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Late estimation of myocardial infarct size by total creatine kinase nomogram
Insights
Enzymatic estimation of myocardial infarct size is possible late after acute myocardial infarction (AMI). A nomogram using lactate dehydrogenase isoenzyme (LDH1) effectively estimates creatine kinase (CK) release for infarct size assessment.
Area of Science:
- Cardiology
- Biochemistry
- Medical Diagnostics
Background:
- Estimating myocardial infarct size late after acute myocardial infarction (AMI) is challenging due to limited early enzymatic data.
- Traditional methods using serum creatine kinase (CK) are less effective beyond 48 hours post-AMI.
Purpose of the Study:
- To investigate the feasibility of enzymatic estimation of myocardial infarct size in patients presenting days after AMI.
- To develop and validate a reliable method for late-stage infarct size assessment.
Main Methods:
- Serial serum enzyme determinations (CK and LDH isoenzymes) were performed in patients following AMI.
- Correlations between cumulative CK release and lactate dehydrogenase isoenzyme 1 (LDH1) activities were analyzed.
- A nomogram was developed using serum LDH1 levels (days 2-6) to estimate cumulative total CK release.
Main Results:
- Significant correlations (r=0.863-0.870) were found between cumulative CK release and serum LDH1 activities from day 2 to day 6 post-AMI.
- The developed nomogram demonstrated high reliability in estimating cumulative total CK release (r=0.923-0.946).
- The nomogram requires minimal blood samples for accurate late-stage infarct size estimation.
Conclusions:
- Enzymatic estimation of myocardial infarct size is feasible using serum LDH1 levels between days 2 and 6 post-AMI.
- The developed CK nomogram provides a reliable and practical tool for late infarct size assessment.
- This method aids in managing patients admitted several days after the onset of AMI.
Abstract:
We studied the possibility of enzymatic estimation of myocardial infarct size in patients late (between days 2 and 6) after the onset of acute myocardial infarction (AMI), in whom estimation of infarct size was difficult by analysis of time-activity curves of serum creatine kinase (CK) because of the lack of the enzymatic information during the initial 48 hours. Serial determinations of serum enzymes were performed in 32 patients within 6 hours after the onset of AMI and significantly close correlations were observed between cumulative total CK release and the cardiac fraction of lactate dehydrogenase isoenzyme (LDH1) activities from day 2 to day 6 after the onset of AMI (r = 0.863 to 0.870; p less than 0.001). We developed a nomogram to estimate cumulative total CK release by serum LDH1 activities obtained between days 2 and 6 after AMI and evaluated the reliability of the nomogram. Cumulative total CK release obtained from serial serum CK activities correlated closely with total CK release obtained from the nomogram in the second group of patients with AMI (r = 0.923 to 0.946; n = 24; p less than 0.001). Our total CK nomogram requiring few blood samples was useful in late estimation of infarct size in patients who were admitted to the hospital between days 2 and 6 after the onset of AMI.