TARGETING OF DOBUTAMINE TO ISCHEMIC MYOCARDIUM WITHOUT SYSTEMIC EFFECTS BY SELECTIVE SUCTION AND PRESSURE-REGULATED RETROINFUSION

Objective: To study the effects of low-dose dobutamine and/or glyceryl trinitrate in addition to selective suction and pressure-regulated re troinfusion with arterial blood on regional myocardial function of the ischemic myocardium and systemic hemodynamics. Methods: Using a pig m odel of repeated brief (90 s) occlusions of the left anterior descendi ng artery, selective suction and pressure-regulated retroinfusion was carried out either with arterial blood alone (SSRalone) or with arteri al blood and simultaneous application of low-dose dobutamine (0.1 mu g /kg/min) (SSRDOB) glyceryl trinitrate (0.03 mg/kg/min) (SSRNIT) or the combination of both drugs (SSRDOB+NIT). Regional myocardial function of the ischemic and non-ischemic myocardium was determined by sonomicr ometry (segment shortening). Results: Segment shortening in the ischem ic area after 90 s of ischemia was preserved at 57.5 +/- 9.2% with SSR alone but at 78.0 +/- 22.3% of baseline with SSRDOB (P < 0.05). The ad dition of glyceryl trinitrate did not improve regional myocardial func tion further. No effects of locally applied dobutamine were observed w ith regard to non-ischemic myocardium or heart rate. Cardiac output an d mean arterial blood pressures tended to be further stabilized with S SRDOB. Conclusions: Local application of low-dose dobutamine together with arterial blood by selective suction and pressure-regulated retroi nfusion during brief myocardial ischemia resulted in improved regional myocardial function without undesired effects on non-ischemic myocard ium or systemic hemodynamics. (C) 1997 Elsevier Science B.V.