THE CLINICAL importance of ischemic heart disease has provided a powerful stimulus for the development of new and better methods for the study of the coronary circulation. In the animal laboratory, the electromagnetic flowmeter has replaced the rotameter as the standard method of measuring coronary blood flow. Flowmeter probes can be implanted around a dog's coronary artery and utilized to stud...

The physiologic response to the chronic administration of digoxin was studied in 12 adult and 13 newborn sheep. Vascular pressures, cardiac output, isovolumic contraction phase indexes and systolic time intervals were measured before and after 2 weeks of digoxin therapy. Physiologic measurements were correlated with drug levels in plasma and myocardium. Resting myocardial function in newborns e...

T HE CHARACTERISTICS of the electrocardiographic tracing are determined by three independent variables. The first of these involves the potentials generated by the myocardium during depolarization and repolarization. These potentials can be altered by a wide variety of physiologic states, as well as by intrinsic disease of the myocardium. The second factor relates to the properties of the extra...