Heart failure is one of the most common and fastest-growing cardiac problems, especially as more people survive cardiac events that prior to modern therapies would have been fatal and as the population ages. It can be defined as an inability for the heart to supply the needs of the body, and can be present either with depressed contractile ("squeezing") function of the heart, known as systolic heart failure, or with apparently normal contraction of the heart muscle, known as diastolic heart failure. Common symptoms include fatigue, shortness of breath, coughing, swelling (particularly of the legs and feet), abdominal distention, and poor appetite; in around 50 percent of patients this is associated with coronary artery disease (i.e., blockages in the arteries of the heart) but can also be associated with valve problems, diseases of the heart muscle itself, or systemic medical illnesses. Evaluation will typically start with an echocardiogram (ultrasound of the heart) and in appropriate patients some kind of assessment of the presence or absence of coronary artery disease. If reversible causes of heart failure are found, they will be treated; almost all if not all patients can be significantly helped by a combination of medicines and minimally invasive procedures. An assessment of the risk of life-threatening arrhythmias will inform the decision about whether an implantable device called a defibrillator or ICD is necessary. Finally, in the extreme cases in which severe symptoms persist despite medical management, more advanced therapies such as stem cell transplantation, implantation of left ventricular assist devices, or cardiac transplantation are considered.