G. Kaye

A randomised, controlled study of rate versus rhythm control in patients with chronic atrial fibrillation and heart failure: (CAFÉ-II Study)

Background: Atrial fibrillation (AF) and heart failure (HF) often coexist. The aim was to investigate whether restoring sinus rhythm (SR) could improve cardiac function, symptoms, exercise capacity and quality of life (QoL) in patients with chronic heart failure. Methods: Patients with HF and persistent AF receiving guideline-recommended treatments, including anticoagulants, were eligible for the study. Patients were randomised to either rhythm (treated with amiodarone for at least 3 months prior to attempting biphasic external cardioversion and continued amiodarone long-term if SR was restored) or rate control. Anticoagulants were continued throughout the study regardless of rhythm, unless contraindications developed. Both groups were treated with beta blockers and/or digoxin to reduce the heart rate to <80 bpm at rest and <110 bpm after walking. Symptoms, walk distance (6-minute corridor walk test, 6MWT), QoL and cardiac function were assessed at baseline and 1 year. Results: 61 patients with HF and persistent AF (median duration 14 months (IQR 5 to 32)) were randomly assigned to a rate or rhythm control strategy. Of patients assigned to rhythm control (n = 30), 66% were in SR at 1 year, and 90% of those assigned to rate control (n = 31) achieved the heart rate target. At 1 year, NYHA class (p = 0.424) and 6MWT distance (p = 0.342) were similar between groups but patients assigned to rhythm control had improved LV function (p = 0.014), NT-proBNP concentration (p = 0.046) and QoL (p = 0.019) compared with those assigned to rate control. Greatest improvement was seen in patients in whom SR was maintained. Conclusion: Restoring SR in patients with AF and heart failure may improve QoL and LV function when compared with a strategy of rate control.

Prevalence and Incidence of Arrhythmias and Sudden Death in Heart Failure

Patients with heart failure are prone to a variety of arrhythmias, symptomatic and asymptomatic, that are prognostically significant and have an important bearing on the management of these patients. However there are some inherent problems in assessing the frequency of these arrhythmias within a large patient population, due to a lack of uniformity in defining heart failure and the transient nature of these rhythms. Patients with heart failure commonly die suddenly. The causes of these deaths are difficult to ascertain accurately and are often presumed arrhythmic. With the advent of effective interventions to prevent sudden death, accurately defining the causal relationship between the arrhythmias and sudden death has assumed great importance to appropriately target therapy. Several attempts have been made to predict such deaths on the basis of non-invasive and invasive diagnostic investigations with variable success. In this article we review the incidence and prevalence of atrial and ventricular arrhythmias and sudden deaths in epidemiological studies, surveys and randomised control trials of patients with heart failure. We discuss the prognostic significance of these arrhythmias, the inherent problems in their diagnosis and whether their presence predicts the risk of sudden deaths and the mode of such deaths in the heart failure population. The role of various investigations in risk stratification of sudden death has also been discussed

Effect of right ventricular pacing lead site on left ventricular function in patients with high-grade atrioventricular block: results of the Protect-Pace study

AIM Chronic right ventricle (RV) apical (RVA) pacing is standard treatment for an atrioventricular (AV) block but may be deleterious to left ventricle (LV) systolic function. Previous clinical studies of non-apical pacing have produced conflicting results. The aim of this randomized, prospective, international, multicentre trial was to compare change in LV ejection fraction (LVEF) between right ventricular apical and high septal (RVHS) pacing over a 2-year study period. METHODS AND RESULTS We randomized 240 patients (age 74 ± 11 years, 67% male) with a high-grade AV block requiring >90% ventricular pacing and preserved baseline LVEF >50%, to receive pacing at the RVA (n = 120) or RVHS (n = 120). At 2 years, LVEF decreased in both the RVA (57 ± 9 to 55 ± 9%, P = 0.047) and the RVHS groups (56 ± 10 to 54 ± 10%, P = 0.0003). However, there was no significant difference in intra-patient change in LVEF between confirmed RVA (n = 85) and RVHS (n = 83) lead position (P = 0.43). There were no significant differences in heart failure hospitalization, mortality, the burden of atrial fibrillation, or plasma brain natriutetic peptide levels between the two groups. A significantly greater time was required to place the lead in the RVHS position (70 ± 25 vs. 56 ± 24 min, P < 0.0001) with longer fluoroscopy times (11 ± 7 vs. 5 ± 4 min, P < 0.0001). CONCLUSION In patients with a high-grade AV block and preserved LV function requiring a high percentage of ventricular pacing, RVHS pacing does not provide a protective effect on left ventricular function over RVA pacing in the first 2 years. PROTECT-PACE ClinicalTrials.gov number NCT00461734.

Shock coil failure secondary to external irradiation in a patient with implantable cardioverter defibrillator.

The use of implantable cardioverter defibrillator (ICD) in the management of malignant ventricular arrhythmia is well established. Radiation treatment is common in malignant neoplasms, but the direct effect of irradiation in ICD is largely not well understood. We describe a case where radiation treatment probably led to shock coil failure. (PACE 2004; 27:690–691)

The Atrial Fibrillation Paradox of Heart Failure

The prevalence of atrial fibrillation (AF) in patients with heart failure (HF) is high, but longitudinal studies suggest that the incidence of AF is relatively low. The authors investigated this paradox prospectively in an epidemiologically representative population of patients with HF and persistent AF. In all, 891 consecutive patients with HF [mean age, 70+/-10 years; 70% male; left ventricular ejection fraction, 32%+/-9%] were enrolled. The prevalence of persistent AF at baseline was 22%. The incidence of persistent AF at 1 year was 26 per 1000 person-years, ranging from 15 in New York Heart Association class I/II to 44 in class III/IV. AF occurred either at the same time or prior to HF in 76% of patients and following HF in 24%. A risk score was developed to predict the occurrence of persistent AF. The annual risk of persistent AF developing was 0.5% (0%-1.3%) for those in the low-risk group compared with 15% (3.4%-26.6%) in the high-risk group. Despite a high prevalence of persistent AF in patients with HF, the incidence of persistent AF is relatively low. This is predominantly due to AF coinciding with or preceding the development of HF. The annual risk of persistent AF developing can be estimated from clinical variables.

The effect of right ventricular apical and nonapical pacing on the short- and long-term changes in left ventricular ejection fraction: a systematic review and meta-analysis of randomized-controlled trials

The right ventricular apex (RVA) is the traditional lead site for chronic pacing but in some patients may cause impaired left ventricular (LV) systolic function over time. Comparisons with right ventricular nonapical (RVNA) pacing sites have generated inconsistent results and recent meta‐analyses have demonstrated unclear benefit due to heterogeneity across studies.

Seven years experience of a nurse-led elective cardioversion service in a tertiary referral centre: an observational study

BACKGROUND Traditionally the provision of elective external direct current cardioversion (EDCCV) for patients with atrial arrhythmias has been doctor-led. Increasing demands on hospital beds and time pressures for doctors has driven the desire for an alternative approach. We established a nurse-led cardioversion service in 2006 and present our experience. METHODS A prospective database of patients undergoing elective EDCCV between July 2006 and July 2013 was collected. Demographic data, arrhythmia, success and immediate complications of cardioversion were recorded. RESULTS A total of 974 EDCCV were performed on 772 patients. The mean patient age was 62.7 years, 564 (73.1%) were male. In 530 patients (69.0%) AF was the primary arrhythmia, in 242 (31.0%) atrial flutter. All EDCCVs were performed in a high dependency unit. Sinus rhythm was obtained in 692 patients (89.6%). Of 640 outpatients, 629 (98.3%) were discharged on the same day of their procedure. Eleven patients (1.7%) required admission to hospital. No patients required urgent temporary transvenous or permanent pacing, and there were no deaths in association with this procedure. CONCLUSIONS Nurse-led elective EDCCV is a safe and effective way of restoring sinus rhythm in patients with AF or atrial flutter, with additional benefits to resource provision.

Imaging and Right Ventricular Pacing Lead Position: A Comparison of CT, MRI, and Echocardiography.

Right ventricular nonapical (RVNA) pacing may reduce the risk of heart failure. Fluoroscopy is the standard approach to determine lead tip position, but is inaccurate. We compared cardiac computed tomography (CT), magnetic resonance imaging (MRI), two‐dimensional and three‐dimensional transthoracic echocardiography (TTE), and chest x‐ray (CXR) to assess which provides the optimal assessment of right ventricular (RV) lead tip position.

Characteristics of Cavotricuspid Isthmus Ablation for Atrial Flutter Guided by Novel Parameters Using a Contact Force Catheter.

This study sought to investigate specific contact force (CF) parameters to guide cavotricuspid isthmus (CTI) ablation and compare the outcome with a historical control cohort.

An Audit of Amiodarone-induced Thyrotoxicosis - do Anti-thyroid Drugs alone Provide Adequate Treatment?

INTRODUCTION Amiodarone is a widely used anti-arrhythmic drug. A common long-term complication is amiodarone-induced thyrotoxicosis (AIT). We examined retrospectively the efficacy of anti-thyroid drugs with or without prednisolone and the role of surgical thyroidectomy in the treatment of AIT in a single centre, in an iodine-replete region of Australia. METHODS A retrospective audit of patients with AIT was performed between 2002-2012 at this centre. Twenty-seven patients, mean age 60.9 ± 2.3 years were identified. Medical therapy (anti-thyroid drugs, prednisolone) was commenced according to the treating endocrinologist. The main outcomes were time to euthyroidism and number proceeding to thyroidectomy. RESULTS Of 11 patients commenced on anti-thyroid drugs alone, seven (64%) required the addition of prednisolone. Baseline free T4 was significantly higher in those ultimately treated with prednisolone (58.4 ± 6.3pmol/L) versus those not (31.7 ± 3.4pmol/L, P<0.05). Although similar results were seen with free T3, the difference was not significant (P=0.06). In patients with baseline free T4 <30pmol/L, 75% (3/4) achieved euthyroidism without prednisolone. Neither the use of prednisolone nor continuation of amiodarone significantly influenced time to euthyroidism. Eleven patients (41%) proceeded to surgical thyroidectomy, which was undertaken by an experienced surgical team without significant complications and no mortality. CONCLUSION Patients with AIT generally required glucocorticoids. Mild disease (free T4 <30pmol/L) may be successfully treated with anti-thyroid drugs alone. Surgical thyroidectomy is a safe and effective treatment for those refractive to medical therapy.