In the domain of circulatory disease the physician has benefited greatly from physiologic methods. Likewise, of all the medical specialties cardiology has been most inspirational to physiology. The idea of determining the cardiac debit (cardiac output), i. e. the quantity of blood expelled by the left ventricle into the aorta, in unit time, is old. Its history is the more interesting, since a study of this one problem in its diverse aspects demonstrates the evolution of physiologic thought.
Dr. Lequime, in this well written monograph reviews the significant literature, describes the various methods available and makes important personal contributions. He concludes: The direct method of Fick permits accurate measurement of cardiac output in the unanesthetized dog. During chloral or pentobarbital sodium anesthesia, the considerably reduced cardiac output parallels the diminution in respiratory exchange. Application of the principle of Fick to man, according to the technic of Meakins and Davies, can