Multiple. Most common: coronary artery disease. Others: viral illness, drugs/ toxins, infiltrative disorders, hyper and hypothyroid, tachycardia, , and many more.
Hmm here are a few. One of those list answers - here r a few - only 400 characters - cardiac ischemia (not getting enought blood to the heart) myocardial infarction (dead heart tissue can't pump right) arrythmia (heart can't beat in sync) virus / alcohol - weakens and stretches the heart - autoimmunie disease - heart under attack - can't pump any of the above that r under control but knocked out of control (salt/water).
Controversial. Controversial data on lead and mercury. Few jama articles in early 2000.
Depends. Congestive heart failure or CHF can be from many things. Different types include systolic dysfxn wich means a weak heart. Usually from a virus, heart attack, or post partum. Diastolic dysfxn where the heart is stiff is usually due to hyer tension. High out put heart failure is when things such as hyperthyroidism or anemia. So your question is very broad and you need to narrow it down.
Many. Weak heart muscles /hypertrophed heart / valve lek of moderate to severe degree valve narrowing -aoric stenosis /mitral stenosis hypertension to name a few.
Multiple. Coronary artery disease (Angina) Diseases of the heart muscle (cardiomyopathy). High blood pressure (hypertension). Diseases of the heart valves. Abnormal heart rhythms (arrhythmias). Medicines, alcohol excess, cocaine and some types of chemotherapy. Severe anaemia, thyroid disease (hypothyroidism or hyperthyroidism) and Paget's disease of bone.
Chf. Being bedridden in and of itself would be unlikely to cause heart failure.
The tests for Heart failure include: Electrocardiogram, Echocardiogram, Xray of chest, Complete blood count, Thyroid blood tests, Comprehensive metabolic panel, Troponin, B type natriuretic peptide, Liver function test, Lipid panel, Cardiac catheterization, Right heart catheterization, Basic metabolic panel, Heart biopsy, Probnp, N terminal.