[Analysis of influencing factors of heart rate deceleration capacity in patients with dilated cardiomyopathy].

Objective: To investigate the determinants affecting the heart rate deceleration capacity (DC) in patients with dilated cardiomyopathy (DCM). Methods: One hundred patients with DCM (DCM group) and 202 healthy subjects (control group) were respectively enrolled. Echocardiography and 24 hours electrocardiogram were performed in all subjects. DC value was compared between the two groups. Multiple regression analysis was made to evaluate the related determinants of DC ((age, sex, echocardiographic parameters including the left atrial diameter (LAD) and left ventricular ejection fraction (LVEF)). Results: (1) DC value was significantly lower in DCM group than in control group( (4.40±2.03) ms vs. (7.30±1.81) ms, P<0.01), prevalence of DC value≤4.5 ms was significantly higher in DCM group than in control group (62% vs. 6%, P<0.01). (2) DC value in the DCM group decreased in proportion to increasing LAD dimension, DC value was (5.60±2.04) ms, (4.50±2.07) ms and (3.60±1.62) ms (P<0.05) in DCM patients with LAD≤40 mm, 40 mm50 mm, respectively. (3) DC value in the DCM group was negatively related to the LAD (r=-0.366, P<0.01), positively related to the LVEF (r= 0.241, P<0.01), but not related with age and sex. Multiple factors regression analysis showed that increased LAD was related to the reduced DC values independtly. Conclusion: DC value of the patients in the DCM group is decreased, which indicate the decrease of the vagus nerve tension, and increased LAD is related to the reduced DC value independtly in DCM patients.

Method Of Complete Triads: An Investigation Of Unreliability In Multidimensional Perception Of Nations.

In many instances investigators are hesitant to use "too many" objects or stimuli in a multidimensional scaling study using the method of complete triads. One of the major reasons for this is that such use is postulated to lead to subject fatigue/boredom effects or practice effects which may produce unreliability in the judgments. In the present study an experimental design was constructed in an attempt (a) to investigate the presence of subject fatigue/boredom effects or practice effects and (b) to assess the influence of these effects on the configurations and distances resulting from multidimensional scaling of nations. The results showed that the postulated effects were present, but they did not influence the multidimensional scaling solutions.