Thoracic fluid content and impedance cardiography: a novel and promising noninvasive method for assessing the hemodynamic effects of diuretics in hypertensive patients.

INTRODUCTION: Impedance cardiography (ICG) is a reliable, noninvasive method allowing the assessment of the hemodynamic profile in hypertensive patients. The aim of the study was to evaluate the potential hemodynamic effects of diuretics with ICG and examine whether the empiric administration of diuretics actually has a substantial impact on thoracic fluid content (TFC).
METHODS: The study population included 248 hypertensive and 68 healthy subjects (35-87 years old) and was divided into 4 groups: group A comprised hypertensive patients under treatment including diuretic; group B consisted of hypertensive patients under treatment without diuretic; group C included untreated hypertensive patients; and group D included healthy subjects. The measurements were performed using the Cardio Screen ICG system (Medis, Germany). Men and women were examined separately, since TFC seems to be sex-dependent.
RESULTS: In the men's subgroup, the highest TFC value (41.7 +/- 4.9) was found in Group C (untreated hypertensive group), while the lowest TFC (36.4 +/- 5.7) was seen in Group A (diuretic hypertensive group). Women treated empirically with diuretics (group A) had a mean TFC of 27.3, while the other no-diuretic groups had a mean TFC of approximately 30. The mean TFC in men was significantly higher than in women in all study groups examined.
CONCLUSIONS: Both men and women who were treated empirically with diuretics showed a significantly lower TFC in comparison with patients treated with other antihypertensive drugs, untreated patients and healthy control subjects. TFC is an ICG parameter that is associated with the administration of diuretics and has interesting clinical applications in optimizing and tailoring antihypertensive treatment.