Congestive Heart Failure Congestive heart failure, a condition which occurs as the heart weakens and can no longer pump blood as well as it should, can affect the left side, right side or both sides of the heart. Congestive heart failure does not mean a patient’s heart has stopped or failed, but rather that the heart has failed to keep up with the volume of blood flowing through it. Congestive heart failure requires immediate medical attention. A variety of conditions can cause congestive heart failure, including: Coronary artery disease High blood pressure Diabetes Heart attack Several