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Evolution of late potential parameters in thrombolyzed acute myocardial infarction might predict patency of the
D A Kontoyannis1, J N Nanas, S A Kontoyannis
1University of Athens Medical School, Department of Clinical Therapeutics, Alexandra, General Hospital, Greece.
Insights
Signal-averaged electrocardiography (SAECG) can predict artery patency after thrombolysis for acute myocardial infarction. Changes in late potential parameters effectively indicate early treatment success or failure.
Area of Science:
- Cardiology
- Medical Imaging
- Biomedical Engineering
Background:
- Acute myocardial infarction (AMI) treatment relies on restoring blood flow.
- Thrombolytic therapy is a key intervention for AMI.
- Predicting treatment success is crucial for patient outcomes.
Purpose of the Study:
- To predict infarct-related artery patency grade post-thrombolysis.
- To analyze the time course of late potential parameters.
- To assess the efficacy of signal-averaged electrocardiography (SAECG) in predicting thrombolysis outcomes.
Main Methods:
- 51 AMI patients receiving thrombolytic therapy were studied.
- Multiple SAECGs were recorded before, during, and after thrombolysis.
- Late potentials were defined by QRS duration, low amplitude signals (LASs), and root mean square (RMS) values.
Main Results:
- Late potentials were initially present in 37% of patients.
- Late potentials disappeared in most patients within 89 minutes.
- Persistent late potentials indicated an occluded artery (grade 0).
- Improvement in late potential parameters was faster and more pronounced in patients with a patent artery.
- The late potential parameter index predicted artery patency with 0.94 sensitivity and 0.79 specificity.
Conclusions:
- SAECG can predict the patency grade of infarct-related arteries.
- Changes in late potential parameters are valuable indicators of thrombolytic therapy success.
- SAECG is a useful tool for predicting early thrombolysis outcomes in AMI patients.
Abstract:
The objective was to predict the patency grade of an infarct-related artery by identifying the time course of the changes of the late potential parameters before, during, and shortly after thrombolysis. The study population consisted of 51 patients with acute myocardial infarction (AMI) who received thrombolytic therapy within 3.2 +/- 1.3 hours from the onset of symptoms. Multiple signal-averaged electrocardiograms (SAECGs) were recorded before, during, and shortly after thrombolysis. A total of 489 single-averaged electrocardiographic tracings were evaluated. Late potentials were defined as: QRS duration > 114 ms, low amplitude signals (LASs) > 38 ms, and root mean square (RMS) < 20 microV. Late potentials were found in 37% of patients (21 before and 16 during the first 2 hours of thrombolysis), disappeared in all of patients within 89 +/- 75 minutes (range 25 to 350) but reappeared and persisted in 12% of patients, all with an occluded artery (grade 0). The late potential parameters (QRS, LAS, RMS) showed a gradual improvement which occurred earlier (2 vs 4 hours) and was more marked (0.01 vs 0.05) in cases with a patent artery. This improvement expressed by the late potential parameter index (LnQRS + LnLAS - LnRMS) predicts the patent artery with a sensitivity of 0.94 and specificity of 0.79. The improvement of late potential parameters jointly with close to normal initial values or the late potential parameter index and its changes constituted a satisfactory prediction of the patency grade. Thus, the signal-averaged electrocardiographic technique is capable of predicting the early success or failure of thrombolytic therapy.