Continuous ambulatory monitoring of absolute right ventricular pressure and mixed venous oxygen saturation in patients with heart failure using an implantable haemodynamic monitor: results of a 1 year multicentre feasibility study. - Ohlsson A; Kubo SH; Steinhaus D; Connelly DT; Adler S; Bitkover C; Nordlander R; Rydén L; Bennett T (European heart journal, 2001)