Functional improvement of jeopardized myocardium following intracoronary streptokinase infusion in acute myocardial infarction.

Abstract

A B S T R A C T The effect of reperfusion on regional left ventricular performance following acute myocardial infarction in man was determined. Intracoronary streptokinase was administered in 24 patients within 6 h of the onset of symptomns. 15 patients (62%) were successfully recanalized during the initial study. Mean percent radial shortening (%RS) in both the jeopardized and compensatory regions were determined using 23 radii from the centroid of diastolic and systolic angiographic silhouettes. Sequential measurements were obtained during repeat cardiac catheterization studies at 24 h in 19 patients and before discharge from the hospital (16±11 d) in 15 patients. At the time of the predischarge study, each acutely reperfused patient showed improvement in %RS in the jeopardized region (P = 0.01) with 56% returning to the normal range. Despite the uniform improvement in the contractile function of the jeopardized region in each reperfused patient, the global ejection fraction showed no improvement or a decrease at the time of the chronic study in 44%. This was due to a decrease in the compensatory wall motion in the uninvolved segments between the acute and chronic study in each case. Neither the %RS nor the ejection fraction changed significantly at the time of the chronic study in the patients who could not be acutely recanalized. These data indicate (a) significant salvage of jeopardized myocardium associated with recovery of contractile function in patients reperfused during the first 6 h of chest pain following acute myocardial infarction; (b)

Medical and Cellular Implications of Stunning, Hibernation, and Preconditioning

“…Improvement in ventricular function occurred gradually over the course of a few weeks. [81][82][83][84] One report 85 suggested that stunned myocardium could be recruited after thrombolytic therapy with small boluses of inotropes. These studies suggest that the ultimate return of cardiac function cannot be determined immediately after reperfusion.…”

Mechanisms of augmented segment shortening in nonischemic areas during acute ischemia of the canine left ventricle.

“…Some studies using epicardial strain gauges did not find an apparent hyperfunction of nonischemic areas (Banka and Helfant, 1974;Vokonas et al, 1976;Wyatt et al, 1976), indicating that the effects may not always be reflected transmurally. An increase in systolic motion in nonischemic areas has been noted in patients by echocardiography (Corya et al, 1975;Nieminen and Heikkila, 1976) and angiography (Rigaud et al, 1979;Stack et al, 1983;Sheehan et al, 1983).…”

Relationship of the lytic state to successful reperfusion with standard- and low-dose intracoronary streptokinase.

“…14. [21][22][23][24][25][26][27][28][29] This difference could not be explained by skewing of the known pretreatment clinical or laboratory risk factors, such as the delay before treatment or unusual resistance to SK, and could be ASuccessful treatment in 12 patients includes six who responded to initial infusions of low-(n = 2) or standard-dose SK (n = 4) plus six who responded to retreatment at standard dose after failure at low-dose SK.…”