which portion of the heart is in failure when it can no longer effectively pump blood into the lungs?
Failure on the left side is linked to a general weakening of the heart muscle. This is the more common type of heart failure. The weakened heart muscle no longer can keep up with the demands of the body for oxygen-rich blood. Back-up into the lungs occurs. Symptoms of left-side heart failure include: 1  Tiredness (fatigue). 2  Shortness of breath. 3  Asthma-like wheezing.