Heart failure means that the heart is not able to adequately pump blood to satisfy the metabolic demands of the body. Heart failure is a serious condition, but it does not mean cardiac arrest or that the heart completely ‘failed’; rather, the heart does not work well enough to meet the demands of all body organs. Heart failure is caused by either weakness or abnormal heart muscle stiffness. Heart failure is more common in elderly people, and its prevalence is increasing due to the ageing population.
Coronary artery disease (CAD) and heart attack leading to damage to the heart muscle are the most common causes of heart failure. Other causes include dilated cardiomyopathy (enlarged and weakened heart with normal coronary arteries), hypertension (high blood pressure), heart valve disease, myocarditis (infection of the heart muscle) and arrhythmias (heart rhythm disturbances).
Acute heart failure appears suddenly due to a new-onset problem; chronic heart failure develops gradually over a longer period of time. Heart failure can be effectively controlled, and appropriate treatment enables many patients to lead normal lives.
Symptoms of heart failure may appear slowly with gradually increasing tiredness, breathlessness and reduced exercise tolerance. The symptoms may progress from initially appearing only on strenuous exertion up to onset on even mild exercise or ultimately at rest. Later symptoms and signs include swollen legs, the necessity to sleep on an incline (orthopnoea) and waking up from sleep at night due to breathlessness (paroxysmal nocturnal dyspnoea, PND). According to NYHA (New York Heart Association), the severity of symptoms is graded with grades I to IV (I being the mildest up to IV with symptoms at rest).
American Heart Association has proposed a newer classification system; heart failure is described in stages A (presence of risk factors but no heart disease and no symptoms) up to stage D (advanced heart disease with continued symptoms requiring aggressive medical therapy).
Heart failure can also be classified depending on contractility (pumping function) of the left ventricle (ejection fraction, EF, is a parameter summarizing the contractility of LV):
The diagnosis of heart failure and its subtypes is based on clinical examination, history, ECG, blood tests (BNP, brain natriuretic peptide, elevated in heart failure) and echocardiogram (heart ultrasound).
Heart failure can be treated with lifestyle measures, a combination of medicines, including beta-blockers (bisoprolol, carvedilol), ACE inhibitors (ramipril, lisinopril), ARBs (candesartan, valsartan), diuretics (furosemide, bumetanide), aldosterone antagonists (spironolactone, eplerenone), digoxin; devices (biventricular pacemaker, CRT = cardiac resynchronization therapy and implantable cardioverter-defibrillator, ICD), LV assist devices and ultimately in some cases with heart transplantation.