Showing papers by "Andrzej Rynkiewicz published in 2011"

Reading multifractal spectra: Aging by multifractal analysis of heart rate

Abstract: The method of effective reading of multifractal properties is proposed. The method consists in the analysis of a given signal together with the analysis of an integrated signal. A practical way to separate monofractal-type signals from other signals is given. The method is applied to 24-hour ECG recordings of RR-interbeat intervals to assess the effect of aging on autonomic regulation of the heart in healthy adults. Heart rate variability is evaluated by multifractal analysis in the VLF band. A switch from mono- to multifractality is observed between diurnal and nocturnal parts of series in the group of young adults. With aging the multifractal structure of nocturnal signals declines. The observed changes can be related to the circadian alternation in the central mechanisms controlling the cardiovascular system which becomes impaired with advance in age in human. Indices for age impairment of autonomic regulation are proposed.

Aging in autonomic control by multifractal studies of cardiac interbeat intervals in the VLF band.

Abstract: The heart rate responds dynamically to various intrinsic and environmental stimuli. The autonomic nervous system is said to play a major role in this response. Multifractal analysis offers a novel method to assess the response of cardiac interbeat intervals. Twenty-four hour ECG recordings of RR interbeat intervals (of 48 elderly volunteers (age 65–94), 40 middle-aged persons (age 45–53) and 36 young adults (age 18–26)) were investigated to study the effect of aging on autonomic regulation during normal activity in healthy adults. Heart RR-interval variability in the very low frequency (VLF) band (32–420 RR intervals) was evaluated by multifractal tools. The nocturnal and diurnal signals of 6 h duration were studied separately. For each signal, the analysis was performed twice: for a given signal and for the integrated signal. A multifractal spectrum was quantified by the hmax value at which a multifractal spectrum attained its maximum, width of a spectrum, Hurst exponent, extreme events hleft and distance between the maxima of a signal and its integrated counterpart. The following seven characteristics are suggested as quantifying the age-related decrease in the autonomic function ('int' refers to the integrated signal): (a) hsleepmax − hmaxwake > 0.05 for a signal; (b) hintmax > 1.15 for wake; (c) hintmax − hmax > 0.85 for sleep; (d) Hurstwake − Hurstsleep 0.07; (f) widthint 0.75. Eighty-one percent of elderly people had at least four of these properties, and ninety-two percent of young people had three or less. This shows that the multifractal approach offers a concise and reliable index of healthy aging for each individual. Additionally, the applied method yielded insights into dynamical changes in the autonomic regulation due to the circadian cycle and aging. Our observations support the hypothesis that imbalance in the autonomic control due to healthy aging could be related to changes emerging from the vagal function (Struzik et al 2006 IEEE Trans. Biomed. Eng. 53 89–94).

Relationship between periodontal status and the incidence of acute myocardial infarction Zależności pomiędzy stanem przyzębia a występowaniem zawału mięśnia sercowego

Abstract: Summary Introduction: Recent scientific reports indicate that periodontitis is a potential risk factor for myocardial infarction (MI). Comparison of results obtained by authors is difficult due to non-homogenous parameters used in periodontal examination. A new Periodontal Index of Risk of Infectiousness (PIRI) has been proposed to assess reliably the influence of periodontal disease on the systemic health of an individual. Aim of the study: To assess the correlation between varied clinical periodontal parameters, including the PIRI, and the risk of MI. Material and methods: The study involved 86 individuals with history of MI, aged 61.21 years, SD=7.9 (group 1), and 84 individuals with stable coronary heart disease, aged 62.15 years, SD=7.7 (group 2). The periodontium was examined clinically using indices: API, mSBI, PPD, CAL, CPITN and PIRI. Multivariable logistic regression adjusted for known risk factors for MI was used in statistical analysis. Results: Significantly higher mean values of mSBI, PPD, CAL and PIRI were observed in group 1. In multivariable analysis calculated for parameter PIRI as MI risk factor it was significant (12.9), but with wide 95% confidence interval 1.06-452.7. Conclusion: The PIRI index was found to be the one most highly associated with the incidence of MI.

Contemporary trans-catheter treatment of severe aortic stenosis.

Abstract: INTRODUCTION Significant improvements in medical care and lifestyle in recent years have resulted in prolongation of life. Among our growing elderly population, aortic stenosis (AS) is becoming an important and increasingly prevalent condition. It is well known to have a poor prognosis once it is symptomatic and moreover is associated with significant morbidity, multiple and prolonged hospital admissions and a significant reduction in the quality of life. The prevalence of calcific, degenerative AS increases with advancing age and affects ~40% of people aged over 80 years [1]. Once AS becomes symptomatic, life expectancy decreases dramatically (Fig. 1). Until recently, the only definitive treatment for severe AS has been surgical aortic valve replacement (AVR). In the general population, the risk of conventional aortic valve surgery is low (about 3%) and even when valve replacement is associated with concurrent coronary artery by-pass grafting, the operative risk does not exceed 5%. However, the risk of aortic valve surgery is significantly higher in the elderly, who are therefore often denied treatment [2]. It is the combination of an unmet need with a desire to find lower risk and less invasive approaches that has driven the development of percutaneous valve therapy, which is now an extremely fast-growing area of cardiology. Percutaneous and minimally invasive treatment of valvular heart disease presents a very attractive option for this high risk group. In this article, we discuss the percutaneous alternatives to open valve surgery and review the currently available techniques.