Collateral Blood Flow in the Myocardium of Dogs Measured with Krypton85

Abstract

AbstractJohansson, B., E. Linder and T. Seeman. Collateral blood flow in the myocardium of dogs measured with Krypton85. Acta physiol. scand. 1964. 62. 263–270. — Methods have recently been developed for determination of regional blood flows from wash‐out curves recorded externally after close‐arterial injection of radioactive Krypton (Kr85). In the present study this technique has been applied to measurement of collateral capillary blood flow in the myocardium of dogs during acute occlusions of coronary arteries. A monoexponential fall in activity was found during elimination of Krypton from the normal myocardium indicating a homogeneous distribution of blood flow. The wash‐out curves recorded during coronary occlusions could be dissolved into two separate components. There was a rapid phase related to the elimination of Krypton from normally perfused regions of the myocardium and a slow phase due to the de‐saturation of the ischemic portion. The magnitude of the collateral capillary blood flow was determined from the decay rate of the slow component. The relative size of the ischemic region could be estimated from the zero time values of the two phases. Collateral blood flow seemed to be fairly homogeneously distributed within the ischemic part of the myocardium. Release of an occlusion was followed by a rapid fall in activity in association with the reactive hyperemia.