The influence of right heart catheterisation on pulmonary arterial pressure in chronic heart failure: relationship to neuroendocrinal changes.

Continuous ambulatory measurement of pulmonary arterial pressure was used to investigate changes following right heart catheterisation in patients with chronic heart failure. Ten males, mean age 56 years, with chronic heart failure, underwent 24 hour pressure recording using a micromanometer tipped catheter with in vivo calibration and frequency modulated recording. Eight patients were taking diuretics and 3 vasodilators. Blood was drawn for catecholamines, plasma renin activity and atrial natriuretic peptide 1 hour before catheterisation (-1 h), at the time of catheterisation (0 h) and 1, 2, 3, 4 and 6 hours later and aldosterone, cortisol and growth hormone at -1, 0 and 6 hours. Analysis of variance was used to determine changes in pulmonary arterial pressure, heart rate and hormones from the time of catheterisation in lying, sitting and standing postures. There was no significant change in pulmonary arterial pressure or heart rate over the 12 hours following or 24 hours after catheterisation in any posture. In the majority of patients plasma noradrenaline, plasma renin activity, atrial natriuretic peptide, aldosterone and cortisol were elevated. There was no significant change in hormone levels during the 6 hours following catheterisation. These findings suggest that the effect of invasive haemodynamic monitoring and chronic medical therapy on central haemodynamics is minor, and that a delay between insertion of catheters and measurement of pressure is unnecessary.