Experimental Verification of Wilson's Derivation of the Principle of the Ventricular Gradient
The concept of the ventricular gradient is based upon the theoretical representation of the electrogram of a myocardial fiber as the sum of two monophasic action potential (M.A.P.) curves, each of which represents the electrical activity of one-half of the fiber. Wilson showed that from this premise certain mathematical deductions are possible: (1) that the area of the electrogram is equal to the sum of the areas of the two MAP. curves; (2) that this area is independent of the rela tion of the two M.A.P. curves with respect to time and, therefore, that it is independent of the path of excitation; and (3) that as a corol lary of the latter, the measurement of the area of the electrogram may be used as a measure of the net electrical effect of local differences in repolarization.
The present paper reports the results of experiments in which the electrical effects of a segment of a strip of turtle heart muscle were recorded as biphasic complexes and as two M.A.P. curves. Accurate measurement of the areas by means of an electronic integrator supports Wilson's premise. These observations furnish experimental confirmation of the theo retical basis of the concept of the ventricular gradient.
- Received March 3, 1961.
- © 1961 American Heart Association, Inc.