Routine blood tests like haemoglobin, creatinine, electrolytes are useful to plan treatment. More recently the blood natriuretic peptide levels have been used to assess heart failure. BNP (brain natriuretic peptide) may be increased early in left ventricular dysfunction. It is synthesized mainly by the ventricles and released early in heart failure.
The Framingham study group has come out with criteria for diagnosis of heart failure incorporating symptoms, signs, investigations and response to treatment. It is a useful criteria for the clinicians.
Major Criteria
Paroxysmal nocturnal dyspnoea
Neck vein distention
Rales
Radiographic cardiomegaly
Acute pulmonary edema
S3 gallop
Central venous pressure >16 cm H2O
Circulation time >25 sec
Hepatojugular reflux
Pulmonary adema, visceral congestion, or cardiomegaly at autopsy
Weight loss >4.5 kg in 5 days in response to treatment of congestive heart failure.
Minor Major
Bilateral ankle edema
Nocturnal cough
Dyspnoea on ordinary exertion
Hepatomegaly
Pleural effusion
Decrease in vital capacity by one third from maximal value recorded
Tachycardia (rate >120 beats/min)
Note: The diagnosis of congestive heart failure in this study required that two majoror one major and two minor criteria be present concurrently. Minor criteria were acceptable only if they could not be attributed to another medical condition.