Showing papers by "Andrzej Rynkiewicz published in 2009"
TL;DR: Two popular estimators of multifractal properties: the Wavelet Transform Modulus Maxima method and Multifractal Detrended Fluctuation Analysis are applied to investigate signals consisting of normal RR-series in 39 healthy subjects and 90 patients suffering from systolic dysfunction of the left ventricle.
Abstract: Two popular estimators of multifractal properties: the Wavelet Transform Modulus Maxima method and Multifractal Detrended Fluctuation Analysis are applied to investigate signals consisting of normal RR-series in 39 healthy subjects and 90 patients suffering from systolic dysfunction of the left ventricle. However, differently from standards for multifractal analysis the scaling is performed separately in intervals corresponding to standard power spectral bands: low (LF), very low (VLF) and ultra low frequencies (ULF). Tests on fractional Brownian motions (fBm) are done to quantify properties of the estimators as detectors of monofractality in LF, VLF and ULF bands. Arguments are given that multifractal analysis of RR-series performed in these bands has a physiological meaning. The increased activation of the sympathetic nervous system caused by heart disease is detected evidently only by analysis in LF. The transition in multifractal characteristics between diurnal and nocturnal activity takes place when the analysis moves from LF and VLF to ULF. Only in ULF, the diurnal heart rate variability can be approximated by fBm with a self-similarity index of H = 0.20 .
40 citations
TL;DR: The care of these patients should be redirected toward screening and treatment of crucial comorbidities such as hypertension, coronary artery disease, atrial fibrillation, obesity, diabetes, and chronic kidney disease.
Abstract: PURPOSE OF REVIEW Diastolic heart failure (DHF) is the most common form of heart failure (HF) seen by clinicians today in practice. With the increasing prevalence of DHF, the need for greater spectrum of proven therapies in this condition is clear. RECENT FINDINGS There are few data available to guide the therapy of these patients, and no treatment has been shown to improve survival in DHF. The results of the Hong Kong DHF trial, the first comparative study between an angiotensin converting enzyme inhibitor (ACEI) and an angiotensin receptor blocker (ARB), again did not provide evidence for a superior effect of ACE inhibitors or ARBs in patients with diastolic heart failure. SUMMARY Traditionally, treatments for congestive HF with decreased ejection fraction have been used to treat DHS, without much proof of benefit. The high mortality and morbidity of these patients underscore the urgent need to find ways to improve outcomes for these patients. Consequently, the care of these patients should be redirected toward screening and treatment of crucial comorbidities such as hypertension, coronary artery disease, atrial fibrillation, obesity, diabetes, and chronic kidney disease.
20 citations
Journal Article•
TL;DR: In this article, a multifractal formalism is tested if it can work as a robust estimator of monofractals when scaling intervals are chosen to be consistent with known frequency bands of power spectralanalysis used in estimates of heart rate variability.
Abstract: Multifractal formalism is tested if it can work as a robust estimatorof monofractals when scaling intervals are fixed Intervals for scaling areselected to be consistent with known frequency bands of power spectralanalysis used in estimates of heart rate variability: low frequency (LF),very low frequency (VLF), and ultra low frequency (ULF) Tests on frac-tional Brownian motions and a binomial cascade are performed to vali-date popular multifractal methods: Wavelet Transform Modulus Maximaand Multifractal Detrended Fluctuation Analysis Then the methods areapplied to identify monofractal elements of control processes driving theheart rate A transition is found in the dynamic organization of autonomicnervous system control of the heart rate related to the change in scalingintervals The control over the diurnal heart rate is of a multifractal typewhen considered in LF and of a monofractal type when observed in ULFAdditionally, this transition affects on a switch in a relation between widthsof diurnal and nocturnal multifractal spectraPACS numbers: 9575Wx, 8790+y, 8975Da, 0565+b
3 citations
Journal Article•
2 citations
Journal Article•
TL;DR: Early therapy with anticoagulants, steroids, immunoglobulins and plasmaferesis was beneficial in the presented case and CAPS should be considered as a cause of acute heart failure in a women with systemic lupus erythematosus.
Abstract: A case of a 29-year-old woman 18 days after delivery with catastrophic antiphospholipid syndrome secondary (CAPS) due to undiagnosed systemic lupus erythematosus, leading to cardiogenic shock is reported Laboratory evaluation revealed increased anticardiolipin antibodies, lupus anticoagulant, antinuclear antibody and thrombocytopenia Left ventricular ejection fraction was 20%, neurologic deficit and acute renal failure were also present Cardiac involvement is common in CAPS, but cardiomyopathy due to microvascular thrombosis is rare CAPS should be considered as a cause of acute heart failure in a women with systemic lupus erythematosus In the presented case early therapy with anticoagulants, steroids, immunoglobulins and plasmaferesis was beneficial
1 citations
11 Dec 2009
TL;DR: The significant difference is found between multifractal spectra describing healthy hearts and hearts suffering from left ventricle systolic dysfunction.
Abstract: Understanding of real world phenomena needs to incorporate the fact that observations on different scales each carry essential information. Multifractal formalism is tested if it can work as a robust estimator of monofractal properties when scaling interval is consistent with low-frequency (LF) band of power spectral analysis used in estimates of heart rate variability. Tests with fractional Brownian motions are performed to validate two popular multifractal methods: Wavelet Transform Modulus Maxima (WTMM) and Multifractal Detrended Fluctuation Analysis. Only WTMM method passes the tests when scaling is limited to LF band. Then WTMM method is applied in analysis of short-time control processes driving the heart rate. The significant difference is found between multifractal spectra describing healthy hearts and hearts suffering from left ventricle systolic dysfunction.
1 citations
01 Jan 2009
TL;DR: Early therapy with anticoagulants, steroids, immunoglobulins and plasmaferesis was beneficial in the presented case and CAPS should be considered as a cause of acute heart failure in a women with systemic lupus erythematosus.
Abstract: A case of a 29-year-old woman 18 days after delivery with catastrophic antiphospholipid syndrome secondary (CAPS) due to undiagnosed systemic lupus erythematosus, leading to cardiogenic shock is reported. Laboratory evaluation revealed increased anticardiolipin antibodies, lupus anticoagulant, antinuclear antibody and thrombocytopenia. Left ventricular ejection fraction was 20%, neurologic deficit and acute renal failure were also present. Cardiac involvement is common in CAPS, but cardiomyopathy due to microvascular thrombosis is rare. CAPS should be considered as a cause of acute heart failure in a women with systemic lupus erythematosus. In the presented case early therapy with anticoagulants, steroids, immunoglobulins and plasmaferesis was beneficial.
01 Jan 2009
TL;DR: Heart rate variability of people suffering from the left ventrical systolic dysfunction and healthy ones is considered in terms of multifractal analysis in order to investigate the scaling properties in the low, very low and ultra low frequency bands of standard power spectral analysis.
Abstract: Heart rate variability of people suffering from the left ventrical systolic dysfunction and healthy ones is considered in terms of multifractal analysis in order to investigate the scaling properties in the low, very low and ultra low frequency bands of standard power spectral analysis. Two methods: Wavelet Transform Modulus Maxima and Multifractal Detrended Fluctuation Analysis, are used to assess multifractal properties. They are applied to two types of signals: a sequence of RR intervals and a sequence of moments in time when subsequent heart beats occur (integrated RR-intervals). The increased activation of the sympathetic nervous system caused by left ventricle systolic dysfunction is detected directly in both signals in the low frequency band. In the ultra low frequency band a monofractal-type of dependences is found suggesting that driving process of autonomic control is close to a monofractal one.