Congenital Heart Disease & Eisenmenger’s Syndrome
February 4th-7th is Congenital Heart Disease Awareness week. The incidence of congenital heart disease today is 1:100 live births. With today’s post , I wanted to discuss a complicated problem that adults who are born with congenital heart disease may suffer from for their entire lives: Eisenmenger’s Syndrome.
A normally structured heart has four chambers, two receiving chambers, one which receives deoxygenated blue blood from the veins and one which receives red oxygenated blood from the lungs. There is a wall which separates these two chambers that usually closes after birth. Sometimes this wall does not completely form, leaving a hole. This hole can have different variations, and even different names, the most common is an atrial septal defect. When the hole doesn’t close, and isn’t closed surgically, there are a number of changes that occur over the lifetime of a patient. The same kind of hole may also exist between the pumping chambers and is called a ventricular septal defect.
Initially, the hole allows an increased volume of oxygenated red blood to pass into the adjacent catching chamber or atrium. Over time, that increased volume of blood slowly stretches the atrium larger and larger. As the child ages, the atrium eventually reaches the limits it can stretch and blue blood begins to mix through the hole. This process occurs slowly over time, and is called bidirectional as part of each heartbeat allows alternately red and then blue blood to mix between the chambers.
As time passes, the increased volume in the pulmonary arteries changes the lining of the arteries. They become stiff and hard and, as this process occurs, the pressure in the pulmonary arteries increases. As this pressure increases, more and more of each heartbeat results in blue blood going into the red oxygenated catching chamber. This process may take decades, and patients may present much later in life in their 20’s, 30’s, 40’s or even 50’s.
The end result of this hole is constant blue deoxygenated blood passing into the red oxygenated chamber and then out to the body. On the outside these patients may have blue tinged-lips, blue fingernail beds, and oddly shaped fingernails called clubbing. On the inside these patients may have other changes like increased blood volume or a high hemoglobin and hematocrit. They are also at risk for iron deficiency and often need iron supplementation to make more red blood cells. Gout is also a related process due to a build up of break down products from all the extra blood cells.
The good news is that there are now medications that have been studied and found to improve quality of life and exercise capacity in these patients. There are ongoing trials for these patients including MAESTRO, a multicentered international trial to see if a new medicine could help. These complex patients should be followed closely by an adult congenital heart disease specialist and a pulmonary hypertension specialist.