The earliest descriptions of heart failure date back to ancient Egyptian, Greek, and Roman medical literature. In the last two centuries, as our knowledge of the structure and function of the heart has advanced, so has our understanding of the abnormal or diseased function of the heart advanced.

We currently define heart failure as the inability of the heart to pump out sufficient blood to meet the needs of the body. The mechanisms behind this are incredibly complex, and we continue to make significant strides in the unraveling of these processes.

The pumping function of the heart is divided into two phases: firstly, the ability of the heart to relax properly so that blood can return into the relaxed heart, and secondly, the ability to be actively pumped out to the body. The first phase is called diastole; the second is called systole. When the heart begins to malfunction, both of these functions usually become abnormal. The issue in treatment is what are the relative percentages of diastolic or systolic dysfunction in each particular person with heart failure.

We know the most about the systolic mechanisms of heart failure and less about diastolic mechanisms of heart failure. This is heavily reflected in our ability to treat heart failure, with the most known treatments directed to systolic dysfunction and the least known treatments for diastolic dysfunction.

The most significant advances recently have been in our understanding of how the rest of the body adapts to the dysfunction of the heart in an attempt to correct and counteract these changes. These adaptations, which initially keep things functioning the same, eventually become maladaptations and actually worsen the situation. This new knowledge has translated into the most important improvements in therapy.