Related Experiment Videos
Correlation of heart rate and radionuclide index of left ventricular contraction and relaxation
H Adachi1, H Sugihara, H Nakagawa
1Second Department of Internal Medicine, Kyoto Prefectural University of Medicine, Japan.
Insights
Cardiac function indices from radionuclide ventriculography (RNV) are influenced by heart rate. A new correction method was developed to adjust these RNV indices for accurate cardiac function assessment.
Area of Science:
- Cardiology
- Medical Imaging
Background:
- Cardiac function indices from radionuclide ventriculography (RNV) are widely used.
- These indices are suspected to be influenced by heart rate variations.
Purpose of the Study:
- To investigate the relationship between systolic and diastolic cardiac function indices derived from RNV and heart rate.
- To develop a heart rate correction method for RNV-derived cardiac indices.
Main Methods:
- Studied correlations between heart rate and various systolic and diastolic indices in patients with normal RNV.
- Developed a heart rate correction method using regression equations.
Main Results:
- Significant correlations were found between heart rate and several systolic indices (ET, PER, TPE).
- Numerous diastolic indices (FT, RFT, SFT, 1/3 FF, PFR, 1/3 PFR, TPF) also showed significant correlation with heart rate.
- Some indices (EF, MNSER, AFT, AFF) were found to be independent of heart rate.
Conclusions:
- Many RNV-derived cardiac function indices are significantly affected by heart rate.
- It is recommended to use heart rate-independent indices or apply heart rate correction for accurate cardiac function evaluation.
- A novel, computer-adaptable rotating correction method was proposed for RNV indices.
Abstract:
Since the cardiac function indices derived from radionuclide ventriculography (RNV) are considered to depend on the heart rate, we studied the relationship between systolic or diastolic indices and heart rates in patients with normal RNV and devised a method of correcting these indices according to the heart rate. For the systolic indices, the heart rate showed significant correlation with ET (r = -0.640), PER (r = 0.791) and TPE (r = -0.401) but not with EF, 1/3 EF, MNSER or 1/3 MNSER. For the diastolic indices, the heart rate correlated with FT (r = -0.938), RFT (r = -0.736), SFT (r = -0.803), 1/3 FF (r = -0.758), PFR (r = 0.759), 1/3 PFR (r = 0.742) and TPF (r = -0.389) but not with AFT, 1/3 MNDFR or AFF. These results indicate that many systolic and diastolic indices derived from RNV are affected by the heart rate. So when cardiac function is evaluated with the use of radionuclide indices, those which are independent of the heart rate should be used, or they should be corrected for the heart rate. As a method of correction, we proposed a rotating method obtained by manipulation of the regression equation of heart rates and indices. This new method is certain and easier to use when the correcting equations are set into a computer program.