[Post-extrasystolic potentiation for the study of regional left ventricular asynergy (author's transl)].

In 120 P. with ischemic heart disease, left ventricolar wall motion was analyzed from the left ventriculogram in a regular sinus beat as compared to the first beat following one or more premature ventricular contractions (PExP). The response of asynergic segment to PExP was determined with a qualitative as wall as a quantitative technique. Of a total of 225 asynergic segments, 62% showed a positive response to PExP. In the absence of pathologic Q waves in the electrocardiogram, the response was positive in 77% and negative in 23% of the cases. In the presence of Q waves, PExP was present only in 33% of the cases (p less than 0.001). In respect to the severity of asynergy, 68% of 145 hypokinetic segments and 52% of 80 akinetic-dyskinetic segments responded to PExP; in the presence of pathologic Q waves, the number of positive responses decreased to 36% in the case of segmental hypokinesis, and to 31% in the case of more severe asynergy. The study of PExP has appeared as an useful diagnostic technique, capable of detecting a residual myocardial function in left ventricular asynergic segments, even in the presence of electrocardiographic signs of infarction.