ISSN:
1432-2013
Keywords:
Myocardial Wall Thickness
;
Strain Gauge Device
;
Coronary Artery Occlusion
;
Reactive Hyperemia
;
Isoprenaline
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Changes in left ventricular myocardial wall thickness (MWT) were studied in open-chest dogs using a specially designed strain gauge device. The total systolic increase in MWT was 10%, of which about 30% occurred during the isovolumic phase of contraction. These values are lower than those obtained with cineradiographic techniques. A possible explanation for this divergency is discussed. Calculation of MWT changes showed that increases between 7% and 18% are required to eject resting stroke volumes. Intravenous injections of isoprenaline showed a log dose-dependent augmentation of the total increase in MWT during systole. Coronary artery occlusion resulted in a fall in the total systolic MWT increase and a decrease in MWT at the end of diastole, which can both be explained by an increase in left ventricular end-diastolic volume. The temporary rise in total systolic MWT increase over the control value, following release of a prolonged occlusion, disappeared when an induced coronary artery stenosis had abolished diastolic reactive hyperemia. This indicates a relationship between coronary blood flow and the extent of total MWT increase in systole.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00592195
