Measurement of Coronary Blood Flow Using Radioactive Iodine Compared with Nitrous Oxide

Abstract

Q UANTITATIVE measurement of coronary blood flow by indicator-dilution methods has been attempted by various groups within the past five years. The theory upon which these studies have been based is that after injection into either the pulmonary artery or left ventricle, the first activated blood to reach the right ventricle on recirculation returns by way of the coronary vessels. 1Henly and eo-workers rapidly injected a bolus of I 131 human serum albumin into the distal pulmonary artery and monitored the curves in the right side of the heart.2 The resulting calculations gave coronary-flow values averaging less than 5 per cent of the cardiac output. No standard was used for comparison. Precordial counting to approximate coronary blood flow has been investigated by Love and Burch and compared with a direct method of measuring the blood emptying from the coronary sinus, using an infusion of the radioactive tracer. Supported in part by a research grant (H1817) from the National Heart Institute, U.S. Public Health Service, and in part by grants from the Tobacco Industry Research Committee (QH17), the Committee on Problems of Alcohol of the National Academy of Sciences-National Research Council (UV25), Ciba Pharmaceutical Products Inc., and the Heart Association of Southeastern Pennsylvania.A preliminary report of this investigation was made by Ivan E. Forte on April 12, 1960, before the American Physiological Society at Chicago, Illinois (Fed. Proc. 19: 90, 1960).Dr. Schmitthenner was a Postdoctoral Research Fellow of the National Heart Institute (HF6498) at Lankenau Hospital, Philadelphia, Pennsylvania, 1956-1958 Received for publication November 14, 1960. possible, by injecting a radioactive bolus into the left side of the heart, to record an isotopedilution curve in the blood of the coronary sinus draining the left ventricle, and if so, is this dilution reflected in the proximal pulmonary arterial circulation curve or in a precordial curve? (b) If such curves following bolus injection into the left side of the heart are meaningful, how does the quantitative estimate of the myocardial blood now and of its ratio to the cardiac output, similarly derived, compare with a blood-flow value recorded almost simultaneously by the nitrousoxide desaturation method, and what fraction of the Fick cardiac output is this value ? Injections were made into the distal pulmonary artery, aortic root, left ventricle, or coronary artery. As to question (b), our familiarity with the application and use of the formulas for the nitrous-oxide technique and Fick cardiac output during the past few years afforded the opportunity to compare calculated isotope-dilution formula values. It was in this way that the indirect nitrous-oxide method was calibrated against direct measurement of coronary blood flow by moans of a bubble flowmeter. 4 However, no formulas have been found which, when applied to our data, have yielded acceptable fractions of the cardiac output. Therefore, the present report deals with our interpretation of question (a) ab...

Wert und Grenzen klinischer Koronardurchblutungsmessungen

“…Nach der Injektion werden fiber dem Herzen zun/ichst zwei Aktivit/itsgipfel registriert, die die Passage des Indikators durch den rechten und linken Ventrikel anzeigen. [54] experimentell best/itigt. Mena et al [136] haben eine verwandte Technik angegeben, bei der aus der Differenz des Abfalls der Aktivitfitskurven fiber dem Herzen und fiber einer peripheren Arterie auf die Grfl3e der Koronardurchblutung geschlossen wird.…”

Studies of Coronary Blood Flow by Multiple Dye Dilution Curves*

“…Another is based on the claim that coronary blood flow can be quantitated from precordial radioactivity curves (2). These observations have been challenged on both experimental and theoretical grounds (3)(4)(5)(6). The radioactive method has been re-examined by comparing intraarterial indicator dilution curves with those obtained by surface counting from the precordium and brain (7).…”