Doctor who studies sudden death weighs in on Lindsey Graham’s passing
Medical examiners are preliminarily attributing the death of U.S. Sen. Lindsey Graham, of South Carolina, to an aortic dissection caused by “arteriosclerotic cardiovascular disease.”
Medical examiners are preliminarily attributing the death of U.S. Sen. Lindsey Graham, of South Carolina, to an aortic dissection caused by “arteriosclerotic cardiovascular disease,” a broad term referring to the hardening and narrowing of the arteries.
Graham, 71, passed away on Saturday “from a brief and sudden illness,” his office said in a statement. He had just returned to the U.S. from a trip to Ukraine, where he was helping finalize an agreement to place sanctions on countries and companies that buy Russian oil, according to the Associated Press.
What is an aortic dissection, and how can it lead to sudden death?
Dr. Gian Corrado, head team physician for Northeastern University athletics, who studies sudden death, said an aortic dissection occurs when a tear in the inner layer of the aorta, the body’s largest artery, causes blood to flow abnormally within the vessel wall. That wall is demarcated into layers known as the tunica intima and tunica media, and a dissection typically occurs when the interior layer (intima) rips from the mechanical stress of blood being pumped from the heart.
The condition is a medical emergency because the tear can rapidly disrupt blood flow to the heart, brain and other vital organs, Corrado said.
“When it does happen, it tends to be sudden and deadly,” he added.
How common is an aortic dissection?
It is a relatively rare condition affecting three out of every 100,000 people, most commonly in individuals over the age of 60, experts say.
There are two types of aortic dissections — ascending, or Type A, and descending, or Type B; and the ascending variety is generally the more dangerous, Corrado said.
“The ones that cause sudden death tend to be the ascending ones that involve the aortic root,” the part closest to the heart, he said. “That aortic root is where the heart gets most of its blood. All the coronary arteries get their blood supply off the aortic root.”
Corrado likened the aorta to a long tube, with blood flowing down the middle hollow channel, called the lumen.
“Imagine a tube or a pipe with two layers to it: an outer layer and an inner layer. During a dissection, all of a sudden, the blood gets routed in between the two layers instead of down the center of the pipe,” he explained. “As the dissection spreads, it can block the major arteries branching off the aorta and cut off blood flow to the brain, heart and other vital organs.”
What causes an aortic dissection, and how is it diagnosed?
Corrado said that chronic hypertension, or high blood pressure, and longstanding vascular disease increase the risk of dissection. Most authorities list hypertension as the primary risk factor, but there are a number of genetic conditions that can raise risk, most commonly Marfan syndrome, an inherited connective tissue disorder, Loeys-Dietz syndrome, a connective tissue disorder that affects craniofacial features, and vascular Ehlers-Danlos syndrome, a disorder characterized by hypermobility, skin hyperextensibility and tissue fragility.
Once a dissection occurs, it often presents suddenly and can mimic a heart attack, pulmonary embolism or gastrointestinal disease or symptoms, Corrado said.
In the aftermath of Graham’s death, questions swirled about whether the physical strain of long flights and disrupted sleep across different time zones may have contributed to the fatal event — though Corrado cautioned that any such link is speculative.
“There is some research on cortisol and circadian rhythm as they relate to the risk of coronary artery disease and other problems,” he said. “Certainly, his cortisol levels potentially being out of whack from lack of sleep or poor sleep could have been playing a role. But it may have just been a slow-building problem that was going to happen eventually.”
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Is an aortic dissection always fatal?
The tear itself isn’t necessarily what proves fatal in such cases, Corrado said. But once there is a tear, and blood tunnels down the false channel created within the aortic wall, it can compress the true lumen, which would lead to ischemia, or an inadequate blood flow to a specific organ.
At that point, the risk of a fatal occlusion, the complete and sudden blockage of a vital blood vessel, rises significantly. And if blood flow to the heart is cut off, the heart muscle can begin to die, which can cause the heart to stop beating, or cardiac arrest. A dissection can also lead to the vessel bursting, known as an aortic rupture, Corrado said.
“There are major arterial branches coming out of the aorta that keep us alive,” he said. “If a dissection goes through there, it dissects out all those vital exit points” supplying blood to the brain, heart and other vital organs.
What are some of the other causes of ‘sudden death?’
“There’s sort of a short list of things that cause sudden death like this,” Corrado said. “One is in the brain — a massive, sudden bleed from an aneurysm, or an abnormal bulging of a weakened section of a blood vessel. The second would be a widowmaker-type lesion in the left anterior descending coronary artery. They call it a widowmaker for a reason because it causes almost global loss of blood flow to the heart muscle. And then the last one involves the aorta and that’s an aortic dissection that leads to a rupture.”
