Biomedical subjects

D Avgoustakis

Publications and source records attributed to D Avgoustakis.

34 records · Page 2Linked to original sources

PubMed1976

Length of main left coronary artery in relation to atherosclerosis of its branches. A coronary arteriographic study.

The relation between the length of the main left coronary artery and the presence of atherosclerosis in its branches or the presence of complete left bundle-branch block was studied by selective coronary arteriography in 43 persons. The length of the main left coronary artery was found to be significantly shorter in patients with coronary atherosclerosis than in subjects without angiographic evidence of coronary artery disease. In patients with electrocardiographic evidence of complete left bundle-branch block, the length of the left main coronary artery was significantly shorter than that in both previous groups. In view of these findings, it is suggested that a short main left coronary artery should be considered as a congenital factor predisposing to the development of coronary artery disease. The possible mechanisms leading to atherosclerosis of the left coronary arterial branches in the presence of a short main trunk are discussed.

Angiography↗

PubMed1976

The contribution of right ventricular angiocardiography to the diagnosis of tricuspid valvular stenosis (Observations made on 3 patients).

The right ventricular angiocardiographic findings, in the anterioposterior projection, are described on three patients with tricuspid valvular stenosis. During diastole, the tricuspid valve was delineated as an arcline contour, placed between the non opacified right atrium and the opacified right ventricle, and it was displaced to the left of the spine. Its mobility was diminished. Right ventricular angiocardiography seems to be a useful method for the diagnosis of the tricuspid valvular stenosis and the estimation of the pathology and the functional condition of the tricuspid valve. The method is recommended for further evaluation.

Adult↗

PubMed1976

Haemodynamic alterations of the left ventricle during right atrial pacing.

The left ventricular haemodynamic alterations during right atrial pacing were studied in 12 cases. Cardiac index varied little: during maximal rate however, its mean value was slightly lower than the resting one. Stroke index decreased inversely to the heart rate. The course of these indices did not separate the normal from abnormal cases. Ventricular function curves (VFCs) were constructed by relating the changes of left ventricular (LV) end-diastolic pressure (EDP) to those of stroke index (SI). In 4 normal cases the curves were steep, showing a fall of EDP with relatively large decrease of SI; in 3 cases of congestive myocardiopathy they were flat, showing fall of EDP in two and increase in one, with relatively small decrease of SI; in 5 patients with effort angina LVEDP initially decreased. This initial fall of VFCs was steep in two with normal and flattened in three with impaired resting LV function. Increase of EDP, evidently due to development of ischaemia, followed in all; it exceeded resting EDP in two out of three cases developing angina and in one out of two not developing angina. Our findings support the view that the increase of LVEDP is due to decrease of both myocardial contractility and compliance.

Adult↗

PubMed1976

Mechanical alterations of the left ventricle during right atrial pacing.

The effect of increasing heart rate by right atrial pacing on the peak value of the first derivative of left ventricular (LV) pressure(dp/dt) and the maximal velocity of the contractile element (KVmax) was studied in 12 cases. Peak dp/dt was poor as regards its sensitivity in reflecting the changes of contractility, due to its strong dependence on LV end-diastolic (EDP) and systolic pressure. KVmax increased constantly in the 4 normals and in 2 cases of ischaemic heart disease which did not develop angina; the increase exceeded 90 ml sec-1 in the former and one of the latter cases in which resting LV function was normal. In contrast, it decreased during the development of ischaemia in two of the three cases which developed angina; in the third case, in which also resting LV function was seriously impaired, the course of KVmax was almost flat. A similar flat course was observed in the three cases of congestive myocardiopathy. the above alterations of KV max were independent of the EDP and proportional to the basic contractility and its anticipated changes during pacing.

Adult↗

PubMed1975

The significance of intraventricular electrocardiogram in artificial heart pacing. Observations made on 232 patients.

From 1972-1975, 232 consecutive patients suffering from A/V block were paced intravenously in the Cardiac Department. Medical School, University of Athens. Of these, 124 were female and 108 male. Their age range was between 49 and 85 years. Besides fluoroscopic and threshold control, the intraventricular electrocardiogram (E.C.G.)., recorded from the tip of the electrode, was used as a guide for the accurate positioning of the catheter-electrode in the right ventricle. An injury pattern with an elevation of the ST segment of at least 3 mV and characteristic and steady morphology was obtained when the electrode tip was satisfactorily impacted in the right position. As a consequence of this, an initial stimulation threshold below 0.7 mA was obtained in all cases and pacing failure, due to catheter displacement was noted in only 11 cases (5%), without any apparent increase in the incidence of right ventricular perforation.

Action Potentials↗

PubMed1974