The effect of acupuncture stimulation on human cardiac functions was studied by radionuclide ventriculography (RV). Heart rate (HR) and blood pressure (BP) were continuously observed in nine healthy men (from 20 to 38 years old; average 26.6±5.8 years old) using a polygraph system (RM-6000, Nihon Kohden Co., Ltd.). Indocyanine green and radioactive isotope (^99mTcO₄) were simultaneously injected into these subjects from the cubital vein while they were in a supine position. Images were then acquired and cardiac output (CO) was measured. Before and during the acupuncture stimulation, RV data in synchronization with the R wave of the electrocardiogram were collected within a short time and cardiac functions were measured by data processing with a computer connected to a gamma camera (ZLC-7500, Siemens Co., Ltd.). Acupuncture stimulation using a stainless steel needle was applied by the tapping method to the right Ximén Point (the center of the anterior surface of the forearm).
All nine subjects showed a decrease (65.3±7.1% v. s. 57.5±4.8%, P<0.001) in left ventricular ejection fraction (EF) and diffused reduction of the left cardiac wall motion during acupuncture stimulation, suggesting cardiac hypofunction during the stimulation.