Assessment of Left Ventricular Function with Echocardiography in Patients Treated with Adriamycin: A Load-Independent Index of Myocardial Contractility and Comparisons between Rest and Exercise

PURPOSE: The aim of this study was to evaluate myocardial injury in children treated with adriamycin by echocardiography, which is non-invasive and safe measurement for children. METHODS: Left ventricular dimensions, wall stress, and contractile function were determined by echocardiographic methods in 17 patient recepients with adriamycin chemotherapy at rest(group 1) and during stress(group 2). Twenty age-matched normal subjects were established as control group. RESULTS: End-diastolic dimension was decreased in both groups(group 1; 92+/-7% of normal, group 2; 87+/-8% of normal, P<0.05). Left ventricular end diastolic volume and wall mass were also decreased in both groups(group 1; 96+/-12 mL/m2 and 145+/-18 g/m2, group 2; 87+/-8 mL/m2 and 137+/-16 g/m2, respectively, P<0.05 and P<0.05) and group 2 showed lower values than group 1. Meridional end systolic stress(ESSm) was increased in both groups but there was no significant difference between the two groups(group 1; 52.6+/-6.2 g/cm2, group 2; 63.5+/-8.5 g/cm2, P<0.05, normal value 45.7+/-3.5 g/cm2). The load-independent relation of rate-corrected circumferential fiber shortening velocity(Vcfc) to ESSm has a significant abnormal change in 7 out of 17(41%) in group 1 and 12 out of 17(71%) in group 2. CONCLUSION: The load-dependent systolic index, such as fractional shortening, may fail to show abnormality because of the compensatory changes in preload and afterload which can mask the impaired contractility. Therefore, systolic performance also should be monitored by a load-indepedent contractility index such as slope value of the end-systolic pressure-dimension relation and the position of the left ventricular stress-fiber shortening velocity after exercise.

Left Ventricular Systolic Function Indexes by Echocardiography in Hypertensive Subjects

BACKGROUND: The evaluation of cardiac performance is very important to management and prognostication in hypertensive patients. Although ejection phase indexes have been used for assessing left ventricular systolic function they are highly dependent on cardiac loading conditions. In addition, these load-dependent indexes may not differentiate accurately between the effects of altered loading canditions and intrinsic abnormalities in contractile function of cardiac muscle. In recent years, the end-systolic pressure to volume of dimension relations have emerged as a reliable measure of the myocardial contractility. The authors studied the changes of end-systolic pressure to volume or dimension relations according to pre-load and after-load by using the Echocardiogram. METHODS: By 2-D and M-mode Echocardiogram we measured the ratio of end-systolic wall stress to end-systolic volume index(EWS/ESVI), peak systolic pressure or end-systolic dimension of left ventricle(PSP/ESD), peak systolic pressure to end-systolic volume index(PSP/ESVI) to assess myocardial contractility in 139 normal subjects and 55 patients with untreated essential hypertension. Then we compare these indexes to systemic blood pressure & left ventriclular end-diasolic dimension. RESULTS: 1) EF, %FS, and mVcf were similar in both groups, but PSP/ESD, PSP/ESVI, EWS/ESVI for the hypertensive group were greater than that for the normal group. 2) There was poor relation between arterial blood pressure and EWS/ESVI than oter load independent indexes in both groups. 3) There was poor reation between left ventricle end diastolic dimension than oter load independent indexes in both groups. CONCLUSION: The ratio of end-systolic wall stress to end-systolic volume index(EWS/ESVI) is a relible load independent index to assess myocardial contractility in hypertension.