MEASUREMENT
OF DIFFUSION CAPACITY AND IMPEDANCE CARDIOGRAPHY IN ERGOSPIROMETRY
Koch, W., Weipert, J(1), Hess, J
Klinik fur Kinderkardiologie,(1) Klinik für
Herz- und Gefäßchirurgie, Deutsches Herzzentrum, Munich
OBJECTIVE: Ergospirometric exercise testing in young patients is
highly dependent on patient compliance. We tested wether impedance cardiography
under these circumstances might be a more suitable technique for the assessment
ofcardiopulmoanry function testing.
METHODS: 25 healthy pupils (mean age 16.8 years, min. 14 to
max 18.5 years) underwent ergospirometric testing (0.5 watt/kg body weight/ 3
min). Lung perfusion (QC) was measured by absorbtion of acethylen compared to
an inert gas (methan), simultanously diffusion capacity was measured. At the
same time cardiac output (CO) was evaluated with impedance cardiography.
RESULTS:
|
(mean±SD) |
at
rest |
anaerobic
threshold |
max. exercise |
|
|
|
|
|
|
heart
rate (beats/min) |
90
±16 |
145
± 14 |
176±13 |
|
QC(ltr/min) |
6.8
±2.2 |
13.9
±2.6 |
17.6
±2.9 |
|
cardiac
output (Itr/min) |
11.0±3.1 |
18.4±4.1 |
22.9±4.8 |
|
Power
(watt/kg BW) |
0 |
1.9
±0.4 |
2.7
±0.4 |
|
V02(ltr/min) |
0.44
±0.09 |
2.2
±0.6 |
3.0
±0.8 |
|
AVD02
(ml/ltr) |
7.1
±2.5 |
15.7
±3.4 |
16.9
±3.9 |
CONCLUSION: Modified ergospirometric testing by the acethylen
absorbtion method revealed exercise data for QC, V02, and AVD02 in accordance
to invasive measurements. Impedance cardiography data revealed consistantly
higher absolute cardiac output data. Impedance cardiography is less demanding
for patient compliance. The data revealed with this method are consistantly
above the normal range and conclusions can be drawn only after transformation.