Warning: This is written by a non-doctor. So please, don't take this as actual medical expertise. It's the best I can do, and it's probably 'way too simplified. If you think you're having or have had stroke or TIA symptoms, see a doctor. Now.
I offer these details to illustrate how it can happen to a relatively young, relatively fit person.
The small hole between the two atrial chambers is called a patent foramen ovale. Everyone is born with the hole and, depending on who you ask, somewhere between 75 and 80 percent of the time, it seals up shortly after birth. That means about 1 out of 4 or 5 people actually have a foramen ovale, which is not a huge problem. For most.
There are exceptions to that statement, though; my particular problem centers on the muscular wall between the two chambers, called the atrial septum. It should be smooth and flat. If so, the vast majority of people with a foramen ovale never know and no problems ever develop. In some instances, though, the atrial septum is misshaped, called an atrial septal aneurysm. That's where the problem arises.
Normally, the right atrium receives blood from the vein side of the circulatory system, then passes it along to the lungs. In addition to processing oxygen for the blood supply, the lungs also use a filtering mechanism to remove debris, such as clots. From the lungs, the blood is moved back to the other side of the heart and pumped out to the arterial system, supplying oxygen-rich filtered blood to the body. However, if the atrial septum has a divot, if you will, then debris can collect. When pressure builds up in the chest -- say, from coughing or sneezing -- then blood and debris can move through the foramen ovale from the right atrium to the left atrium, circumventing the lung's filtering system. Unfiltered blood is pumped out into the body, including the brain.
Because of this, nine years ago I experienced a cryptogenic stroke -- that is, a stroke with no obvious cause. Last April, a much more minor episode occurred, which triggered a round of tests recently completed. As long as the current conditions remain, my risk of stroke is several percentage points higher than the rest of the population, despite the fact that I don't smoke, have low cholesterol levels, excellent blood pressure readings and, being a distance runner going on 20 years, am generally quite fit.
Dr. LaSala will use an arterial catheter to insert a metal-mesh object that, once in place, will expand into shapes that look like two small umbrellas and cover the hole, one on one side and one on the other. Over time, scar tissue should cover the patch and permanently seal it against the atrial septum.
The final result: My stroke risk will fall dramatically and should actually be lower than the general population. I anticipate a complete recovery and, in fact, to be in better health than ever.
That, at least, is the plan. What will happen? It's not up to me. But I trust the one who is in charge.