By now, most people have heard that the sudden death of U.S. Sen. Lindsey Graham was caused by an aortic dissection, a rare but devastating cardiovascular emergency. While the condition affects no more than 30 people per million each year, it is among the deadliest medical emergencies because every minute counts. His death has also prompted many people to ask an important question: How is an aortic dissection different from the more commonly diagnosed aortic aneurysm? “The aorta is the body’s largest blood vessel,” explained Dr. Harb Harb, a cardiologist with Cleveland Clinic Indian River Hospital. “It comes out of the heart and carries oxygen-rich blood from the heart to the rest of the body.” An aortic dissection occurs when the inner lining of the aorta tears. Blood then forces its way between the layers of the vessel wall, creating a dangerous split that can block blood flow to vital organs or cause the aorta to rupture. “An aortic dissection is a medical emergency and can lead to sudden death,” Dr. Harb said. An aortic aneurysm, by comparison, develops slowly. “When we talk about an aortic aneurysm, we’re talking about the same large blood vessel,” Dr. Harb explained. “Instead of a tear, there is a dilation, stretching or enlargement of a portion of the aorta. An aneurysm develops gradually, usually causes no symptoms, and is often discovered incidentally during imaging performed for another reason.” Once an aneurysm is identified, physicians typically monitor it with periodic imaging every one to two years while controlling blood pressure with medication. Surgery is generally recommended only if the aneurysm enlarges enough to place the patient at significant risk for rupture. Simply put, an aneurysm is a balloon-like bulge caused by a weakened artery wall, while a dissection is a sudden tear that allows blood to split the layers of the vessel apart. “Acute aortic dissection one of the most lethal cardiovascular emergencies that we deal with,” Dr. Harb said. “Once it’s identified, it’s considered a surgical emergency. It happens fast, and nearly 40 percent of people never even make it to the hospital. It’s estimated that one to two percent of patients die with every passing hour, so immediate surgical intervention is critical.” Fortunately, the outlook improves dramatically for those who reach the hospital in time. “The good news is that if the patient makes it to the hospital and undergoes emergency surgery, the mortality rate is dramatically reduced,” he said. Advances in surgical techniques, anesthesia and critical care have steadily improved survival over the past two decades, with hospital mortality following emergency repair of the most dangerous dissections falling to approximately 18 percent at experienced medical centers. The hallmark symptom of an aortic dissection is a sudden, severe pain that patients often describe as sharp, tearing or stabbing. It typically begins in the chest and radiates into the back. That sensation differs from the pain of a heart attack, which many patients describe as crushing pressure or heaviness in the chest, often accompanied by shortness of breath. “When someone has a heart attack, the pressure can build and linger, and sometimes it ebbs and flows,” Dr. Harb explained. “With an aortic dissection, it’s typically a much more acute, stabbing pain. It’s not something to sit on and see if it passes. People should seek emergency medical attention immediately.” Because the symptoms can sometimes resemble a heart attack, a pulmonary embolism or even severe back pain, diagnosing an aortic dissection can be challenging. Physicians typically confirm the diagnosis with an emergency CT angiogram, which produces detailed images of the aorta and pinpoints the location and extent of the tear. Treatment depends on where the tear occurs. A dissection involving the ascending aorta – the section closest to the heart – is classified as a Type A dissection and almost always requires emergency open-heart surgery. Surgeons remove the damaged section of the aorta and replace it with a durable synthetic Dacron graft while the patient is supported by a heart-lung bypass machine. If the tear occurs farther down in the descending aorta, it is classified as a Type B dissection. Many of these patients can initially be treated with aggressive blood pressure control using medications such as beta blockers. If complications develop, surgeons often perform a minimally invasive procedure known as Thoracic Endovascular Aortic Repair (TEVAR), inserting a stent graft through a small incision in the groin to reinforce the damaged vessel. Recovery from surgery typically includes one to two weeks in the hospital, beginning in the intensive care unit, followed by several months of healing at home. Aortic dissection most commonly affects adults between the ages of 50 and 70. Men are diagnosed more frequently than women, although pregnancy increases the risk for women. So, what can you do to reduce your risk? Years of uncontrolled high blood pressure can weaken and stress the wall of the aorta, making it more susceptible to both aneurysms and dissections. “High blood pressure is a silent killer,” Dr. Harb said. “You need to make sure your blood pressure is reaching the proper targets because uncontrolled blood pressure substantially worsens the situation. A tear in the aorta is like a leak in a pipe. The higher the pressure, the faster the leak. Getting the patient on the right medication to control blood pressure is the number one thing we can do to minimize further tearing.” Current guidelines recommend maintaining blood pressure below 130/80 mm Hg for most adults at risk for aortic disease. Quitting smoking, maintaining a healthy weight, exercising regularly, limiting alcohol and avoiding stimulant drugs such as cocaine, which can trigger dangerous spikes in blood pressure, all reduce the risk. An aortic dissection is rare, but its consequences can be devastating. Recognizing the warning signs and calling 911 immediately can make the difference between life and death. Harb Harb, M.D., MPH, MBA, is a board-certified cardiologist at Cleveland Clinic Indian River Hospital specializing in cardiovascular disease and non-invasive cardiac imaging. He is a Fellow of the American College of Cardiology and is dedicated to improving cardiovascular health through prevention and patient education. He sees patients at the Rosner Family Health and Wellness Center at Cleveland Clinic Indian River Hospital, 877-463-2010.