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K Wrabec

Publications and source records attributed to K Wrabec.

At least 19 recordsLinked to original sources
PubMed1998

Ventilatory response to exercise correlates with impaired heart rate variability in patients with chronic congestive heart failure.

In chronic congestive heart failure (CHF) an overactivity of muscle ergoreceptors and peripheral chemoreceptors may lead to an increased ventilatory response to exercise and contribute to the autonomic imbalance. The analysis of heart rate variability (HRV), which is a reliable method of studying autonomic regulations within the cardiovascular system, showed depressed HRV indexes in CHF, but predictors of abnormal HRV pattern in CHF remain controversial. Considering a common mechanism involved in generation of both abnormal ventilation and autonomic dysfunction in CHF, we hypothesized that impaired ventilation may be better than other variables of CHF severity in determining HRV parameters. Seventy-two patients with CHF (57+/-9 years, ejection fraction: 28+/-11%) underwent cardiopulmonary exercise testing; the relation between ventilation and carbon dioxide production (VE/VCO2) was used as an index of the ventilatory response to exercise. Time and frequency-domain measurements of HRV were derived from 24-hour electrocardiographic monitoring. Patients had reduced exercise tolerance with abnormal ventilatory response (peak oxygen consumption [VO2max]: 17.8+/-5.5 ml/kg/min, VE/VCO2: 36.0+/-9.8). Correlations were found between HRV measures and etiology, New York Heart Association (NYHA) functional class, and VO2max, but the strongest relation was observed for VE/VCO2 slope (r values from -0.33 to -0.65, p <0.01). In the multiple regression analysis only VE/VCO2 was found to correlate independently with all HRV measurements. To investigate the role of peripheral chemoreceptor overactivity as the mechanism of autonomic imbalance and the increased ventilatory response to exercise, we assessed peripheral chemosensitivity in 22 patients (mean value of peripheral chemosensitivity: 0.62+/-0.34 L/min/%SaO2, significantly higher than in normal controls, mean value: 0.29+/-0.20 L/min/%SaO2 in our laboratory). The activity of the peripheral chemoreflex inversely correlated with all parameters of HRV. Increased ventilatory response to exercise correlated with depressed HRV measures in patients with CHF better than other clinical variables. An important role of the increased peripheral chemosensitivity in this relation may be relevant, being also a potential link between functional severity and sympathovagal imbalance in CHF.

Administration, Inhalation↗
PubMed1997

Depressed heart rate variability as an independent predictor of death in chronic congestive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy.

After acute myocardial infarction, depressed heart rate variability (HRV) has been proven to be a powerful independent predictor of a poor outcome. Although patients with chronic congestive heart failure (CHF) have also markedly impaired HRV, the prognostic value of HRV analysis in these patients remains unknown. The aim of this study was to investigate whether HRV parameters could predict survival in 102 consecutive patients with moderate to severe CHF (90 men, mean age 58 years, New York Heart Association [NYHA] class II to IV, CHF due to idiopathic dilated cardiomyopathy in 24 patients and ischemic heart disease in 78 patients, ejection fraction [EF], 26%; peak oxygen consumption, 16.9 ml/kg/min) after exclusion of patients in atrial fibrilation with diabetes or with chronic renal failure. In the prognostic analysis (Cox proportional-hazards model, Kaplan-Meier survival analysis), the following factors were investigated: age, CHF etiology, NYHA class, EF, peak oxygen consumption, presence of ventricular tachycardia on Holter monitoring, and HRV measures derived from 24-hour electrocardiography monitoring, calculated in the time (standard deviation of all normal RR intervals [SDNN], standard deviation of 5-minute RR intervals [SDANN], mean of all 5-minute standard deviations of RR intervals [SD], root-mean-square of difference of successive RR intervals [rMSSD], and percentage of adjacent RR intervals >50 ms different [pNN50]) and frequency domain (total power [TP], power within low-frequency band [LF], and power within high-frequency band [HF]). During follow-up of 584 +/- 405 days (365 days in all who survived), 19 patients (19%) died (mean time to death: 307 +/- 315 days, range 3 to 989). Cox's univariate analysis identified the following factors to be predictors of death: NYHA (p = 0.003), peak oxygen consumption (p = 0.01), EF (p = 0.02), ventricular tachycardia on Holter monitoring (p = 0.05), and among HRV measures: SDNN (p = 0.004), SDANN (p = 0.003), SD (p = 0.02), and LF (p = 0.003). In multivariate analysis, HRV parameters (SDNN, SDANN, LF) were found to predict survival independently of NYHA functional class, EF, peak oxygen consumption, and ventricular tachycardia on Holter monitoring. The Kaplan-Meier survival curves revealed SDNN < 100 ms to be a useful risk factor; 1-year survival in patients with SDNN < 100 ms was 78% when compared with 95% in those with SDNN > 100 ms (p = 0.008). The coexistence of SDNN < 100 ms and a peak oxygen consumption < 14 ml/kg/min allowed identification of a group of 18 patients with a particularly poor prognosis (1-year survival 63% vs 94% in the remaining patients, p <0.001). We conclude that depressed HRV on 24-hour ambulatory electrocardiography monitoring is an independent risk factor for a poor prognosis in patients with CHF. Whether analysis of HRV could be recommended in the risk stratification for better management of patients with CHF needs further investigation.

Aged↗
PubMed1997

[Value of classical and new criteria of electrocardiography in diagnosis of hypoxic cor pulmonale evaluated by hemodynamics tests].

Electrocardiogram is commonly used in the diagnosis of cor pulmonale in patients with chronic obstructive pulmonary disease (COPD). Pulmonary hemodynamics being the definite method for diagnosis the disease can be used to vary the ecg criteria for diagnosis cor pulmonale. After excluding patients with old myocardial infarction and with pulmonary wedge pressure > 12 mm Hg in 66 patients aged 65.2 with advanced COPD (FEV1 0.78 +/- 0.3 litre) pulmonary hemodynamics and ecg were performed at the same time. The signs of right ventricular hypertrophy were sought for using 3 sets of criteria: the World Health Organisation criteria, new compiled Lehtonen et al. Criteria and right ventricular precordial leads. WHO criteria had a specificity and sensitivity of 50% and 57.6%, the modified right precordial leads-53% and 64.5% and compiled Lehtonen's criteria -57% and 59% respectively. In 32 patients with mild pulmonary hypertension (20-29 mm Hg) sensitivity of WHO criteria was 46.8%, right precordial leads -51.6%, and Lethonen and co. Criteria -50%, in 10 patients with moderate pulmonary hypertension (30-39 mm Hg) 59%-62.5%-50%, in 9 patients with severe hypertension (> or = 40 mm Hg) 100%-100%-100% respectively. Our studies confirm the poor sensitivity and of ecg criteria for diagnosis of cor pulmonale (pulmonary hypertension) in COPD. However, in mild and moderate pulmonary hypertension, sensitivity of ecg diagnosis of cor pulmonale is improved if right modifieds precordial leads are used. New, compiled Lehtonen's criteria failed to improved diagnosis of diagnosis of cor pulmonale. All studied sets of criteria are highly sensitive in COPD patients with severe pulmonary hypertension.

Adult↗
PubMed1994

[Effect of acute exercise on cardiac arrhythmias in the course of chronic obstructive pulmonary disease].

It is suggested that ventricular arrhythmias may be the reason of sudden death in stable patients with COPD. Strenuous effort might provoke danger ventricular arrhythmias in those patients. The impact of maximal exercise test on cardiac ventricular arrhythmias was studied in 24 patients with advanced chronic obstructive pulmonary disease (COPD). The treadmill, self limited exercise test according to Bruce protocol and accompanied by pulse oximetry was performed during 24 hour Holter monitoring. We found ventricular extrasystoles in all patients, in an average 492 +/- 770, complex ventricular extrasystoles in 17 patients and nonsustained ventricular tachycardia in 8 patients. 81% of all ventricular extrasystoles, 80% complex ventricular extrasystoles and 70% nonsustained ventricular tachycardia occurred during the test and up to 2 hour after the test. Patients with complex ventricular arrhythmias were younger and mostly achieved more MET during exercise, but they did not differ in advancing of COPD as measured by spirometry, gas measurements and echocardiography. Although maximal exercise test enhances ventricular arrhythmias it produced no sustained, symptomatic ventricular arrhythmias in patients with advanced and stable COPD.

Aged↗
PubMed1993

[Atrial fibrillation with chronic obstructive pulmonary disease].

We compared 8 patients with COPD and fixed atrial fibrillation (group I) and 46 patients with COPD and sinus rhythm in ecg (group II). None of the patients had valvular heart disease, arterial hypertension or clinical signs of coronary artery disease. The studied groups did not differ while comparing their gas measurements, spirometry, pulmonary hypertension and right ventricular diameter (as measured in echo study). Patients with fixed atrial fibrillation had larger circuit and area of right atrium (p = 0.001), left atrial and left ventricular diameter (p = 0.001) as well as lower LV function (expressed by FS%). In conclusion, enlargement of both atria may be considered as a cause for fixed atrial fibrillation in patients with COPD. However symptomless coronary artery disease rather then COPD may be the reason for this arrhythmia.

Aged↗
PubMed1993

[Dissecting aortic aneurysm complicated by rupture of the right coronary artery and acute myocardial infarction--in a person treated with fibrinolysis].

A case report of 45-year-old woman with acute inferior wall and right ventricle myocardial infarction treated with i.v. Streptokinase is presented. Few days later acute aortic dissection involving right coronary artery was detected. After six days the patient was successfully operated. She is in good condition 10 months afterwards.

Aortic Dissection↗
PubMed1993

[Constrictive pericarditis in a patient following prosthetic aortic valve replacement caused by postpericardiotomy syndrome].

A case of a 53-year old man is presented who developed postpericardiotomy syndrome and subsequently constrictive pericarditis following prosthetic aortic valve replacement due to severe aortic stenosis. The diagnosis was based on clinical picture and confirmed invasively. Nearly total excision of thickened fibrous pericardium resulted in a slow but full disappearance of constriction signs.

Aortic Valve↗
PubMed1993

[Chronic thromboembolic pulmonary hypertension--observation of personal case reports].

The clinical picture, differential diagnosis and prognosis in chronic thromboembolic pulmonary hypertension (CTEPH) is being discussed on the basis of a dozen of the authors' cases. The clinical course of CTEPH in 2 patients fulfilling the main criterium for pulmonary thromboendarterectomy and undergoing one year anticoagulation is examined. As a result patient with one large pulmonary vessel occlusion (a. lobaris superior sinistra) improved his clinical status as well as hemodynamic and echocardiographic outcome. In patient with multivessel pulmonary occlusion gradual clinical aggravation and hemodynamic-echocardiographic progression of CTEPH was observed.

Adult↗
PubMed1992

Long-term prazosin therapy for COPD pulmonary hypertension.

A 51-year-old patient with COPD, obesity, and pulmonary hypertension underwent long-term prazosin therapy after a successful hemodynamic response to 1 mg of oral prazosin. The 18-month administration of prazosin, in a dose of 3 mg a day, resulted in continued hemodynamic and echocardiographic benefits.

Humans↗
PubMed1992

[Chronic obstructive lung disease: does accompanying arrhythmia have any clinical significance?].

Clinical significance of cardiac arrhythmias in patients with advanced and stable chronic obstructive pulmonary disease was assessed 22-24 hour Holter monitoring revealed supraventricular and ventricular arrhythmias in all 65 patients. There was a great variation of arrhythmia quality and quantity in the study group. Among others, 1808 complex ventricular extrasystoles in 33 patients and 302 episodes of nonsustained ventricular tachycardia in 19 patients were recorded. No sustained symptomatic ventricular arrhythmias were observed. We found no correlation between the intensity of ventricular and supraventricular extrasystoles and clinical parameters as assessed by echocardiography, spirometry and gasometry. However, patients with complex ventricular arrhythmias had larger right ventricular diameter in echocardiography. Of 65 studied patients, 14 (21%) died during follow-up ranging from 1 month to 3.2 years, mean 12.2 months. Two outpatients died suddenly. These 14 patients had larger right ventricle and left atrial dimension, more pronounced PaO2 decrease as well as lowered FEV1 as compared to the survivors. No differences in the incidence of cardiac arrhythmias were noted. Summarizing, despite the great prevalence of cardiac arrhythmias in patients with advanced stable COPD we found no life-threatening ventricular arrhythmias during approximately 1500 hours of holter monitoring. Cardiac arrhythmias seem not to influence the prognosis in these patients.

Adult↗
PubMed1992

[Enalapril improves hemodynamics and exercise tolerance in pulmonary heart disease caused by obstructive lung disease].

Chronic enalapril therapy was assessed in 11 patients with cor pulmonale due to chronic obstructive pulmonary disease. Enalapril was added to the maintenance dose of diuretics and digitalis and when clinical stabilisation was achieved haemodynamics, spirometry, blood gases and maximal treadmill exercise test accompanied by +pulse oximetry were performed before and after 30 days, 10-20 mg a day, enalapril therapy. Haemodynamic study showed moderate but significant decrease in mean pulmonary artery pressure, from 24 +/- 3 to 21 +/- 5 mmHg (p = 0.05). There were no substantial differences in cardiac output as well as in blood gases and spirometry after enalapril therapy. Slight decrease in oxygen delivery, on an average from 9157 +/- 3808 to 8074 +/- 3574 (p = NS), was accompanied by a concomitant fall in haemoglobin. We noted significant improvement of maximal exercise test results after enalapril therapy. Maximal workload achieved and the time of exercise increased. It was accompanied by subjective improvement as assessed by Borg scale. We observed no adverse effects of enalapril during one month therapy in patients with cor pulmonale and COPD.

Aged↗
PubMed1991

[Respiratory rehabilitation of patients with chronic obstructive lung diseases in the subjective and objective evaluation].

An intensive 14 day respiratory rehabilitation program was carried out in 24 COPD patients of mean age 66.0 +/- 10.0 yrs (FVC 1.56 +/- 0.52 L, FEV1 0.94 +/- 0.4 L/s). A statistically objective improvement was seen measured by the 100 meter tread mill test (p = 0.001) which was not seen in spirometric analysis. Seventeen patients reported a subjective improvement in their clinical state. The authors have demonstrated usefulness of the 100 meter walk test in analysis of rehabilitation processes.

Administration, Inhalation↗