Biomedical subjects

Jeffrey S Healey

Publications and source records attributed to Jeffrey S Healey.

5 recordsLinked to original sources

PubMed2006

Cardiovascular outcomes with atrial-based pacing compared with ventricular pacing: meta-analysis of randomized trials, using individual patient data.

BACKGROUND: Several randomized trials have compared atrial-based (dual-chamber or atrial) pacing with ventricular pacing in patients with bradycardia. No trial has shown a mortality reduction, and only 1 small trial suggested a reduction in stroke. The goal of this review was to determine whether atrial-based pacing prevents major cardiovascular events. METHODS AND RESULTS: A systematic review was performed of publications since 1980. For inclusion, trials had to compare an atrial-based with a ventricular-based pacing mode; use a randomized, controlled, parallel design; and have data on mortality, stroke, heart failure, or atrial fibrillation. Individual patient data were obtained from 5 of the 8 identified studies, representing 95% of patients in the 8 trials, and a total of 35 000 patient-years of follow-up. There was no significant heterogeneity among the results of the individual trials. There was no significant reduction in mortality (hazard ratio [HR], 0.95; 95% confidence interval [CI], 0.87 to 1.03; P=0.19) or heart failure (HR, 0.89; 95% CI, 0.77 to 1.03; P=0.15) with atrial-based pacing. There was a significant reduction in atrial fibrillation (HR, 0.80; 95% CI, 0.72 to 0.89; P=0.00003) and a reduction in stroke that was of borderline significance (HR, 0.81; 95% CI, 0.67 to 0.99; P=0.035). There was no convincing evidence that any patient subgroup received special benefit from atrial-based pacing. CONCLUSIONS: Compared with ventricular pacing, the use of atrial-based pacing does not improve survival or reduce heart failure or cardiovascular death. However, atrial-based pacing reduces the incidence of atrial fibrillation and may modestly reduce stroke.

Arrhythmias, Cardiac↗

PubMed2006

Universal access -- but when? Treating the right patient at the right time: access to electrophysiology services in Canada.

The Canadian Cardiovascular Society Access to Care Working Group has published a series of commentaries on access to cardiovascular care in Canada. The present article reviews the evidence for timely access to electrophysiology services. Using the best available evidence along with expert consensus by the Canadian Heart Rhythm Society, the panel proposed a series of benchmarks for access to the full scope of electrophysiology services, from initial consultation through to operative procedures. The proposed benchmarks are presented herein.

Canada↗

PubMed2006

Clinical trials, the renin angiotensin system and atrial fibrillation.

PURPOSE OF REVIEW: Atrial fibrillation is the most common clinical arrhythmia. Current treatment strategies are far from optimal. One new research direction is to target the atrial fibrillation substrate and to examine whether drugs can produce atrial structural and/or electrophysiological remodeling and whether this results in a reduction in atrial fibrillation burden. RECENT FINDINGS: Two prospective randomized studies have shown that the addition of an angiotensin converting enzyme inhibitor or an angiotensin receptor blocker to amiodarone reduces the recurrence rate of atrial fibrillation after electrical cardioversion. There are ten completed prospective clinical trials with atrial fibrillation as a secondary endpoint or assessed in post-hoc analysis. Five of these studies have reported a positive impact of angiotensin converting enzyme inhibitors or angiotensin receptor blockers on atrial fibrillation burden. A meta-analysis showed that active drugs reduced the overall risk of development of atrial fibrillation by 28%. Patients in the heart failure trials obtained most benefit from these drugs (relative risk reduction 44%, P = 0.07). SUMMARY: The initial basic science and clinical trial data suggest that modulation of the renin angiotensin system may be an effective treatment for atrial fibrillation. The following, however, remain to be clarified: do these drugs have a clinically meaningful impact on atrial fibrillation burden; if there is an impact, is it similar in all atrial fibrillation patients or just in certain subsets; do angiotensin converting enzyme inhibitors and angiotensin receptor blockers have similar benefits; and is there a role for aldosterone antagonists?

Angiotensin Receptor Antagonists↗

PubMed2003

Prognostic use of cardiac troponin T and troponin I in patients with heart failure.

BACKGROUND: Troponin T (cTnT) and troponin I (cTnI) are present in the sera of some heart failure (HF) patients and have potential importance as prognostic markers. OBJECTIVE: To prospectively evaluate the prognostic value of cTnT and cTnI in well-characterized HF patients and clarify their relationship to other clinical markers of HF severity. METHODS: cTnT and cTnI were measured in 78 HF patients (45 inpatients, 33 outpatients) who were followed up prospectively for 12 months. RESULTS: Plasma cTnT (> or =0.02 ng/mL) and cTnI (> or =0.3 ng/mL) were detected in 51% and 46% of patients, respectively. These patients were more likely to be inpatients (70% versus 45% for cTnT, 75% versus 43% for cTnI, P<0.05 for both), have a higher plasma creatinine (153 versus 119 micromol/L for cTnT; 157 versus 118 micromol/L for cTnI, P<0.05) and lower plasma sodium (134 versus 138 mmol/L for both, P<0.05). At 12 months, they were more likely to have died or undergone cardiac transplantation (41% versus 14%, P=0.01 for cTnT; 43% versus 15%, P=0.004 for cTnI). After adjustment for New York Heart Association class, plasma sodium and inpatient status, a significant association with events was still evident for both troponins. CONCLUSIONS: Both cTnT and cTnI are strongly associated with other clinical indicators of HF severity and remain independent predictors of prognosis after adjustment for these factors. These results indicate a potential role for cTnT and cTnI in the clinical management of HF patients.

Aged↗

PubMed2002

Pacemakers, recent directions and developments.

PURPOSE OF REVIEW: Pacemaker and implantable cardiovertor defibrillator utilization is evolving rapidly. Expanding indications are reviewed. RECENT FINDINGS: Current pacemakers are smaller, more dependable, longer lasting and have rate-adaptive features. Implantable cardiovertor defibrillators use transvenous leads and have advanced pacing abilities. Primary pacing indications remain sinus node dysfunction or atrioventricular conduction abnormalities. Dual-chamber pacemakers compared with single chamber ventricular pacemakers, have small quality of life advantages and result in less atrial fibrillation, but decrease stroke rates and mortality. In congestive heart failure patients with delayed ventricular conduction, cardiac resynchronization therapy (atrially timed biventricular pre-excitation) improves physiological parameters, performance indices and quality of life. Atrial arrhythmias may be prevented or treated with appropriate pacing strategies. Pacing-related improvements for symptomatic neurally mediated syncope and symptomatic hypertrophic obstructive cardiomyopathy have been demonstrated. For patients with coronary artery disease and low ejection fractions, implantable cardiovertor defibrillators are well established in the secondary prevention of sudden death, and may be helpful for primary prevention if there are inducible ventricular arrhythmias. Combining cardiac resynchronization and implantable cardiovertor defibrillators in similar patients is under investigation. The role of atrial defibrillators is being defined. Electromagnetic interference remains possible with these devices, particularly in electromagnetically hostile environments. SUMMARY: More pacemakers and implantable cardiovertor defibrillators will be encountered. Despite increasing sophistication, most often only basic anti-bradycardia modes are essential in the perioperative setting. Understanding the indications for implantation will help the anesthesiologist better support the physiological needs of the patient. Existing perioperative pacemaker-related guidelines for the anesthesiologist still apply.

Journal Article↗