Automated autonomic nervous system function analysis

The automated system was used to evaluated autonomic nervous-system function for four conditions: (1) valsalva maneuver; (2) beat-beat variation in heart rate during deep breathing; (3) isometric muscular contraction; and (4) heart-rate response to standing and orthostatic tolerance. Interrupt routines were used to collect electrocardiogram (ECG) data through a computer during the four recording conditions and, in certain cases, special interrupt routines were used to synchronize with minute-to-minute blood pressure measurements. Paper tracings were recorded at the same time for hand calculation. The R-R interval and heart rate were calculated by hand from the ECG tracings and compared to the results of the automated analysis system. No statistically significant (p>0.05) differences were observed between the two methods. Also significant correlations (p<0.05) ranging from 0.98 to 0.99 were found between them. The advantages of the automated system include the elimination of the need for recording papers and observer subjectivity and the higher speed of analysis.<>