E. COPD – Explanation
Heart failure: diagnosis
NICE issued updated guidelines on diagnosis and management in 2010. The choice of investigation
is determined by whether the patient has previously had a myocardial infarction or not.
Previous myocardial infarction
- arrange echocardiogram within 2 weeks
No previous myocardial infarction
- measure serum natriuretic peptides (BNP)
- if levels are ‘high’ arrange echocardiogram within 2 weeks
- if levels are ‘raised’ arrange echocardiogram within 6 weeks
Serum natriuretic peptides
B-type natriuretic peptide (BNP) is a hormone produced mainly by the left ventricular myocardium in
response to strain. Very high levels are associated with a poor prognosis.
| BNP | NTproBNP | |
| High levels | > 400 pg/ml (116 pmol/litre) | > 2000 pg/ml (236 pmol/litre) |
| Raised levels | 100-400 pg/ml (29-116 pmol/litre) | 400-2000 pg/ml (47-236 pmol/litre) |
| Normal levels | < 100 pg/ml (29 pmol/litre) | < 400 pg/ml (47 pmol/litre) |
Factors which alter the BNP level:
| Increase BNP levels | Decrease BNP levels |
| Left ventricular hypertrophy Ischaemia Tachycardia Right ventricular overload Hypoxaemia (including pulmonary embolism) GFR < 60 ml/min Sepsis COPD Diabetes Age > 70 Liver cirrhosis |
Obesity Diuretics ACE inhibitors Beta-blockers Angiotensin 2 receptor blockers Aldosterone antagonists |
