Dear Dr. Roach: Articles on strokes or TIAs rarely mention that they can be caused by a congenital heart defect. I had a family member with a patent foramen ovale, found at age 54, after he’d had several strokes. He had surgery to repair it and has been well ever since.
I would like to know why a PFO isn’t often mentioned or considered. When I see an obituary for a young person who died suddenly, it makes me wonder if there was an undiagnosed hole in the person’s heart. One in 6 people has a hole in the heart; that is a high percentage.
I think the public should be educated and made aware of this congenital condition.
Dear J.R.: A patent foramen ovale (which literally means “open oval-shaped window”) is a remnant of our embryology. The foramen ovale is a small open flap that is necessary to send oxygenated blood from the placenta to the body of the developing fetus.
In about 25 percent of people (that’s 1 in 4, even higher than you thought), the “hole” does not completely close. PFO is the most common of the “holes” in the heart (ventricular septal defect and atrial septal defects are some of the other common ones).
A stroke is caused by the death of brain cells. PFOs are certainly implicated in strokes.
In general, the younger and healthier the person, the more likely it is that a “cryptogenic” stroke (one with no obvious cause) may be due to a PFO. What is likely is that a blood clot can pass through the foramen ovale and go to the brain’s blood vessel, blocking off blood supply to an area of the brain, causing a stroke.
The absolute increase in stroke risk is hard to quantify. For people who have never had a stroke, it is generally not recommended to close the PFO. This surgery has risks, and these risks probably outweigh the small potential benefit.
For people who have had a stroke, the risk of recurrent stroke from PFO is higher. One group has created a model (the RoPE score) to help predict the likelihood of recurrent stroke. This can help the clinician examine the benefits of surgical repair of the PFO.
Surgery is most likely to benefit younger people without traditional risk factors for stroke.
Dear Dr. Roach: Can skim milk or oat bran cause gas?
Dear J.R.: Both certainly can cause gas. Skim milk contains the milk sugar lactose, to which many people are intolerant. In mild cases, it causes some gas; severe cases can cause diarrhea.
Oat bran is a good fiber source, and all good sources of fiber can cause gas, especially if they are taken in amounts that are greater than the person is used to.
Email questions to ToYourGoodHealth@med.cornell.edu.