RESIDUAL MYOCARDIAL PERFUSION IN REVERSIBLY DAMAGED MYOCARDIUM BY DIPYRIDAMOLE CONTRAST ECHOCARDIOGRAPHY

In patients with previous myocardial infarction and left ventricular a synergy, dipyridamole infusion may have the capacity to unmask myocard ial viability through transient recovery of contractile function in as ynergic segments. The purpose of this study was to assess simultaneous changes in myocardial perfusion and LV function-elicited by dipyridam ole infusion - in infarcted, asynergic segments. The echo contrast age nt Albunex was injected into the left coronary artery of 19 patients ( 17 males, age 49-70 years) with previous myocardial infarction and bas eline left ventricular asynergy, both before and after dipyridamole in fusion (up to 0.56 mg.kg(-1), i.v.). Analysis was not possible in thre e patients due to inadequate image quality and in two due to weak cont rast. There were no major adverse events, or changes in vital signs or demonstrated on the electrocardiogram. After dipyridamole, 7/14 patie nts, showed an improvement in regional function of asynergic segments ('responders'), whereas seven patients did not ('non-responders'). Amo ng non-responders, five had a myocardial perfusion deficit correspondi ng to 41% of the total left ventricular area before dipyridamole and t o 38% after dipyridamole, No baseline perfusion deficits were observed in the remaining two non-responders; one of these, however, developed transient asynergy and perfusion deficit after dipyridamole. Among re sponders, five showed a normal perfusion pattern, both before and afte r dipyridamole, while the remaining two showed a perfusion deficit whi ch markedly decreased after dipyridamole (from 32% to 13% of total lef t ventricular area). Thus, residual contractile reserve of asynergic, infarcted ventricular segments appears to be associated with myocardia l perfusion either preserved at baseline or recruitable by a coronary dilator stimulus.