Aortic Stenosis (AS) is a narrowing or tightening of the ascending aorta and/or aortic valve. Blood flows through this valve immediately after leaving the heart to travel through the large blood vessel (aorta), which delivers blood to the heart muscle itself and to the body. The narrowing prevents blood from passing through the valve effortlessly. Aortic stenosis can come in a variety of degrees of severity, from mild to critical.
Aortic stenosis results in a muscle enlargement, or compensatory ventricular hypertrophy, of the left ventricle. The degree of hypertrophy is generally related to the severity of the stenosis.
Symptoms of mild to moderate aortic stenosis may not be noticeable at first and may only be found if a murmur is heard during a routine examination. Aortic stenosis can reduce blood flow to the heart muscle, causing myocardial ischemia, changes in diastolic heart function, and later stages systolic heart function. Aortic stenosis can also compromise perfusion to the body, leading to metabolic injury of organs like the brain, kidneys, liver, and bowels. Infants may show signs and symptoms of congestive heart failure such as breathing fast, difficulty or working hard to breathe, elevated heart rate, not taking feedings and other babies, not growing well for their age, being tired, or sleeping more often than other babies. Later in life, symptoms may appear with chest pain when exercising, decreased stamina, fainting and/or palpitations of the heart (skipped beats).
While the surgical techniques for each of these valvular narrowings are different, the objective is the same: to relieve the obstruction. Surgical treatment for aortic stenosis involves making an incision through the breastbone (sternotomy). A machine that allows the heart and lungs to rest (cardiopulmonary bypass) is used to allow the surgery team to repair the area of concern.
After an aortic stenosis repair, monitoring in the post-operative period will include invasive lines, such as an arterial line and central venous line, to monitor blood pressure and deliver medications. Medications may be needed to control hemodynamics (nitroprusside or nicardipine), provide sedation and maintain hydration during recovery. Perfusion is monitored by pulse oximetry and NIRS (near-infrared spectroscopy) probes. Depending on various factors specific to each individual, the breathing tube (endotracheal tube) may or may not still be present after surgery. Pacing wires, which can assist with any rhythm issues that may arise in the post-operative period, will be placed in the operating room. Pacing wires are typically removed 1-2 days after surgery if not needed. Chest tubes will be present to remove air, blood and/or fluid from around the heart or lungs. These tubes will be removed in the ICU as soon as possible, typically the next day or so.
Length of stay can vary but typically ranges from 1-3 weeks, depending on the degree of stenosis and associated surgical repair required.