Sometimes, football doesn't matter.
According to ESPN's Adam Schefter, Fox became dizzy while playing golf over the weekend, setting in motion the sequence of events that culminated in the news of his impending operation.
Numerous reports initially stated that Fox suffered from symptoms indicative of a heart attack, but thankfully, further developments—specifically a tweet from team spokesman Patrick Smyth—made it clear that Fox had not suffered a heart attack.
In fact, according to Schefter, Fox already knew that he had an existing heart condition. Latest reports suggest that Fox will follow a very serious, but relatively routine, course of medical treatment.
UPDATE 5:15 pm ET, November 4, 2013
According to Pro Football Talk's Michael David Smith, Fox underwent surgery earlier today.
Front office boss John Elway and interim head coach Jack Del Rio spoke with reporters in Denver, where they said they expect business as usual while Fox is away in the coming weeks. Elway said the early indications are that surgery was a success and Fox will be OK.
The happy news represents the first sigh of relief since the ordeal began, and Fox can now turn toward recovery. Everyone certainly hopes for only the best in the coming weeks.
--End of update--
While exact medical details are not available, it seems likely that Fox suffers from a chronic aortic valve disorder. Specifically, he most likely carries a diagnosis of aortic valve stenosis.
A relatively common disease, aortic stenosis represents a condition where the aortic valve progressively narrows over time.
The aortic valve is the doorway out of the left ventricle—the main chamber of the heart that pumps blood to the rest of the body. The valve opens and shuts with each heartbeat, allowing blood to flow forward when open.
During aortic stenosis, the steadily narrowing valve allows less and less blood to move out of the heart. When the amount of blood leaving the heart reaches a critically low point, symptoms develop.
The most obvious symptom is lightheadedness or dizziness—which Fox experienced Saturday—representing decreased blood flow to the brain.
Aortic regurgitation—where blood flows backward through a leaky aortic valve—can cause a similar set of symptoms and is also possible in Fox's case.
Fox's doctors likely first identified his condition during a prior routine physical exam. For example, abnormal blood flow in the heart can cause a heart murmur—or an extra heart sound.
Imagine a straight water pipe. When water flows through it, it does so silently. In a bent, narrowed or kinked pipe, the water must change directions to continue flowing forward, causing it to slosh around and produce miniature eddies and a turbulent flow within the pipe.
A similar situation occurs in aortic stenosis, or regurgitation.
As blood flows through a narrowed valve in aortic stenosis, portions of the bloodstream must change directions to make it through. The change in flow creates a "whoosh" sound between the two 'lub dubs" of the heartbeat.
In aortic regurgitation, blood produces a similar sound as it flows back through the leaky valve. This time, doctors hear the "whoosh" after the second of the two beats.
If doctors heard a murmur in Fox's heart, they likely ordered an echocardiogram—an ultrasound of the heart.
Echocardiograms directly visualize a beating heart and allow technicians to view how much blood is flowing through the valve, how big the valve is and how fast the blood is moving.
In aortic stenosis, the narrower the valve, the faster the blood travels through it.
Many cases of aortic stenosis arise for unknown reasons and progress very slowly over time. Some people are born with an already-narrowed valve. In others, it becomes apparent decades later.
That said, doctors generally do not intervene until it becomes symptomatic.
For Fox, that occurred on Saturday.
Whether or not his aortic stenosis or regurgitation became acutely worse remains unclear, but all signs point to a chronic condition that turned symptomatic earlier than expected.
Why can't Fox's surgery wait until the offseason? Simply because it's too dangerous.
For instance, during exertion or exercise, a severely or critically defective valve can prevent enough blood from flowing forward to the brain, leading to a fainting spell.
In addition, while the heart must pump blood to the rest of the body, it must also pump blood to itself. If the heart cannot meet its own demands, potentially life-threatening irregular heartbeats can develop.
Due to the symptomatic nature of his condition, Fox may very well remain in the hospital until his procedure on Tuesday.
For his operation, surgeons will use a prosthetic heart valve to replace the narrowed or leaky valve. The replacement valve can be mechanical or—believe it or not—from a pig. The procedure proceeds via either an open route—where surgeons open the rib cage to access the heart—or by using minimally invasive techniques.
The route taken—as well as the type of valve used—depends on the surgeon and individual patient characteristics and preferences.
In the operating room, doctors usually need to briefly stop a patient's heart to carry out the procedure. A heart-lung bypass machine temporarily replaces its function at that time.
Following surgery, Fox will most likely remain in the ICU for a few days under close observation. He will then be moved to the general medical floor until doctors deem it safe for him to head home to continue his recovery.
The recovery process will likely require upwards of two months both in and out of the hospital.
That is for good reason. After all, when the heart is involved, it's better to be safe than sorry. The entire NFL will certainly continue sending him its collective thoughts and prayers as he presses onward.
Nevertheless, it seems that while one can take the man away from football, it's far more difficult to take football away from the man. According a statement from Fox tweeted by NFL.com's Albert Breer, Fox seems to already be in game-planning mode in:
I sincerely appreciate all of the support from friends, Denver Broncos fans and so many around the league today. Although I am disappointed I must take some time away from the team to attend to this pre-existing health condition, I understand that it’s the right thing to do. I have great confidence in our coaches and players, who are fully committed to our goals. I look forward to returning to coaching as soon as possible.
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