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The relationship between left ventricular filling shortly after an uncomplicated myocardial infarction and subsequent
R Urek1, M Cubrilo-Turek, M Crncević-Urek
1Department of Cardiology, Sveti Duh, General Hospital, Zagreb, Croatia.
Insights
Left ventricular diastolic function, specifically normalized E/A ratio and diastolic filling period, effectively predicts exercise capacity after acute myocardial infarction (AMI). These parameters offer crucial insights beyond systolic function for cardiac recovery assessment.
Area of Science:
- Cardiology
- Echocardiography
- Exercise Physiology
Background:
- Resting left ventricular systolic function alone is insufficient for predicting exercise capacity in cardiac patients.
- Left ventricular diastolic function assessment shortly after acute myocardial infarction (AMI) may offer predictive value for exercise tolerance.
Purpose of the Study:
- To prospectively evaluate left ventricular filling parameters post-AMI as predictors of subsequent exercise capacity.
- To determine if diastolic function indices can predict exercise time during recovery from uncomplicated AMI.
Main Methods:
- Prospective study of 63 participants (33 AMI patients, 30 healthy controls) within 48 hours of infarction.
- Doppler and two-dimensional echocardiography assessed systolic (WMSI) and diastolic (E, A, E/A, normalized E/A, DFP) function.
- Myocardial infarction size measured by Selvester's QRS scoring system (QRSSI). Symptom-limited stress testing performed during recovery.
Main Results:
- Strong positive correlations found between exercise time and WMSI (r=0.77) and DFP (r=0.56).
- Weak negative correlation with QRSSI (r=-0.17) and better negative correlation with normalized E/A ratio (r=-0.56).
- Normalized E/A ratio and DFP were identified as significant predictors of exercise capacity, unaffected by beta-blocker therapy.
Conclusions:
- Left ventricular diastolic function parameters, particularly normalized E/A ratio and DFP, are valuable predictors of exercise capacity post-AMI.
- These diastolic indices provide prognostic information beyond traditional systolic function measures.
- Diastolic function assessment shortly after uncomplicated AMI aids in predicting recovery of exercise tolerance.
Abstract:
Resting measurement of only left ventricular systolic function, is not enough sufficient parameter that predicts exercise capacity in patients with cardiac disease. Therefore, left ventricular filling shortly after an acute myocardial infarction (AMI) was prospectively studied to determine whether it could predict subsequent exercise time. Consecutive AMI patients underwent Doppler and two-dimensional echocardiography within 48 hours of infarction. The study group consisted of 63 participants: 33 patients with an uncomplicated AMI who had undergone symptom-limited stress testing during recovery and 30 healthy subjects. Systolic function was evaluated by wall motion score index (WMSI), and diastolic one was assessed by the peak transmitral Doppler velocity in early diastole (E) and atrial systole (A), then by their ratio (E/A), normalized E/A ratio, and by diastolic filling period (DFP). Myocardial infarction (MI) size was measured electrocardiographically, using Selvester's QRS scoring system (QRSSI) and then expressed in percentages. Healthy participants and patients were compared, through common parameters. The patients receiving BB treatment at the time of exercise testing, had a lower resting pulse, and achieved a lower maximal pulse, yet their exercise time was similar incomparison to that of the group not receiving BB therapy. Our results have shown a strong positive correlation between exercise time and WMSI (r = 0.77, p < 0.001) DFP (r = 0.56, p < 0.001), respectively weak negative correlation with QRSSI (r = -0.17, p < 0.001) and better negative correlation with normalized E/A ratio (r = -0.56, p < 0.001). This correlation was not influenced by beta-blokers (BB) at the time of stress testing. Normalized E/A ratio and DFP are the only diastolic function parameters, which predict exercise capacity during recovery, measured soon after an uncomplicated AMI.