PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “heart ventricles”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1992

Force-frequency relationship, contraction duration and recirculating fraction of calcium in postnatally developing rat heart ventricles: correlation with heart rate.

Heart rates (HR) of awake unrestrained animals, isometric contraction duration and force-frequency relationship of ventricular tissue were determined in adult and postnatally developing rats. Resting HR was lowest in newborns (256 beats min-1), reached maximum at the age of 2.5 weeks (506 beats min-1) and then declined to the level of adult rats (381 beats min-1). Duration of isometric contraction correlated negatively with HR. Time to peak tension (TPT) was 185 ms in newborns but fell rapidly during the first days of post-natal life. Minimum was attained at the age of 2.5 weeks (TPT = 98 ms), followed by a slight prolongation towards adulthood. Recirculating fraction of activator Ca2+ increased parallel with HR, being 6% in newborns, 33% in 11-day-old pre-weanlings, and 87% in adult rats. Similar developmental pattern of the parameters suggests that a post-natal increase in HR and a shortening of contraction duration are closely associated with a shift from extracellular to intracellular source of activator Ca2+. Force-frequency curves were similar at different developmental stages and consisted of three phases; a negative staircase between 0.05 and 1.0 Hz, a positive staircase between 1.0 and 4.0 Hz, and a secondary decline above 4.0 Hz. In adult rats the positive force staircase was weak or absent. Furthermore, our results show that negative staircase is not only a property of adult rat heart but is present, and even more pronounced, in pre-weanling and weanling rat heart. Therefore negative staircase is not solely explained by quantitative changes in the contribution of sarcoplasmic reticulum (SR) to contractile activation, but rather by the mechanisms which regulate loading and/or release of sarcoplasmic reticular Ca2+.

Animals↗
PubMedDate not supplied

[State of the kallikrein-kinin system in blood from the heart ventricle in the dynamics of spontaneous hypertension in the rat].

Estimations of prekallikrein and kallikrein inhibitor by means of TAME-esterase method and of the content of kininogen by biological procedure were carried out in blood plasma, isolated from right and left ventricles of heart, of rats with spontaneous hypertension, Okamoto-Aoki strain, and of the normotensive animals Wistar-Kyoto strain. The animals were 2=3 months, 6=8 months and 12=14 months old. Development of spontaneous hypertension was accompanied by an increase in the kallikrein-kinin system components studied. Content of prekallikrein and kininogen was higher in blood plasma from left heart ventricle than in blood from right ventricle, independently of the age of the rats, by 6=10% and 33=40%, respectively. Lung tissue was shown to carry out a definite reserve function in the compensatory increase of the kallikrein-kinin system potential under conditions of spontaneous hypertension.

Age Factors↗
PubMedDate not supplied

[The formation of the right and left heart ventricles from the ventricular portion of the heart tube in embryogenesis].

It has been generally assumed that the initial rudiment of the heart ventricle is divided by the longitudinal interventricular septum into the right and left ventricles. This paper presents evidence for the hypothesis that the right and the left ventricles are produced during normal development from different sequentially located segments of the cardiac tube. These segments yielding rudiments of the right and left ventricles could be detected even during early embryogenesis. This hypothesis requires a new explanation for the process of the formation of two separate outlets from the heart ventricles.

Animals↗
PubMed1994

Anatomical basis for the separation of four cardiac zones in the walls of human heart ventricles.

The coronary vessels of 70 human hearts were visualized postmortem by injection of the coronary arteries with a X-ray opaque substance (for angiographic studies) or with a low viscosity resin (to obtain vascular casts). Analysis of the data suggests a new anatomical systematization of the vascularization of the myocardial tissue of human heart ventricles: it can be divided into four zones each having a different origin of the arterial vessels. These four components of the heart ventricles are the antero-septal (AS), postero-septal (PS), left-lateral (LL), and right-lateral (RL) zones. They correspond to the territories of the anterior interventricular branch of the left coronary artery (AS zone), of the posterior interventricular branch of the right coronary artery (PS zone), of the left circumflex artery (LL zone), and of the right coronary artery (RL zone) up to the origin of the posterior interventricular artery. This systematization of the arterial heart ventricles in zones offers a balanced division of the myocardial tissue, since each of the four zones occupied about one fourth of the total volume of the ventricles. In our samples, the most common distribution of segments in the wall of heart ventricles was the following: 16 segments in the AS zone, 11 segments in the PS zone, 5 segments in the LL zone, and 4 segments in the RL zone. The separation of four zones in the walls of heart ventricles, each of them made up of different segments, may be helpful in the understanding of the pathophysiology of myocardial ischemia, and also in the choice of surgical strategies to treat aneurisms of the heart ventricle wall.

Adolescent↗
PubMed1989

[Quantitative evaluation of hypoplasia of the heart ventricles and its significance for heart surgery].

The quantitative anatomy and morphology of hypoplastic ventricles were studied in 28 afflicted hearts (15 with left ventricular hypoplasia, 13 with right ventricular hypoplasia). The control comprised 10 normal heart specimens. All the 38 specimens were studied morphometrically; this was complemented with angiocardiometry and ventricular volume estimations in diagnosing right ventricular hypoplasia. Based on the study results, the morphometric criteria of ventricular hypoplasias and their variant forms were established. The linear characteristics were found to be informative enough both in hypoplasia diagnosis and in its degree assessment. To choose a therapeutic method, two degrees of right ventricular hypoplasia were distinguished. Radical correction aimed at eliminating concomitant conditions was found to be feasible and performed in 27 patients with moderate right ventricular hypoplasia.

Heart Defects, Congenital↗
PubMed1991

[State of the coronary arteries and function of the left heart ventricle in patients with ischemic heart disease with silent episodes of myocardial ischemia].

The results of multiviewed coronary angiography with left ventriculography were compared in 36 patients with coronary heart disease concurrent with Functional Classes II-IV stable angina pectoris, who had had frequent episodes of silent myocardial ischemia (SMI), as evidenced by Holter monitoring, and in 23 patients with coronary heart disease in the presence of Functional Classes II-IV stable angina pectoris without SMI episodes. In patients with SMI, the changes in coronary arteries were found to have some features: the extension of an atherosclerotic process (common lesion of all three major arteries), its frequent site in the main trunk of the left coronary artery, high collateralization in the diseased vascular channels, and great extent of stenoses. There were no differences between the groups in the major functional parameters of the left ventricular myocardium.

Adult↗
PubMed1990

A study of ventricular electrogenesis and contractility in acute pressure overload of the right heart ventricle.

A model of fat embolism induced acute pressure overload of rabbit right ventricle of heart is presented. A decrease in right ventricular contractility is registered as early as the first minutes after loading. Changes in spatial magnitude and polar coordinates of vectors of ventricular depolarization, and myocardial ischemia manifestations are recorded. The changes in electrogenesis described are attributed basically to ensuing development of hemodynamic disorders.

Animals↗
PubMed2001

Atrial and ventricular electromechanical function in 1-ventricle hearts: influence of atrial flutter and Fontan procedure.

OBJECTIVE: Echocardiography was used to study electromechanical atrial and ventricular function in adult patients with a 1-ventricle heart who were in sinus rhythm to better understand the recurrence of atrial flutter in these conditions. Patients who had recent atrial flutter, with and without the Fontan procedure, were compared with those who had no arrhythmia. METHODS: This was a prospective study that used M-mode and 2-dimensional Doppler echocardiography and electrocardiography. Conventional measurements were used to evaluate ventricular long-axis function. Basic data were drawn from case notes. The setting was a designated quaternary service for grown-up congenital heart patients (GUCH) in a tertiary referral center for cardiology and cardiac surgery. From January 1997 to February 1998, 26 consecutive adult patients (aged >16 years) with a heart with one functioning ventricle and a history of atrial flutter were studied: group 1, with non-Fontan palliative surgery or no surgery (10 patients), and group 2, with Fontan-type repair (16 patients). Also studied were 20 patients with a 1-ventricle heart but no history of atrial flutter. These 20 patients were divided into 2 groups: control 1, which comprised 14 patients with previous shunts or no surgery, and control 2, which consisted of 6 patients with Fontan repair. RESULTS: P-wave duration on the electrocardiogram was similar in the 4 patient groups, but the amplitude was reduced in group 2 and control 2 (patients with Fontan surgery) (P <.016). Bifid P wave was seen in 5 (50%) of 10 patients in group 1 and in 6 (43%) of 14 patients in control 1, but it was not seen in patients with Fontan (P <.01). Ventricular systolic and diastolic dimensions and fractional shortening were not different between patients and controls. Right atrial transverse dimensions were greater in group 2 patients compared with those in controls. Significant atrioventricular valve regurgitation was seen in 9 of 10 group 1 patients but in none of the others. Right-sided total long-axis excursion and atrial A-wave amplitude were depressed in group 2 patients compared with the values in the others. The onset of right atrial shortening was delayed by 50 ms in group 2 compared with control 2, whereas the left atrial shortening was delayed by 30 ms in group 1 compared with control 1. This particular disturbance remained 6 months after cardioversion. CONCLUSION: In 1-ventricle hearts, significant atrioventricular valve regurgitation is commonly associated with atrial flutter in patients who did not undergo the Fontan procedure, and with electromechanical disturbances in those who did. Recognition of disturbances in ventricular long-axis function may thus assist in the identification of patients with a 1-ventricle heart who are prone to atrial flutter.

Adolescent↗
PubMed1991

Subcellular compartmentalization of myosin isoforms in embryonic chick heart ventricle myocytes during cytokinesis.

Embryonic chick heart ventricle myocytes retain the ability to alternate between proliferation and functional differentiation. A cytoplasmic isoform of myosin is present in cleavage furrows of various nonmuscle cells during cytokinesis, whereas one or more of the cardiac myosin isoforms are localized in sarcomeres of beating cardiomyocytes. Antibodies were employed to reveal the subcellular localizations of cytoplasmic and cardiac myosin isoforms in embryonic chick ventricle cardiomyocytes during cytokinesis. Monoclonal anticytoplasmic myosin antibodies were prepared against myosin purified from brains of 1-day-posthatched chickens and shown to react with chick brain myosin heavy chain by Western blots and/or ELISA tests. One monoclonal antibrain myosin antibody also cross-reacted with chick cardiac myosin but not with skeletal or smooth muscle myosins. Two antichick cardiac myosin monoclonal antibodies and one antichick skeletal myosin polyclonal antibody that cross-reacts with cardiac myosin were employed to identify cardiac sarcomeric myosin. Cells were isolated from day 8 embryonic chick heart ventricles, enriched for myocytes, grown in vitro for 3 days, and then examined by immunofluorescence techniques. Monoclonal antibodies against cytoplasmic myosin preferentially localized in the cleavage furrows of both cardiofibroblasts and cardiomyocytes in all stages of cytokinesis. In contrast, antibodies that recognize cardiac myosin were distributed throughout cardiomyocytes during early stages of cytokinesis, but became progressively excluded from the furrow area during middle and late stages of cytokinesis. These data suggest that in cells that contain both cytoplasmic and sarcomeric myosin isoforms, only cytoplasmic myosin isoforms are mobilized to from the contractile ring for cytokinesis.

Animals↗
PubMed1995

Elevated lipid peroxidation and vitamin E-quinone levels in heart ventricles of streptozotocin-treated diabetic rats.

Diabetic patients develop cardiomyopathy characterized mainly by left ventricular contractile dysfunction and congestive heart failure. This study has investigated the effects of diabetes and insulin treatment on lipid peroxidation, vitamin E, and vitamin E-quinone levels in the heart ventricles of rat made diabetic by streptozotocin treatment. Controls were injected with buffer alone; a subgroup of diabetic rats were injected daily with insulin for 2 months. Membrane lipid peroxidation was measured by determining the thiobarbituric acid (TBA)-reactivity. Vitamin E and vitamin E-quinone were measured by using the high pressure liquid chromatography. There was a significant (p < 0.02) increase in the vitamin E-quinone in the heart ventricles of diabetic rats (0.33 +/- 0.05 microgram/mg phospholipid) compared with control rats (0.19 +/- 0.02). This increase was prevented in insulin-treated diabetic rats (0.20 +/- 0.03). Vitamin E levels were higher (14.15 +/- 1.17 micrograms/mg phospholipid) in diabetic rats compared to control rats (9.93 +/- 1.29 (p < 0.03). However, insulin treatment to diabetic rats did not cause any change in vitamin E levels (11.75 +/- 1.02) compared with diabetic rats. TBA reactivity was higher in the heart ventricles of diabetic rats (1.09 +/- 0.11 nmole/mg phospholipid) compared with controls (0.78 +/- 0.08, p < 0.04). Insulin treatment to diabetic rats prevented the increase in the lipid peroxidation (0.79 +/- 0.07); there were no statistically significant differences in TBA-reactivity levels in heart ventricles of insulin-treated diabetic and control rats. This study documents accumulation of vitamin E-quinone and lipid peroxidation products in heart ventricles in diabetic rats, which may have a role in the altered contractile property of the heart ventricles in diabetes.

Animals↗
PubMed1975

Fine structural changes in embryonic chick heart ventricle induced by lead poisoning.

The embryonic chick heart ventricle of day 11 was studied electron microscopically to learn the structural changes that develop in lead poisoning. The chick embryos were administered with 0.015 mg/egg of lead acetate at day 2. The most pronounced changes observed in the ventricle were: malformed mitochondria, disorganized, short and scanty myofibrils and abundance of swollen vacuoles. The ultrastructure of the ventricle from the control chick embryos was normal. The most frequent change noted in the ventricular tissue was an alteration in the myofibrils. This study indicates that electron microscopic changes can be induced in the embryonic chick heart ventricle by lead poisoning.

Animals↗
PubMed1997

[Ventricular arrhythmias in patients with mitral valve prolapse and spurious cords in heart ventricles].

The aim of the work to assess the frequency of ventricular arrhythmias in patients with isolated mitral valve prolapse isolated spurious cords in heart ventricles as well as in those patients who had both, mitral valve prolapse and spurious cord in heart ventricle. Out of 4156 successive electrocardiographic investigations carried out at the Department and Clinic of Cardiology, Medical Academy in Wroclaw, coexistence of spurious cords in heart ventricle and mitral valve prolapse was diagnosed in 32 patients (0.8% of all subjects), isolated mitral valve prolapse--in 184 patients (4.4%) and presence of isolated spurious cords not accompanied by mitral valve prolapse--in 91 patients (2.2%). In 20 patients with coexistence of spurious cords in heart ventricles and mitral valve prolapse, ventricular arrhythmias occurred in 12 subjects (60.0%) and in 5 of them they were significant. In the group of 29 patients with isolated spurious cords, disturbances of the ventricular rhythm occurred in 13 subjects (44.8%), while significant ventricular arrhythmias were found in 6 patients (20.7%). Out of 60 subjects with isolated mitral valve prolapse disturbances of the ventricular rhythm were found in 20 patients (33.3%) and significant arrhythmias--in 12 subjects (20.0%). The observations did not reveal increased prevalence of significant ventricular disturbances of the heart rhythm in patients with coexisting mitral valve prolapse and spurious cords in the heart ventricles.

Adult↗
PubMedDate not supplied

[Flow structure in artificial heart ventricle].

The flow structure in the artificial heart ventricle has been investigated by laser knife visualization method using fluorescence. It is shown that the flow structure is essentially three-dimensional. The effect of inlet artificial valve orientation on the flow structure is demonstrated. The artificial ventricle elastic cover deformation process is reviewed.

Coronary Circulation↗
PubMed1977

[Relationship between the myocardial mass and the volume of human heart ventricles in hypertrophy].

The weight and volume values of heart ventricles from patients dying of cardio-vascular and some other diseases were studied. Measuring of sarcomeres in freely fixed and controlled pressure-fixed hearts showed that with the former method of fixation heart ventricles were contracted and the volume of their cavity approached the tidal volume. In freely fixed and "fresh" hearts removed at autopsies within 2-27 hours after death, concentric and excentric hypertrophy of ventricles may be characterized by numeric values of the relative mass: the ratio of ventricle mass to volume of its cavity, and in the left ventricle--by the relative diameter of the cavity: the ratio of the cavity diameter in cross-section to the thickness of the ventricle wall.

Autopsy↗