Relation of kinetocardiogram to systolic time intervals in patients with old myocardial infarction.

Left ventricular function was studied noninvasively in a group of 35 patients with noncomplicated and complicated old myocardial infarction (MI) by means of kinetocardiography (KCG) and systolic time intervals (STI). Discriminant analysis with a group of 130 normal subjects documented that STI were significantly abnormal and that the abnormalities, i.e. prolongation of the preejection period, shortening of left ventricular ejection time and increase of PEP/LVET were more evident in patients with complicated old MI. KCG was more or less abnormal in all the patients studied, with the more striking abnormalities in those with complications. A good correlation was found between KCG and STI abnormalities. We consider that KCG is able to detect in a sensitive way abnormalities of left ventricular contraction in patients with old MI and that, most probably, alterations of STI in these patients are mainly due to incoordinate left ventricular contraction.