[Noninvasive evaluation of cardiac index and ejection fraction in ischemic heart disease. Comparison of thoracic bioimpedance, thermodilution and cineventriculography].

Aim of the study was to verify the reliability of thoracic bioimpedance cardiography (TEB) in detection, non-invasively, cardiac index (IC) and ejection fraction (FE), compared to simultaneous evaluation by invasive thermodilution (TD) in 39 patients with acute myocardial infarction in Killip class I-II (group I), and by cineventriculography (CVG) in 26 patients with chronic coronary artery disease in NYHA class I-II (group II). In order to define the reproducibility of TEB values, in the latter patients, the above mentioned parameters were evaluated 6 times more, running the first evaluation. The statistical analysis was performed by the linear regression test and the Student's "t" test and by the test of variance for the reproducibility evaluation. Results (mean +/- SD) were as follows: group I: TEB-IC 2.89 +/- 0.63; TD-IC 2.83 +/- 0.56 (1/min/m2); r = 0.68; p < 0.01. Group II: TEB-IC 2.88 +/- 0.71; CVG-IC 3.48 +/- 0.66; r = 0.77; p < 0.001; TEB-FE 57.7 +/- 6.8%; CVG-FE 58.1 +/- 13.7%; r = 0.40; p = ns. Results of the reproducibility referred to the 6 measurements (mean +/- SD) were the follows: TEB-IC (1/min/m2) (1) 2.83 +/- 0.76; (2) 2.85 +/- 0.73; (3) 2.8 +/- 0.79; (4) 2.83 +/- 0.71; (5) 2.87 +/- 0.81; (6) 2.88 +/- 0.8, p = ns, the variability was assesses within +/- 9.3%. TEB-FE (%): (1) 56.7 +/- 6.2; (2) 55.8 +/- 5; (3) 57.1 +/- 5.5; (4) 56.1 +/- 6.1; (5) 55.4 +/- 5.8; (6) 57.3 +/- 6.3, p = ns; the variability was assessed within +/- 9.1%. The analysis of the results showed a good correlation in the IC detection among TEB and the compared techniques, conversely TEB evaluation of FE appear of poor values in this kind of patients. Relatively to the results of the reproducibility this unquestionable characteristic of TEB was demonstrated.