Aug. 30, 2016
Each year in the United States, more than 800,000 people experience a stroke. It is the fourth-leading cause of death and the leading cause of serious, long-term disability in adults. Preventing stroke or transient ischemic attack is complicated by the fact that patients often have coexisting neurological and cardiovascular conditions.
Patient with large patent foramen ovale with an atrial septal aneurysm
A 63-year-old woman with a remote history of migraine headache awakened with a headache with visual aura, as well as nausea, vomiting and incoordination. She was a former smoker but had no history of hypertension or estrogen replacement, and no family history of stroke. A and B. MRI demonstrated a left cerebellar infarct. C and D. Transesophageal echocardiography demonstrated a large patent foramen ovale (arrow) with an atrial septal aneurysm. E. Contrast injection demonstrated generous flow across the patent foramen ovale (arrow) with Valsalva maneuver. Percutaneous closure was performed.
Mayo Clinic in Rochester, Minnesota, has created a Heart Brain Clinic to provide multidisciplinary evaluations for patients with neurological symptoms that may be due to a cardiac etiology, such as atrial fibrillation (AF) or patent foramen ovale (PFO).
Specialists from Cerebrovascular Diseases in Mayo Clinic Neurology and specialists in Cardiovascular Diseases collaboratively evaluate patients, meet to discuss cases, make joint recommendations for management, and educate patients and their families.
"One can get a very different perspective on a patient's cardiac and neurological evaluations when they are discussed directly between a neurologist and a cardiologist, rather than being considered in isolation," says Robert D. Brown Jr., M.D., M.P.H., a consultant in Neurology at Mayo Clinic's campus in Minnesota and co-director of the Heart Brain Clinic. "That's the beauty of both groups coming together to evaluate the patient at the same time, in the same setting."
Expertise in AF and PFO
About 25 percent of cerebral infarctions are caused by a cardiac disorder. In addition to its top ranking in neurology, Mayo Clinic is highly ranked in cardiology and cardiac surgery. Specialists in the Mayo Clinic Cardiac Catheterization Laboratory pioneered catheterization-based techniques for diagnosis and treatment of cardiac conditions.
AF is associated with up to 20 percent of strokes, and is particularly common in older patients. Based on autopsy and echocardiographic studies, the vast majority of strokes in individuals with nonvalvular AF are believed to be embolic in nature. Although anticoagulation has been found to be effective for stroke prevention, standard anticoagulation regimens may be problematic for individuals who have had prior brain or systemic hemorrhage, or those who are otherwise at high risk of having a bleeding complication.
"With both cardiologists and neurologists discussing the best management approach, we can collaboratively assess the risks compared with the benefits of putting patients on an anticoagulant medication, or considering their suitability for treatment with what is called a closure device," Dr. Brown says.
Similar balancing of risks and benefits is applied to patients with PFO, which are present in as many as 25 percent of adults. Although these interatrial shunts often are asymptomatic and of no hemodynamic importance, there are some patients in whom the PFO will allow a venous clot to pass into the arterial system, leading to a potential ischemic event. Sluggish blood flow and the funnel-shaped interatrial connection created by some PFOs may facilitate the in situ formation of thrombi. However, PFO can be an incidental finding in a patient who has had a stroke or transient ischemic attack, posing limited, if any, risk of future stroke occurrence.
"When the neurologist sits down with cardiologists to discuss stroke patients who have been found to have a PFO, we can determine whether every other cause of stroke has been ruled out and, if so, whether the PFO may have been related to the stroke. We can then decide whether the PFO should be treated medically or with PFO closure," Dr. Brown says. "By having this conversation, we can talk through the complexities of the individual patient's history and exam and evaluation results, and then arrive at the best treatment recommendation."