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Updated: Aug 13, 2026
Primary Outcome Assessment in a Pig Model of Acute Myocardial Infarction
Published on: October 14, 2016
Usefulness of T-wave loop and QRS complex loop to predict mortality after acute myocardial infarction
Juha S Perkiömäki1, Miia Hyytinen-Oinas, Mari Karsikas
1Division of Cardiology, Department of Medicine, University of Oulu, Oulu, Finland. juha.perkiomaki@oulu.fi
Insights
T-wave loop dispersion (TWLD) effectively predicts cardiac mortality in acute myocardial infarction (AMI) survivors. This electrocardiography parameter is a specific indicator of cardiac death, independent of other clinical risk factors.
Area of Science:
- Cardiology
- Medical Technology
- Biomedical Engineering
Background:
- Acute myocardial infarction (AMI) survivors require risk stratification for long-term prognosis.
- Current risk assessment models may not fully capture all prognostic information available from electrocardiography.
- Novel electrocardiographic parameters derived from T-wave and QRS loops warrant investigation for predictive value.
Purpose of the Study:
- To evaluate if T-wave loop and QRS loop parameters predict mortality, specifically cardiac mortality, in patients surviving AMI.
- To identify specific electrocardiographic markers that offer prognostic insights beyond established clinical risk factors.
Main Methods:
- 437 AMI survivors underwent digital high-resolution electrocardiography 5-14 days post-event.
- Analysis included T-wave loop dispersion (TWLD) and other loop parameters derived from orthogonal Frank leads.
- Cox regression analysis adjusted for clinical risk markers was performed.
Main Results:
- During a 43-month follow-up, 53 patients (12%) died, 35 from cardiac causes.
- TWLD and TCRT showed significant univariate association with cardiac mortality.
- After multivariate adjustment, TWLD remained a significant predictor of cardiac mortality (p < 0.05), while TCRT did not.
- TWLD showed no significant association with non-cardiac mortality.
Conclusions:
- T-wave loop dispersion (TWLD) is a specific and independent predictor of cardiac death in AMI survivors.
- TWLD offers valuable prognostic information in the contemporary treatment era for AMI.
- This parameter may enhance risk stratification beyond traditional clinical markers.
Abstract:
The aim of the study was to assess whether parameters based on the T-wave loop and QRS loop predict mortality, and cardiac mortality in particular, during follow-up of consecutive survivors of acute myocardial infarction (AMI). Patients with AMI (n = 437), treated according to contemporary guidelines, underwent digital high-resolution electrocardiography in orthogonal Frank leads (X, Y, Z) 5 to 14 days after AMI. Several T-wave and QRS loop parameters, such as the width and height of the loops and their ratio, T-wave loop dispersion (TWLD), QRS loop dispersion, and co-sine of the angle between the main vectors of the T-wave and QRS loops (TCRT), were calculated using a custom-made software package. During an average follow-up period of 43 +/- 14 months, 53 patients (12%) died. Of these 53 deaths, 35 were cardiac. TWLD and TCRT were the T-wave loop/QRS loop parameters that best predicted for cardiac mortality on univariate comparison (35.4 +/- 5.62 vs 32.8 +/- 2.87 for TWLD, p < 0.001 and -0.135 +/- 0.665 vs -0.657 +/- 0.518 for TCRT, p < 0.001, alive vs cardiac death, respectively). After adjustment for clinical risk markers in the Cox regression analysis, TWLD still significantly predicted for cardiac mortality (p < 0.05); however, TCRT had lost its predictive power. TWLD did not have significant univariate or multivariate association with noncardiac mortality. In conclusion, TWLD that describes the shape of the T-wave loop is a specific predictor of cardiac death and independent of the clinical risk markers in the current treatment era of patients with AMI.
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