[Clinical value of DC and DRs in warning sudden cardiac death of patients with coronary artery disease].

OBJECTIVE: To make risk stratification of aged patients with coronary artery disease by deceleration capacity of rate (DC) and heart rate deceleration runs (DRs) and to investigate the value of the two detection technologies in warning sudden cardiac death. METHODS: Two hundrend and eighteen patients diagnosed with coronary artery disease (CAD) by coronary angiography (CAG) were selected as observa-tion group:including 55 patients with latent coronary artery disease (LCHD), 56 patients with acute myocardial infarction (AMI), 53 patients with angina pectoris (AP), 54 patients with ischemic heart failure. Fifty-five healthy controls in our hospital were selected at the same time (control group). All patients were detected by 24-hour dynamic electrocardiogram while values of DC and DRs were automatically analyzed and calculated by software. RESULTS: The values of DC and DRs descended significantly in all CHD groups (AMI group, AP group, Ischemic Heart Failure group, LCHD group) and the difference was statistically significant (P < 0.01) compared with normal group; DC and DRs indicated the risk classification of each CAD subgroup was obviously higher than those in normal group and the difference was statistically significant(P < 0.01); CAG showed that the more coronary lesions, the larger the rage, prompt the heavier the illness, which was consistent with the risk classification of each CHD subgroup indicated by DC and DRs. CONCLUSIONS: DC and DRs can be used to analyze the function of vagus nerve, it also can be used to make risk classification of patients with CHD, and it has a higher value of pre-warning for high-risk groups. DC and DRs can be used as sensitive indexes in warning sudden cardiac death of patients with CHD.

[Preconcentration with crosslinked chitosan for determination of trace manganese in waters by flame atomic absorption spectrometry].

A novel method for the preconcentration with crosslinked chitosan (CCTS) and determination of trace manganese in waters by flame atomic absorption spectrometry has been presented. The absorption rate of manganese (VII) by CCTS was 98% at pH 3.00. The effect of preconcentration time, dosage of CCTS, temperature, sample volume and co-existing elements have been investigated. The mechanism of adsorption of CCTS for Mn(VII) was also discussed. The detection limit of the method was 1.86 microg x L(-1), and the relative standard deviation (RSD) was 2.0% (n = 10). The method has been applied to the determination of trace manganese in south lake and Changjiang water with satisfactory results.