Angiographic determination of left ventricular muscle mass in the dog.

Left ventricular (LV) cineangiography in the right anterior oblique projection was carried out in 7 dogs. Calculation of LV muscle mass (LMM) was based on the determination of end-diastolic volume (EDV) and posterior wall thickness (h). Three different procedures of calculation were used. (A) EDV was determined according to the technique of Greene [8]; h was assumed to be equal around the LV cavity. (B) Systematic overestimation of EDV by Greene's method was corrected according to the regression equation proposed by Bentivoglio [9]; h was the same as in A. (C) EDV was corrected as in B; h at the ends of the long axis was assumed to be only half of that at the minor axis (i.e. h/2). The calculated values of LMM (4 to 11) in the individual dogs were averaged and compared with the true LMM determined at autopsy. True LMM in 7 dogs was 96 +/- 6 g (SE). Method A yielded 122 +/- 9 g (P less than 0.01) and method C 91 +/- 6 G (P greater than 0.05). Linear regression analysis between calculated and weighed LMM yielded a correlation coefficient of 0.936 in A, 0.938 in B and 0.931 in C. The SEE was 8.8 g, 7.5 g and 6.6 g, respectively. It is concluded that LMM can be determined with reasonable accuracy from linear regression equations whereby method C appears to be the preferable mode of calculation (smallest SEE).