AJP - Heart and Circulatory Physiology, Vol 241, Issue 4 541-H546, Copyright © 1981 by American Physiological Society
Cardiac electrical resultant dipole moment of spontaneously hypertensive rats
B. C. Hodgkin, C. V. Nelson and E. T. Angelakos
The cardiac electrical resultant dipole moment (RDM) of 17 spontaneously
hypertensive rats (SHR) was compared with that of 17 Wistar-Kyoto rats
(WKY), 65-100 days of age. Relative to body weight, left ventricular weight
was 23% greater and right ventricular weight was 18% greater for SHR than
for WKY. Left ventricular wall thickness was 11% larger and myocyte
diameter was 13% larger for SHR than for WKY. RDM orientation for SHR was
more dorsal, leftward, and cranial from middle to end of qRS. The second
spatial magnitude peak of QRS, M2, was significantly smaller for SHR than
for WKY (P less than 0.001) whereas M3 for SHR was significantly greater
than for WKY (P less than 0.001). The alterations in RDM of SHR are greater
than can be accounted for simply on the basis of increased cell size. The
excitation sequence for SHR might be different from that of WKY. Results
show the necessity of considering the details of the spatial magnitude
curve during QRS.
