[The effect of ventricular pacing on plasma atrial natriuretic factor levels and its clinical significance]

The effects of increasing pacing rate on cardiac hemodynamics and the release of atrial natriuretic factor (ANF), cGMP and cAMP were studied in 21 patients underwent ventricular pacing. ANF levels elevated insignificantly in patients without VA conduction, but elevated significantly in patients with VA conduction at pacing rate of 90,110 and 160 beat/min. The intracardiac pressure between these two groups of patients did not show significant difference. The conclusions are: (1) elevation of ANF levels at increasing pacing rate is mainly due to atrial distension rather than atrial pressure per se. (2) The elevation of ANF levels may reflect the changes of hemodynamics, the higher the ANF level, the more increase in intracardiac pressure. (3) marked elevation of ANF level may suggest presence of VA conduction in patients during ventricular pacing.