Aortic sclerosis is a common heart valve condition, primarily associated with aging, that involves structural changes to the aortic valve. The aortic valve is one of four valves in the heart, located between the left ventricle and the aorta, and its function is to ensure blood flows out to the rest of the body without leaking backward. This condition is defined by the thickening and stiffening of the valve’s delicate leaflets, the flaps that open and close to control blood flow, but importantly, it does not significantly impede that flow. It is generally considered a mild finding when detected, though it does serve as a marker for potential future health concerns.
Defining Aortic Sclerosis
Aortic sclerosis is characterized by a degenerative process affecting the valve’s leaflets, the thin, flexible structures that regulate blood flow. The physical changes involve the accumulation of lipids and a gradual hardening of the tissue, known as calcification and fibrosis. This thickening makes the leaflets less pliable than a healthy valve, often giving them a brighter, more calcified appearance on an ultrasound image.
Despite these visible changes, the movement of the leaflets remains largely unrestricted, which is the defining factor of the condition. Blood can still be ejected from the left ventricle into the aorta without difficulty or significant obstruction. Aortic sclerosis is highly prevalent in the older population, affecting between 25% and 30% of people over the age of 65.
Primary Causes and Risk Factors
The primary driver of aortic sclerosis is age, as it is largely considered a degenerative process. The condition develops over many years, with a higher incidence observed in individuals over 60. The underlying mechanisms share many similarities with atherosclerosis (hardening of the arteries).
The development of sclerosis involves similar biological processes to plaque buildup, including inflammation, lipid deposition, and subsequent calcification within the valve tissue. Therefore, conditions that increase the risk for heart attack and stroke also contribute to aortic sclerosis. Major risk factors include high blood pressure (hypertension), high cholesterol (hypercholesterolemia), diabetes mellitus, and a history of smoking. Aggressive management of these factors is advised to help slow the degenerative process.
The Difference Between Sclerosis and Stenosis
Understanding the difference between aortic sclerosis and aortic stenosis is important to determining the seriousness of the diagnosis. Aortic sclerosis represents the early stage of the disease, where the valve leaflets are thickened and hardened, but the valve still opens fully, meaning there is no significant restriction of blood flow. Because blood flow is not compromised, aortic sclerosis typically causes no symptoms and is often discovered incidentally.
Aortic stenosis, in contrast, is a more advanced condition. It develops when calcification and stiffening progress to the point where the valve opening is significantly narrowed. This narrowing creates a substantial obstruction to blood flow, forcing the left ventricle to work much harder to pump blood against the resistance. This increased workload can eventually lead to symptoms like chest pain, shortness of breath, and fainting.
While sclerosis can progress to stenosis, this progression is not guaranteed, with the rate of progression to clinically significant stenosis being relatively low, under 2% per year. The distinction is often made using an echocardiogram, which measures the velocity of blood flowing through the valve. In aortic sclerosis, the peak blood flow velocity is typically less than 2.5 meters per second, indicating minimal obstruction. A finding of aortic stenosis is characterized by a significantly higher velocity and a much greater pressure difference across the valve.
Diagnosis and Ongoing Monitoring
Aortic sclerosis is frequently first suspected during a routine physical examination when a physician detects a soft, turbulent heart sound called an ejection systolic murmur. This murmur is caused by the slightly rougher surface of the thickened valve leaflets creating minor flow disruption. The definitive diagnosis requires an echocardiogram, a non-invasive test that uses sound waves to visualize the heart’s structure and function.
The echocardiogram confirms the presence of leaflet thickening and calcification while simultaneously measuring the blood flow velocity to ensure there is no significant obstruction. Since aortic sclerosis does not significantly impair blood flow, there is currently no specific medical treatment to reverse the valve changes. Management centers on aggressively controlling the underlying cardiovascular risk factors, such as lowering cholesterol and managing high blood pressure and diabetes, to reduce the overall risk of heart events and potentially slow the disease’s progression.
Ongoing monitoring is a fundamental part of managing aortic sclerosis. Periodic follow-up echocardiograms are recommended to track the condition and ensure it has not progressed to the more serious stage of stenosis. For those with mild sclerosis, an echocardiogram every three to five years may be suggested. Patients are also educated to be aware of new symptoms, such as shortness of breath or chest discomfort, which would signal the need for an immediate re-evaluation of the valve’s function.