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Results for “Heart Septum”

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At least 19 recordsLinked to original sources
PubMedDate not supplied

Effect of avian basal forebrain lesions, including septum, on heart rate conditioning.

The possible involvement of basal telencephalic structures in visually conditioned heart rate change (established by pairing light and foot-shock) was studied in 156 pigeons by evaluating conditioning performance following lesions of the septum or lobus parolfactorius. Extensive destruction of the septal complex had no effect on either the orienting response or the development of the conditioned response. Lesions of the lobus parolfactorius did not affect the orienting response or overall conditioned response levels, but it did slightly prolong the latency of the conditioned heart rate change. It is concluded that the septum, despite its being cardioactive, is not involved in conditioned heart rate change and that the lobus parolfactorius participates minimally. Thus, of the principal limbic structures of the avian telencephalon, only the amygdalar homologue appears critical in this defensive conditioning task [3].

Animals↗
PubMed1979

[Sequence of the spread of excitation in bird heart ventricles].

Intramural multipolar technique revealed primary sites of excitation in the subendocardium of central areas of border line of the apical and middle thirds of the bird heart septum. From the zone of primary depolarization the excitation wave spread on the subendocardium of ventricles. A number of sites of negativity were observed over the epicardium. The main mass of myocardium of free walls and the lower two thirds of the septum are activated by means of myocardium of free walls and the lower two thirds of the septum are activated by means of multifocal depolarization. The base third of the septum is the last to be activated. These features of the excitation of bird myocardium can be accounted for by the special character of distribution of the Purkinje fibers in the muscles of myocardium ventricles.

Animals↗
PubMed1979

The normal anatomy of the atrial septum in the human heart.

The atrial septum is a blade-shaped structure with a concave anterior margin that reflects the curve of the ascending aorta, a convex posterior margin, and an inferior margin along the mitral annulus. The fossa ovalis comprises an average of 28 per cent of the total septal area, or 43 mm.2 in infants and 240 mm.2 in adults. The channel that persists between the fossa ovalis and the muscular atrial septum is patent except at the limbus, providing a useful explanation for the success of blunt transseptal atrial catheterization and right-to-left shunts in individuals with elevated right atrial pressure.

Adolescent↗
PubMed1979

Chronic oral vasodilator therapy to control heart failure in postinfarction ventricular septal defect.

This report describes a 70-year-old woman with biventricular failure following an anteroseptal infarction complicated by interventricular septal rupture. Treatment with nitroprusside followed by oral hydralazine eliminated the failure and reduced the shunt from 2.75 to 1 to 1.7 to 1. She is asymptomatic post-discharge. Chronic medical therapy including oral vasodilators may be an acceptable alternative to surgery in a small minority of patients with this complication of myocardial infarction.

Administration, Oral↗
PubMed1975

Ultrasonic identification and examination of fetal heart structures.

Ultrasonic studies were performed on normal fetuses ranging from 36 to 40 weeks gestational age in an attempt to visualize anatomical details of the fetal heart. We were able to visualize cardiac structures hitherto thought to be unidentifiable. Two-dimensional B-scan exposures of sections showed transverse and longitudinal sections of the fetal heart, including the cardiac septa and inlet and outlet sites of the large vessels. To attempt to elucidate the dynamics of the fetal heart, the motility patterns of the cardiac structures were examined by time-motion mode scanning and the patterns obtained were compared to those observed in the postnatal heart. The reliability of the theories advanced and the further prospects are discussed.

Coronary Vessels↗
PubMed1978

[Myocardial lesions in acute increase of the intracranial pressure (author's transl)].

Myocardial lesions occuring in diseases with acute increase of intracranial pressure were investigated. Morphologic alterations in heart muscle in spite of different lengh of surviving and various causes of the death were of similar type. In every case subendocardial haemorrhage could be observed on the septal surface and on the papillary muscle of the left ventricle. Focal intracellular edema, myocytolysis were revealed in 76%, focal necrosis of hypercontractic type developed in 52% of the cases. Cellular infiltration occurred around the alternations observed in 3 cases. It is concluded, that damage to the heart muscle is not caused directly by the increased intracranial pressure or catecholamine mobilisation, but seems to be the consequence of the acute myocardial hypoxia.

Adolescent↗
PubMed1979

Reduction in ventricular endocardial and epicardial potentials during acute increments in left ventricular dimensions.

Unipolar potentials were recorded from the endocardium (Endo-Pot) and the epicardium (Epi-Pot) of the left and right ventricles of anesthetized open-chested dogs during acute changes in left ventricular dimension by blood transfusion. A pair of implanted ultrasonic crystals were used to detail changes in left ventricular (LV) anteroposterior diameter. When the diameter increased by an average of 11 per cent, LV Endo-Pot decreased by 28 per cent and LV Epi-Pot decreased by 15 per cent. Right ventricular Endo-Pot and Epi-Pot concurrently decreased by similar magnitude (-36 per cent). The relationship between potentials and LV diameter showed negative linearity over the ranges examined, and was not influenced by changes in hematocrit. No inverse relation between changes in Endo-Pot and Epi-Pot was observed. It is suggested that potentials when recorded directly from the endocardium or epicardium mainly reflect the electrical activity of the tissues in the immediate vicinity of the electrode. It is postulated that an increase in ventricular volume by producing stretching and thinning of ventricular walls, reduces the effective tissue mass represented in the electrode signal, thereby accounting for a reduction in both endo and epicardial potentials. Although the precise mechanisms of changes in ventricular potentials remains unclear, such changes, nevertheless, may indicate, in clinical circumstances, an acute shift in left ventricular volume.

Action Potentials↗
PubMed1976

Prolapse of the mitral valve is described in two patients with the Ebstein's anomaly of the tricuspid.

Prolapse of the mitral valve is described in two patients with the Ebstein's anomaly of the tricuspid valve. This association has not been described previously. It is probable, however, that this association is not a rare one, but that clinical features of the prolapsing mitral valve are obscured by those resulting from the malformed tricuspid valve. Opportunity also was provided to study anatomically the mitral valve of a patient known to have a systolic click and a late systolic murmur (the Barlow syndrome). Although there have been several anatomic descriptions of floppy mitral valve at necropsy, they have been extremely rare in patients known to have the classic auscultatory features of the Barlow syndrome.

Adolescent↗