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Electrocardiographic characteristics indicating a risk of irreversibly impaired myocardial function in chronic aortic
S H Recke1, J Marienhagen, H Feistel
1University Heart Centre, University of Erlangen, Nuremberg, Germany.
Insights
Electrocardiogram (ECG) variables like R-peak time prolongation can predict irreversible impaired heart function after aortic valve replacement. These ECG findings, combined with ejection fraction, accurately identify patients with lasting systolic dysfunction.
Area of Science:
- Cardiology
- Cardiac Electrophysiology
- Cardiovascular Surgery
Background:
- Chronic aortic regurgitation can lead to impaired myocardial function.
- Aortic valve replacement is a common treatment, but some patients experience persistent systolic dysfunction.
- Identifying pre-operative indicators of irreversible myocardial damage is crucial for patient management.
Purpose of the Study:
- To determine which electrocardiogram (ECG) variables predict irreversibly impaired myocardial function after aortic valve replacement.
- To assess the diagnostic value of specific ECG parameters in patients with chronic aortic regurgitation.
Main Methods:
- Stratified 54 patients based on radionuclide left ventricular ejection fraction (LVEF) post-aortic valve replacement (normal LVEF ≥ 50% vs. subnormal LVEF < 50%).
- Analyzed preoperative ECG variables including QRS duration, R-peak time (RPT) prolongation, R-peak delay, and T-wave abnormalities.
- Utilized stepwise linear discriminant analysis with preoperative ECG variables, angiographic LVEF, and end-systolic volume index.
Main Results:
- Patients with subnormal LVEF showed significantly greater preoperative QRS duration, RPT prolongation, R-peak delay, and negative T-waves.
- Maximum RPT, angiographic LVEF, and RPT relative to S-peak time were the most promising predictors.
- A combination of these three variables correctly classified 82.9% of patients with normal LVEF and 84.6% with subnormal LVEF.
- RPT prolongation and R-peak delay showed high specificity as indicators of impaired function when applied separately.
Conclusions:
- Specific preoperative ECG variables, particularly RPT prolongation and R-peak delay, are valuable indicators of irreversibly impaired systolic function post-aortic valve replacement.
- Combining these ECG findings with preoperative LVEF enhances the ability to differentiate between preserved and impaired cardiac function.
- These ECG markers can aid in risk stratification and patient management following aortic valve replacement.
Abstract:
In order to define which of selected ECG variables could indicate irreversibly impaired myocardial function in chronic aortic regurgitation 54 patients were stratified according to normal (> or = 50%; Group A, n = 41) or subnormal radionuclide left ventricular ejection fraction (LVEF < 50%; Group B, n = 13) late after aortic valve replacement. Preoperatively, Group B patients had a significantly greater QRS duration, greater R-peak time (RPT) prolongation in I, V5 or V6, greater RPT relative to the S-peak time of the maximum S in V1, V2 or V3 (R-peak delay) and a greater negative T-wave in I or V6, as compared with Group A. These ECG variables together with preoperative angiocardiographic LVEF and end-systolic volume index were subjected to stepwise linear discriminant analysis. The maximum RPT, angio-LVEF and the maximum RPT relative to the S-peak time of the maximum S in V1, V2 or V3 emerged as the most promising variables. Of of Group A patients 82.9% and 84.6% of Group B patients were correctly classified by the three variables. If applied separately, APT prolongation or the presence of the R-peak delay in the left-sided leads, although less sensitive, have reasonably high specificity as risk indicators of irreversibly impaired chamber function, their positive predictive value being 60 and 62.5%, respectively. In conjunction with preoperative LVEF the diagnostic contribution of the two ECG variables amounts to the greatest overall separation of postoperatively preserved from irreversibly impaired systolic function.