HEMODYNAMIC &MECHANICAL CONTROL OF MYOCARDIAL PERFUSION

  • Ritman, Erik L, (PI)

Project: Research project

Description

The overall objective of this proposal is to evaluate the relative
importance of mechanical factors within the myocardium, and hemodynamic
aspects of the coronary circulation, in control of regional and transmural
distribution of myocardial perfusion. The basis for quantification of
these factors will be the simultaneous measurement of regional myocardial
structure, perfusion and coronary artery anatomy. The approach is based on
the use of a unique imaging device, the Dynamic Spatial Reconstructor
(DSR). The DSR is a multiple x-ray source CAT scanner which differs from
commercially available CT scanners in that it scans a volume instead of a
slice, scans the volume in stop action and repeats the scan 60 times per
second so that the angiographic delineation of dynamic functional geometry
of the heart wall and coronary arterial tree can be evaluated
simultaneously. Direct confirmation of the location and extent of the
spatial distribution of myocardial perfusion, as judged by postmortem
angiogram and distribution of radiolabelled microspheres, will be sought to
establish accuracy of the DSR-based techniques. Three phases are to be
executed in sequence. In Phase I the specific DSR-based angiographic and
finite element analysis techniques will be developed and evaluated in
experimental animals. In Phase II the role of physiological mechanical
factors such as heart rate, afterload, and coronary vasodilatation in
myocardial perfusion distribution will be evaluated. In Phase III the role
of pathophysiological states such as myocardial hypertrophy, aortic valve
insufficiency and coronary artery stenosis will be evaluated using the
techniques developed. The significance of this proposal is that multiple
interactive pathophysiological processes involved in myocardial perfusion
can be evaluated simultaneously and that there is a strong possibility that
only a single intravenous injection of relatively small volumes of roentgen
contrast agent will be required for a detailed DSR-based study. This
minimally invasive procedure may form the basis for investigation of
subclinical disease states in humans.
StatusFinished
Effective start/end date7/1/846/30/88

Funding

  • National Institutes of Health
  • National Institutes of Health

Fingerprint

Perfusion
Hemodynamics
Coronary Circulation
Coronary Stenosis
Microspheres
Vasodilation
Intravenous Injections
Hypertrophy
Anatomy
Coronary Vessels
Myocardium
Heart Rate
X-Rays
Equipment and Supplies

ASJC

  • Medicine(all)