Extravascular lung water measured with99mTc-RBC and99mTc-DTPA is increased in left-sided heart failure

Abstract

Extravascular lung water (EVLW) was quantitatively measured in 81 patients consisting of 10 subjects with normal cardiac function and 71 patients with left-sided heart diseases, using 99mTc-RBC as a non-diffusible indicator and 99mTc-DTPA as a diffusible indicator in the equilibrium phase. EVLW averaged 3.0 +/- 1.4 (ml/kg, mean +/- SD) in subjects with normal cardiac function (n = 10), 4.3 +/- 1.7 in New York Heart Association functional class I patients (n = 30), 4.8 +/- 2.4 in NYHA functional class II patients (n = 33) and 9.4 +/- 5.4 in NYHA functional class III (n = 8) patients. EVLW was greater in NYHA class III than in normal controls or NYHA classes I or II (p < 0.01). Lung thermal volume (LTV) was also measured in 31 of the 81 patients using a double indicator dilution technique with sodium and heat. LTV averaged 6.0 +/- 1.2 (ml/kg) in normal subjects (n = 4), 8.6 +/- 2.0 in NYHA functional class I patients (n = 11), 9.7 +/- 3.0 in NYHA functional class II patients (n = 13), and 15.9 +/- 8.2 in NYHA functional class III patients (n = 3). The correlation between EVLW and LTV was significant (EVLW = 0.79 x LTV - 72.8, r = 0.80, p < 0.01). There were significant differences in EVLW/LTV ratio between NYHA class III (0.93 +/- 0.16) and NYHA class I (0.62 +/- 0.22). Thus, it was shown that EVLW was increased in left-sided heart failure and that LTV overestimated the EVLW.

Role of nocturnal rostral fluid shift in the pathogenesis of obstructive and central sleep apnoea

“…PCWP is, in turn, determined by severity of heart failure and degree of intravascular fluid volume overload (Schober et al . 1985; Nawada et al . 1993; Yu et al .…”

“…Mechanisms by which hyperventilation occurs in patients with heart failure include increased peripheral and central chemosensitivity, and stimulation of pulmonary vagal irritant receptors by pulmonary congestion due to elevated PCWP (Roberts et al 1986;Yu et al 1998;Javaheri, 1999;Solin et al 2000). PCWP is, in turn, determined by severity of heart failure and degree of intravascular fluid volume overload (Schober et al 1985;Nawada et al 1993;Yu et al 2005). For example, in heart failure patients, P CO 2 is inversely proportional to PCWP (Lorenzi-Filho et al 2002).…”