Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 9 de 9
Filter
Add more filters











Database
Publication year range
1.
Kardiologiia ; 63(1): 42-47, 2023 Jan 31.
Article in Russian, English | MEDLINE | ID: mdl-36749200

ABSTRACT

Aim      To study intracardiac hemodynamics in healthy men in supine and prone positions.Material and methods  This echocardiography study included 14 apparently healthy men at a mean age of 38 years.Results In a prone position, the heart configuration and location in the chest changed, the heart rate increased by 7.3 %, and the transaortic flow velocity decreased by 13.7 %. Also, early and late right ventricular diastolic filling velocities and the pulmonary artery flow velocity were increased by 31.7, 11.4, and 5.6 %, respectively. In the intact tricuspid valve, the velocity and regurgitation pressure gradient were reduced by 7 % and 14.2 %, respectively.Conclusion      In a prone position, spatial changes in the location of the heart and its structures influence velocities of intracardiac blood flow, which may initiate the development of heart failure if the prone position is long-lasting.


Subject(s)
Heart Failure , Tricuspid Valve , Male , Humans , Adult , Hemodynamics , Diastole/physiology , Pulmonary Artery , Blood Flow Velocity/physiology
2.
Bull Exp Biol Med ; 172(6): 775-778, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35501654

ABSTRACT

We studied the combined effect of hypokinesia and external cooling on structural and morphological changes in the ventricular myocardium and parameters of homeostasis of the blood system in male and female WKY (normotensive) and SHR (hypertensive) rats. Simultaneous exposure to hypokinesia and cold caused destructive processes in the myocardium and high dynamics of heart remodeling with diverse structural and morphological changes in the left ventricle in rats of both sexes. The thickness of the left ventricular wall most rapidly decreased in male hypertensive SHR rats. The thickness of the wall of the right ventricle significantly increased in male and female rats of both strains. In WKY and SHR females, structural transformations in the heart were less pronounced than in males. The key role in different degree of morphological remodeling of the myocardium in male and female probably belongs to sex hormones.


Subject(s)
Hypertension , Hypokinesia , Animals , Blood Pressure , Female , Heart , Male , Myocardium , Rats , Rats, Inbred SHR , Rats, Inbred WKY
3.
Bull Exp Biol Med ; 169(6): 738-741, 2020 Oct.
Article in English | MEDLINE | ID: mdl-33123917

ABSTRACT

We studied the effect of hypokinesia alone and in combination with cold exposure on HR and total cholesterol content in the blood serum of Wistar, WKY, and SHR rats. Irrespectively of the season, hypokinesia was associated with a decrease in HR, which is probably a result of reduced body needs due to deceleration of metabolic processes. A significant increase in total cholesterol was found under conditions of cold exposure combined with hypokinesia, which indicates qualitative structural rearrangement of energy metabolism under the influence of environmental factors. In winter, the increase in total cholesterol concentration was more pronounced (by 51.5%) in the group of hypertensive animals. Presumably, the increase in the serum concentration of total cholesterol under conditions of hypokinesia and cold exposure is a predictor of structural changes in the heart.


Subject(s)
Blood Pressure/physiology , Cholesterol/blood , Heart Rate/physiology , Hypertension/blood , Hypokinesia/blood , Animals , Cold Temperature , Heart/physiology , Hypertension/physiopathology , Hypokinesia/physiopathology , Male , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Rats, Wistar , Seasons
4.
Bull Exp Biol Med ; 167(6): 720-722, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31655994

ABSTRACT

We studied the effect of hypokinesia combined with cold exposure on morphological parameters of the heart in Wistar-Kyoto rats and rats with spontaneous genetically determined hypertension (SHR). The pathological processes developing in the heart of white laboratory rats significantly affected cardiac function and manifested in the deterioration of the morphological structure of the heart: reduction of heart weight, thinning of the free wall of the left ventricle. These changes indicate transition to a lower energy level of functioning. At the same time, hypertrophy of the right free wall develops in both rat lines. Combined effect of hypokinesia and cold is probably a factor indirectly promoting the development of pulmonary heart.


Subject(s)
Blood Pressure/physiology , Body Temperature/physiology , Heart/physiopathology , Hypertension/physiopathology , Hypokinesia/physiopathology , Ventricular Remodeling/physiology , Animals , Female , Hypertension/complications , Hypertension/pathology , Hypokinesia/complications , Hypokinesia/pathology , Male , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Temperature
5.
Bull Exp Biol Med ; 166(2): 207-212, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30488217

ABSTRACT

We studied electrophysiological mechanisms of ventricular arrhythmias in dogs (n=7) under conditions of antiorthostatic hypokinesia (head-down tilt 45°). Abnormal transmural heterogeneity of repolarization in the base and apex of the left ventricle and increased dispersion of myocardial repolarization were revealed. By minute 30 of antiorthostatic hypokinesia, an increase in the duration of repolarization was revealed after a period of ventricular arrhythmia in all segments and regions of heart ventricles, which was accompanied by impairment of the pumping function of the heart. A hypothesis on the physiological role of ventricular tachycardia as a mechanism of electromechanical homeostatic stabilization in the heart was proposed. The obtained results suggest that under conditions of antiorthostatic hypokinesia, canine heart after a paroxysm of irregular ventricular tachycardia becomes more resistant to arrhythmia.


Subject(s)
Adaptation, Physiological , Heart Conduction System/physiopathology , Heart Ventricles/physiopathology , Hypokinesia/physiopathology , Tachycardia, Ventricular/physiopathology , Animals , Biomechanical Phenomena , Dogs , Electrocardiography , Head-Down Tilt , Hemodynamics/physiology , Male
6.
Bull Exp Biol Med ; 165(5): 606-609, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30225718

ABSTRACT

The contractile function of the heart was studied in adult frogs Rana temporaria under the influence of a toxic dose of isoprenaline under conditions of natural sinoatrial rhythm and during heart pacing. The dynamics of ventricular pressure was recorded with a Prucka MacLab 2000 instrument via a catheter introduced into the ventricle through the ventricular wall. Reduced (p<0.05) parameters of the pump function (HR, maximum ventricular systolic pressure, isovolumic indices dP/dtmax and dP/dtmin) and lengthening of QRS complex and QT interval on ECG attested to impairment of contractile function and electrical processes after exposure to isoprenaline. Electrical stimulation of the right atrium improved myocardial contractility and ECG parameters after the administration of isoprenaline.


Subject(s)
Adrenergic beta-Agonists/adverse effects , Heart Ventricles/drug effects , Isoproterenol/adverse effects , Myocardial Contraction/drug effects , Ventricular Pressure/drug effects , Animals , Cardiac Catheters , Electric Stimulation , Electrocardiography , Female , Heart Rate/drug effects , Heart Ventricles/metabolism , Heart Ventricles/physiopathology , Male , Myocardium/metabolism , Myocardium/pathology , Rana temporaria , Sinoatrial Node/drug effects , Ventricular Function/drug effects
7.
Bull Exp Biol Med ; 164(4): 409-412, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29500806

ABSTRACT

Pumping function of the heart ventricles under conditions of electrical stimulation was examined in adult dogs and rabbits. Pacing induced different changes in intracardiac hemodynamics manifested in impairment of pumping function of the right ventricle, which is largely determined by the functional state of the left ventricle. Initially high HR in rabbits more deeply limited functional reserve of the myocardium in response to electrical stimulus and was accompanied by more pronounced disturbances of pumping function of both ventricles.


Subject(s)
Heart Rate/physiology , Heart/physiology , Hemodynamics/physiology , Myocardial Contraction/physiology , Ventricular Function, Left/physiology , Ventricular Function , Animals , Cardiac Pacing, Artificial , Dogs , Electric Stimulation , Female , Heart Ventricles , Male , Rabbits , Species Specificity
8.
Bull Exp Biol Med ; 161(2): 232-4, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27383159

ABSTRACT

Repolarization properties of ventricular myocardium were studied in anesthetized adult dogs of both sexes subjected to antiorthostatic hypokinesia (head-down tilt at 45° and 60° to the horizontal) and during recovery period (horizontal position for 15 min). The time of repolarization of ventricular myocardium during recovery surpassed the initial value, which represents an adaptive response of the heart to antiorthostasis.


Subject(s)
Heart Ventricles/physiopathology , Animals , Dogs , Female , Humans , Immobilization , Male , Myocardial Contraction
9.
Bull Exp Biol Med ; 146(2): 168-71, 2008 Aug.
Article in English, Russian | MEDLINE | ID: mdl-19145308

ABSTRACT

The duration of ventricular myocardium excitation increases during atrioventricular stimulation of dog heart and the sequence of depolarization of the right and left ventricles is desynchronized. Significant shortening of the activation-recovery interval in the intramural and subendocardial layers of the left ventricular base leads to modification of the repolarization sequence in this area and to an increase of total dispersion of activation-recovery intervals in the cardiac ventricles, as a result of which repolarization sequence starts partially repeating the depolarization sequence.


Subject(s)
Heart/physiology , Ventricular Function, Left/physiology , Ventricular Function, Right/physiology , Animals , Dogs , Electric Stimulation , Electrodes , Female , Male , Membrane Potentials
SELECTION OF CITATIONS
SEARCH DETAIL