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Biomedical subjects

V Jezek

Publications and source records attributed to V Jezek.

At least 19 recordsLinked to original sources
PubMed1991

Three echocardiographic methods in right ventricular function evaluation.

We employed two-dimensional echocardiography for the assessment of right ventricular (RV) volumes and/or function in a series of 44 patients. The results of three different echocardiographic approaches were compared with the data obtained from single-plane RV angiography following ultrasound within a 7-day interval. Only the echocardiographic area length method with two orthogonal imaging planes employed (apical 4-chamber and subcostal projections) yielded the beneficial results. The correlations between echocardiographic and angiographic RV volume estimates were rather high (end-diastolic volume: r = 0.83, end-systolic volume: r = 0.82, stroke volume: r = 0.81) and satisfactory in ejection fraction (r = 0.75). Using the method mentioned, the differentiation of patients with an angiographic evidence of RV failure (echocardiographic ejection fraction less than 0.55) from those without it was possible with a sensitivity of 0.68 and a specificity of 0.82. Concerning the clinical impact of the presented study, we can recommend the technique in question as a screening procedure for the detection of changes in RV function exceeding 12% (95% confidence limits).

Cineangiography↗
PubMed1991

The effect of acute and chronic nitrate administration in precapillary and postcapillary pulmonary hypertension.

The effect of nitrates was monitored in 16 patients with precapillary, and in 12 patients with postcapillary pulmonary hypertension (PH). The patients had haemodynamic examination on acute administration of 10 mg of isosorbide nitrate (ID) in infusion and after 2-month therapy with 120 mg of isosorbide dinitrate retard daily. Acute ID administration decreased filling pressure of both ventricles, pulmonary and aortic pressure, pulmonary and systemic resistance and increased blood flow. No significant difference was found between the two types of PH. Long-term administration resulted in a statistically significant decrease in filling pressure (in both ventricles) and pulmonary pressure, even though the decrease was less pronounced than those seen following acute administration. Again, no statistical differences were noted between the two types of PH. While acute administration of nitrates decreases both preload and afterload, chronic administration decreases only preload. The implications of this finding for therapeutic practice are discussed.

Cardiomyopathy, Dilated↗
PubMed1991

[2-dimensional echocardiography in the evaluation of right ventricular volume and function. Comparison with echocardiography].

Using two-dimensional echocardiography (ECHO), the authors examined within one week preceding right-sided catheterization of the right ventricle (RV) 44 patients. Of three tested ECHO techniques for calculation of right ventricular volumes and/or function the best correlations were obtained by the method of evaluation of area-length of the right ventricle from two orthogonal projections (apical 4-cavity and subcostal with visualization of the outflow portion of the RV). The following correlations were assessed: telediastolic volume--r = 0.831, telesystolic volume--r = 0.815 stroke volume--r = 0.810 and ejection fraction (EF)--r = 0.752 (p less than 0.001 for all correlations). The tested method enables us at the same time to screen at least existing right ventricular dysfunction (sensitivity 0.68; specificity 0.82). In the presence of tricuspidal insufficiency (TI) increase in right ventricular function occurs which may mask its existing failure (dependence of EF on the mean pressure level in pulmonary artery was proved only in patients without TI--r = 0.594). We assume that information on right ventricular function is important not only in diseases affecting primarily the right heart but also in advanced stages of left-sided failure. Follow-up of the natural course of the disease and the effect of provided treatment by the non-invasive ECHO method is thus useful not only in research but also in clinical practice.

Cardiac Volume↗
PubMed1990

[Estimation of systolic pressure in the right ventricle (pulmonary artery) using Doppler and its importance in the detection of pulmonary hypertension].

Using the pulsed Doppler system with a high reparative frequency (HPRF), the authors made within 1 hour and 3 days after diagnostic right-sided catheterization 38 measurements of the trans-tricuspid pressure gradient in 31 consecutive patients. To the gradient calculated from the absolute velocity of flow through the jet of tricuspid regurgitation the authors added two different arbitrarily determined pressure values in the right atrium to obtain the systolic pressure in the right ventricle--RVSP (which assuming the absence of an obstruction between the right ventricle and pulmonary artery equals the systolic pressure in this artery). The calculated RVSP from the Doppler assessment correlated highly significantly with the directly manometrically obtained values of the same indicator (r = 0.973; p less than 0.001). An even closer correlation was obtained when using a differentiated estimate of the pressure in the right atrium/according to the filling of the jugular veins) (r = 0.977; p less than 0.001). From the RVSP values the authors tried to predict the presence of pulmonary hypertension (PH) diagnosed from the median pressure in the pulmonary artery (PAP greater than or equal to 20 mm Hg which was considered conclusive). Using the arbitrarily assessed range of systolic PH greater than 35 mm Hg, the sensitivity of the ultrasonographic estimate was 79% with a 60% specificity, while when the criterium of greater than 40 mm Hg was used, the corresponding values were 64% and 90%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Noninvasive quantification of the severity of aortic defects using the Doppler method].

Using Doppler method (HPRF and CW regime), the authors assessed the peak velocity of flow in an aortal spurt in 41 patients with aortal stenosis. For calculation of the transaortal pressure gradient they used a modified Bernoulli equation. The values of the calculated gradients were compared with those obtained by direct manometric assessment during catheterization of the heart after an interval of several hours to five days. Combination of two Doppler techniques correlated closely with direct assessment (r = 0.811; p less than 0.001). By application of the continuity equation in the best records of spectral analysis of velocity curves the authors calculated in 8 patients the area of the reduced aortal orifice which was very close to the area calculated by means of Hakki's formula from direct haemodynamic indicators (r = 0.948; p less than 0.001). In 33 patients the authors quantified by Doppler method the severity of aortal regurgitation from the ratio of forward and backward flow in the descending portion of the aortal arch (expressed as the % regurgitation fraction--RF). The RF values correlated well with the angiographic semiquantitative scale of severity of aortal insufficiency (r = 0.805; p less than 0.001), although they enabled the authors only to make a partial differentiation of haemodynamically severe regurgitations and mild or insignificant ones. The authors conclude that the Doppler approach makes it possible to evaluate sufficiently accurately the severity of aortic valve disease (in insufficiencies the authors recommend a more comprehensive approach), which when correctly applied and interpreted, can make non-invasive clinical diagnosis more accurate and thus permits also more accurate indication of surgical treatment of these patients.

Aortic Valve Insufficiency↗
PubMed1990

[Cor pulmonale and cor pulmonale decompensation--what is the future of these terms?].

Decompensated cor pulmonale is a clinical syndrome manifested by signs of congestive heart failure in pulmonary disease. The authors emphasize that the haemodynamic characteristic of the syndrome differs substantially from the classical picture of chronic heart failure: the cardiac output is usually normal at rest and sometimes even during exercise, signs of impaired contractility of the right ventricle are absent and the effect of cardiac glycosides is minimal. It is possible that the clinical syndrome of decompensated cor pulmonale is caused mainly by respiratory failure and subsequent impaired function of some organs, in particular the kidney.

Heart Failure↗
PubMed1990

Long-term effect of isosorbide dinitrate and nifedipine, singly and in association, in patients with chronic heart failure.

The effect of 2-month treatment with isosorbide dinitrate (120 mg day-1), nifedipine (2 x 20 mg day-1) and their combination has been assessed in 16 patients with mild to moderate chronic cardiac failure. Isosorbide dinitrate decreased right atrial (-23%), pulmonary wedge (-20%) and pulmonary arterial (-17%) pressures but did not significantly change either cardiac output or systemic and pulmonary vascular resistance. Nifedipine increased cardiac output (+13%) and decreased systemic and pulmonary vascular resistance (both -17%) with no change of pressures. Combined therapy with both drugs decreased ventricular filling pressures (-8% and -15%), systemic (-20%) and pulmonary (-13%) arterial pressures, increased cardiac output (+26%) and decreased both systemic (-29%) and pulmonary (-29%) vascular resistances. Changes during exercise were almost the same as at rest. The effect of both drugs was more pronounced in patients with more severely pathological haemodynamic measurements before treatment. We conclude that combined treatment with both preload- and afterload-reducing agents can preserve or even potentiate a favourable haemodynamic effect of individual drugs.

Blood Pressure↗
PubMed1989

[Non-invasive diagnosis of pulmonary hypertension: Doppler versus echocardiography].

The authors examined a group of 50 patients incl. 28 (56%) with pulmonary hypertension (PH) at rest, mostly postcapillary. Using a Doppler device, they measured the acceleration time (ACT) in the outflow tract of the right ventricle and trunk of the pulmonary artery. Under conditions of concurrent Doppler and direct, catheterization measurements the authors found a close correlation between ACT and the mean pressure in the pulmonary artery (r = -0.88), which was, however, not confirmed after a 1-10 day interval (r = = -0.64). The authors conclude that Doppler ACT reflects only the actual pressure in the pulmonary circulation. The authors found a close correlation between ACT values in the right ventricular outflow tract and the pulmonary artery (r = 0.95), and no significant difference. Comparison of Doppler diagnosis of PH with former echocardiographic methods revealed unequivocally the priority of the Doppler method. Failure of echocardiography is most probably associated with the postcapillary type of PH in the group of patients and does not rule out the validity of original findings in precapillary PH. Rapid and easy assessment along with a simpler interpretation is in favour of the Doppler technique.

Adolescent↗
PubMed1989

[Long-term prognosis of patients with chronic post-infarct aneurysms. II. Comparison of patients treated conservatively and surgically].

UNLABELLED: Survival rates were determined for a group of 136 patients in whom left ventricular aneurysm was determined by angiography. They were treated medically (99 patients) or surgically (37 patients). Congestive heart failure was predominant in all patients. The two groups did not differ in regard to clinical and haemodynamic data except for a more extensive coronary artery disease in the surgical group. Survival rates at the 5, 7 and 9 years were 62.5%, 52.5% and 37.5% in the medicaly treated group and 50%, 40% and 32.5% in the surgical group. Functional improvement at least one Functional Class NYHA was present in 75% patients postoperatively, and in 27% of patients treated medically. CONCLUSION: In patients with left ventricular aneurysm with predominant congestive heart failure surgical treatment improved quality of life but did not increase long-term survival.

Chronic Disease↗
PubMed1989

[Long-term prognosis in patients with chronic postinfarct aneurysms. I. Conservative treatment of patients].

Natural history of 99 patients with angiographically defined left ventricular aneurysm (LVA) has been studied. Congestive heart failure (CHF) was predominant in 52.5% patients. Mean follow-up was 94 months. The cumulative survival at 1, 5, 7, 10 years were 92, 65, 60 and 28% respectively. Left ventricular end-diastolic pressure averaged 2.8 kPa (LVEDP), ejection fraction (EF) 31%, contractile segment ejection fraction (CSEF) 45%, stroke work 6.7 mj. g-1, diastolic compliance 0.36 kPa-1 and passive elastic modulus 64.1 kPa. High risk groups of patients were those with LVEDP more than 3.3 kPa, CSEF less then 40%, EF less then 20% and with extent of LVA more then 40% of the diastolic area of the left ventricle. The Cox analysis of survival indicated following variables predicted outcome: functional impairment due to CHF, LVEDP, LVEDVI and number of vessels diseased.

Heart Aneurysm↗
PubMed1988

Long-term reduction of pulmonary hypertension in interstitial lung fibrosis by isosorbide dinitrate.

The effect of isosorbide dinitrate (ID) on the development of pulmonary hypertension (PH) has been examined in 18 patients with idiopathic diffuse interstitial lung fibrosis (IDILF) during two years of treatment. All patients responded favourably to acutely administered ID by a decrease in pulmonary vascular resistance (PVR) by 38 +/- 13% and of the pulmonary arterial pressure (PAP) by 35 +/- 11%. Two years ID therapy led to sustained haemodynamic improvement in patients in whom blood gases were stable PAP was reduced from 38 +/- 5 to 30 +/- 6 mmHg and PVR from 483 +/- 197 to 364 +/- 175 dyne s cm-5. No haemodynamic changes were noted in the subjects with progressive hypoxaemia whereas steady deterioration of central haemodynamics was recorded in those patients who died during the follow-up. It is concluded that some patients with IDILF and PH may benefit from long-term ID treatment, but that the outcome of this treatment cannot be reliably predicted from the results of the initial first ID administration.

Adult↗
PubMed1988

The treatment of chronic pulmonary hypertension by vasodilators: hope and hesitation.

Contemporary therapy of most advanced cases of chronic lung disease is not yet satisfactory; even long-term oxygen treatment has shortcomings and limitations. Many authors have tried to find another therapeutic approach for the correction of either pulmonary hypertension or oxygen delivery, both factors being related to long-term survival. Vasodilators seem to be the subject of further intensive research rather than an established therapy. The results of acute experiments with different drugs are promising but studies of long-term treatment are incomplete. Some of the most pertinent questions for further research are: the classification of the reversibility of pulmonary hypertension, reliable evaluation of the results of therapy, the application of animal experiments to human pathology, haemodynamic conception of an ideal vasodilator, and the attenuation of the effect of some vasodilators during long-term treatment.

Animals↗
PubMed1988

Haemodynamic requirements for an ideal pulmonary vasodilator.

An ideal vasodilator should be selective for the pulmonary vascular bed, thus minimizing side-effects from reduced systemic resistance. It must achieve not only a drop in pulmonary vascular resistance but also a marked decrease in pulmonary arterial pressure. The ideal drug should increase cardiac output and pulmonary venous oxygen saturation. An increase in oxygen delivery to the peripheral tissues should be achieved at a lower right ventricular afterload both at rest and during exercise. Right ventricular function should be improved. The effects of vasodilator therapy should be so marked that it should be possible to follow them non-invasively by radionuclide methods and exercise tolerance tests. The aim of vasodilator therapy is a regression of pulmonary hypertension and of right ventricular hypertrophy, an improved quality of life, and above all a longer survival.

Blood Pressure↗
PubMed1988

Doppler echocardiography in the diagnosis of pulmonary hypertension.

Review of the current state of knowledge about Doppler diagnosis of pulmonary hypertension is presented. The authors compare the findings of numerous studies with their own data and analyse the causes of discrepancies and controversies that have remained to date. Doppler estimation of mean pulmonary artery pressure (PAP) using acceleration time (ACT) measurement in the right ventricular outflow tract or main pulmonary artery has been shown to correlate closely with simultaneously measured values of PAP both at rest and during exercise (r = -0.92 and -0.94, respectively). ACT values show sufficient sensitivity for the detection of pulmonary hypertension (89%), at maximum (100%) specificity. However, Doppler values not obtained simultaneously do not necessarily correlate with PAP in view of rapid physiological variations of PAP. For everyday diagnostic practice in cardiology, prediction based upon mere qualitative estimation of the type of velocity curve seems sufficient. Doppler diagnosis of pulmonary hypertension, little demanding on both technical skills and equipment, is gaining a priority status among the non-invasive methods available.

Echocardiography, Doppler↗