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Nonlinear dynamics of the cardiovascular parameters in sleep and sleep apnea. In memory of Alberto Malliani [1935-2006] - a brave heart and beautiful mind

100%

Smietanowski M. , Szelenberger W. , Trzebski A.

Journal of Physiology and Pharmacology. Supplement

2006

tom 57

nr 11

55-68

The aim of our study was to characterize the dynamics of heart rate variability (HRV) during sleep in healthy subjects and in patients with obstructive sleep apnea syndrome (OSAS). Present results were compared with earlier data obtained in healthy subjects (1) performing intermittent voluntary apneas. Power spectra in low (LF) and high (HF) frequency band and non linear indices: correlation dimension (CD) and recurrence plots were computed. New indices were applied: a beat-to beat control (BBC) for the assessment of cardiovascular regulatory mechanisms as cardiac, vascular or mixed type control and COT for quantification of relative contribution of cardiac and vascular component in blood pressure variability. During Wake stage in OSAS patients mean LF component was augmented (0.035 s2/Hz) comparing to healthy subjects (0.012 s2/Hz). Nonlinear indices suggest reduced HRV dynamics complexity in OSAS patients. Similar pattern could be observed when comparing LF component, CD and recurrence parameters during spontaneous breathing and in consecutive voluntary apneas. The results correlate with 20% increase in BBC vascular control type and COT inversion form +0.08 to - 0.12. Changes in BBC and COT along with power spectra and nonlinear dynamics indices appear to signal risk and/or initiation of arterial hypertension in OSAS patients.

Repetitive apneas reduce nonlinear dynamical complexity of the human cardiovascular control system

100%

Trzebski A. , Smietanowski M. , Zebrowski J.

Journal of Physiology and Pharmacology

2001

tom 52

nr 1

The role of cardiac and vascular components in blood pressure variability during voluntary apnea in snoring subjects

88%

Tafil-Klawe M. , Radel A. , Klawe J. J. , Smietanowski M. , Zlomanczuk P.

Journal of Physiology and Pharmacology. Supplement

2006

tom 57

nr 4

359-364

The aim of this study was to evaluate the cardiovascular response to the activation of arterial chemoreceptors during voluntary apnea in snoring subjects. Fifty five men were enrolled in the study: 33 snorers and 22 non-snorers (control group). The majority of snorers were overweight and hypertensive. The experimental session consisted of 20 voluntary inspiratory apneas interspersed with 1 min free breathing periods, and 20 min recovery. The following parameters were recorded noninvasively: blood pressure, ECG, and arterial oxygen saturation. Data analysis was based on the Smietanowski procedure, written in the 4-th generation script language of MATLAB environment, which allows assessing the relative contribution of cardiac and vascular components to blood pressure variability. The results indicate that repetitive apneas led to significantly greater increases in blood pressure in the snorers. In this group, the domination of vascular influences during apnea periods reached 67 ±2.0%, which was greater than the 56 ±1.8% in the non-snorers (P<0.01). In contrast, the contribution of the cardiac component in the blood pressure response to apnea was greater in the non-snorers: 33 ±3% vs. 20 ±2% in the snorers (P<0.01). We conclude that activation of carotid chemoreceptors during voluntary apnea evokes a greater cardiovascular response in snorers, related to the reflex increase in total peripheral vascular resistance, and, consequently, a greater increase in blood pressure.

Daily changes in cardiac and vascular blood pressure components during breath holding episodes in obstructive sleep apnea patients after day-shift and night-shift work

75%

Tafil-Klawe M. , Klawe J. J. , Zlomanczuk P. , Szczepanska B. , Sikorski W. , Smietanowski M.

Journal of Physiology and Pharmacology. Supplement

2007

tom 58

nr 5