Initial experience with a novel re-sterilisable decapolar electrophysiology catheter.

PURPOSE: Diagnostic electrophysiology catheters are single-use and their expense can act as a barrier to their use. A decapolar catheter with a re-sterilisable handle and inner core was developed, along with a disposable outer sheath. This initial experience evaluated the performance of the Khelix partially recyclable steerable decapolar electrophysiology catheter. METHODS: Sequential patients requiring a decapolar steerable catheter were included in the study. Parameters such as time to positioning from right femoral vein, fluoroscopy time and dose, pacing and sensing thresholds, and the requirement for reposition and/or support sheath were recorded. A retrospective analysis from cases using a standard disposable decapolar catheter was used to compare CS cannulation success, support sheath requirement and cost. RESULTS: 11 re-sterilisable catheter handles were used in 64 patients, each time with a disposable sheath, at two New Zealand centres from December 2017 to June 2018. Pre-defined safety measures were met in all patients, with no catheter-related adverse events. The catheter was successfully positioned in the coronary sinus for 59 cases (92%). Based on initial manufacturer recommendations, the inner recyclable portion of the catheter was able to be re-used successfully up to 12 times with re-sterilisation between cases. CONCLUSIONS: This initial study of an innovative, partially reusable, steerable decapolar electrophysiology catheter demonstrates that it may be used safely and successfully. Use of such a catheter may decrease the cost required for electrophysiology studies.

Availability of automated external defibrillators in Hamilton, New Zealand.

BACKGROUND: Last year, there were 2,000 out-of-hospital cardiac arrests (OHCA) in New Zealand, 74% received CPR but only 5.1% accessed an automated external defibrillator (AED). The average survival rate of OHCA is 13%. The aim of this study was to visit all 50 AED locations shown on www.hamiltoncentral.co.nz to assess their true availability and visibility to the public in the event of an OHCA. METHOD: All premises were visited and the first staff member encountered was asked if they were aware an AED was onsite, its location, hours of availability, if restricted access applied and whether it had been used. RESULTS: Of the 50 locations, three sites no longer exist and two AEDs were listed twice. Therefore, only 45 AEDs exist. Two sites had grossly inaccurate locations. Three AEDs (7%) were continuously available. Nine AEDs were accessible after 6pm at least one day of the week. Thirteen AEDs were available on weekends; however, five required swipe card access. None of the AEDs were located outdoors. CONCLUSION: Far fewer than 50 listed AEDs are freely available to the public, especially after 6pm and on weekends. Lack of signposting and restrictions to access would lead to delayed defibrillation. This important health issue needs addressing.

Progression of paroxysmal to persistent atrial fibrillation: 10-year follow-up in the Canadian Registry of Atrial Fibrillation.

BACKGROUND: Progression from paroxysmal to persistent atrial fibrillation (AF) has important clinical implications and is relevant to the management of patients with AF. OBJECTIVE: The purpose of this study was to define the long-term rate of progression from paroxysmal to persistent AF and the relevant clinical variables. METHODS: The Canadian Registry of Atrial Fibrillation enrolled patients after a first electrocardiographic diagnosis of paroxysmal AF. Associations between baseline characteristics and clinical outcomes were evaluated using a multivariable Cox proportional hazard model and a competing risk model accounting for death as a competing risk, where appropriate. RESULTS: We enrolled 755 patients (61.7% men) aged between 14 and 91 years (mean age 61.2 ± 14.2 years). The median follow-up was 6.35 years (interquartile range 2.93-10.04 years), with a rate of progression to persistent AF at 1, 5, and 10 years was 8.6%, 24.3%, and 36.3%, respectively. All-cause mortality was 30.3% at 10 years. Factors associated with AF progression were increasing age (hazard ratio [HR] 1.40; 95% confidence interval [CI] 1.23-1.60, for each 10-year increment), mitral regurgitation (HR 1.87; 95% CI 1.28-2.73), left atrial dilatation (HR 3.01; 95% CI 2.03-4.47), aortic stenosis (HR 2.40; 95% CI 1.05-5.48), and left ventricular hypertrophy (HR .47; 95% CI 1.04-2.08). Factors associated with a lower rate of progression were a faster heart rate during AF (HR 0.94; 95% CI 0.92-0.96 per 5-beat/min increment) and angina (HR 0.54; 95% CI 0.38-0.77). After accounting for death as a competing risk, left ventricular hypertrophy and aortic stenosis were no longer significant. CONCLUSION: Within 10 years of presenting with paroxysmal AF, >50% of patients will progress to persistent AF or be dead. Increasing age, mitral regurgitation, aortic stenosis, left ventricular hypertrophy, and left atrial dilatation were associated with progression to persistent AF.

Cardiac resynchronisation therapy after percutaneous mitral annuloplasty.

Percutaneous approaches to reduce mitral regurgitation in ischemic cardiomyopathy have stirred interest recently. Patients with ischemic cardiomyopathy and functional mitral regurgitation often meet criteria for cardiac resynchronisation therapy to improve left ventricular function as well as mitral regurgitation, and alleviate symptoms. This case shows that implantation of a pacing lead in the coronary sinus to restore synchronous left and right ventricular contraction is feasible, despite the presence of a remodeling device in the coronary sinus.

Seasonal Variations in Hospital Admissions for ST-Elevation Myocardial Infarction in New Zealand.

BACKGROUND: Increased numbers of ST Elevation Myocardial Infarction (STEMI) admissions have been observed during winter in many countries. Our aim was to assess if seasonal variation of STEMI was present in the Waikato region of New Zealand. METHODS: Case notes of patients admitted to Waikato hospital with STEMI between July 1998 and December 2007 were analysed. The incidence of STEMI during summer (December to February), autumn (March to May), winter (June to August) and spring (September to November) were calculated. The individuals were divided into 2 age groups of ≤ 70 and > 70 years of age. RESULTS: A total of 3,569 patients (mean age 66.9 ± 14.1 years, 64% men) were included. STEMI presentation during winter was significantly higher compared with summer (35 ± 13 versus 27.3 ± 11.3 cases per month, P < 0.02) with 3 additional STEMI admissions per fortnight during winter months. The increase in STEMI in winter was more apparent in patients > 70 years of age, with an 8.5% increase in winter admissions compared to summer (P < 0.01). There was no significant difference in the incidence of STEMI between other seasons. CONCLUSION: There is a higher incidence of STEMI during winter in the Waikato region compared with summer. This increased incidence is particularly pronounced in patients over 70 years of age. Further investigations are necessary to elicit potential causes.