To explore a non-invasive method for measuring cardiac reserve during painless early pregnancy termination surgery and its safety evaluation.

From February 2007 to February 2008, 179 pregnant women with 8.0±1.9 weeks, 20-40 years old, who chose painless early pregnancy termination surgery were recruited in this study. The heart rate (HR) and the ratio of the amplitude of the first heart sound to the second heart sound (S1/S2) were measured before and after the anesthesia, and during painless early pregnancy termination surgery. The study protocol was approved by the Ethical Review Board of Investigation in Human Being of Chengdu Maternal and Child Health Care Hospital. Informed consent was obtained from each participating.

The heart rates were increased after anesthesia, and decreased during operation. There were significant differences of heart rate between before and after anesthesia, and between after anesthesia and during the operation (P<0.05). Ratio of the amplitude of the first heart sound to the second heart sound was raised after anesthesia, a opposite amplitude was found during operating. Nevertheless, there was no significantly differences (P>0.05).

Cardiac function were up-regulated after anesthesia in painless early pregnancy termination surgery. The mobilization were observed in heart rate reserve and cardiac function reserve, there was opposite mobilization during operating. Cardiac accident did not happen. A non-invasive measure of cardiac reserve maybe predict cardiac safety during painless early pregnancy termination surgery.