Harvard Heart Letter

Hole in the heart opens questions

Popular treatment for preventing stroke hasn't been proven.

The most common type of stroke, ischemic stroke, occurs when a clot blocks blood flow to part of the brain. Doctors can often tell what caused the clot to form. Ischemic strokes with a more mysterious origin are called cryptogenic strokes. One possible cause of a cryptogenic stroke is a hole in the wall separating the heart's right atrium from the left. Whether fixing this opening prevents such strokes has yet to be determined.

Before birth, a baby gets oxygen from its mother through the placenta. In the fetal heart, blood bypasses the lungs by moving from the right atrium to the left through an opening called the foramen ovale (foe-RAY-men oh-VAH-lee). It usually closes after birth. In about one in eight people, though, the opening (which is more like the space between two swinging doors than a hole) fails to close completely. This is called a patent (PAY-tent) foramen ovale (PFO).

To continue reading this article, you must login.
  • Research health conditions
  • Check your symptoms
  • Prepare for a doctor's visit or test
  • Find the best treatments and procedures for you
  • Explore options for better nutrition and exercise
Learn more about the many benefits and features of joining Harvard Health Online »