Progressive changes in cardiovascular function after unilateral heart irradiation

¹ Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi

Chronic heart failure was produced by giving 20,000 r Co⁶⁰ irradiation to either the right or left ventricle in nine closed-chest animals. Measurements of right and left atrial pressures, arterial pressure, pulse rate, body weight, and blood volume were made before and after irradiation. The right and left atrial pressures rose progressively until death in three animals irradiated on the right side. In six animals irradiated on the left side, the left atrial pressure rose progressively, but the right atrial pressure either did not rise or rose only during the latter stages of failure. Declining arterial pressure and increasing pulse rate were common to both groups. Increases in blood volume were observed in all animals, but this increase was only significant in the group irradiated on the left side. At autopsy, 70–100% of the right ventricular muscle was damaged in dogs irradiated on the right side, and 40–70% of the left ventricle in dogs irradiated on the left side. Hydrothorax and liver congestion were found in the right-sided group and pulmonary congestion in the left-sided group.

Note:
With the Technical Assistance of Bob Ledbetter and Julian Carroll

Key Words: heart failure • congestive failure • cardiac damage • irradiation of heart

Submitted on August 1, 1963