Opacification phase effects of angiographic contrast medium on left ventricular size and function: influence of...

Prior studies of the opacification-phase effects of left ventricular (LV) injection of angiographic contrast medium (CM) on LV size and function have yielded discrepant results. A sensitive ultrasonic technique was used to measure LV dimension (Di) in 10 open-chest dogs with physiologic heart rates, and injection of saline (S) was compared with injection of CM. The influence of initial LV volume (LVVi) and that of the pericardium were analyzed. Changes in contractile state (CS) were assessed from the end-systolic (ES) pressure-Di relation. With both low and high LVVi, S and CM produced indistinguishable early (beat 5) increases in end-diastolic (ED) Di and ESDi. EDDi and ESDi subsequently returned to baseline after S but remained elevated through beat 12 after CM. The latter increase was progressive only with low LVVi. Depression of CS was evident by beat 7 after CM, while pericardiectomy did not alter the response to CM. Thus, CM produces opacification-phase depression of CS and increases in LV size which are in part dependent in LVVi.