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Effect of chronic anemia on left ventricular ejection time and myocardial performance in man
Insights
This study on anemia and heart function found that correcting anemia slowed heart rate and lengthened left ventricular ejection time (LVET). However, the preejection period to LVET ratio remained unchanged, indicating stable myocardial performance.
Area of Science:
- Cardiology
- Hematology
- Physiology
Background:
- Anemia, characterized by low hemoglobin, can affect cardiovascular function.
- Systolic time intervals (STI) are non-invasive measures of cardiac performance.
Purpose of the Study:
- To investigate the impact of anemia correction on systolic time intervals.
- To assess changes in myocardial performance at rest following anemia treatment.
Main Methods:
- Simultaneous recording of electrocardiogram, phonocardiogram, and carotid pulsation in anemic individuals.
- Calculation and averaging of preejection period (PEP), left ventricular ejection time (LVET), and PEP/LVET ratio.
- Repeat measurements after anemia correction over approximately 3.5 weeks.
Main Results:
- Heart rate decreased after anemia correction.
- Left ventricular ejection time (LVET) significantly lengthened.
- The ratio of preejection period to LVET (PEP/LVET) remained unchanged.
Conclusions:
- The lengthening of LVET was attributed to a slower heart rate.
- The stable PEP/LVET ratio suggests no significant alteration in resting myocardial performance despite anemia.
- LVET can be predicted using established formulas for normal individuals even in the context of anemia correction.
Abstract:
The duration of systolic time interval in ten anemic, (mean Hb 3.46) and otherwise healthy individuals (mean age 15) was measured from simultaneous recording of electrocardiogram, phonocardiogram and carotid pulsation. The preejection period (PEP); left ventricular ejection time (LVET) and ratio of PEP/LVET from 20 consecutive beats were calculated and averaged. Anemia was corrected slowly and study was repeated (mean 3 1/2 weeks) later and a similar data for comparison was obtained; heart rate decreased, LVET lengthened and the ratio of PEP/LVET remained unchanged. The lengthening of the LVET was due to slower heart rate. LVET before and after correction of anemia could be predicted from regression formula reported for normals. The unchanged PEP/LVET before and after the anemia indicates no significant alteration in myocardial performance at rest.