Burden Of Ventricular Arrhythmias Research Articles

Ventricular arrhythmia burden during different physical activities in patients with arrhythmogenic right ventricular cardiomyopathy: preliminary analysis

Abstract Background Patients suffering from arrhythmogenic right ventricular cardiomyopathy (ARVC) should avoid intense endurance exercise to reduce the risk of adverse cardiac events and disease progression. While an active lifestyle would be preferable to a sedentary one, evidence for safe levels of physical activity in ARVC, however, is scarce. Purpose This study aimed to describe the ventricular arrhythmia burden experienced during exercise and immediate recovery - estimated as the prevalence of premature ventricular contractions (PVC) - of different exercise modalities and intensities on ARVC patients. Methods This preliminary analysis includes four (1F, 33±12 yrs, BMI 24±4 kg/m2) ARVC patients harboring a pathogenic plakophilin-2 variant and carrying an implantable cardioverter-defibrillator that performed different exercises while monitored via 12-lead ECG. The order of modalities was randomized and participants instructed to stop when surpassing perceived exertion of 15 on the Borg 6-20 scale. Resistance exercises included two-legged squats and single arm biceps curls (20 repetitions and 2 min duration). Endurance exercise included 5 min of treadmill walking and 3-min cycling bouts at heart rates (HR) of 80, 100 and 120 bpm, as well as cycling at 120 bpm with 2 additional min of active cool down. Blood lactate concentration was assessed after each cycling bout. Results No adverse cardiac event or early termination for medical reasons occurred. Figure 1 summarizes the relationship between HR, perceived exertion and PVC burden. During walking (HR 76 ± 8 bpm), PVC burden was 11 ± 6% (range 4 – 18%). Cycling at 82 ± 4 bpm induced a PVC burden of 7 ± 5% (range 3 – 14%), which increased to 13 ± 8% (range 3 – 21%) at 93 ± 2 bpm and increased further to 16 ± 16% (range 7 – 37%) at 105 ± 3 bpm. In all three intensities the PVC burden was higher in the first 3 min of recovery than during the activity itself. Adding a 2-min active cool down increased the PVC burden to 25 ± 16% (range 6 – 45%). 2-legged squats (HR 101 ± 15 bpm) had a PVC burden of 9 ± 12%, which increased to 19 ± 14% at recovery. One arm biceps curls (HR 75 ± 13 bpm) had a PVC burden of 4 ± 3% during the activity and 9 ± 5% during recovery. Perception of effort varied widely when cycling at 80 bpm (range 6 – 12) or 100 bpm (range 8 – 14), but less so at 120 bpm (range 13 – 15). Blood lactate concentration when cycling at 120 bpm ranged between 2.2 and 3.5 mmol/L, typically associated with exercise in the "heavy" intensity domain. Conclusions PVC burden was high and seemingly intensity-dependent during exercise and immediate recovery. The wide range of PVC burden for physiological or subjective markers of effort call for personalized recommendations on physical activity. Exercises with small muscle mass such as biceps curls seem to minimize the PVC burden, thus, training the different muscles separately could be an interesting avenue to maintain physical fitness in ARVC patients.

Useful aid or futile hassle - continuous rhythm monitoring following acute myocardial infarction

Abstract Background Patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) face an increased risk of cardiac events, including arrhythmias. Current guidelines therefore recommend ECG monitoring for at least 24 hours after AMI in patients with ST segment elevation myocardial infarction (STEMI) and high-risk non-ST segment elevation myocardial infarction (NSTEMI). However, in the last decades medical treatment of AMI has been substantially improved, limiting the risk of arrhythmias post-PCI. Furthermore, continuous ECG monitoring puts additional strain on healthcare personnel during an international healthcare crisis. Purpose To evaluate the contemporary burden of ventricular arrhythmias (VA) in AMI patients post-PCI. Methods This is a retrospective analysis of consecutive patients undergoing PCI for AMI between 2016 and 2020 at a secondary care centre. We defined the primary endpoint as any VA requiring intervention (electric cardioversion or pharmacologic treatment) after PCI. Baseline characteristics and outcome were compared in patients with NSTEMI vs. STEMI. Results A total of 931 patients were included in the analysis, with a mean age of 65 years and 28.6% were female. Patients with NSTEMI (47.3%) were older (median 66 vs. 63 years) and had significantly more comorbidities: hypertension (67.5% vs. 52.1 %), diabetes mellitus (25.4% vs. 15.8%), chronic obstructive pulmonary disease (11.5% vs. 6.7%), and peripheral arterial disease (11.4% vs. 5.3%, p<0.05 for all). VAs requiring intervention occurred in 3.6% vs. 7.1% (p = 0.017) before PCI and in 0% vs. 2.2% (p < 0.001) during PCI in NSTEMI vs. STEMI patients. After PCI the primary endpoint occurred in no NSTEMI patient and in 1.6% of patients with STEMI (p = 0.004). Discussion In a cohort of contemporary AMI patients, ventricular arrhythmias occurred rarely and significantly less often in NSTEMI patients compared to STEMI patients. Due to the low risk of VAs in patients with NSTEMI after PCI, the need for post-procedural rhythm monitoring in NSTEMI patients may be questioned. The identification of predictors for VA after AMI should be subject for future trials.

Mid-term outcomes after stereotactic arrhythmia radioablation for refractory ventricular tachycardia

Abstract Introduction stereotactic arrhythmia radioablation (STAR) is used as a rescue treatment for refractory ventricular tachycardia (VT) originating from unreachable myocardial substrate following unsuccessful radiofrequency catheter ablation (RFCA). The mid-term outcomes of STAR, however, remain poorly known. Objective to report the mid-term efficacy and safety outcomes in our series of 21 patients (pts) treated by STAR over 6 years. Methods Inclusion of consecutive pts treated by STAR with a Cyberknife system between 2017 and 2023. 3D-electroanatomical maps (EAM) of the VT substrate during unsuccessful RFCA were used to delineate the planned target volumes (PTV) on a 4D CT scan. Patients were followed up at least every 6 months by echocardiography and ICD interrogation at the outpatient clinic. Results 21 pts [16 (76 %) male, age 66±8 years] with a mean LVEF of 40±15% were included. The underlying substrate was ischemic in 7 (33 %); non-ischemic dilated in 7 (33 %); inflammatory in 4 (19%); hypertrophic in 1 (5%); neoplasic in 1 (5%); and malignant mitral valve prolapse in 1 (5%). A dose of 21±2 Gray was delivered to the PTV (26 ml, IQR 18-43 ml). After a median follow-up of 39 [IQR, 14-48] months, 12 pts (57%) remained in stable condition, 1 (5%) underwent a heart transplantation, 1 (5%) a left ventricular assistance device, 1 (5%) was in an incessant slow VT and 6 (29%) pts died (3 from end stage heart failure). 15 (71%) pts presented VT recurrences [7 (33%) ATPs; 3 (14%) shocks; 4 (19%) VT storm and 1 (5%) with a well-tolerated slow VT (100 bpm) with an LVAD till transplantation, of whom 9 (43%) required redo RFCA. The median value of total ventricular arrhythmic burden (defined as any arrhythmia requiring ICD therapies) decreased significantly from 31 (IQR, 4-100) to 7 (IQR, 1-23) (p<0.05); for nsVT from 57 (IQR, 1.5- 1196) to 41 (IQR, 0.5-584) (p ns); or ICD shocks from 1.5 (IQR, 0-5.5) to 0 (IQR, 0-2) (p<0.05); for ATPs from 21 (IQR, 2.5-94) to 4 (IQR, 0.5-13) (p<0.05). Figure 1 shows a graphic representation of arrhythmic burden before and after STAR. Conclusion in this cohort of highly selected pts with refractory VT, STAR significantly reduced the arrhythmic burden by a factor of 4 over a 3-year follow-up. Death rate remained high (29%), mostly by terminal heart failure. Nevertheless, a high proportion of pts had VT recurrences that were successfully managed by redo RFCA.VT burden before and after STAR

Ventricular arrhythmia events in patients with implantable cardioverter-defibrillator before and after the treatment with sodium-glucose co-transporter 2 inhibitors

Abstract Background The role of sodium-glucose co-transporter 2 inhibitors (SGLT2i) in the treatment of chronic heart failure is expanding. However, the timing of implantable cardioverter-defibrillator (ICD) implantation for primary prevention in relation to the use of SGLT2i remains unclear. A small case series has described appropriate shocks from ICD in two patients following the initiation of SGLT2i, but a comprehensive analysis is lacking in the literature. Methods This study aimed to investigate the rate of ventricular arrhythmic burden and appropriate anti-tachycardia therapy from ICD before and after the initiation of SGLT2i therapy. We conducted a retrospective single-center analysis, comparing ventricular events from home monitoring reports three months before and three months after SGLT2i therapy initiation. Results Seventeen patients were enrolled in the study. At baseline, clinical characteristics were as follows: 13 (76%) were male, 9 (53%) had ischemic, 2 (12%) had valvular, and 6 (35%) had idiopathic cardiomyopathy. The mean end-diastolic volume (EDV) was 203 ± 90 ml, and the mean left ventricular ejection fraction was 0.36 ± 0.09. All patients were treated with beta-blockers, 14 (82%) with sacubitril-valsartan, 13 (76%) with aldosterone antagonists, 16 (94%) with furosemide, and 5 (29%) with amiodarone. SGLT2i started with dapagliflozin for 13 patients (76%), empagliflozin for 3 patients (18%), and canagliflozin for 1 patient (6%). Ten patients (59%) had single-chamber or dual-chamber ICDs, and 7 had implantable cardiac resynchronization therapy (CRT) defibrillators. In the three months before SGLT2i treatment, 4/17 patients had non-sustained ventricular tachycardia (NSVT), compared to 8/17 (23% vs. 47%, p-value 0.23) patients with NSVT after treatment. Seven patients (41%) experienced an increase in the rate of NSVT events, with one patient having 28 NSVT events after treatment versus none before treatment. No patients had anti-tachycardia therapy in the three months before treatment, while in the three months after SGLT2i treatment, 1 patient had ventricular tachycardia treated with anti-tachycardia pacing (110 days after the beginning of the treatment), and 2 patients had ventricular tachycardia treated with appropriate shocks (2 and 25 days after the initiation of SGLT2i treatment). Conclusion This small retrospective analysis revealed an increase in ventricular arrhythmic events in the three months following the initiation of SGLT2i. These findings highlight the need for a more extensive analysis to establish a stronger statistical correlation.

Strauss criteria for left bundle branch block in cardiac resynchronization therapy: improved response with lower ventricular arrhythmic burden

Abstract Objectives The study sought to evaluate the impact of the stricter Strauss criteria for left bundle branch block (St-LBBB) on cardiac resynchronization therapy (CRT) response, hospitalizations, ventricular arrhythmia (VA) events and mortality. Background Although left bundle branch block (LBBB) is a strong predictor of response to CRT, a significant number of patients remain non-responders. Methods This is a retrospective analysis of prospectively collected data on heart failure (HF) patients with LBBB admitted for CRT implantation. Patients were divided in two groups according to the fulfillment or not of St-LBBB criteria. Results 82 patients with ischemic (ICM) and non-ischemic (NICM) HF [46 (56%) with St-LBBB and 36 (44%) with non-St-LBBB] were included. CRT response was more likely to occur in patients with St-LBBB (p<0.01), with the group of NICM exhibiting the greatest benefit (p<0.01). St-LBBB CRT responders displayed significantly lower rates of HF hospitalization (p<0.0001) compared to non-St-LBBB group. This was mostly evident in patients with NICM (p<0.0001) according to Kaplan-Meier time curves. CRT responders displayed significantly fewer VA events (p<0.001) and lower mortality rates (p<0.0001) than non-responders. Kaplan-Meier estimates demonstrated a significantly lower incidence of VAs in NICM patients with St-LBBB (p:0.049) in comparison to ICM patients with St-LBBB (p:0.25). Lower mortality rates were observed in CRT responders than non-responders (p<0.0001) with the group of NICM with St-LBBB criteria exhibiting the greatest benefit (p:0.0238). Conclusions Patients with NICM and St-LBBB present the greatest benefit with respect to CRT response, HF hospitalizations, VA events, and mortality. St-LBBB criteria may improve patient selection for CRT.

VENTRICULAR ARRHYTHMIA EVENTS IN PATIENTS WITH IMPLANTABLE CARDIOVERTER–DEFIBRILLATOR BEFORE AND AFTER THE TREATMENT WITH SODIUM–GLUCOSE CO–TRANSPORTER 2 INHIBITORS

Abstract Background Role of sodium–glucose co–transporter 2 inhibitors (SGLT2i) in the treatment of chronic heart failure is increasing. However, some case series described appropriate shocks from ICD in patients following the initiations of SGLT2i and a larger analysis is not present in the literature. Methods The aim of this study is to investigate the rate of ventricular arrhythmic burden and appropriate anti–tachycardia therapy from ICD before and after the initiation of SGLT2i therapy. A retrospective single–center analysis was performed, comparing ventricular events from home monitoring reports 3 months before and 3 months after SGLT2i therapy treatment. Results Seventeen patients were enrolled in the study. The baseline clinical e therapy characteristics of patients are shown in the table. Ten patients (59%) had mono cameral or dual cameral ICD and 7 had implantable cardiac resynchronization therapy (CRT) defibrillators.During the 3 months before SGLT2i treatment, 4/17 patients had nun–sustained ventricular tachycardia (NSVT) vs 8/17 (23% vs 47%, P value 0.23) patients with NSTV after the treatment. Seven patients (41%) had an increase in the rate of NSVT events (with a patient with 28 NSVT after treatment vs 0 before treatment). No patients had anti–tachycardia therapy in the 3 months before treatment, while during the 3 months after the SGLT2i treatment, 1 patient had a ventricular tachycardia treated with anti–tachycardia pacing (110 days after the beginning of the treatment) and 2 patients had a ventricular tachycardia treated with appropriate shock (2 and 25 days after the beginning of SGLT2i treatment). Conclusion This small retrospective analysis showed an increase in ventricular arrhythmic events in the 3 months after the initiation of SGLT2i. These data prospect the need for a larger analysis for a stronger statistical correlation.

Serial Cardiac Magnetic Resonance Imaging in Patients with Mitral Valve Prolapse-A Single-Center Retrospective Registry.

Background: Mitral valve prolapse (MVP) and mitral annular disjunction (MAD) are common valvular abnormalities that have been associated with ventricular arrhythmias (VA). Cardiac magnetic resonance imaging (CMR) has a key role in risk stratification of VA, including assessment of late gadolinium enhancement (LGE). Methods: Single-center retrospective analysis of patients with MVP or MAD who had >1 CMR and >1 24 h Holter registration available. Data are presented in detail, including evolution of VA and presence of LGE over time. Results: A total of twelve patients had repeated CMR and Holter registrations available, of which in four (33%) patients, it was conducted before and after minimal invasive mitral valve repair (MVR). After a median of 4.7 years, four out of eight (50%) patients without surgical intervention had new areas of LGE. New LGE was observed in the papillary muscles and the mid to basal inferolateral wall. In four patients, presenting with syncope or high-risk non-sustained ventricular tachycardia (VT), programmed ventricular stimulation was performed and in two (50%), sustained monomorphic VT was easily inducible. In two patients who underwent MVR, new LGE was observed in the basal inferolateral wall of which one presented with an increased burden of VA. Conclusions: In patients with MVP and MAD, repeat CMR may show new LGE in a small subset of patients, even shortly after MVR. A subgroup of patients who presented with an increase in VA burden showed new LGE upon repeat CMR. VA in patients with MVP and MAD are part of a heterogeneous spectrum that requires further investigation to establish risk stratification strategies.

Long-Term Effects of Sacubitril/Valsartan After Chemotherapy for Breast Cancer in Patients With Chronic heart Failure

Background: As the survival of patients with malignant neoplasms is improving, the urgent need for cardioprotective agents to counteract toxic effects of chemotherapy is growing.Objective: To compare the cardioprotective efficacy of sacubitril/valsartan and candesartan in women with chronic heart failure and baseline reduced left ventricular ejection fraction (LVEF) during a 5-year prospective follow-up after chemotherapy for breast cancer.Materials and methods: In this randomized study, 127 women with chronic heart failure and reduced LVEF after radical surgical treatment of breast cancer received potentially cardiotoxic adjuvant polychemotherapy (fluorouracil+ doxorubicin + cyclophosphamide). In addition, the patients received sacubitril/valsartan at a dose of up to 97/103 mg twice daily (n = 63) or candesartan at a dose of up to 32 mg once daily (n = 65), and this treatment was monitored for 5 years.Results: The combination of sacubitril/valsartan was significantly superior to candesartan in improving left ventricular function and reducing the burden of ventricular arrhythmias and the risk of cardiovascular death (P = .039) at the long-term follow-up. Sacubitril/valsartan group and candesartan group did not differ in terms of mortality due to breast cancer progression or recurrence (P = .628).Conclusions: Sacubitril/valsartan can be considered an effective and safe option for protecting the cardiovascular system during potentially cardiotoxic polychemotherapy for breast cancer in patients with chronic heart failure and baseline reduced LVEF.

A Multicenter Study of Stellate Ganglion Block as a Temporizing Treatment for Refractory Ventricular Arrhythmias

BackgroundVentricular tachycardia (VT) and ventricular fibrillation (VF) are life-threatening conditions and can be refractory to conventional drug and device interventions. Stellate ganglion blockade (SGB) has been described as an adjunct, temporizing intervention in patients with refractory ventricular arrhythmia. We examined the association of SGB with VT/VF in a multicenter registry. ObjectivesThis study examined the efficacy of SGB for treatment/temporization of refractory VT/VF. MethodsThe authors present the first analysis from a multicenter registry of patients treated for refractory ventricular arrhythmia at a clinical site in the Czech Republic and the United States. Data were collected between 2016 and 2022. SGB was performed at the bedside by anesthesiologists and/or cardiologists. Outcomes of interest were VT/VF burden and defibrillations at 24 hours before and after SGB. ResultsIn total, there were 117 patients with refractory ventricular arrhythmias treated with SGB at Duke (n = 49) and the Institute for Clinical and Experimental Medicine (n = 68). The majority of patients were male (94.0%), were White (87.2%), and had an implantable cardioverter-defibrillator (70.1%). The most common etiology of heart disease was ischemic cardiomyopathy (52.1%), and monomorphic VT was the most common morphology (70.1%). Within 24 hours before SGB (0-24 hours), the median episodes of VT/VF were 7.5 (Q1-Q3: 3.0-27.0), and 24 hours after SGB, the median decreased to 1.0 (Q1-Q3: 0.0-4.5; P < 0.001). At 24 hours before SGB, the median defibrillation events were 2.0 (Q1-Q3: 0.0-8.0), and 24 hours after SGB, the median decreased to 0.0 (Q1-Q3: 0.0-1.0; P < 0.001). ConclusionsIn the largest cohort of patients with treatment-refractory ventricular arrhythmia, we demonstrate that SGB use was associated with a reduction in the ventricular arrhythmia burden and need for defibrillation therapy.

Ventricular arrhythmia burden during different physical activities in patients with arrhythmogenic right ventricular cardiomyopathy: Preliminary analysis

Introduction&#x0D; Patients suffering from arrhythmogenic right ventricular cardiomyopathy (ARVC) should avoid intense endurance exercise to reduce the risk of adverse cardiac events and disease progression. On the other hand, an active lifestyle might be preferable to a sedentary one, which also brings a host of complications. Evidence for safe levels of physical activity in ARVC, however, is scarce. This is study aimed to describe the ventricular arrhythmia burden - estimated as the prevalence of premature ventricular contractions (PVC) - of different exercise modalities and intensities on ARVC patients.&#x0D; Methods&#x0D; The pilot analysis includes four (1F, 33 ± 12 yrs, BMI 24 ± 4 kg/m2) ARVC patients harboring a pathogenic plakophilin-2 variant and carrying an implantable cardioverter-defibrillator performed different exercises while monitored via 12-lead ECG. The order of modalities was randomized and participants instructed to stop when surpassing perceived exertion of 15 on the Borg 6-20 scale. Resistance exercises included two-legged squats and single arm biceps curls (each with 20 repetitions and 2 min duration) while endurance exercise included 5 min of treadmill walking, 3 min cycling bouts at heart rate (HR) of 80, 100 and 120 bpm as well as cycling at 120 bpm with 2 additional min of active cool down. Blood lactate concentration was assessed at the end of the cycling bouts.&#x0D; Results&#x0D; No adverse cardiac event were noted and no exercise was terminated for medical reasons. During walking HR was 76 ± 8 bpm, whereas PVC burden was 11 ± 6% (range 4-18%). Cycling at 82 ± 4 bpm induced a PVC burden of 7 ± 5% (range 3- 14%), which increased to 13 ± 8% (range 3- 21%) at 93 ± 2 bpm and further to 16 ± 16% (range 7-37%) at 105 ± 3 bpm. In all three modalities the PVC burden was higher in the first 3 min of recovery than during the activity itself. Adding a 2 min active cool down increased the PVC burden to 25 ± 16% (range 6-45%). 2-legged squats performed at 101 ± 15 bpm had a PVC burden of 9 ± 12%, which increased to 19 ± 14% at recovery. One arm biceps curls at 75 ± 13 bpm had a PVC burden of 4 ± 3% during the activity and 9 ± 5% during recovery. Perception of effort varied widely when cycling at 80 bpm (range 6-12) or 100 bpm (range 8-14), but less so at 120 bpm (range 13-15). Blood lactate concentration when cycling at 120 bpm ranged between 2.2 and 3.5 mmol/L, typically associated with exercise in the “heavy” intensity domain.&#x0D; Discussion/Conclusion&#x0D; ARVC patients present a high, intensity-dependent PVC burden during exercise and short-term recovery. However, we observed widely different PVC burdens and perceived exertion at a given HR during different exercise modalities, which calls for personalized recommendations on physical activity. Exercises with small muscle mass seem to minimize the PVC burden and training the different muscles separately could be an interesting avenue to maintain physical fitness in ARVC patients.

Catheter Ablation for Ventricular Tachycardia in Patients With Desmoplakin Cardiomyopathy

BackgroundDesmoplakin (DSP) pathogenic/likely pathogenic (P/LP) variants are associated with malignant phenotypes of arrhythmogenic cardiomyopathy (DSP-ACM). Reports of outcomes after ventricular tachycardia (VT) ablation in DSP-ACM are scarce. ObjectivesIn this study, the authors sought to report on long-term outcomes of VT ablation in DSP-ACM. MethodsPatients with P/LP DSP variants at 9 institutions undergoing VT ablation were included. Demographic, clinical, and instrumental data as well as all ventricular arrhythmia (VA) events were collected. Sustained VAs after the index procedure were the primary outcome. A per-patient before and after ablation comparison of rates of VA episodes per year was performed as well. ResultsTwenty-four DSP-ACM patients (39.3 ± 12.1 years of age, 62.5% male, median 6,116 [Q1-Q3: 3,362-7,760] premature ventricular complexes [PVCs] per 24 hours, median 4 [Q1-Q3: 2-11] previous VA episodes per patient at ablation) were included. Index procedure was most commonly endocardial/epicardial (19/24) The endocardium of the right ventricle (RV), the left ventricle (LV), or both ventricles were mapped in 8 (33.3%), 9 (37.5%), and 7 (29.2%) cases, respectively. Low voltage potentials were found in 10 of 15 patients in the RV and 11 of 16 in the LV. Endocardial ablation was performed in 18 patients (75.0%). Epicardial mapping in 19 patients (79.2%) identified low voltage potentials in 17, and 16 received epicardial ablation. Over the following 2.9 years (Q1-Q3: 1.8-5.5 years), 13 patients (54.2%) experienced VA recurrences. A significant reduction in per-patient event/year before and after ablation was observed (1.4 [Q1-Q3: 0.5-2.4] to 0.1 [Q1-Q3: 0.0-0.4]; P = 0.009). Two patients needed heart transplantation, and 4 died (3 of heart failure and 1 noncardiac death). ConclusionsVT ablation in DSP-ACM is effective in reducing the VA burden of the disease, but recurrences are common. Most VT circuits are epicardial, with both LV and RV low voltage abnormalities. Heart failure complicates clinical course and is an important cause of mortality.

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.

Cardiovascular Effects of Chronic Hormone Therapy: Study on Olympic Female Athletes

Female physiology is regulated after puberty by the menstrual cycle, whose hormonal fluctuations create a multitude of effects on several systems, including the cardiovascular one. The use of hormone therapy (HT) is quite common in female athletes and data on cardiovascular effects in this population are lacking. We sought to investigate the effects of HT in highly trained athletes to assess any difference associated with HT on cardiac remodelling, exercise capacity and clinical correlates. We studied 380 female elite athletes (mean age 25.5 ± 4.8) competing in endurance and mixed sports. 67 athletes (18%) were in chronic HT therapy. All athletes underwent baseline ECG, exercise ECG stress test, transthoracic echocardiogram, complete blood tests including lipid profile and inflammation indexes. The echocardiographic study showed a characteristic left ventricular (LV) remodelling, defined by lower LV mass index (86.2 vs. 92.5 g/m2, p<0.006), end-diastolic LV diameter (28.3 vs. 29.4 mm/m2, p<0.004) and end-diastolic LV volume (61.82 vs. 67.09 mL/m2, p<0.010) compared to controls, without changes in systolic function and diastolic relaxation/filling indexes. A lower burden of ventricular arrhythmias on exercise was observed in HT athletes (1.5% vs 8.6% in those without therapy, p=0.040). Linear regression analysis showed that HT had independent effect on LVEDDi (p=0.014), LVEDVi (p=0.030) and LVMi (p=0.020). In conclusion, chronic treatment with HT in female athletes is associated with less cardiac remodelling, including a lower LV cavity, volume and mass, with preserved systolic and diastolic function, and decreased burden of exercise-induced ventricular arrhythmias. HT, therefore, appears to be responsible for a more economic, but equally efficient, cardiac adaptation to intensive athletic conditioning.

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.

High-intensity interval training in patients with an implantable cardioverter defibrillator: a randomized controlled study

Abstract Background Exercise is an effective treatment in a broad spectrum of cardiovascular diseases. High-intensity interval training (HIIT) has shown superior effect on cardiorespiratory fitness and equal or superior effect on morbidity and quality of life (QoL) compared to moderate continuous exercise training. However, evidence of the efficacy and risks of HIIT in patients with increased risk of ventricular arrhythmia remains limited. Purpose To evaluate the effects of HIIT on exercise capacity, QoL and burden of ventricular arrhythmias in patients with an implantable cardioverter defibrillator (ICD) with or without cardiac resynchronization therapy. Methods Patients with ischemic or dilated cardiomyopathy and ICD were randomized to a supervised 12-week HIIT program or to a control group continuing their usual exercise routines. HIIT consisted of four 4-minute intervals aiming at 85-95% of maximum heart rate (HRmax), and 3-minute active recovery aiming at 60-70 % of HRmax in between intervals, 3 times a week for 12 weeks. Primary outcomes were exercise capacity measured as peak oxygen uptake (VO2 peak) and QoL assessed with the Short Form 36 (SF-36) questionnaire. Main secondary outcome was the burden of ventricular arrhythmias analysed from remote patient monitoring data. Results Fifty-six patients were included (table 1). Three patients in the HIIT group did not complete the intervention. Two withdrew due to a knee injury and due to fear of SARS-CoV-2 exposure, respectively. One experienced an appropriate shock during exercise and was excluded from further training after clinical consideration. Fifty-three patients completed all follow-up examinations. HIIT significantly increased VO2 peak with 7.0 %, with no changes in the control group (p=0.001) (figure 1A). There was a significant increase in the SF-36 subscale scores on physical functioning (p&amp;lt;0.05), general health (p&amp;lt;0.05) and health change (p=0.001) in the HIIT group compared to the control group (figure 1B). There were no significant differences between groups in number of non-sustained or sustained ventricular tachycardias, anti-tachycardia pacing therapy or ICD shocks. Conclusions In patients with ICD due to ischemic or dilated cardiomyopathy, a supervised 12-week HIIT-program significantly increased VO2 peak and QoL without increasing the burden of ventricular arrhythmias.Table 1:Patient characteristicsFigure 1:Peak oxygen uptake and QoL

Impact on clinical outcome of ventricular arrhythmias in patients undergoing transcatheter aortic valve implantation (TAVI)

Abstract Background Transcatheter aortic valve implantation (TAVI) in the treatment of severe aortic stenosis has considerably grown in the latest years. There are limited data, however, about predictors of long-term prognosis in this population. Particularly, whether ventricular arrhythmic burden is associated with clinical outcome has poorly been investigated. Purpose The aim of our study was to investigate the association between ventricular arrhythmias and adverse clinical outcomes in patients undergoing TAVI. Methods We performed a 24-hour 3-channel ECG Holter monitoring (HM) in 267 consecutive patients who underwent TAVI for severe aortic stenosis at our Centre within 30 days from a successful procedure (average 10.2 days, range 2-30). For each patient we obtained the number of premature ventricular complexes (PVCs) and the presence of non-sustained ventricular tachycardia (NSVT, &amp;gt;3 PVCs with a rate &amp;gt;100 bpm). Frequent PVCs were defined as the presence of at least 30 PVCs per hour. We also collected clinical and echocardiographic findings for each patient. Assessment of clinical events at follow-up was performed by clinical visits or telephone interviews of patients or relatives (in case of fatal events). The primary endpoint of the study was the occurrence of cardiovascular events (CVE), a composite of cardiovascular death and resuscitation from cardiac arrest. All-cause-mortality was assessed as secondary endpoint. Survival Cox regression was applied to assess the univariate and multivariate association of clinical, echocardiographic and HM variables with endpoints. Results Clinical outcome could be obtained for 228 patients (85%), for an average follow-up of 3.5 years (range 1.0-8.6). Among these patients, frequent PVCs (≥30/hour) and episodes of NSVT at HM were found in 47 (20.6%) and 52 (22.4%) patients, respectively. CVE occurred in 26 patients (11.4%) and 63 patients died (27.6%). Frequent PVCs at HM were detected in 12 patients with (46.2%) and 35 patients without (17.3%) CVE (HR 2.29; 95% CI 1.03-5.09; p=0.04). One or more episodes of NSVT were detected in 9 patients with (34.6%) and 43 patients without (21.3%) CVE (HR 2.29; 95% CI 1.03-5.09; p=0.04), although it was not predictive of all-cause mortality (HR 1.18; 95% CI 0.48-2.77; p=0.52). Both the presence of PVCs&amp;gt;30/hour (HR 1.19; 95% CI 0.69-2.08; p=0.53) and NSVT (HR 0.93; 95% CI 0.52-1.65; p=0.22) were not significantly associated with all-cause mortality. Moreover, no clinical (age, gender, cardiovascular risk factors) and echocardiographic (aortic valve area, trans-aortic mean gradient, left ventricle mass and ejection fraction) variable showed significant association with both the primary and secondary outcome in our patients. Conclusions In our study the detection of frequent PVCs at HM after TAVI was a major predictor of CVE (cardiovascular death/cardiac arrest), suggesting that a 24-hour HM after TAVI can be helpful for risk stratification of these patients.

Impact of sodium-glucose cotransporter-2 (SLGT2) inhibitors treatment initiation on the reduction of atrial and ventricular arrhythmias in patients with implanted cardiac devices

Abstract Introduction Sodium-glucose cotransporter-2 (SLGT2) inhibitors have demonstrated benefits on survival and hospital admissions in patients with heart failure and reduced ejection fraction. However, their impact on the burden of ventricular (VA) and atrial arrhythmias (AA) is unknown. Methods Retrospective multicentric study of heart failure patients with implantable cardiac defibrillator device (ICD) from 2015 to 2020 with or without cardiac resynchronization therapy (CRT) receiving SGLT2 inhibitors. Device-registered arrhythmic events were analyzed and compared during one year following SLGT2 inhibitor initiation and during one year before initiation. Relevant VA were defined as the occurrence of any sustained VT (SVT) (&amp;gt;30 seconds), ventricular fibrillation (VF), or appropriate therapy (antytachycardia pacing or shock). All VA included all the relevant VA and the occurrence of non-sustained ventricular tachycardia (NSVT). AA included atrial fibrillation (AF) burden, and episodes of more than 24 hour of AF. Results 147 patients (67 ± 10 years, 82.3% males, LVEF 30.3 ± 11%, CRT 39.3%), were included in the study. 77.6% had complete remote tele-monitoring during the entire follow up and there was no difference in the antiarrhythmic therapy between the two periods. Following SGLT2 inhibitor initiation, there was a significant reduction in the percentage of patients with relevant VA (19.7% pre vs 10.9% post; p=0.019) and all VA (47.6% pre vs 30.6% post; p&amp;lt;0.001) (Figure 1 and 2). There was a reduction in the prevalence of NSVT (40.1% pre vs. 27.2% post; p&amp;lt;0.001), of SVT (17.7% vs 8.8%; p&amp;lt;0.001), of VF (4.1% vs 2%; p=NS) and appropriate therapies (14.3% vs 9.5%; p=NS). Among patients with any VA, there was a significant reduction in the incidence of NSVT (p&amp;lt;0.001), but not in the incidence of SVT or appropriate therapies (p=NS). There was no impact on atrial fibrillation burden or in the number of AF episodes lasting more than 24 hours (p=NS). Conclusions In our study, initiation of a SGLT2 inhibitor in patients with heart failure, was associated with a reduction in the prevalence of relevant VA and any VA, with a significant reduction in the number of NSVT per patient. There was no impact on AF burden or the number of AF episodes lasting more than 24 hours. Prospective studies should be performed to sustain these conclusions.Relevant ventricular arrhythmiasAny ventricular arrhythmia

Perfomance of sudden cardiac death prediction strategies before and after Septal Reduction Strategies in patients with Hypertrophic Cardiomyopathy

Abstract Background Actual sudden death (SD) risk stratification strategies for Hypertrophic Cardiomyopathy have not been validated for patients after a septal reduction treatment (SRT). Therefore, it is largely unresolved the quantification of the ventricular arrhythmias (VA) burden after an SRT and how risk stratification should be performed in such patients. Purpose To evaluate the performance of ESC SD Risk stratification model and AHA ACC Risk Factors for SD in the identification of patients with lethal ventricular arrhythmias after SRT. Methods Data from 11 high-volume HCM specialty centers from the international SHaRe Registry were used to describe the natural history of patients with SRT. Patients were followed from SRT until last follow-up or meeting the composite outcome of ventricular arrhythmias (sudden cardiac death (SCD), resuscitated cardiac arrest, or appropriate implantable cardioverter-defibrillator (ICD) therapy). Cox proportional hazards models were used to identify predictors of prognosis and incident development. Calculation of SD score was performed before the SRT and at 1 year from the procedure. Results Of the 10385 patients part of the ShaRe Registry, 1835 (18%, 968 (53%) males) underwent a SRT during a median follow-up of 6.8 (IQR 3.4-9.8). A total of 455 (25%) had Alcohol Septal Ablation (ASA) and 1377 (75%) had myectomy. Patients who underwent myectomy were younger (49±18 vs 56±15 years, p&amp;lt;0.01), more frequent with a sarcomeric mutation (396 (29%) vs 111 (24%), p&amp;lt;0.01). Over 6.8 years after the procedure, 77 (4%) died because of HCM (0.6%/year) and 87 (5%) presented a composite VA outcome (0.7%/year). Development of the composite VA event was associated with younger age at procedure (38±20 vs 54±18 years, p&amp;lt;0.01), the development of a LV EF&amp;lt; 50% (29 (33%) vs 351 (20%), p&amp;lt;0.01), a more severely dilated LA (47±7 vs 43±11 years, p&amp;lt;0.01) and greater LV maximal wall thickness (24±6 vs 21±6 years, p&amp;lt;0.01). Significant predictor of the composite VA outcome was the presence of a LA diameter ³ 45 mm (HR, 2.6 [95% CI, 1.7–3.5]). Patients who presented the VA outocome were classified according to ESC SCD Risk pre and post SRT as: 40 (46%) as high risk, 31 (36%) as intermidiate risk, 16 (18%) as low risk pre intervention and 26 (46%) as high risk, 41 (47%) as intermidiate risk, 20 (18%) as low risk post procedure. AHA ACC SCD risk factors pre and post SRT classified patients as: 56 (64%) as class IIA 25 (29%) as Clas IIB, 6 (7%) as Class III and post SRT 42 (48%) as Class IIA, 31(36%) as Class IIB, 14 (16%) as Class III. Conclusions Current stratification strategies potentially underestimate the risk of SD pre and post SRT. Specifically, ESC SD risk strategies underperformed in the identification of intermidiate high risk patient, whereas AHA ACC were capable of identifying 84% of patients who had a malignant VA.

Modulation of myocardial inflammation, fibrosis development and ventricular arrhythmogenicity by endurance exercise in murine coxsackievirus B3 myocarditis

Abstract Aims Nonischaemic myocardial fibrosis is associated with progressive deterioration of myocardial function and forms the substrate for arrhythmias in atria and ventricles. In the absence of a specific aetiology, its origin is commonly attributed to preceding viral myocarditis. Athletes presenting with ventricular arrhythmias often demonstrate nonischaemic fibrosis on magnetic resonance imaging. Previous translational studies have shown an adverse effect of exercise on the course of acute viral myocarditis. Nevertheless, the effect on myocardial fibrosis development, a frequent and important consequence of viral myocarditis, has not yet been investigated. In the present study, we evaluate for the first time the impact of endurance exercise on longer-term myocardial inflammation, myocardial fibrosis and arrhythmogenicity using a murine viral myocarditis model. Methods and results Male C57BL/6J mice (11 weeks of age, n=72) were randomly assigned to 8 weeks of treadmill running (EEX) or without exercise (SED). Two weeks into the study (training or control), animals were injected intraperitoneally with either coxsackievirus B3 to induce acute viral myocarditis (CVB) or vehicle (PBS). Exercising myocarditis mice showed lower mortality (11% vs. 27%), albeit without statistical significance (P=0.23). At sacrifice (i.e. 6 weeks after inoculation), prominent myocardial inflammatory infiltration and cardiomyocyte loss was observed in both CVB groups, without difference on semiquantitative histological scoring. Nevertheless, the infiltrating cells in the CVB-EEX group were more often proinflammatory in nature (predominantly iNOS-reactive macrophages and positive CD8+/CD4+ ratio) compared to these in CVB-SED (predominantly arginase-1-reactive macrophages and higher CD4+/CD8+ ratio). In addition, the EEX group showed more haemosiderin-laden macrophages and spindled fibroblasts as signs of organisation. At that time, the majority of virus was cleared from the heart. Treadmill running during myocarditis enhanced development of interstitial fibrosis (with limited or extensive distribution)(82.4% in CVB-EEX vs. 56.3% in CVB-SED; P=0.049) and perivascular and/or interstitial fibrosis with extensive distribution (64.7% &amp; 64.7% in CVB-EEX vs. 50% &amp; 31.3% in CVB-SED; P=0.048). The highest scar counts were observed in CVB-EEX, but the mean count (1.9 vs. 1.2; P=0.19) did not significantly differ between the myocarditis groups. In CVB-EEX, the lesions contained denser and more organised collagen bundles. In vivo electrophysiology studies showed similar ventricular arrhythmia inducibility (P&amp;gt;0.20) and arrhythmia burden (P=0.49) in the myocarditis groups, although the longest arrhythmias and highest cumulative burden occurred in CVB-EEX. Conclusion Endurance exercise training during viral myocarditis modulates the longer-term inflammatory process and promotes perivascular and interstitial fibrosis development, potentially enhancing ventricular arrhythmogenicity.

Abstract 18880: Ventricular Arrhythmia Prevalence and Burden in Patients With Third Generation Continuous Flow Left Ventricular Assist Devices

Background: Ventricular arrhythmias (VAs) are common in patients with left ventricular assist devices (LVADs). Little is known about the impact of third-generation LVADs (Heartmate 3, HM3) on VAs prevalence and burden. Aims : To characterize the impact of HM3 LVAD implantation on VAs prevalence and burden in patients with advanced heart failure (HF) and implantable cardioverter-defibrillators (ICDs). Methods: We included consecutive patients with advanced HF and ICDs who received HM3 devices at our center between 2016 and 2022. The study outcomes were the prevalence of sustained VAs, defined as &gt;30s VA episode detected by the ICD monitor zone or appropriately treated (ATP or shock), sustained VA burden (total number of episodes), and VA storm (≥3 appropriate ICD interventions in 24/h period). Data was collected over the 1 year before and after HM3 implantation. Results: A total of 321 patients were included (28% female, mean age 60±12 years, mean INTERMACS score 3±0.95). At 1 year follow-up after HM3 implantation, 27 patients died. A total of 128 patients (43%) had at least one sustained VA episode in the year before the HM3 implantation compared to 51 patients (17%) in the year following the HM3 (p&lt;0.001 for comparison). The sustained VA burden decreased from a mean of 3.8 events per person-year (PPY) to a mean of 0.8 events PPY (p=0.005). Similarly, appropriate ICD therapy occurred in 123 patients (38%) before implantation and 46 patients (14%) after implantation (p&lt;0.001). The burden of appropriate therapy was also reduced (from a mean of 2.57 events PPY to a mean 1.32 events PPY; p=0.03). The prevalence of VA storm was reduced from 19% to 8% (p&lt;0.001). Conclusions: In patients with advanced HF and ICDs undergoing HM3 implantation, the prevalence of sustained VAs, VAs burden, appropriate ICD interventions, and VA storm were all significantly reduced in the year following HM3 implantation.