Can inactivity by itself (no exercise at all) cause heart failure?

No, but not good. Inactivity contributes to high blood pressure, high cholesterol and diabetes, all risk factors for coronary disease, but it does not cause heart failure. Even modest exercise, such as walking 20-30 minutes, is very helpful at reducing your risk factors. Besdies, being active usually makes you feel better.
No. No heart failure is caused either by a heart that does not pump blood normally or a stiff heart exercise can play a role in strengthing a heart but lack of exersize will not cause heart failure.

Related Questions

What are the causes of heart failure?

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 . Read more...
Many. Weak heart muscles /hypertrophed heart / valve lek of moderate to severe degree valve narrowing -aoric stenosis /mitral stenosis hypertension to name a few. Read more...
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. Read more...

What are some of the causes of the heart failure?

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). Read more...
Multiple. Most common: coronary artery disease. Others: viral illness, drugs/ toxins, infiltrative disorders, hyper and hypothyroid, tachycardia, , and many more. Read more...

How many deaths are caused by heart failure each year?

Heart failure. About 5.1 million people in the United States have heart failure.1 One in 9 deaths in 2009 included heart failure as contributing cause.1 About half of people who develop heart failure die within 5 years of diagnosis.1. Read more...