Biomedical subjects

P Kozák

Publications and source records attributed to P Kozák.

At least 19 recordsLinked to original sources

PubMed1991

Doppler echocardiographic assessment of the diastolic properties of the cardiac ventricle in ischaemic heart disease.

The authors offer their experience with diastolic function assessment using Doppler echocardiography in ischaemic heart disease. Information on the diastolic properties of the ventricle is obtained from recordings of the blood flow velocity curve in mitral and tricuspid valve orifices. Doppler echocardiography, allowing to monitor the velocity curve of ventricular filling, represents one of the most modern techniques of examination. Diastolic function is commonly significantly affected by ischaemic heart disease, not only in terms of energy requirements; other factors such as the volume of venous return, extent of ischaemia, its time course, and so on, come into play. Changes in myocardial rigidity and filling pressures are two factors which exert a substantial effect on the character of inflow curves. The article describes typical recordings obtained from individual clinical manifestations of acute and chronic states in ischaemic heart disease, and reviews the still limited body of data regarding the effect of drug and/or surgical therapy on the diastolic properties of the affected ventricle.

Blood Flow Velocity↗

PubMed1990

[The effect of stimulated tachycardia on diastolic left ventricular filling in patients with ischemic heart disease].

The authors examined 20 patients with ischaemic heart disease (IHD) by pulsed Doppler echocardiography before and after a load of stimulated tachycardia. The character of left ventricular filling depended on the blood pressure reading in a wedged position only in patients who had an elevated pressure (r = -0.65 and r = -0.81 resp. after a load for A/E, r = -0.62 and r = -0.79 after a load for DT). When the pressure is normal, it declines in a wedged position and the left ventricular filling in early diastole becomes protracted and the ratio of the atrial filling rises (A/E increased after the load p greater than 0.001, DT was protracted after the load p greater than 0.01). This change is due in particular to the protracted relaxation of the heart muscle. When the pressure is elevated in a wedged position, i.e. when the elasticity of the left ventricle declines, the rate of early filling rises and its duration is reduced. This relationship was more marked after the load (A/E after the load declined p greater than 0.01, DT after the load was shorter p greater than 0.001). Examination of the flow through the mitral orifice after a load by stimulated tachycardia makes it possible to differentiate patients with a mild and more severe affection of the left ventricle associated with IHD. It permits also prediction of an increased intraventricular pressure and this to monitor the course of the disease or to evaluate the success of treatment.

Adult↗

PubMed1989

[The effect isometric exertion on left ventricular function in patients after myocardial infarct].

24 patients, after transmural cardiac infarction, were exposed to isometric exercise ("handgrip"). The haemodynamic response was checked by means of impedance plethysmography. The stroke volume decreased on average from 64 +/- 14 to 60 +/- 15 ml (p less than 0.05), cardiac output increased from 4.8 +/- 1.0 to 5.4 +/- 1.2 l/min. (p less than 0.01). Peripheral resistance significantly increased and left ventricular performance was non-significantly reduced. Compared with a group of healthy control, their stroke and cardiac output and cardiac work kept increasing during isometric exercise. Isometric exercise is an adequate means of checking left ventricular performance.

Blood Pressure↗

PubMed1989

[Reliability of electrocardiographic signs in left atrial enlargement. Electrocardiographic and echocardiographic study].

In 85 patients with left atrial enlargement proved by echocardiography the authors tested the information capacity of electrocardiography for the diagnosis of this disorder. Only in half the patients enlargement of this cardiac cavity could be assumed from the electrocardiogram. From the results ensues the small sensitivity of ECG signs of enlargement of the left atrium.

Adult↗

PubMed1989

[Diastolic function of the hypertrophic left cardiac ventricle in hypertensive patients evaluated with Doppler echocardiography].

The authors examined by Doppler and one-dimensional echocardiography 20 patients with concentric hypertrophy of the musculature of the left ventricle and hypertension and 20 healthy subjects of similar age. As compared with the control group, they found in all patients deterioration of indicators of left ventricular diastolic function. The rate of blood flow in the early diastolic phase (Ev) was reduced and the ratio of the atrial contraction (Av) in the filling of the left ventricle increased (p less than 0.001). The maximal blood flow across the mitral orifice in early diastole (PFR) was lower (p less than 0.05) and the slowing down of the early diastolic flow (E-F) was more marked (p less than 0.001). The peak rate of relaxation (Vr) was also lower in the group of hypertonics (p less than 0.01). These disorders are an early sign of cardiac affection in hypertension and precede changes of systolic function. The impaired diastolic function is directly proportional to the weight of the left ventricle (for Av/Ev r = 0.76, PFR r = 0.68, E-F r = -0.82). The results of examinations obtained by Doppler echocardiography correlate with relaxation of the myocardium of the left ventricle assessed by computer processing of the TM echocardiogram (for Av/Ev r = 0.72, DHT r = 0.66, E-F r = 0.76).

Adult↗

PubMed1989

Regurgitation across an obviously normal valve orifice as a possible prerequisite for non-organic cardiac murmur.

Using pulsed and continuous wave Doppler echocardiography, the author examined 359 subjects referred to ultrasound examination for a variety of reasons. Thorough examination of persons with morphologically unchanged valves revealed regurgitation in the tricuspid, pulmonary, mitral and aortic valves in 49.4%, 20%, 14.5% and 0.8%, respectively. The degree of regurgitation was invariably haemodynamically insignificant. Some patients had a positive finding in several valves at a time. Overall, regurgitation was found in 247 subjects (69%). While it is evident from the study that the finding of regurgitation in normal valves is relatively frequent, evaluation of its clinical importance remains an open question.

Adolescent↗

PubMed1988