[Postinfarction left ventricular aneurysm. A method for volume determination and its correlation with hemodynamic and...

On the hypothesis that encroachment on left ventricular performance by postinfarction aneurysm (An) is related to its size, a method was investigated for the measurement of aneurysmal dimensions. On radioopaque plastic casts grossly ellipsoidal in shape with addition of masses in different position to simulate aneurysms, satisfactory data for volume calculation were obtained by the association of the ellipsoid formula applied to the contractile portion with the formula of the hemispheroid applied to the aneurysmal section, the difference between real and calculated volumes being not more than +/-5%. In 100 Pts. with previous myocardial infarction, showing at ventriculography akinetic-diskinetic segments of the left ventricular wall, the absolute volume of An and its percentage value of the total left ventricular volume (V An%) were measured. A statistical correlation was studied with other hemodynamic and angiographic parameters of left ventricular function. Cardiac index and angiographic stroke volume decreased with increasing V An%, but with a low correlation, of no statistical significance; only for An with a volume of 60% or more C.I. and SV were constantly reduced. The LVEDP, higher than normal in 80% of the cases, rose with increasing V An%, but with a correlation of low statistical significance. The EDV increased progressively and significatively with increasing V An%, resulting therefore in relation with the extension of noncontracting segment.