Graded infusions of angiotensin revealed that patients with cardiac disease had flat or descending left ventricular function curves, whereas patients without disease exhibited steep ascending limbs.
Observational (n=18)
Does increasing resistance to ventricular ejection with intravenous angiotensin infusion allow for the construction of left ventricular function curves to detect impairment of myocardial function in humans?
Graded angiotensin infusions can safely increase resistance to left ventricular ejection to construct ventricular function curves, providing a quantitative physiological method to detect and assess myocardial impairment in humans.
The performance of the left ventricle was studied in 18 patients by determining the effects of increasing the resistance to left ventricular ejection with graded infusions of angiotensin. By this means, left ventricular function curves, i.e., the relationship between ventricular end-diastolic pressure and stroke work, were constructed. In patients without left ventricular disease the ventricular function curves exhibited steep ascending limbs, large increases in stroke work occurring with small elevations of left ventricular end-diastolic pressure; in contrast, in patients with cardiac disease, the ventricular function curves were either flat, i.e., small changes in stroke work occurred with large elevations in left ventricular end-diastolic pressure, or the function curves exhibited descending limbs. Prior to the infusion of angiotensin many patients with and without depression of their left ventricular function curves had comparable values of left ventricular end-diastolic pressure and stroke work. Thus, the angiotensin test may prove useful for detecting impairment of myocardial function and for expressing the severity of the impairment in a quantitative form.
Ross et al. (1964) conducted an observational in Left ventricular disease (n=18). Angiotensin vs. Patients without left ventricular disease was evaluated on Left ventricular function curves (relationship between ventricular end-diastolic pressure and stroke work). Graded infusions of angiotensin revealed that patients with cardiac disease had flat or descending left ventricular function curves, whereas patients without disease exhibited steep ascending limbs.