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[Relation of the impedance cardiogram to the course of myocardial contraction]
Insights
This study found correlations between impedance cardiography and angiocardiography for measuring stroke volumes and ejection fraction in coronary heart disease patients. These findings help link impedance changes to left-ventricular volume dynamics.
Area of Science:
- Cardiovascular Physiology
- Biomedical Engineering
- Diagnostic Imaging
Context:
- Coronary heart disease (CHD) diagnosis and monitoring require accurate assessment of cardiac function.
- Non-invasive methods for evaluating stroke volume and ejection fraction are highly desirable.
- Impedance cardiography (ICG) offers a potential non-invasive alternative to invasive hemodynamic measurements.
Purpose:
- To investigate the correlation between impedance cardiography (ICG) and invasive hemodynamic measurements in patients with coronary heart disease.
- To assess the relationship between stroke volumes, systolic time intervals, ejection fraction, and the parameter dz/dt max derived from ICG and traditional methods.
- To explore the utility of ICG in understanding left-ventricular volume changes during the cardiac cycle.
Summary:
- Fifty-three patients with coronary heart disease underwent simultaneous investigation using impedance cardiography and angiocardiography, alongside invasive pressure measurements.
- Significant correlations were observed between stroke volumes and systolic time intervals determined by both methods.
- A notable correlation was found between ejection fraction and the maximal rate of pressure increase (dz/dt max) from ICG, while invasive pressures showed limited correlation with ICG parameters.
Impact:
- The established correlations allow for the coordination of thoracic impedance curve changes with left-ventricular volume dynamics in CHD patients.
- This research supports the potential of impedance cardiography as a valuable non-invasive tool for assessing cardiac function in coronary heart disease.
- Findings pave the way for improved non-invasive monitoring and assessment of cardiac performance in clinical settings.
Abstract:
53 patients with coronary heart disease were investigated synchronously by means of impedance and angiocardiography combined with the measurement of the pressure in the aorta and the left ventricle. In these cases relatively close correlations were found between the stroke volumes and systolic time intervals, determined by the two methods, as well as between the ejection fraction on the one hand and the parameter dz/dt max on the other. The pressures, measured invasively, do not correlate significantly with the impedance cardiography parameters. With help of the relations found it is possible to coordinate the changes of the thoracic impedance curve depending on the heart action with the various phases of the left-ventricular volume change.