PMID- 8052172
OWN - NLM
STAT- MEDLINE
DCOM- 19940908
LR  - 20081121
IS  - 0047-6552 (Print)
IS  - 0047-6552 (Linking)
VI  - 19
IP  - 4
DP  - 1993-1994
TI  - Assessment of cardiac output during exercise. Transthoracic impedance vs. heart 
      rate alone.
PG  - 173-8
AB  - Previous investigators demonstrated divergent results, when comparing impedance 
      to other established methods for the assessment of cardiac output. Cardiac output 
      is defined as stroke volume multiplied by heart rate. Heart rate is easy to 
      measure and the main determinant of cardiac output during exercise under 
      physiologic conditions. Therefore, cardiac output (CO) by tetrapolar impedance 
      cardiography (TIC) was compared to thermodilution (TD) in 35 patients (P). In a 
      second step it was examined how heart rate alone would perform as a predictor of 
      CO under exercise. Measurements were done at rest, 25, 50, 75, and 100 w. Results 
      were corrected for hematocrit (HCT). There was no correlation between CO by TD 
      and by TIC at rest (r = -0.006). Under exercise correlation was somewhat better 
      with r = 0.45 despite correction for HCT. Mean values were similar, but scatter 
      was wide. Relative increase in CO by both methods was also correlated (r = 0.46), 
      while heart rate alone correlated best to TD (r = 0.65). Transthoracic impedance 
      cardiography is not a reliable technique to measure absolute values of cardiac 
      output at rest. During exercise large scatter limits this method to the 
      measurement of CO in larger groups. At exercise heart rate alone appears to be a 
      better indicator of increase of cardiac output than impedance cardiography.
FAU - Horstmann, E
AU  - Horstmann E
AD  - Knappschaftskrankenhaus, University of Bochum, Germany.
FAU - Konn, B
AU  - Konn B
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - United States
TA  - Med Prog Technol
JT  - Medical progress through technology
JID - 0331260
SB  - IM
MH  - Cardiac Output/*physiology
MH  - *Cardiography, Impedance
MH  - Electrocardiography
MH  - Exercise Test
MH  - Female
MH  - Forecasting
MH  - Heart Rate/*physiology
MH  - Hematocrit
MH  - Humans
MH  - Male
MH  - Oxygen Consumption/physiology
MH  - Phonocardiography
MH  - Physical Exertion/*physiology
MH  - Stroke Volume/physiology
MH  - Thermodilution
EDAT- 1993/01/01 00:00
MHDA- 1993/01/01 00:01
CRDT- 1993/01/01 00:00
PHST- 1993/01/01 00:00 [pubmed]
PHST- 1993/01/01 00:01 [medline]
PHST- 1993/01/01 00:00 [entrez]
PST - ppublish
SO  - Med Prog Technol. 1993-1994;19(4):173-8.