Does biventricular pacing improve quality of life and exercise tolerance in patients with heart failure and intraventricular conduction delay?
Biventricular pacing improves quality of life and NYHA class in patients with advanced heart failure and intraventricular conduction delay. The attenuated benefit seen over time may be related to initial placebo effect or simple dual- chamber pacing, or the natural history of the underlying disease. Identification of patients most likely to respond to biventricular pacing was not possible.
The quality assurance program developed for this contraceptive implant has helped ensure that a safe product was being introduced into developing country family planning programs. This program provides a template for establishing quality assurance programs for other cost-effective pharmaceutical products that have not yet received stringent regulatory approval and are being distributed in resource-poor settings.