Sunday, February 21, 2016

Post-Op, Part 2



My post-op left ventricular indices are:


Left ventricular diastolic dimension: 57 mm
Left ventricular systolic dimension: 46 mm
Left ventricular ejection fraction: 48%


I'm very encouraged by the dramatic reduction in the diastolic dimension, immediately into the normal range. Normal for me is another matter, but my LV can't shrink overnight. This reduction must purely result from having a competent valve; that is, from no longer having at least half of my enormous stroke volume rushing back into my LV. 

As Dr. Chris Simpson predicted over in the discussion at Facebook, the initial effect is seen mostly in the diastolic dimension. My systolic dimension actually increased a little bit. Accordingly, my EF dropped from 60 to 48%*, but I'm not in the least bit worried that this might represent any significant irreversible contractile dysfunction, and like Dr. Simpson, I also think that it has no known prognostic significance. 

Loading conditions are everything here, and my LV has suddenly been dramatically under-filled.

My aortic regurgitation had been significant for more than 5 years, probably more than 10, prior to operation. It's going to take years for my LV to remodel, and the available data is clear: given my LV size, if pre-op LVEF was normal, it's normal during follow up (excluding a peri-operative myocardial infarction or some other catastrophe).

As my LV physically shrinks (LV mass declines), I'm sure that my ejection fraction, which is close to normal now, will once again end up in the normal range. My read of the literature suggests that most of the changes happen in the first six months, but my surgeon told me to expect continued remodelling over 2-3 years.

It will never be the heart that I would have had without aortic regurgitation, but the available follow up data strongly suggests that it should be a heart that will last me a long time into the future without any specific anticipated problems.

Here's an interesting question for my medical colleagues: if you were me, and you knew that your post-op EF was 0.48, would you take any medication for LV dysfunction to try to help my LV remodel over time?  A beta blocker, perhaps? An ACE-I? Both? None?

*measured several times using different methods and matching visual estimates as well.

Saturday, February 20, 2016

Post-Op



When I was first diagnosed with severe aortic regurgitation, there was a great deal of disagreement about what to do. A significant majority of cardiologists and surgeons I saw recommended surgery within 6 months, while a small minority suggested that I could safely wait several years, perhaps even ten (or more), before requiring my valve operation.

As I wrote before, the advantage to early operation is that it minimizes the chances of waiting too long. At a certain point, as the left ventricle undergoes chronic volume overloading, irreversible contractile dysfunction develops, and I certainly didn't want to be left with a weak heart after surgery that would last the rest of my days. Not only that, we know that if one operates too late, survival is reduced.

The advantages to waiting are numerous. Firstly, it delays an event that has a mortality of about 1%. Secondly, it delays the onset of life with a mechanical valve, meaning that it delays the risks of valve clot and stroke, infection, as well as the risks of anticoagulation with warfarin. Thirdly, as soon as a valve is put in, a clock starts ticking until it will need to be replaced, too. The later one can operate, the higher the chances are that only one operation will be needed.

So whom to listen to among the disagreement was one of the early conundrums I faced after diagnosis. I decided to go with the available data which coincided with the opinion of the cardiologist most experienced in timing such operations, both indicating that I should not undergo surgery at that time but rather delay delay it as long as possible, possibly for years.

Well, after three years of following my heart size and function closely with serial ultrasound and MRI examinations, my ventricle showed clear signs of increasing in size just a little bit too much, and the opinions of all involved aligned: it was time to operate. Now we get a chance to see if my initial choice of waiting was a mistake, or not.

Three years ago, when I was diagnosed, the relevant parameters were as follows:
Left ventricular diastolic dimension: 63 mm
Left ventricular systolic dimension: 42 mm
Left ventricular ejection fraction: 54%

Pre-operatively, those parameters were:
Left ventricular diastolic dimension: 67-70 mm
Left ventricular systolic dimension: 44 mm
Left ventricular ejection fraction: 60%

What do you think those parameters are on my post-op echo? If my LV remains large and my function (ejection fraction) drops dramatically, then I probably made a mistake (though, to be fair, we must give my heart some time to remodel and get used to the new conditions of a fully competent mechanical valve). On the other hand, if my left ventricle has shrunk, and my function remains good, then we can only expect improvement over time, and I probably made the right choice to wait and enjoy three years without the burdens of a mechanical valve. (And they were three very good years.)

Chime in below with your predictions. In a few days, I'll reveal what the numbers actually are.