science · 26 January 1925 · 100 years ago
death
Died 26 Jan 1925 at age 71 (born 12 Apr 1853).
Scottish cardiologist, pioneer in the study of cardiac arrhythmias. He was first to make simultaneous records of the arterial and venous pulses to evaluate the condition of the heart, a procedure that laid the foundation for much future research. Mackenzie also drew attention to the question of the heart's capacity for work, paving the way for the study of the energetics of the heart muscle. His work was particularly important in distinguishing atrial fibrillation and in treating this common condition with digitalis. In 1892, he built a machine for detecting and recording physiological activity, such as pulse rate and blood pressure, since known as a polygraph, and later used as a lie detector.