In 1952, John Kirklin and associates from cardiology, anesthesiology, physiology, and engineering launched a program at Mayo Clinic to develop a method for performing open-heart surgery.Collaborating with IBM Corporation, they modified John Gibbon's cardiopulmonary bypass machine and successfully tested it in 10 dogs; nine survived following 30-45 minutes of heart-lung bypass.The team then carefully selected 8 patients to undergo heart surgery, and on March 22nd 1955 Dr. Kirklin and his team performed a successful operation on a 5-year old girl with a VSD.Four of the first 8 patients survived, ushering a new era of open-heart surgery.Many technical developments followed including organization of the world's first cardiac surgery intensive care unit.The success of this early effort was due to the brilliance and courage of Dr. Kirklin and his colleagues as well as the multidisciplinary culture of our Clinic.This teamwork focused not only on help with building and testing the cardiopulmonary bypass machine, but also on patient selection with correct diagnosis and an accurate plan for operation.Cardiac surgery using mechanical circulatory support continued after Dr. Kirklin's pioneering work, and the program at Mayo Clinic is the longest continuously active cardiac surgery program in the world.Today, 10 staff surgeons, three associate surgeons, and 16 residents and fellows perform over 3,000 cardiovascular procedures each year.This presentation will highlight the milestones in development of our practice and research activities and give details on the lives and contributions of two other pioneers in cardiac surgery at our Clinic, Drs.
Mitral valve function was assessed by roentgen videodensitometry. Mitral reflux was rare when single ventricular ectopic systoles were produced by electronic stimulation of the right or left ventricle at various times in the cardiac cycle. It was also rare during the compensatory pause after the ectopic systole or with the following postectopic systole. Recurrent ventricular ectopic systoles interposed once per cycle were associated with minor reflux when introduced in mid-cycle. Such extrasystoles occurred late enough in the cardiac cycle for the ventricle to relax after the primary systole and for the mitral valve to open before the extrasystole. The extrasystolic contractions were, however, weak and incapable of opening the aortic valve. When interposed early in the cardiac cycle, extrasystolic potentiation of the primary ventricular contraction occurred, and no or minimal mitral reflux was observed.
Blood is nonhomogeneous; hence, the relationship between light transmission and increasing concentration of dye in whole blood is never the perfect exponential curve predicted by Beer's law. Instead, as the concentration of indocyanine green is increased to high levels (40 mg/liter) the light transmission decreases exponentially toward an asymptote at 6–8% transmission for nearly monochromatic densitometers (half-band width: 13–20 mμ), but at 30–40% for densitometers using light of wide-band width. Consequently, following recording of a dilution curve, circulating background dye reduces the change in transmission per unit increase in dye concentration in subsequent curves. This decrease in sensitivity cannot be compensated for by a simple increase in the sensitivity of the densitometer or in the intensity of its light source. Compensation can be attained, however, if increasing densitometer sensitivity is associated with the automatic scale expansion provided when a suppressed zero point is used. At correct zero suppression, the deflection for zero output of the densitometer coincides with the asymptotic transmission value mentioned above. indicator-dilution in circulation; blood flow measurement; blood optical density; dye dilution technic; cardiac output measurement Submitted on April 15, 1963
