One hundred five pacemakers with bipolar electrodes have been observed in a pacemaker clinic serving a rural population. Pacemaker stimulus wave-form analysis and electronic stimulus interval counting were employed. Also, in selected cases, radiographic analysis of battery depletion was performed. Results show that a 1% increase in pacemaker rate is an accurate predictor of impending failure in units that are designed to undergo a rate change with battery depletion, and that radiography is helpful in cases of doubt. Wave-form analysis was useful only when other factors were unequivocally abnormal because of difficulty in standardizing the test.
Robinson N, Sutton R, Craige E. Implanted Bipolar PacemakersAnalysis of Function. JAMA. 1973;223(5):505–511. doi:10.1001/jama.1973.03220050015004