Computerized M-mode echocardiographic analysis of left ventricular dysfunction in cardiac amyloid

SUMMARY We assessed left ventricular (LV) function in cardiac amyloid using computer-assisted anali-sis of M-mode echocardiograms from 20 patients with biopsy-proved amyloid and compared them with similar data from 20 normal subjects. Patients with cardiac amyloid had a consistent and characteristic set of quantitative echocardiographic findings: (1) LV cavitv size was normal or small. (2) The peak rate of diastolic cavity filling was decreased (p < 0.01). (3) Isovolumic relaxation was prolonged (p < 0.01). (4) Fractional shortening and peak Vcf were decreased (p < 0.01). (5) Peak rates of both systolic thickening and diastolic thinning of the septum and posterior LV wall were decreased (p < 0.01). LV function in patients with cardiac amyloid was compared with that in patients with aortic stenosis and normal coronary arteries, who were used as a model of similar wall thickness and cavitx size. There was significantly greater impairment of regional and global LV function in amyloid, that is, more than could be accounted for by increased wall thickness alone, indicating that the further abnormalities of LV function were caused by an intramyocardial restriction secondary to amyloid deposition per se. LV function was also compared in amyloid and in patients with nonobstructive hypertrophic cardiomvopathv, as these two groups of patients may be confused both clinically and echocardiographically. The technique we used differentiated between these two disorders in terms of cavity and regional LV dynamics when patients were considered as a group