Effect of pulmonary circulation on vector impedance cardiogram

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Diagnostic Imaging

Background:

• Conventional impedance cardiography (ICG) provides insights into cardiac function.
• The utility of vector impedance cardiography in a horizontal lead configuration (VICG(H)) for diagnosing specific cardiac conditions requires further investigation.

Purpose of the Study:

• To evaluate the diagnostic potential of VICG(H) in various cardiac disorders.
• To compare VICG(H) waveforms with conventional ICG in normal subjects.
• To determine the cardiac structures contributing to the VICG(H) waveform.

Main Methods:

• VICG(H) was recorded in 34 healthy individuals and 107 patients with conditions including mitral stenosis, mitral regurgitation, aortic regurgitation, and non-cyanotic septal defects.
• Phase reversal points and waveform characteristics of VICG(H) were analyzed.
• VICG indices were calculated and compared across different subject groups.

Main Results:

• Phase reversal points in VICG(H) waveforms did not consistently align with those of conventional ICG in normal subjects.
• Significant alterations in VICG(H) waveform shape and indices were observed in patients with pulmonary circulation changes.
• Observed changes were specific to the type of cardiac disorder, suggesting diagnostic value.

Conclusions:

• VICG(H) exhibits distinct characteristics compared to conventional ICG.
• VICG(H) shows promise in identifying and differentiating cardiac conditions, particularly those impacting pulmonary circulation.
• The right side of the heart appears to be the primary contributor to the VICG(H) waveform.