Plasma Atrial Natriuretic Peptide as a non-invasive biochemical marker of dyspnoea in congestive heart failure patients
Plasma Atrial Natriuretic Peptide (ANP) levels on exercise were measured in 10 male patients suffering from congestive heart failure and 10 male subjects not presenting with any cardiac problems. A standardised 12min walking test was performed with ANP venous levels measured by radioimmunoassay pre and post exercise. Normal subjects aged 36 ± 6 yr manifested a non-significant increase of plasma ANP level from 5.2± 0.3 to 7.2 ± 0.2 pg/ml (P=0.15). The same exercise was also associated with a non- significant decrease from 64.6 ± 0.3 to 55.4 ± 0.2 pg/ml (P=0.34) in the Class II & III NYHA classification heart failure patients (mean age = 65 ± 5 yr). Our biochemical data showed a correlation (r=0.68, P=0.04) with a mean dyspnoea score assessed by a 10 graded visual analogue scale in the control group (mean score = 1) and an increased from 1.6 to 6.4 in the heart failure patients. In conclusion, as compared to normal adults, heart failure patients are characterised by a high ANP level at rest with a decrease in ANP levels on a dyspnoea-producing exercise.
Keywords : ANP, congestive heart failure, dyspnoea, visual analogue scale, exercise.