Showing papers by "Andrzej Rynkiewicz published in 1996"

Heart rate power spectral analysis in patients before and 6 weeks after coronary artery bypass grafting.

Abstract: Decreased cardiac vagal activity is a known risk factor in coronary artery disease. The aim of our study was to determine the effect of coronary artery bypass grafting (CABG) on heart rate variability (HRV) before and 6 weeks after CABG. The study group consisted of 34 patients (4 women, 30 men, mean age 56 +/- 9 years). ECGs were recorded in 10 minutes periods in both supine and standing position with controlled breathing rate (0.25Hz). The analysis of HRV power spectrum was done by means of fast Fourier transformation. The total spectral power (TPS), power in very low frequency band (VLF: < 0.05 Hz), low frequency band (LF:0.05-0.15Hz), high frequency band (HF:0.15-0.5Hz), LF/HF ratio and percentage fraction of total power in these frequency bands (%VLF, %LF, %HF) were analysed. Significant attenuation of all spectral components of HRV were found during orthostatic load before CABG (p < 0.05). TPS, VLF, LF, %HF decreased in standing position to about half of their level in supine position, HF decreased to as little as one fourth, while LF/HF ratio and %LF increased significantly (p < 0.05). After the CABG these changes were not significant. We have found significant increase of HF (p < 0.05) and %HF (p < 0.01) in standing position after the CABG. The results suggest that CABG causes an improvement in cardiac vagal activity especially in standing position.

Ambulatory blood pressure and insulinaemia in different clinical conditions.

Abstract: The aim of our study was to examine the relation between insulin and ambulatory blood pressure (ABPM) in several clinical conditions. ABPM monitoring was performed with Spacelabs device. Fasting plasma insulin (FPI) was measured by radioimmunoassay. In young, non-obese normotensive subjects (n = 32) there were correlations between FPI and both asleep (r = 0.61, p 10 years) there was a significant negative correlation between the daily dose of insulin and 24-h systolic ABPM (r =-0.63, p < 0.02). In 20 patients with renal failure on chronic haemodialysis we have found a significant negative correlation between FPI and 24-h systolic APBM (r = 0.80, p < 0.001) and 24-h diastolic ABPM (r = -0.55, p < 0.05). Similar negative correlations were found in 20 nondialysed subjects with moderate chronic renal failure. Taken together, our results suggest that insulin could reveal its hypertensive or vasodilatory effect which depends on a clinical condition of the studied subjects.