Automatic Capture Verification in Pacemakers (Autocapture) Utility and Problems

The concept of a closed loop feedback system, that would automatically assess pacing threshold and self -adjust pacing output to ensure consistent myocardial capture, has many appeals. Enhancing patient safety in cases of an unexpected rise in threshold, reduced current drain, hence prolonging battery longevity and reducing the amount of physician intervention required are just some of the advantages. Autocapture (AC) is a proprietary algorithm developed by St Jude Medical CRMD, Sylmar, CA, USA, (SJM) that was the first to commercially provide these automatic functions in a single chamber pacemaker (Microny and Regency), and subsequently in a dual chamber pacemaker (Affinity, Entity and Identity family of pacemakers). This article reviews the conditions necessary for AC verification and performance and the problems encountered in clinical practice