ST-segment changes as a non-invasive marker of coronary artery patency following streptokinase therapy in acute myocardial infarction

ABSTRACT

ST-segment changes and angiocardiographic findings were compared in 42-patients with AMI soon after thrombolysis. The% ST-segment change 3 hours after treatment [In the lead showing the greatest initial ST-segment elevation] was compared with the TIIMI perfusion grades [Thrombolysis in Myocardial Infarction Trial] obtained 24 hours after treatment. Global ejection fraction and regional wall motion were assessed by cineventriculography 14 days later. Prediction of coronary artery pantency by a reduction of >25%in ST-segment elevation 3 hours after thrombolytic treatment had a sensitivily of 96% and specificity of 43%. Where the ST-segment elevation was reduced by > 25% the global ejection fraction was well maintained whether or not the infarct related vessel was patent. In patients with a reduction of <25%in ST-elevation, the ejection fraction was significantly lower and regional wall motion abnormality was more severe. Reduction in ST-elevation of>25% within 3-hours of thrombolysis indicates either a patent infarct related artery or preservation of left ventricular function when the ST-elevation dose not fall by >/= 25%. Persistent coronary artery occlusion is likely [predictive accuracy 86%] and is associated with a lower ejection fraction. These patients may benefit from further treatment or additional interventions: