Sudden cardiac death (SCD) due to recurrent ventricular tachycardia is an important clinical sequela in patients with structural heart disease. As a result, ventricular tachycardia (VT) has emerged as a major clinical and public health problem. The mechanism of VT is predominantly mediated by re-entry in the presence of arrhythmogenic substrate (scar), though focal mechanisms are also important. Catheter ablation for VT, when compared to standard medical therapy, has been shown to improve VT-free survival and burden of device therapies. Approaches to VT ablation are dependent on the underlying disease process, broadly classified into idiopathic (no structural heart disease) or structural heart disease (ischemic or non-ischemic heart disease). This update aims to review recent advances made for the treatment of VT ablation, with respect to current clinical trials, peri-procedure risk assessments, pre-procedural cardiac imaging, electro-anatomic mapping and advances in catheter and non-catheter based ablation techniques.

Sudden cardiac death (SCD) due to recurrent ventricular tachycardia is an important clinical sequela in patients with structural heart disease. As a result, ventricular tachycardia (VT) has emerged as a major clinical and public health problem. The mechanism of VT is predominantly mediated by re-entry in the presence of arrhythmogenic substrate (scar), though focal mechanisms are also important. Catheter ablation for VT, when compared to standard medical therapy, has been shown to improve VT-free survival and burden of device therapies. Approaches to VT ablation are dependent on the underlying disease process, broadly classified into idiopathic (no structural heart disease) or structural heart disease (ischemic or non-ischemic heart disease). This update aims to review recent advances made for the treatment of VT ablation, with respect to current clinical trials, peri-procedure risk assessments, pre-procedural cardiac imaging, electro-anatomic mapping and advances in catheter and non-catheter based ablation techniques.

Background and Objectives: There is little emphasis on the efficacy of catheter ablation for ventricular arrhythmia (VA) when using VA burden reduction as a marker for success. We examined the efficacy of catheter ablation using VA burden, rather than VA recurrence as a marker of success, following catheter ablation of structural heart disease (SHD) related VA. Methods: Catheter ablation of SHD related VA was performed at a single centre over 4-years.VA episodes and implantable cardioverter defibrillator (ICD) therapies were recorded over the 6-months before and after final ablation. Outcomes were reported in terms of burden reduction and compared to singular VA recurrence. Results: Overall, 108 patients were included in the study. Mean age 64.2±13.9 years, 86% male, mean left ventricular ejection fraction (LVEF) 42±16%. Median VA episodes and ICD therapy were significantly reduced after ablation (VA before: 10 [interquartile range, IQR:2–38] vs. VA after: 0 [IQR: 0–2], p<0.001; anti–tachycardia pacing [ATP] before: 16 (IQR: 1.5– 57) vs. ATP after: 0 [IQR: 0–2], p<0.001; shocks before: 1 [IQR: 0–5] vs. shocks after: 0 [IQR: 0–0], p<0.001). Procedural success at 6-months was significantly higher when considering ≥75% reduction in VA burden, rather than a singular VA-free survival (83% vs. 67%, p=0.001). Conclusions The vast majority (>80%) of patients achieve reduction in VA burden (≥75% reduction) after catheter ablation for VA. This data suggests that catheter ablation is highly therapeutic when procedure success is defined as reduction in VA, rather than using a single VA recurrence as a metric for failure.

Background and Objectives: There is little emphasis on the efficacy of catheter ablation for ventricular arrhythmia (VA) when using VA burden reduction as a marker for success. We examined the efficacy of catheter ablation using VA burden, rather than VA recurrence as a marker of success, following catheter ablation of structural heart disease (SHD) related VA. Methods: Catheter ablation of SHD related VA was performed at a single centre over 4-years.VA episodes and implantable cardioverter defibrillator (ICD) therapies were recorded over the 6-months before and after final ablation. Outcomes were reported in terms of burden reduction and compared to singular VA recurrence. Results: Overall, 108 patients were included in the study. Mean age 64.2±13.9 years, 86% male, mean left ventricular ejection fraction (LVEF) 42±16%. Median VA episodes and ICD therapy were significantly reduced after ablation (VA before: 10 [interquartile range, IQR:2–38] vs. VA after: 0 [IQR: 0–2], p<0.001; anti–tachycardia pacing [ATP] before: 16 (IQR: 1.5– 57) vs. ATP after: 0 [IQR: 0–2], p<0.001; shocks before: 1 [IQR: 0–5] vs. shocks after: 0 [IQR: 0–0], p<0.001). Procedural success at 6-months was significantly higher when considering ≥75% reduction in VA burden, rather than a singular VA-free survival (83% vs. 67%, p=0.001). Conclusions The vast majority (>80%) of patients achieve reduction in VA burden (≥75% reduction) after catheter ablation for VA. This data suggests that catheter ablation is highly therapeutic when procedure success is defined as reduction in VA, rather than using a single VA recurrence as a metric for failure.

Non-ischemic cardiomyopathies are a heterogeneous group of diseases of the myocardium that have a distinct proclivity to ventricular arrhythmias. Of these, ventricular tachycardias pose significant management challenges with the risk of sudden cardiac death and morbidity from multiple causes. Catheter ablation of ventricular tachycardias is becoming an increasingly utilised intervention that has been found to have significant benefits with improving symptoms, reducing anti-arrhythmic drug burden and debilitating device therapies, thereby improving quality of life. Nonetheless, the approach to the ablation of ventricular tachycardias in non-ischemic cardiomyopathies is governed heavily by the disease process, with several distinct differences from ischemic cardiomyopathy including a preponderance to epicardial and deep intramural substrate. This contemporary review aims to present the various disease processes within non-ischemic cardiomyopathies, catheter ablation techniques which have been developed to target ventricular tachycardia and more novel adjunctive therapeutic measures.
Arrhythmias, Cardiac ; Cardiomyopathies ; Catheter Ablation ; Death, Sudden, Cardiac ; Myocardium ; Quality of Life ; Tachycardia, Ventricular

Non-ischemic cardiomyopathies are a heterogeneous group of diseases of the myocardium that have a distinct proclivity to ventricular arrhythmias. Of these, ventricular tachycardias pose significant management challenges with the risk of sudden cardiac death and morbidity from multiple causes. Catheter ablation of ventricular tachycardias is becoming an increasingly utilised intervention that has been found to have significant benefits with improving symptoms, reducing anti-arrhythmic drug burden and debilitating device therapies, thereby improving quality of life. Nonetheless, the approach to the ablation of ventricular tachycardias in non-ischemic cardiomyopathies is governed heavily by the disease process, with several distinct differences from ischemic cardiomyopathy including a preponderance to epicardial and deep intramural substrate. This contemporary review aims to present the various disease processes within non-ischemic cardiomyopathies, catheter ablation techniques which have been developed to target ventricular tachycardia and more novel adjunctive therapeutic measures.

Background: and Purpose Changes to hospital systems were implemented from March 2020 in Australia in response to the coronavirus disease 2019 pandemic, including decreased resources allocated to stroke units. We investigate changes in the quality of acute care for patients with stroke or transient ischemic attack during the pandemic according to patients’ treatment setting (stroke unit or alternate ward). Methods: We conducted a retrospective cohort study of patients admitted with stroke or transient ischemic attack between January 2019 and June 2020 in the Australian Stroke Clinical Registry (AuSCR). The AuSCR monitors patients’ treatment setting, provision of allied health and nursing interventions, prescription of secondary prevention medications, and discharge destination. Weekly trends in the quality of care before and during the pandemic period were assessed using interrupted time series analyses. Results: In total, 18,662 patients in 2019 and 8,850 patients in 2020 were included. Overall, 75% were treated in stroke units. Before the pandemic, treatment in a stroke unit was superior to alternate wards for the provision of all evidence-based therapies assessed. During the pandemic period, the proportion of patients receiving a swallow screen or assessment, being discharged to rehabilitation, and being prescribed secondary prevention medications decreased by 0.58% to 1.08% per week in patients treated in other ward settings relative to patients treated in stroke units. This change represented a 9% to 17% increase in the care gap between these treatment settings during the period of the pandemic that was evaluated (16 weeks). Conclusions During the first 6 months of the pandemic, widening care disparities between stroke units and alternate wards have occurred.