hi Cliff,
Measurement instruments are characterized using 2 terms - Precision and Accuracy (you can find definitions on the web). Echo (ultrasound) instrument may have a 'precision' of 1-2mm (if they are saying so), but it may not be very 'accurate' in the measurement of aorta (but it’s not too shabby either). In comparison, CT scan for aorta is 'relatively' both precise and accurate. In both cases, however, there is a third element - the user (and use conditions). For example, if a subject is at an angle w.r.t. the scanner, 5.0cm measured at an angle may actually be 4.7mm (or vice versa). And perhaps that's why a hand-held echo instrument is more prone to user-errors, even for the measurement of parameters such as LV size and EF, where it's considered a gold-standard (in comparison to CT scanner which doesn't visualize heart LV dimensions and EF etc much at all).
More on the user-error, specifically user-variability. If you go to another echo technician the same day, you may see significantly different readings on LV dimensions, EF etc. But in order to really test that hypothesis, you must not disclose the first echo results, to remove the 'bias' element. There is so much user-variability in echos, that even the same machine and technician, could very easily produce different results. When you visit them year after year, they have access to your previous reports, and they always refer to them so that they can adjust to the 'variability' of their own. I’ve personally witnessed all these permutations and combinations with my echos with various providers, some simultaneously, over the years.
I guess what I'm trying to say is that the variability you have mentioned in your recent echo report is not worth splitting the hair. For all practical purposes, you can consider your root to be 5.0cm and ascending aorta as 4.5mm. And based on that you and your cardio will have to make a decision. It appears that your cardio will not recommend a surgery with those numbers, given the new 2014 guideline, and also because your valve is otherwise fine.
But at your personal level, there are a lot of questions which must be addressed, for you to have a peace of mind. Symptoms are some of those. Even if you lacked symptoms, you probably would not have had a complete sense of security (I don't), having faced with so much information and decisions to make. So let's talk about some of that. You see, aorta (root and ascending) are just some of your (and my) problems, overtime. Ultimately, it's the BAV. So the valve itself is also hovering around somewhere there, even if it's not so bad right now in your case. Let's make a couple of hypothetical scenarios. If you go ahead for surgery now for root and ascending, they would probably spare the valve (and if they could/did not, 10-20 years life left on that go to waste). Reality is that you don't know the current rate of deterioration of valve at this point, since you just started monitoring it less than a year ago. You don't know how your valve may fare in 5-10 years, from today's EF of 55% which is OK but not fantastic (but w/ echo variability who knows), and LV is inside of upper limit of normal. Similarly, the downstream of ascending aorta, i.e. the arch needs to be monitored over the years. It's way too early to call that anything of concern right now (32-34mm?), but having a few more data points over the next 5-10 years may shed more light. Hypothetically, if needed, it could potentially be one job (i.e. aorta and valve) rather than 2 over the next 10-20 years. Who knows. And who knows, if your cardio is thinking somewhat on those lines. You can always take a second opinion, but just as this forum and we as patients factor in decision making, medical practitioners should also be partnering actively in the same process as only they know your situation first hand (and not people like me on the forum).
None-the-less you would have to manage your symptoms and perhaps settle with less than desirable level of physical activity in your current lifestyle. Most importantly, having assurance is also important IF you and your practitioners decide to wait. But first things first. Waiting is remote secondary to handling this one (i.e. aorta) at hand at the moment. After clarifying with your 2nd cardio on the current situation, and if it comes to waiting, a 6 month frequency may be on the cards, with next follow-up involving a CT (or MRI) within 3 months since aorta is your biggest problem. And for whatever it is worth, a 5.0cm root with 4.5cm ascending aorta is probably better than 4.5cm root with 5.0cm ascending.
In any case, all the best and please keep us posted.
