Biomedical subjects

Tomasz Witkowski

Publications and source records attributed to Tomasz Witkowski.

4 recordsLinked to original sources

PubMed2004

Chronic heart failure. The relationship between increased activity of skeletal muscle ergoreceptors and reduced exercise tolerance.

BACKGROUND: In chronic heart failure (CHF), skeletal muscle abnormalities may lead to the overactivation of ergoreceptors which in turn may cause sympathetic overactivation and increased ventilatory response to exercise. AIM: To assess ergoreceptor reflex response to exercise and to evaluate whether ergoreceptor overactivity is related to the progression of CHF. METHODS: In 69 patients with CHF (66 males, mean age 62.7+/-11.6 years, NYHA class I/II/III/IV - 11/32/24/2 patients, respectively) and 24 controls without CHF (22 males, mean age 59+/-4.6 years) the ergoreflex contribution to the ventilatory and haemodynamic responses to exercise was evaluated. Moreover, in 13 patients with CHF, reproducibility of the measurements was assessed by repeating the test 1 to 7 days later. RESULTS: Enhanced ergoreflex effects on ventilation (1.9+/-1.6 vs 0.14+/-0.7 l/min, p<0.05) and systolic blood pressure (19.2+/-14.9 vs 6.1+/-5.9 mmHg, p<0.05) were found in patients with CHF compared with control subjects. Ergoreceptor overactivity was associated with a worse symptomatic state (NYHA class I vs II vs III, IV: 0.9 vs 1.5 vs 2.9 l/min, p<0.05) and lower exercise tolerance (peak V0(2): r=-0.51, p<0.0001; VE/VC0(2): r=0.50, p<0.0001). The mean values of the ergoreceptor reflex did not differ significantly between the two tests (t=1.5, p=0.14; variability coefficient = 21.5%). CONCLUSIONS: In CHF, overactivation of the ergoreflex is associated with the progression of the syndrome and may be responsible for reduced exercise tolerance. Reproducibility of ergoreflex measurements is satisfactory.

Aged↗

PubMed2004

[Clinical use of ventilation measurement during early phase of exercise in patients with chronic heart failure].

BACKGROUND: In patients with chronic heart failure (CHF) augmented exercise ventilation is related to functional severity and increased mortality. Nevertheless, the optimal approach to the assessment of ventilatory response to controlled exercise has not been established. AIM: The study was carried out to evaluate the clinical application of the measurement of ventilatory response to the early phase of exercise in the non-selected group of patients with CHF. MATERIAL AND METHODS: We investigated 180 consecutive patients with CHF (155 men, age: 59 +/- 11 years, left ventricle ejection fraction: 31 +/- 7%; NYHA class I/II/III/IV: 13/90/60/17). All patients underwent the cardiopulmonary exercise testing (CPX) with RER > 1.0 (mean peak oxygen consumption [peakVO2]: 15.5 +/- 4.8 ml/kg/min). Ventilatory response to exercise was assessed: 1) during the whole exercise--expressed as a correlation coefficient of linear regression describing the relationship between minute ventilation (VE) and carbon dioxide production (VCO2) during the whole exercise (VE-VCO2 100%); 2) during the early phase of exercise--expressed as VE-VCO2 derived from VE and VCO2 during first 180 seconds of exercise (VE-VCO2 180 s). RESULTS: Ventilatory responses to early and maximal exercise were significantly augmented in CHF patients (VE-VCO2 100% -36.1 +/- 9.8, VE-VCO2 180% -34.4 +/- 10.3; p < 0.0001 vs values in the reference group without CHF). Ventilatory responses to early and whole exercise were strongly interrelated (r = 0.88, p < 0.0001). Indices of exercise ventilation correlated with the severity of CHF expressed as NYHA class (for VE-VCO2 100% and VE-VCO2 180 s -r = 0.52 and r = 0.51) and peak VO2 (for VE-VCO2 100% and VE-VCO2 180 s, r = -0.49 and r = -0.47, respectively) (p < 0.0001 for all correlations). Among echocardiographic parameters only right ventricular systolic pressure correlated with indices of exercise ventilation (for VE-VCO2 100% -r = 0.45, p = 0.001; for VE-VCO2 180 s -r = 0.35, p = 0.01). The reproducibility of indices of exercise ventilation was assessed in 19 CHF patients (another CPX during 2-9 days), and variability coefficients reached 7.8% for VE-VCO2 100% and 8.5% for VE-VCO2 180 s. CONCLUSIONS: Indices of ventilatory response to both early and maximal exercise can significantly differentiate the CHF patients with regard to their exercise capacity, are highly reproducible, and may therefore constitute useful parameters carrying an important clinical message. The assessment of ventilatory response during the early stage of exercise seems to be of a particular significance in CHF patients who are unable to perform the maximal exercise effort, as diagnostic data obtained during first 180 seconds of exercise are in accordance to those derived from the standard maximal CPX.

Disease Progression↗

PubMed2003

The role of exercise ventilation in clinical evaluation and risk stratification in patients with chronic heart failure.

BACKGROUND: Patients with chronic heart failure (CHF) are characterised by an increased ventilatory response to exercise. The role of exercise ventilation in the risk stratification and evaluation of patients with CHF has not yet been established. AIM: To examine the relationship between exercise ventilation indices and clinical parameters of CHF and to assess the prognostic value of the ventilatory response to exercise. METHODS: The study group consisted of 87 patients with CHF (72 males, mean age 58 years) with a mean left ventricular ejection fraction of 32%. Ten patients were in NYHA class I, 38 - in NYHA class II, 34 - in NYHA class III, and 5 - in NYHA class IV. The control group consisted of 20 patients without CHF (13 males, mean age 58 years, mean LVEF - 61%). All studied subjects underwent maximal exercise test with gas-exchange measurement. The following parameters were analysed: peak exercise oxygen consumption [peak VO(2) (ml/kg/min)], VE-VCO(2) index [a coefficient of linear regression analysis depicting an association between ventilation (VE) and carbon dioxide production (VCO(2)) during exercise] and VE/VCO(2) ratio at peak exercise to VE/VCO(2) ratio while at rest (VE/VCO(2 peak/rest)). RESULTS: Ventilatory response indices were significantly higher in patients with CHF compared with controls: VE-VCO(2) - 37.9+/-11.1 vs 27.1+/-4.1; VE-VCO(2 peak/rest) - 0.89+/-0.14 vs 0.75+/-0.10 (p<0.001). In CHF patients a significant positive correlation between ventilatory response parameters and NYHA class (VE-VCO(2) - r=0.52; VE/VCO(2 peak/rest) - r=0.47) and a negative correlation with peak VO(2) (VE-VCO(2) - r=-0.52; VE/VCO(2 peak/rest) - r=-0.49) were noted (p<0.0001 for all correlations). No correlation was found between ventilatory parameters and echocardiographic variables or CHF aetiology. During the follow-up period lasting at least 12 months, 17 (22%) patients died. In the univariate Cox model, NYHA class III-IV, decreased peak VO(2) and increased VE-VCO(2) and VE/VCO(2 peak/rest) values were significantly associated with the risk of death. The multivariate analysis revealed that VE/VCO(2 peak/rest) > or =1.0 was the adverse prognostic factor, independent of peak VO(2) (p=0.02) and NYHA class (p=0.01). The Kaplan-Meier analysis showed that prognosis during the 18-month follow-up period in patients with enhanced exercise ventilation was worse than in the remaining patients (59% survival in patients with VE/VCO(2 peak/rest) > or =1.0 59% vs 91% survival in patients with VE/VCO(2 peak/rest) <1.0, p=0.001). CONCLUSIONS: In patients with stable CHF simple exercise ventilation parameters may provide important clinical and prognostic information.

Adult↗

PubMed2003

[Glaucoma Service Database].

We present the common problems related to clinical databases. The Glaucoma Service Database created in our clinic is an attempt of developing the optimal medical database. The system organizes our repository of clinical data. It consist of 3 modules: 1) the users list with predefined privileges and rights, 2) lists of coded data for further use, that facilitate filling in the fields, 3) clinical details of all patients. The user interface of our database is very simply, thus it is very easy to use it even by unskilled staff. The accuracy of data is protected by system's internal algorithms. It could be used to investigate clinical epidemiology, risk assessment, post-marketing surveillance of drugs, practice variation and decision analysis. Data from Glaucoma Service Database can also help in the management of health service.

Databases, Factual↗