Incremental value of left atrial structural and functional characteristics for prediction of atrial fibrillation in patients receiving cardiac pacing.

Background: Better prediction of cardiac pacing patients at risk of atrial fibrillation (AF) would enable more effective prophylaxis. We sought whether left atrial (LA) electromechanical conduction time (EMT) and myocardial mechanics were associated with incident AF in patients undergoing dual chamber pacemaker implantation, independent of left atrial volume (LAV).

Methods And Results: Clinical data were obtained prospectively in 146 enrollees (73±10 years) undergoing dual chamber pacemaker implantation in the Protect-Pace study.

Dyssynchrony, contraction efficiency and regional function with apical and non-apical RV pacing.

Background: Recent work has shown no difference in change of LVEF between RV apical (RVA) pacing and non-RVA pacing in patients with normal LV function. We hypothesised that a more sensitive marker (global longitudinal strain, GLS) could identify a detrimental effect of RVA and that assessment of deformation could identify whether dyssynchrony, contraction inefficiency and regional LV impairment were responsible for functional changes.

Methods: In this substudy of Protect-PACE (The Protection of Left Ventricular Function During Right Ventricular Pacing.

Guidelines for the diagnosis, prevention and management of implantable cardiac electronic device infection. Report of a joint Working Party project on behalf of the British Society for Antimicrobial Chemotherapy (BSAC, host organization), British Heart Rhythm Society (BHRS), British Cardiovascular Society (BCS), British Heart Valve Society (BHVS) and British Society for Echocardiography (BSE).

Infections related to implantable cardiac electronic devices (ICEDs), including pacemakers, implantable cardiac defibrillators and cardiac resynchronization therapy devices, are increasing in incidence in the USA and are likely to increase in the UK, because more devices are being implanted. These devices have both intravascular and extravascular components and infection can involve the generator, device leads and native cardiac structures or various combinations. ICED infections can be life-threatening, particularly when associated with endocardial infection, and all-cause mortality of up to 35% has been reported.

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.

Haemogregarine infections of three species of aquatic freshwater turtles from two sites in Costa Rica.

Twenty-five black river turtles (Rhinoclemmys funerea) and eight white-lipped mud turtles (Kinosternon leucostomum) from Selva Verde, Costa Rica were examined for haemoparasites. Leeches identified as Placobdella multilineata were detected on individuals from both species. All turtles sampled were positive for intraerythrocytic haemogregarines (Apicomplexa:Adeleorina) and the average parasitemia of black river turtles (0.

Aubrey Leatham and the introduction of cardiac pacing to the UK.

In the early 1950s, Dr Aubrey Leatham established a cardiac unit at St. George's Hospital, Hyde Park Corner, London. He developed and taught the essential clinical skill of cardiac auscultation.

Sudden death in patients receiving drugs tending to prolong the QT interval.

Aims: To examine risks of sudden death in the community associated with drugs grouped by their risk of causing torsades de pointes (TdP) and to explore the risks for individual drugs.

Methods: Case-control study comparing prior drug intakes and morbidities, using the Arizona classification of drugs causing TdP. Participants included 1010 patients dying suddenly where post-mortem examination did not identify a clear cause of death, and 3030 matched living controls from primary care.

Selective site right ventricular pacing.

The right ventricular apex (RVA) has been the elective site for placing endocardial pacing leads since 1959 when Furman described the use of the transvenous route for pacemaker implantation. This site was used because it is easily accessible, readily identified and associated with a stable position and reliable chronic pacing parameters. It was recognised, however, that pacing from the RVA did not reproduce normal ventricular conduction or contraction.

Treatment of amiodarone-associated thyrotoxicosis.

Background: A 75-year-old man had a myocardial infarction complicated by poor left ventricular function and non-sustained ventricular tachycardia. He began treatment with amiodarone and 12 months later developed symptoms of thyrotoxicosis.

Investigations: Thyroid function tests after commencement of amiodarone revealed a high-normal level of free T4 and low-normal level of free T3 with a normal serum TSH.

Association between serum free thyroxine concentration and atrial fibrillation.

Background: Previous studies have suggested that minor changes in thyroid function are associated with risk of atrial fibrillation (AF). Our objective was to determine the relationship between thyroid function and presence of atrial fibrillation (AF) in older subjects.

Methods: A population-based study of 5860 subjects 65 years and older, which excluded those being treated for thyroid dysfunction and those with previous hyperthyroidism.

Cardiovascular manifestations of hyperthyroidism before and after antithyroid therapy: a matched case-control study.

Objectives: This study sought to prospectively evaluate the prevalence of cardiovascular abnormalities in patients with overt hyperthyroidism before and after antithyroid therapy.

Background: Overt hyperthyroidism is associated with recognized cardiovascular effects believed to be reversed by antithyroid therapy; however, increasing data suggest significant long-term cardiovascular mortality.

Methods: A total of 393 (312 women, 81 men) consecutive unselected patients with overt hyperthyroidism were recruited and compared with 393 age- and gender-matched euthyroid control subjects.

Prevalence of subclinical thyroid dysfunction and its relation to socioeconomic deprivation in the elderly: a community-based cross-sectional survey.

Context: Population-based screening has been advocated for subclinical thyroid dysfunction in the elderly because the disorder is perceived to be common, and health benefits may be accrued by detection and treatment.

Objective: The objective of the study was to determine the prevalence of subclinical thyroid dysfunction and unidentified overt thyroid dysfunction in an elderly population.

Design, Setting, And Participants: A cross-sectional survey of a community sample of participants aged 65 yr and older registered with 20 family practices in the United Kingdom.

Multi-center clinical experience with a lumenless, catheter-delivered, bipolar, permanent pacemaker lead: implant safety and electrical performance.

Purpose: Reduced lead diameter and reliability can be designed into transvenous permanent pacing leads through use of redundant insulation and removal of the stylet lumen. The model 3830 lead (Medtronic Inc., Minneapolis, MN, USA) is a bipolar, fixed-screw, steroid-eluting, lumenless, 4.

Clinicians didn't reliably distinguish between different causes of cardiac death using case histories.

Background And Objectives: Routine statistics and epidemiologic studies often distinguish between types of cardiac death. Our aim was to assess agreement between doctors on cause of death given identical clinical information, and to assess agreement between a physician panel and the original cause of death as coded on national statistics.

Methods: Clinical information and autopsy reports on 400 cardiac deaths were randomly selected from a defined population in the West Midlands, UK.

Comparative assessment of right, left, and biventricular pacing in patients with permanent atrial fibrillation.

Aims: Left ventricular (LV) and biventricular (BiV) pacing are potentially superior to right ventricular (RV) apical pacing in patients undergoing atrioventricular (AV) junction ablation and pacing for permanent atrial fibrillation.

Methods And Results: Prospective randomized, single-blind, 3-month crossover comparison between RV and LV pacing (phase 1) and between RV and BiV pacing (phase 2) performed in 56 patients (70+/-8 years, 34 males) affected by severely symptomatic permanent atrial fibrillation, uncontrolled ventricular rate, or heart failure. Primary endpoints were quality of life and exercise capacity.

Heart rate variability and turbulence in hyperthyroidism before, during, and after treatment.

Patients with subclinical and treated overt hyperthyroidism have an excess vascular mortality rate. Several symptoms and signs in overt hyperthyroidism suggest abnormality of cardiac autonomic function that may account in part for this excess mortality rate, but few studies have examined cardiac autonomic function in untreated and treated hyperthyroidism. We assessed heart rate turbulence (HRT) and time-domain parameters of heart rate variability in a large, unselected cohort of patients with overt hyperthyroidism referred to our thyroid clinic (n = 259) and compared findings with a group of normal subjects with euthyroidism (n = 440).