Background

Impedance cardiography (IC) is a noninvasive modality that utilizes changes in impedance across the thorax to assess hemodynamic parameters, including stroke volume (SV).

This study compared aortic valve area (AVA) as assessed by a hybrid approach of transthoracic echocardiography (TTE) and impedance cardiography (IC) to AVA determined at cardiac catheterization using the Gorlin equation.

Methods

A total of 30 patients with moderate to severe aortic stenosis underwent AVA measurement using two different approaches: using the continuity equation (CE) in a hybrid method combining IC and TTE (AVA = stroke by volume impedance cardiography/trans-aortic-VTI) and using the Gorlin equation. Patient age ranged from 37 to 82 years (mean 48); there were 21 men and 9 women. Twenty-five patients were in sinus rhythm, and five had atrial fibrillation.

Results

There was no statistically significant difference for the mean AVA between the two methods (0.7 ± 0.24 cm² using the Gorlin equation versus 0.7 ± 0.23 cm² using the hybrid approach, p = 0.17; r = 0.76, p < 0.001). The mean difference was 0.004 cm², and the limits of agreement were −0.33 to 0.37.

Conclusion

The hybrid method using impedance cardiography and TTE is a reasonable, clinically applicable approach to evaluate AVA and has significant correlation to invasive measurement using the Gorlin equation.

Keywords: Impedance cardiography, Aortic stenosis, Echocardiography, Heart catheterization, Hybrid approach

Title

BMC Cardiovascular Disorders

Publisher

BioMed Central Ltd.

Publisher Country

United Kingdom

Indexing

Scopus

Impact Factor

2.07

Publication Type

Online only

Volume

--

Year

2016

Pages

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