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The correlation of the treadmill exercise test with cardiac hemodynamics in patients with previous myocardial
1First Department of Internal Medicine, Yamagata University School of Medicine, Japan.
Insights
Treadmill exercise tests reveal that impaired left ventricular function in myocardial infarction patients correlates with shorter exercise duration and increased ST segment elevation and premature ventricular contractions during exercise.
Area of Science:
- Cardiology
- Exercise Physiology
- Clinical Medicine
Background:
- Previous myocardial infarction (MI) can lead to impaired left ventricular function.
- Hemodynamic parameters are crucial for assessing cardiac function post-MI.
- Treadmill exercise testing is a common tool for evaluating exercise capacity and cardiac response.
Purpose of the Study:
- To investigate the correlation between treadmill exercise test results and hemodynamic data in patients with previous MI.
- To classify patients based on left ventricular end-diastolic pressure (LVEDP) and cardiac index (CI) to identify functional subgroups.
- To analyze exercise capacity and ECG changes in relation to left ventricular function.
Main Methods:
- 152 patients with previous MI were enrolled.
- Patients were categorized into four groups based on LVEDP and CI thresholds.
- Treadmill exercise tests were performed, and parameters like exercise duration, ST segment changes, and premature ventricular contractions (PVCs) were recorded.
Main Results:
- Exercise duration was significantly shorter in patients with lower cardiac index and higher LVEDP (Group H4).
- Maximal ST segment elevation and the number of ST segment elevations increased significantly in groups with impaired left ventricular function (H3 and H4).
- Exercise-induced premature ventricular contractions (PVCs) were more frequent in patients with impaired left ventricular function.
Conclusions:
- Impaired left ventricular function in post-MI patients is associated with reduced exercise tolerance.
- Elevated ST segment elevation and increased PVC frequency during exercise indicate compromised cardiac function.
- Hemodynamic status significantly influences exercise test outcomes in patients with prior myocardial infarction.
Abstract:
The correlation between the treadmill exercise test results and the hemodynamic data of 152 patients with previous myocardial infarction were investigated. The patients were classified into 4 groups as follows: H1 left ventricular end-diastolic pressure (LVEDP) less than or equal to 12 mmHg and cardiac index (CI) greater than or equal to 3.0 L/min/m2; H2 LVEDP greater than 12 mmHg and CI greater than or equal to 3.0 L/min/m2; H3 LVEDP less than or equal to 12 mmHg and CI less than 3.0 L/min/m2; and H4 LVEDP greater than 12 mmHg and CI less than 3.0 L/min/m2. The duration of the exercise was significantly shortened for group H4 than group H1 (p less than 0.01). The maximal ST segment elevation (mSTe) was significantly increased for group H3 and group H4, versus group H1 (p less than 0.05). The number of ST segment elevations and mSTe/maximal heart rate were significantly increased for group H3 (p less than 0.05) and group H4 (p less than 0.01) versus group H1. The incidence of exercise-induced premature ventricular contractions (PVCs) was significantly increased in group H3 and group H4, versus group H1 (p less than 0.05). There were no significant differences in the maximal heart rate, double product, and ST segment depression among the 4 groups. Our data indicate that the groups with impaired left ventricular functions tend to decrease the duration of the exercise and to increase ST segment elevation and PVC frequencies during exercise.