New resources help healthcare providers understand, diagnose mystery strokes

A new guide helps healthcare professionals better understand and diagnose strokes of unknown cause. The free resource is part of an American Heart Association/American Stroke Association initiative in collaboration with Medtronic plc. which aims to reduce the rate of recurrent strokes in the U.S.

Every year, nearly 800,000 Americans have a stroke, the fifth leading cause of death and a primary cause of disability. The most common type of stroke, called "ischemic," occurs when blood vessels carrying oxygen and nutrients to the brain are blocked by a clot causing brain cells to die. Thirty percent of ischemic strokes have no known cause, even after thorough diagnostic tests are performed during a stroke patient's hospitalization. These strokes of uncertain origin are deemed "cryptogenic."

Available for download at StrokeAssociation.org/cs, the Cryptogenic Stroke Guide for Healthcare Professionals is the first resource available in the new cryptogenic stroke toolkit. The guide includes information on diagnostic evaluation and details the many potential causes of cryptogenic stroke, like atrial fibrillation (AF).

People with AF —a common heart condition where the heart beats irregularly or rapidly—are five times more likely to have a stroke, but their condition often goes undiagnosed because episodes occur infrequently and are often not detected by conventional monitoring techniques.

"Recent evidence suggests that up to 30 percent of patients with cryptogenic stroke will demonstrate intermittent atrial fibrillation during prolonged heart rhythm monitoring after the stroke," said Lee H. Schwamm, M.D., American Stroke Association volunteer spokesperson, executive vice chairman, department of neurology, and director of stroke services at Massachusetts General Hospital. "As insertable cardiac monitors have become more readily available and convenient, they will likely play an increasingly important role in identifying or excluding the presence of atrial fibrillation, or other arrhythmias, in patients with cryptogenic ischemic stroke."

The guide includes the following sections:

• Background information on cryptogenic stroke
• Suggested diagnostic approaches
• Treatment pathways that factor in the complexity of identifying potential causes
• Case studies

The Cryptogenic Stroke Initiative, announced in February at the American Stroke Association's annual International Stroke Conference, supports the American Heart Association/American Stroke Association's goal to reduce deaths from stroke by 20 percent by 2020.

"We have a common goal with the American Heart Association/American Stroke Association: to improve the care for patients who have experienced unexplained strokes," said Nina Goodheart, vice president and general manager of the Medtronic diagnostics business which is part of the Cardiac and Vascular Group at Medtronic. "Medtronic is committed to investing in projects like this and other research that will help treat and prevent strokes and reduce disability from strokes."