Heart failure

Heart failure is a condition caused by a cardiac disease where the heart is too weak to pump enough blood to maintain sufficient circulation for metabolic purposes. Heart failure affects 1 to 2 per cent of the population. It becomes more common with age, and in the over 75 year-old population, the incidence is 8 to 10%. Heart failure is always a serious condition that affects the quality of life and shortens life expectancy.

For the heart to function, the ventricles should fill with blood prior to contraction and then be efficiently emptied during a contraction. In a case of heart failure, insufficient pumping may be caused by the left ventricle not contracting optimally or by reduced filling of the ventricle due to abnormal stiffness of the myocardium. As such, heart failure is not a disease, but a consequence of persistent high blood-pressure that affects the heart's ability to contract by causing the myocardium to become stiff. It may also be a consequence of myocardial infarction, valvular disease, or cardiomyopathy, for example. The symptoms of heart failure develop slowly over several weeks or months, but may occur acutely in association with a myocardial infarction, for example.
 
The most common symptoms include reduced physical performance and shortness of breath, which at first occurs only during physical activity but, as the condition advances, occurs during very light physical activity and, finally, even at rest. Pumping insufficiency causes fluid retention, which first shows as swelling in the ankles and feet, but later fluid may also accumulate in the abdominal and thoracic cavities.
 
Heart failure is detected based on the symptoms described by the patient, a clinical examination, and findings from ECG, chest X-ray, and laboratory tests. Determining the levels of natriuretic peptide hormone in the blood (BNP or proBNP) is particularly useful in the differential diagnosis of heart failure. Today, echocardiography is the key method in diagnosing cardiac conditions. In addition to identifying the condition, echocardiography also helps in determining the underlying heart disease. If heart failure is caused by coronary artery or valvular disease, diagnosis is often confirmed by catheterisation and coronary angiography. Other examinations include exercise ECG, cardiac MRI, and myocardial biopsy.