Related Experiment Videos
[ECG in acute myocardial infarct. Continuous registration in thrombolytic therapy]
R von Essen1, S Effert, J Silny
1Medizinische Klinik, RWTH Aachen.
Insights
Successful thrombolytic therapy for acute myocardial infarction significantly reduces ST-segment abnormalities on ECG. This reduction indicates successful reperfusion and can be monitored using continuous ECG surveillance.
Area of Science:
- Cardiology
- Medical Imaging
- Biomedical Engineering
Background:
- Acute myocardial infarction (AMI) requires prompt reperfusion therapy.
- Thrombolytic therapy is a common treatment for AMI.
- Assessing treatment efficacy non-invasively is crucial.
Purpose of the Study:
- To correlate electrocardiogram (ECG) changes with angiographically confirmed reperfusion in AMI patients treated with thrombolysis.
- To evaluate the sensitivity of specific ECG parameters in monitoring thrombolytic therapy success.
Main Methods:
- Continuous ECG monitoring using strategically placed precordial and limb leads in 35 AMI patients.
- Angiographic assessment of infarct-related artery patency post-thrombolysis.
- Analysis of ST-segment changes (ST-60 values) and R-amplitude variations during ECG surveillance.
Main Results:
- Successful reperfusion (n=31) showed a significant reduction (64%) in ST-60 values (p<0.004), with a 71% reduction in the most sensitive lead.
- Unsuccessful reperfusion (n=4) or cases requiring mechanical intervention (n=3) did not demonstrate significant ST-60 reduction.
- A >50% reduction in ST-segment abnormalities was observed in 29/31 successfully reperfused patients.
Conclusions:
- Continuous ECG monitoring, particularly ST-60 values, effectively correlates with angiographic outcomes of thrombolytic therapy in AMI.
- A significant reduction in ST-segment abnormalities (>50%) is a reliable indicator of successful reperfusion.
- ECG surveillance provides a valuable, non-invasive method to assess thrombolytic treatment efficacy.
Abstract:
For 35 patients with acute myocardial infarction undergoing thrombolytic therapy (31 patients with streptokinase and 4 with rt-PA), the treatment effect was assessed angiographically and correlated with ECG changes. These ECG changes were found by continuous registration of eight "strategically" located precordial leads in patients with anterior myocardial infarction, and five precordial leads plus three limb leads in those with posterior myocardial infarction. In 31 patients (group A), successful reperfusion could be verified by angiography, while in 4 patients the infarct-related vessel remained closed. In 3 further cases (group B), recanalization could be achieved only by additional mechanical intervention. The average duration of ECG surveillance was 87 min in group A and 85 min in group B. A significant change of R-amplitudes during this period of time could not be observed. ST-60-value of group A (total of ST-elevations and depressions 60 msec after S of all surveillance electrodes, divided by number of electrodes) was reduced under thrombolysis from 0.377 mV (SD +/- 0.270) to 0.133 mV (SD +/- 0.118) (p less than 0.004). This means a reduction of 64%, while the corresponding values in group B did not change (0.535 mV, respectively 0.546 mV) before and after therapy. When only the electrode with the highest ST-60-value was checked before therapy ("sensitive lead"), reduction in group A was as high as 71%. Except for two patients, all other 29 patients with successful reperfusion either precordially or in the limb leads showed a reduction of ST-segment abnormalities (ST 60) of more than 50% during surveillance time. This could not be observed in any of the unsuccessfully treated patients.(ABSTRACT TRUNCATED AT 250 WORDS)