R. Denman

Catheter ablation of papillary muscle arrhythmias: Implications of mitral valve prolapse and systolic dysfunction

The left ventricular (LV) papillary muscles are important components of the mitral valve apparatus. Catheter ablation of ventricular arrhythmias from these sites is challenging. We aim to describe the association between LV papillary muscle ventricular arrhythmias (VAs) and mitral valve prolapse (MVP), and to determine the outcomes of ablation in these patients with a focus on those with MVP and cardiomyopathy.

Ultra-low radiation dose during electrophysiology procedures using optimized new generation fluoroscopy technology

Electrophysiology procedures require fluoroscopic guidance, with the associated potentially adverse effects of ionizing radiation. Newer fluoroscopy systems have more features that enable dose‐reduction strategies. This study aimed to investigate any reduction in radiation dose between an older fluoroscopy system (Philips Integris H5000, Philips Healthcare, Einhoven, Netherlands) and one of the latest systems (Siemens Artis Q, Siemens Healthcare, Erlangen, Germany), optimized with dose‐reduction strategies.

Spontaneous transformation of a concealed to manifest posteroseptal accessory pathway requiring epicardial ablation

Concealed accessory pathways (APs) are considered benign as they can only sustain orthodromic atrioventricular re‐entrant tachycardia (ORT). We describe a unique case of a concealed posteroseptal AP where longitudinal surveillance following repeated failed ablation attempts due to abnormal coronary sinus (CS) anatomy revealed spontaneous development of manifest pre‐excitation. The pathway was ultimately ablated via the percutaneous epicardial approach. The potential for development of Wolff‐Parkinson‐White (WPW) syndrome in patients with concealed APs has implications for ongoing surveillance in these patients.

Leadless Permanent Pacing: A Single Centre Australian Experience

BACKGROUND To describe the performance and clinical outcomes of consecutive patients having a leadless pacemaker (LP) implanted at a single institution. METHODS Clinical data and device parameters were prospectively collected on all patients undergoing LP implantation from November 2015 to April 2018. RESULTS A total of 79 patients (52 male), median age of 78 years, were included. Leadless pacemaker implantation was successful in 76 patients (96%). Implantation failed in two patients due to excessive venous tortuosity and due to inadequate sensing in another. Seventy-three patients (96%) had chronic atrial fibrillation and all had a Class I or II indication for pacing. Procedure time was 29minutes (IQR 21-43) and fluoroscopy time was 8minutes (IQR 5-13). The median R wave at implant was 11.2mV (IQR 6.9-15.0). The median capture threshold at 0.24ms was 0.5V (IQR 0.4-0.9) and impedance was 754Ω (IQR 680-880). Intraprocedural acute dislodgement occurred in one patient following cutting of the tether but successful snaring and reimplantation was performed. During a median follow-up of 355days (range 9-905), overall electrical performance has been excellent. No patients have been readmitted for device revision or complications. Five patients (7%) died during follow-up from unrelated causes. CONCLUSIONS Leadless pacemakers can be implanted safely and effectively in the majority of patients. Device electrical performance was excellent over a median follow-up of 12 months.

Ventricular Ectopy in the Context of Left Ventricular Systolic Dysfunction: Risk Factors and Outcomes Following Catheter Ablation

BACKGROUND Ectopy-mediated cardiomyopathy (EMC) is a potentially reversible form of left ventricular systolic dysfunction. Various risk factors for the development of EMC have been proposed in the literature. We aim to assess medium term outcomes of focal ventricular arrhythmia (VA) ablation in the setting of cardiomyopathy (CMP) and to validate published risk factors for EMC. METHODS Medium term recovery of left ventricular (LV) function and freedom from VA recurrence was assessed and compared between patients undergoing focal VA ablation in the setting of CMP and a control group with normal LV function. Univariate and multivariate analyses for CMP risk factors were performed and compared against prior published risk factors. RESULTS Of 152 patients who underwent 170 focal VA ablation procedures, 54 (36%) had CMP and the remaining 98 patients had normal LV systolic function. At medium term follow-up, 85% of patients with CMP were free of VA recurrence and median left ventricular ejection fraction (LVEF) had improved from 40 to 52%. Age, male gender, premature ventricular complex (PVC) burden, non- right ventricular outflow tract (RVOT) sites of origin, PVC QRS duration and PVC minimum coupling interval were predictive of CMP on univariate analysis, but only gender persisted on multivariate analysis. CONCLUSIONS Medium term outcome in patients undergoing focal VA in the setting of CMP are satisfactory with improvement in LV function achievable in most patients. Prior risk factors described in the literature are variable and inconsistent, likely reflecting heterogeneous study populations.

Systemic Effect of Intrapericardial Triamcinolone Acetate Following Epicardial Mapping and Ablation

lowed up for a period of 610± 536 days. No patient with AT had further AF. One of two patients with slow fast AVNRT had AF reoccurrence and underwent PVI. Five of 10 patients with induced atrial flutter underwent repeat ablation for AF reoccurrence. Conclusion: A significant proportion of young patients presenting with AF have a supra-ventricular tachycardia. Ablation of focal atrial tachycardia or AVNRT prevented AF reoccurrence. In contrast, if the induced arrhythmia was macro-reentry, AF was more common during follow up. In young patients, we advocate the evaluation for a treatable supra-ventricular arrhythmia. http://dx.doi.org/10.1016/j.hlc.2013.05.288