all-cause mortality and long-term HF-related rehospitalization at 30 months. Results: From a total of 2184 patients with HFmrEF, 4.4% experienced ventricular tachyarrhythmias (i.e., 2.0% nsVT, 0.7% sVT, and 1.6% VF). The occurrence of nsVT was associated with higher New York Heart Association (NYHA) functional class, whereas the incidence of sVT/VF was associated with acute myocardial infarction and ischemic heart disease. However, nsVT (25.0%; HR = 0.760; 95% CI 0.419-1.380; p = 0.367) and sVT/VF (28.8%; HR = 0.928; 95% CI 0.556-1.549; p = 0.776) were not associated with a higher risk of long-term all-cause mortality compared to patients with HFmrEF without ventricular tachyarrhythmias (31.5%). In-hospital cardiovascular mortality was more frequently observed in patients with HFmrEF and sVT/VF compared to those with HFmrEF but without sustained ventricular tachyarrhythmias (7.7% vs. 1.5%; p = 0.004). Finally, the risk of rehospitalization for worsening HF was not affected by the presence of ventricular tachyarrhythmias. Conclusions: The occurrence of ventricular tachyarrhythmias in patients hospitalized with HFmrEF was low and not associated with long-term prognosis.

Burden of cardiac arrhythmias in patients with acute myocardial infarction and their impact on hospitalization outcomes: insights from China acute myocardial infarction (CAMI) registry

BackgroundThe coexistence of cardiac arrhythmias in patients with acute myocardial infarction (AMI) usually exhibits poor prognosis. However, there are few contemporary data available on the burden of cardiac arrhythmias in AMI patients and their impact on in-hospital outcomes.MethodsThe present study analyzed data from the China Acute Myocardial Infarction (CAMI) registry involving 23,825 consecutive AMI patients admitted to 108 hospitals from January 2013 to February 2018. Cardiac arrhythmias were defined as the presence of bradyarrhythmias, sustained atrial tachyarrhythmias, and sustained ventricular tachyarrhythmias that occurred during hospitalization. In-hospital outcome was defined as a composite of all-cause mortality, cardiogenic shock, re-infarction, stroke, or heart failure.ResultsCardiac arrhythmia was presented in 1991 (8.35%) AMI patients, including 3.4% ventricular tachyarrhythmias, 2.44% bradyarrhythmias, 1.78% atrial tachyarrhythmias, and 0.73% ≥2 kinds of arrhythmias. Patients with arrhythmias were more common with ST-segment elevation myocardial infarction (83.3% vs. 75.5%, P < 0.001), fibrinolysis (12.8% vs. 8.0%, P < 0.001), and previous heart failure (3.7% vs. 1.5%, P < 0.001). The incidences of in-hospital outcomes were 77.0%, 50.7%, 43.5%, and 41.4%, respectively, in patients with ≥ 2 kinds of arrhythmias, ventricular tachyarrhythmias, bradyarrhythmias, and atrial tachyarrhythmias, and were significantly higher in all patients with arrhythmias than those without arrhythmias (48.9% vs. 12.5%, P < 0.001). The presence of any kinds of arrhythmia was independently associated with an increased risk of hospitalization outcome (≥ 2 kinds of arrhythmias, OR 26.83, 95%CI 18.51–38.90; ventricular tachyarrhythmias, OR 8.56, 95%CI 7.34–9.98; bradyarrhythmias, OR 5.82, 95%CI 4.87–6.95; atrial tachyarrhythmias, OR4.15, 95%CI 3.38–5.10), and in-hospital mortality (≥ 2 kinds of arrhythmias, OR 24.44, 95%CI 17.03–35.07; ventricular tachyarrhythmias, OR 13.61, 95%CI 10.87–17.05; bradyarrhythmias, OR 7.85, 95%CI 6.0-10.26; atrial tachyarrhythmias, OR 4.28, 95%CI 2.98–6.16).ConclusionCardiac arrhythmia commonly occurred in patients with AMI might be ventricular tachyarrhythmias, followed by bradyarrhythmias, atrial tachyarrhythmias, and ≥ 2 kinds of arrhythmias. The presence of any arrhythmias could impact poor hospitalization outcomes.RegistrationClinical Trial Registration: Identifier: NCT01874691.

Whether to implant a defibrillator or not? The Possibility of Using the MADIT-ICD Benefit Score Calculator in Real Practice

To study the predictive capabilities of the MADIT-ICD Benefit Score calculator in assessing the benefit of implantable cardioverter defibrillator (ICD) placement for the primary prevention of sudden cardiac death (SCD). This study included 388 patients with NYHA II-IV functional class chronic heart failure (CHF) with a left ventricular ejection fraction (LVEF) ≤35 % who underwent ICD placement for the primary prevention of SCD. Patients were followed up for two years to record the endpoints of first-time paroxysmal sustained ventricular tachyarrhythmia (VT) or non-arrhythmic death. According to the results of calculation with the MADIT-ICD Benefit Score calculator, 276 (71 %) patients had a high risk of VT (score ≥7) and 150 (39 %) had a high risk of non-arrhythmic death (score ≥3). 336 (94%) patients would benefit from an ICD: 148 (38 %) with a high level of probability and 218 (56 %) with a medium level of probability. According to the incidence of endpoints, VT episodes predominated in the low-ICD benefit group (36%), while the high-ICD benefit group had a relatively high incidence of non-arrhythmic death (12%). The results obtained for a cohort of Russian patients with CHF and reduced LVEF indicated that the use of the MADIT-ICD Benefit Score in routine clinical practice does not improve the stratification of SCD risk compared to the traditional approach to selecting patients with CHF for ICD based on the LVEF value.

Cancer Treatment–Related Complications in Patients With Hypertrophic Cardiomyopathy

ObjectiveTo describe the potential clinical cardiotoxicity of oncological treatments in a cohort of consecutive patients with hypertrophic cardiomyopathy (HCM), systematically followed-up at two national referral centers for HCM. Cardiotoxicity relates to the direct effects of cancer-related treatment on heart function, commonly presenting as left ventricular contractile dysfunction. However, limited data are available regarding cardiotoxic effects on HCM as most studies have not specifically analyzed the effects of oncological treatment in HCM populations. This gap in knowledge may lead to unjustified restriction of HCM patients from receiving curative cancer treatments. MethodsWe retrospectively analyzed clinical and instrumental data of all consecutive HCM patients who underwent oncological treatment between January 2000 and December 2020 collected in a centralized database. ResultsOf 3256 HCM patients, 121 (3.7%) had cancer; 110 (90.9%) underwent oncological surgery, 45 (37.2%) received chemotherapy, and 22 (18.2%) received chest radiation therapy (cRT). After a median follow-up of 5.2 years (Q1-Q3: 2-13 years) from oncological diagnosis, 32 patients died. The cumulative survival at 5 years was 79.9%. The cause of death was mainly attributed to the oncological condition, whereas four patients died of sudden cardiac death without receiving previous chemotherapy or cRT. No patient interrupted or reduced the dose of oncological treatment due to cardiac dysfunction. No sustained ventricular tachyarrhythmia was induced by chemotherapy or radiation therapy. ConclusionCancer treatment was well tolerated in HCM patients. In our consecutive series, none died of cardiovascular complications induced by chemotherapy or cRT and they did not require interruption or substantial treatment tapering due to cardiovascular toxic effects. Although a multidisciplinary evaluation is necessary and regimens must be tailored individually, the diagnosis of HCM per se should not be considered a contraindication to receive optimal curative cancer treatment.

Significant delayed conduction and characteristic ventricular tachycardias in patients with cardiac sarcoidosis and electrical storm.

Electrical storm (ES) of ventricular tachyarrhythmias (VTAs) is an important cause of sudden death in patients with cardiac sarcoidosis (CS). VTAs in CS are associated with myocardial scarring and inflammation. However, little is known about the risk factors of ES in patients with CS and VTAs. The objective of this study is to clarify the characteristics and risk factors for the development of ES in patients with CS. The study population included consecutive 52 patients with CS and sustained VTA. Twenty-five out of 52 patients experienced ES. We evaluated clinical characteristics, imaging modalities, and electrocardiogram (ECG) parameters to determine the risk factors associated with ES. Half of the patients experienced VTAs as the initial symptom of sarcoidosis, and eight patients had ES as the initial VTA episode. There were no differences in cardiac imaging abnormalities between patients with and without ES. Among ECG markers, significant QRS fragmentation (odds ratio [OR]: 7.9, p = .01) and epsilon waves (OR: 12.24, p = .02) were associated with ES. Among the ventricular tachycardia (VT) characteristics, multiple morphologies of monomorphic VTs (OR: 10.9, p < .01), short VT cycle lengths (OR: 12.5, p < .01), and polymorphic VT (OR: 13.5, p < .01) were associated with ES. Bidirectional VTs were detected in 10 patients with ES and one patient without ES. Immunosuppressive therapy relieved ES in some patients. ES was common in patients with CS and VTAs. Significant depolarization abnormalities that appeared as QRS fragmentation, epsilon waves, and specific VT characteristics were associated with ES.

Incidence of sustained ventricular tachyarrhythmias in patients with non-ischemic cardiomyopathy in a multicenter multinational WCD cohort

Abstract Background Defibrillator use in patients with non-ischemic cardiomyopathy (NICM) and HFrEF remains controversial after the DANISH study. The new ESC guidelines recommend individualized risk stratification in these patients. The wearable cardioverter-defibrillator (WCD) seems to be appropriate to both protect and screen patients with HFrEF at risk for sudden cardiac death (SCD). Puropose: To evaluate the rate of ventricular tachyarrhythmias (VT/VF) in NICM vs. ICM patients receiving a WCD for temporary SCD protection. Methods 1157 patients were included in a multicenter registry from eight European centers. Among these patients, 602 patients received a WCD due to ischemic cardiomyopathy (ICM) and 555 patients for non-ischemic cardiomyopathy (NICM). Incidence of VT/VF and/or appropriate WCD shock discharge during WCD use were evaluated. The mean follow-up (FU) time of the whole cohort was 620.2±607.8 days. Results NICM patients were younger (mean 56.5±14.8a vs 63.9±11.6a; p&amp;lt;0.001) and less often male (75% vs. 87.2%; p&amp;lt;0.001) compared to ICM patients. Heart failure medication at hospital discharge did not differ between the two groups except for a higher prescription rate of aldosterone-antagonists in NICM compared to ICM patients (73.8% vs. 66.7%; p=0.02). The index left ventricular ejection fraction (LVEF) was significantly lower in NICM compared to ICM patients (mean 26.1±9.1% versus 29.5±9.2%; p&amp;lt;0.001). A larger extent of LVEF recovery was detected in NICM patients compared to ICM patients up to the end of WCD use (mean LVEF post WCD: 45.7±35.4% vs. 40.2±11.8%; p=0.02). Average daily WCD wear-time was significantly lower in NICM patients compared to ICM patients (mean 20.7±4.9h vs. 21.6±3.7h; p=0.01). NICM patients had a significantly lower incidence of sustained ventricular tachyarrhythmia (VT/VF) compared to ICM patients (3.4% vs. 6.6%; p=0.02). Consistently, rate of appropriate WCD shock was significantly lower in NICM vs. ICM patients (0.7% vs. 3.7%; p&amp;lt; 0.001), as was rate of re-hospitalization (30.2% vs. 46.1%; p&amp;lt;0.001). Both groups showed a similar mortality rate during FU. Conclusions Patients at risk for SCD with NICM showed a more pronounced LVEF recovery, significantly lower incidence of VT/VF with concomitant shocks and hospitalization, while overall mortality was unchanged compared to ICM patients. These results indicate that WCD use might facilitate individual SCD risk stratification in NICM patients.

Functional mitral regurgitation and ventricular arrhythmias in patients with cardiac resynchronization therapy

Abstract Introduction In patients with heart failure (HF), the occurrence of ventricular arrhythmias (VAs) is associated with prognosis, and advanced HF can cause VAs. In HF patients developed moderate to severe functional mitral regurgitation (FMR), a transcatheter mitral valve repair therapy has significantly reduced the hospitalization and mortality rates compared to guideline-directed medical therapy. Although the mechanisms of arrhythmias are multiple, it is unclear whether FMR is involved in the development of VAs advanced HF patients. Methods and results We retrospectively examined 176 cardiac resynchronization therapy (CRT) patients (78% men, median age 67 years) without FMR before CRT implanted between 2010 and 2018. Worsening FMR was defined as developing moderate to severe FMR after CRT. During median follow-up of 40 (quartile range, 23-60) months, worsening FMR was detected in 26 (15%) patients at a median of 30 (quartile range, 12–75) months after CRT implantation. There was no difference in age, New York Heart Association functional class, QRS width before CRT and the rate of responders between patients with and without worsening FMR. Patients with worsening FMR had a tendency of larger left ventricular end-systolic dimension (58 [53-68] vs. 53 [47-60] mm, p&amp;lt;0.10), a significantly higher rate of female (38% vs. 19%, p&amp;lt;0.05) and a significantly larger left atrial volume index (LAVI) (63 [43-81] vs. 48 [35-62] ml/m2, p&amp;lt;0.05). By multivariate logistic regression analysis, female gender (odds ratio 4.3) and baseline LAVI (odds ratio 1.04 per a ml/m2 increase) were independent factors associated with worsening FMR. There was a significantly higher incidence of HF hospitalization (50% vs 15%, log-rank P&amp;lt;0.05) (Figure 1) and a higher incidence of VAs, defined as sustained ventricular tachyarrhythmias requiring implantable-cardioverter defibrillator therapy or external defibrillation, in patients with worsening FMR than patients without worsening FMR (65% vs 38%, log-rank P&amp;lt;0.05) (Figure 2). Multivariate analysis showed that worsening FMR was independently associated with the development of VAs (hazard ratio 2.77, 95% confidence interval 1.13-6.83). Conclusions In patients with HF and CRT, female gender and baseline LAVI were associated with worsening FMR after CRT. We need to pay attention to changes in the FMR that can be associated with developing VAs after CRT implantation.

Lidocaine as an anti-arrhythmic drug: Are there any indications left?

Lidocaine is classified as a class Ib anti-arrhythmic that blocks voltage- and pH-dependent sodium channels. It exhibits well investigated anti-arrhythmic effects and has been the anti-arrhythmic of choice for the treatment of ventricular arrhythmias for several decades. Lidocaine binds primarily to inactivated sodium channels, decreases the action potential duration, and increases the refractory period. It increases the ventricular fibrillatory threshold and can interrupt life-threatening tachycardias caused by re-entrant mechanisms, especially in ischemic tissue. Its use was pushed into the background in the era of amiodarone and modern electric device therapy. Recently, lidocaine has come back into focus for the treatment of acute sustained ventricular tachyarrhythmias. In this brief overview, we review the clinical pharmacology including possible side effects, the historical course, possible indications, and current Guideline recommendations for the use of lidocaine.

Importance of blood biomarker determination in the selection of patients with heart failure for cardioverterdefibrillator implantation

Aim. To conduct a comparative analysis of blood biomarker concentrations, to study their prognostic role in the occurrence of sustained ventricular tachyarrhythmia (VT) or VT episodes requiring electrotherapy in patients with heart failure (HF) and left ventricular ejection fraction (LVEF) ≤35% without prior syncope or sustained ventricular arrhythmias.Material and methods. This single-center prospective clinical study included 319 patients (men, 83%) aged 57 (51-63) years with LVEF of 29 (24-33)% receiving optimal therapy for HF, hospitalized for cardioverterdefibrillator implantation for the purpose of primary prevention of sudden cardiac death. Before the procedure, the concentration of blood biomarkers (blood electrolytes, C-reactive protein, creatinine, Soluble suppression of tumorigenicity 2 (sST2), N-terminal pro-brain natriuretic peptide (NT-proBNP), galectin-3) was determined. Based on blood creatinine concentration, glomerular filtration rate was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. Patients underwent a two-year prospective follow-up to record the end point of newly occurring clinically significant VT episodes detected by an implantable cardioverter-defibrillator.Results. The studied arrhythmic endpoint occurred in 84 (26,3%) patients. The multivariate analysis revealed three blood biomarkers, the concentration of which was associated with the first manifestation of VT. With sST-2 &gt;35 ng/ml, this risk increased by ~3 times (odds ratio (OR)=2,86; 95% confidence interval (CI): 1,23-6,64 (p=0,013)). Galectin-3 level &gt;12 ng/ml had a comparable prognostic value (OR=2,64; 95% CI: 1,06-6,53 (p=0,032)). In case of an increase in NT-proBNP &gt;2000 pg/ml, the risk of the same outcome was 2,2 times lower (OR=0,46; 95% CI: 0,22-0,95 (p=0,034)).Conclusion. Pre-implantation laboratory screening of NT-proBNP, sST-2 and galectin-3 concentrations can help in personalized assessment of arrhythmic risk in patients with HF and LVEF ≤35% referred for interventional primary prevention of sudden cardiac death.

Etiologies, Mechanisms, Management, and Outcomes of Electrical Storm.

Electrical storm (ES) is characterized by three or more discrete sustained ventricular tachyarrhythmia episodes occurring within a limited time frame (generally ≤ 24 h) or an incessant ventricular tachyarrhythmia lasting > 12 h. In patients with an implantable cardioverterdefibrillator (ICD), ES is defined as three or more appropriate device therapies, separated from each other by at least 5 min, which occur within a 24-h period. ES may constitute a medical emergency, depending on the number arrhythmic episodes, their duration, the type, and the cycle length of the ventricular arrhythmias, as well as the underlying ventricular function. This narrative review was facilitated by a search of MEDLINE to identify peer-reviewed clinical trials, randomized controlled trials, meta-analyses, and other clinically relevant studies. The search was limited to English-language reports published between 1999 and 2023. ES was searched using the terms mechanisms, genetics, channelopathies, management, pharmacological therapy, sedation, neuraxial modulation, cardiac sympathetic denervation, ICDs, and structural heart disease. Google and Google scholar as well as bibliographies of identified articles were reviewed for additional references. This manuscript examines the current strategies available to treat ES and compares pharmacological and invasive treatment strategies to diminish ES recurrence, morbidity, and mortality.

Cardiac resynchronization therapy: potential for arrhythmic risk modification

Aim. To evaluate the impact of cardiac resynchronization therapy (CRT) on the risk of sustained ventricular tachyarrhythmias (VT) in patients with heart failure (HF) with a implantable cardioverter-defibrillator (ICD) for the primary prevention of sudden cardiac death.Material and methods. This single-center prospective clinical study included 470 patients (men, 84%) with HF at the age of 57 (51-62) years with a left ventricular ejection fraction (LVEF) of 29 (25-33)%. There were following exclusion criteria: indications for cardiac surgery, known channelopathies, previously registered VT. Depending on intraventricular conduction disorders, dual-chamber ICDs (42%) or CRT-D (58%) were implanted. After ICD implantation, patients were followed up for 24 months to register the end point — a first-time sustained paroxysm of VT detected by the ICD. A positive response to CRT was established in the case of an increase in LVEF by ≥5% of the initial level.Results. A total of 388 patients underwent full postoperative follow-up. The studied arrhythmic endpoint occurred on average 21 (0,6) months after implantation in 104 patients (27%) with higher frequency in the ICD group. However, the differences in the VT rate in the study groups were statistically unreliable (30% in the ICD group versus 24% in the CRT-D group, p=0,142). It was found that the VT rate was reliably lower in CRT-responders (118 patients, 53%): 15% compared to 32% in the group of inefficient CRT. A 5% increase in the LFEF reduced the probability of VT occurrence by 3 times (odds ratio [OR]=0,34; 95% of CI: 0,13-0,86; p=002). Significant modification of arrhythmic risk was verified by increasing LFEF to 36-40% (OR=0,72; 95% CI: 0,63-0,82; p=0,04).Conclusion. The results obtained indicate that effective CRT has the potential to modify arrhythmic risk in patients with HF, especially with an increase in LVEF to the level of 36-40%.

Invasive electrophysiology study guided loop recorder implantation in myotonic dystrophy type 1: a prospective single-center study

Abstract Funding Acknowledgements Type of funding sources: None. Introduction In one third of the patients with myotonic dystrophy type 1 (DMT1) the cause of death is of cardiac origin. The most common cardiac manifestations are arrhythmias and conduction disturbances. Purpose Due to its extreme long monitoring properties, implantable loop recorders (ILRs) are highly suitable to detect rare cardiac arrhythmias. To date, there are only limited data using ILRs in DMT1. We aimed to evaluate the role of the invasive electrophysiology study (EPS)-guided loop recorder implantation in patients with DMT. Methods In our prospective study 18 genetically confirmed DMT1 patients underwent non-invasive cardiac examination including transthoracic echocardiography, 24-hour Holter monitoring and surface ECG. In addition, EPS was performed in all cases to evaluate the risk of sudden cardiac death and infra-Hisian conduction properties. Based on the performed non-invasive diagnostic evaluation and EPS findings, patients were divided into low, intermediate and high-risk groups. For patients with normal investigation results and normal HV interval (&amp;lt;55 ms) only annual cardiac follow-up visits were planned (low-risk group). Patients with increased PR interval (&amp;gt;240 ms), QRS duration (&amp;gt;120 ms), or slightly prolonged HV interval (55-70 ms) underwent implantable loop recorder (ILR) implantation (intermediate-risk group). Permanent pacemaker (PM) or implantable cardiac defibrillator (ICD) was implanted in patients with 2nd/3rd degree atrioventricular block (AVB), significantly prolonged HV interval (&amp;gt;100 ms) or if sustained ventricular tachyarrhythmia could be induced during EPS. All patients were followed for at least 3 years. Results According to our study criteria, 8 patients could be categorized as "intermediate risk", 7 of them received implantable loop recorder (ILR). 1 ILR had to be removed 3 weeks after implantation due to skin infarction. During three-years of follow-up, 2 patients had many asymptomatic atrial high-rate episodes, but no 2nd or 3rd degree AVB, significant asystole or malignant ventricular arrhythmia were detected. Conclusions Our single-center prospective study examined the EPS-guided ILR implantation for the risk stratification of DMT1 patients for the first time. A more extensive, multicenter study is warranted to define optimal management of DMT1 patients with slightly impaired infrahisian conduction.

PO-04-226 RISK OF VENTRICULAR RECURRENT TACHYARRHYTHMIA IN PATIENTS RECEIVING PRIMARY PREVENTION IMPLANTABLE CARDIOVERTER-DEFIBRILLATORS

Implantable cardioverter-defibrillators (ICDs) have demonstrated efficacy in reducing mortality attributable to sustained ventricular tachyarrhythmia (VTA) and have been used for primary prevention of sudden death. However, patients with primary prevention ICDs remain at risk for first and recurrent VTA, which are associated with increased morbidity and mortality. Currently, there are limited data on factors associated with recurrent VTA after the occurrence of a first episode in this population. Improved risk stratification may help tailor advanced therapies, such as catheter ablation or antiarrhythmic medications, to patients at a high risk for recurrence. The objective of this study was to quantify the risk for recurrent VTA after the occurrence of a first VTA episode among patients with a primary prevention ICD. The population comprised patients enrolled in five landmark ICD trials (MADIT-II, MADIT-Risk, MADIT-CRT, MADIT-RIT, RAID) who experienced a first episode of VTA (defined as ventricular tachycardia [VT] ≥170 bpm or ventricular fibrillation [VF]) after ICD implantation (N=789). The primary endpoint was recurrent VTA after a first episode. All-cause mortality associated with recurrent VTA was a secondary endpoint. Among 789 study patients who experienced a first VTA after ICD implantation, mean age was 63 ± 11 years, 17% were women, 64% had ischemic cardiomyopathy, and mean left ventricular ejection fraction (EF) was 24 ± 7%. Kaplan Meier analysis showed the risk of recurrent VTA after a first episode was very high (60% at 3 years [Figure - A]). Findings were consistent regardless of baseline risk factors, including age, sex, NYHA Class, EF. Furthermore, the burden of multiple VTA episodes after a first episode was also high (average of 3.6 episodes per patient at 3 years [Figure B]). Recurrent VTA was associated with a significant two-fold increased risk of subsequent death (HR=2.15, 95% CI 1.40-3.32, p=0.001 [Figure - C]). Among primary prevention ICD recipients who experience a first VTA, the burden of recurrent VTA and subsequent mortality increase is very high regardless of baseline risk factors. Intensification of therapies, including early catheter ablation, should be considered in primary prevention ICD recipients who experience a first VTA.

Conduction Disturbances and Arrhythmia Risk After Septal Reduction Therapy with Alternative Agents: A Pilot Study with EVOH-DMSO and Systematic Review.

Surgical septal myectomy and alcohol septal ablation are recommended treatment modalities for alleviating Left ventricular outflow tract (LVOT) gradient in obstructive HCM. Alcohol septal ablation offers advantages over surgery in many ways. However, it is associated with some life-threatening complications. For this purpose, our center used alternative agents for septal artery embolization. This study compared and evaluated conduction system defects and arrhythmia risk after EVOH-DMSO septal ablation with other alternative agents and alcohol septal ablation. Twenty-five patients who received septal reduction therapy with EVOH-DMSO were analyzed retrospectively, and all non-alcoholic agent's septal ablation studies were systematically reviewed and compared. Twenty-five patients (52% female; mean age: 55.8 ± 17.1) with symptomatic obstructive HCM were enrolled. The Peak LVOT gradient was significantly reduced after the procedure (68 vs. 20 mmHg; P <0.001). During the 12-month follow-up, no mortality occurred. The complete atrioventricular block was noted in 2 (8%) patients. The incidence of right bundle branch block (RBBB) increased after the procedure (pre-procedural 2 patients (8%), post-procedural 9 patients (36%) P = 0.002). On ECG and Holter monitorization, no sustained ventricular tachyarrhythmia occurred during follow-up, and no change was found in the frequency of atrial fibrillation. We systematically compared EVOH-DMSO to other non-alcohol agents, and we found that EVOH-DMSO can cause conduction system problems more commonly than other non-alcohol agents. EVOH-DMSO could cause conduction system problems more common than other non-alcohol agents but less than alcohol septal ablation.

332 RIGHT VENTRICULAR STRAIN IN FABRY CARDIOMYOPATHY: PROGNOSTIC IMPLICATIONS

Abstract Left ventricular (LV) hypertrophy is the main feature of Fabry cardiomyopathy (FC), but the right ventricle (RV) is also frequently affected. Previous studies failed to demonstrate an independent association between RV hypertrophy or conventional parameters of RV function and the occurrence of adverse outcomes in patients with FC. Nevertheless, if RV free wall strain (RV-FWS), assessed by 2D speckle tracking analysis, may provide a better prognostication is currently unexplored. We retrospectively evaluated the association between RV-FWS and the occurrence of cardiovascular events in a cohort of 28 patients with FC. The study endpoint comprises the occurrence of cardiovascular mortality, severe heart failure symptoms, new-onset atrial fibrillation, bradyarrhythmias requiring pacemaker implantation and sustained ventricular tachyarrhythmias. The median value of RV-FWS was 21.4% (interquartile range:17.1-23.9%) and a total of 18 (64%) patients showed reduced RV-FWS (&amp;lt;23%). During a median follow-up of 49 (IQR: 37-51) months, 17 (61%) patients met the study endpoint. A ROC-curve analysis confirmed the previously defined threshold of reduced RV-FWS (23%) as the best cut-off for predicting cardiovascular outcomes at 4 years (area under curve: 0.76; p-value=0.018), but with a lower predictive value in comparison to left-sided parameters (Panel A). Kaplan-Meier survival curves showed significantly lower event-free survival at 4 years in patients with impaired RV-FWS as compared to patients with preserved RV-FWS (log rank p=0.013) (Panel B). On univariable Cox regression analysis, RV-FWS expressed as continuous variable was significantly associated with the study endpoint (Hazard ratio [HR]: 0.85, 95% CI: 0.75-0.96, p=0.009). RV-FWS retained an independent association with outcomes after alternative adjustment for age (p=0.048) or indexed LV mass (p=0.036). Conversely, RV-FWS was not significantly associated with cardiovascular events, after correcting for LV global longitudinal strain or indexed left atrial volume (p=0.401 and p=0.208; respectively). In Conclusion, impaired RV-FWS was not independently associated with the occurrence of cardiovascular events in FC, confirming previous observations that prognosis is mainly driven by the severity of LV cardiomyopathy.