Diving with mitral regurgitation and a small PFO?

[DryFish]

Hi all, apologies for blowing netiquette out of the water with a heavy first post but hopefully you will understand;

The facts
I'm a male in my early 40's, not overwright, don't smoke, drink very little (these days anyway), but work too hard . Fitness is OK (can run 10KM in just under an hour) but not as good as it could be. Have three kids of school age.

Started diving about two years ago. Have completed 53 dives, all in cold UK waters, all in dry suit, all on air including one down to 30m within 1min of time limit but did not exceed it. Never had symptoms of DCS that I am aware of.

Routine medical before PADI Adanced Open Water led to a diagnosis of Mitral Valve Prolapse (MVP) with mild to moderate mitral regurgitation (MR) and a small PFO. I had no obvious symptoms associated with these conditions and there has been no change to the LV size or function. I am not on any medication for the MR and have not been precluded from any other activity.

The risks associated with a PFO are well known here and the cardiologist didn't preclude me from diving so I completed the AOW and have done 18 dives since (including the 30m one). However, in a recent follow up he consulted with a dive medicine specialist who suggested that the MR might lead to an increased risk of pulmonary edema (PE) which is fluid on the lungs.


Questions etc
Although I feel fine I am currently not diving due to my concern of the compounded risks of a PE from the MR and a DCS from the PFO. Are they independent or does the combination of these conditions lead to a greater risk of problems? Another major factor is the risk of insurance companies not paying out should something happen; as much as I love it, I can't let my recreational pursuit affect my family.

Anyone else got a similar combination of conditions and experiences they can share? I'm aware of several people who have dived after valve repair surgery but is there anyone out there diving safely with MR and a PFO?

If I just had one of these conditions I would probably dive but my current thinking is that I should wait either until the MV requires repair or replacement and get them to fix the PFO at the same time. Or, wait until the kids have left home and insurance isn't so crucial... The paradox is that I don't want surgery and may never require it in terms of the MR but it will probably be safer for me to dive after surgery than before.

 

[terrylowe]

Hi all, apologies for blowing netiquette out of the water with a heavy first post but hopefully you will understand;

The facts
I'm a male in my early 40's, not overwright, don't smoke, drink very little (these days anyway), but work too hard . Fitness is OK (can run 10KM in just under an hour) but not as good as it could be. Have three kids of school age.

Started diving about two years ago. Have completed 53 dives, all in cold UK waters, all in dry suit, all on air including one down to 30m within 1min of time limit but did not exceed it. Never had symptoms of DCS that I am aware of.

Routine medical before PADI Adanced Open Water led to a diagnosis of Mitral Valve Prolapse (MVP) with mild to moderate mitral regurgitation (MR) and a small PFO. I had no obvious symptoms associated with these conditions and there has been no change to the LV size or function. I am not on any medication for the MR and have not been precluded from any other activity.

The risks associated with a PFO are well known here and the cardiologist didn't preclude me from diving so I completed the AOW and have done 18 dives since (including the 30m one). However, in a recent follow up he consulted with a dive medicine specialist who suggested that the MR might lead to an increased risk of pulmonary edema (PE) which is fluid on the lungs.


Questions etc
Although I feel fine I am currently not diving due to my concern of the compounded risks of a PE from the MR and a DCS from the PFO. Are they independent or does the combination of these conditions lead to a greater risk of problems? Another major factor is the risk of insurance companies not paying out should something happen; as much as I love it, I can't let my recreational pursuit affect my family.

Anyone else got a similar combination of conditions and experiences they can share? I'm aware of several people who have dived after valve repair surgery but is there anyone out there diving safely with MR and a PFO?

If I just had one of these conditions I would probably dive but my current thinking is that I should wait either until the MV requires repair or replacement and get them to fix the PFO at the same time. Or, wait until the kids have left home and insurance isn't so crucial... The paradox is that I don't want surgery and may never require it in terms of the MR but it will probably be safer for me to dive after surgery than before.

You are right. The PFO should not be a problem. The mitral valve should not be a problem if you have good exercise tolerance with no unusual shortness of breath.

I had just called DAN last week with a very similar question for a patient of mine. I would suggest that no matter what opinions you see here, give DAN a call. They are quite helpful and friendly.

 

[Duke Dive Medicine]

Dryfish,
How were the PFO and mitral valve regurgitation discovered, and how were they diagnosed, i.e. what specific procedure was used (i.e transthoracic echo with bubble contrast, color flow doppler, transesophageal echo?) Also, was the PFO present at rest or with valsalva?

 

[DryFish]

General practioner (UK doctor) originally discoverered a systolic(?) murmur using a stethoscope. He referred me to a cardiologist who also listened to my heart with a stethoscope. He did an ECG and an ultrasound scan plus bubble injection with valsalva. Ultrasound was external so probably TTE? Initial valsalva produced no bubble leakage across the PFO, second valsalva (15-20 seconds) moved a few small bubbles which were caught on the ultrasound. I was blowing way harder and for longer than I ever have on a dive. I usually just move my jaw to equalise.

On the second visit a year later I had an ECG and a colour (doppler?) ultrasound scan - also external. Mild to moderate MR and minor movement of fluid across the PFO both visible on the image. I did not have a bubble test or do the valsalva on this visit so I guess the PFO was leaking at rest. Cardiologist said my scan image was very clear and he could see the MV leaflets etc which is unusual apparently. All other heart functions and chamber sizes were declared normal on both visits. At the end of the second visit he used the stethoscope for a final check and seemed to have trouble detecting the murmur until I moved position.

I'm aware that PFO's can be associated with DCS on benign dive profiles and outwith diving it can also be associated with paradoxical embolism due to it allowing clots to move from L to R (or R to L - I'm no medic!). I'm also aware that MR can lead to dysapnea and a host of other symptoms in severe cases but other than occasional palpitations I don't think I have any symptoms. I only recently learned that MR may lead to pulmonary edema when diving.

One other point to note that I have only just thought of. I recently bought an EU scale peak flow meter and my peak flow is currently about 530 l/min. At my original diagnosis it was 580 l/min. The charts say someone my size and age should be at 650 l/min although anything down to 550 l/min is apparently within normal limits. I sometimes feel slightly short of breath under water although I have not been bothered by it and put it down to inexperience. My typical air useage is around 19-21 l/min.

Given that I have dived on air in cold UK waters (including dealing with free flows in 4°C water on my second OW dive and a leaking dry suit in 8-13° water) I don't think I'm that predisposed to PFO related DCS. However, insurance companies and dive companies recognise it as a risk and I also don't know whether the combined risks associated with a PFO and MR put me in a category that really shouldn't be diving.

 

[Tortuga68]

This article is from 2001 so I don't know if the thinking has changed since then, but it may be of interest to you: http://www.frogkick.dk/library/medicine/smw-09706.pdf

 

[Duke Dive Medicine]

DryFish,

Minor, asymptomatic mitral valve regurgitation with no complications is typically not a contraindication to diving. Mitral valve stenosis may be, and could precipitate pulmonary edema, but you didn't mention that.

Regarding PFO: it sounds as if you've done your research. Our "gold standard" diagnostic method is TTE with bubble contrast, which is considered to be sufficient to detect a clinically significant PFO. Color flow doppler with a good technician will also spot it, as you found out. It's interesting that you had very little shunt on valsalva with the bubble contrast, yet had shunt at rest with the color flow doppler. It's reasonable to conclude, then, that your PFO will shunt at rest and there was perhaps a testing anomaly or error with the bubble contrast echo.

That said, we'd counsel a diver with your condition to dive very conservatively and avoid dives that may result in high venous bubble loads. As you've found out, not every provocative dive you make will result in DCS, but your condition is correlated with severe neurological DCS, inner ear DCS, and perhaps cutis marmorata, or type II skin bends. I think it would be erroneous to conclude that you're not "predisposed to PFO related DCS".

As far as the peak flow numbers, that's hard to tell without seeing you and your medical records. Your gas usage (21 lpm converts to .74 cfm for us Yanks) is well within normal limits for a diver performing light work on the bottom. If you are experiencing shortness of breath under water, it could be inexperience as you say, or it could be something else. I would advise mentioning your concerns to your cardiologist. It may be that you have another underlying condition that could affect your diving.

Best regards,
DDM

 

[DryFish]

Many thanks for the replies.

DryFish,

I think it would be erroneous to conclude that you're not "predisposed to PFO related DCS".

Best regards,
DDM

The comment that DDM quite rightly refuted was more of a hopeful statement than a categorical belief. I based it on the observation that I have had no known DCS incidents in 53 recreational dives in relatively cold water despite the presence of a PFO. However, it is probably more like I'm playing Russian roulette with say a 100 chamber gun and assuming that because the first 53 chambers are empty the rest must be...

Mitral stenosis has not been mentioned during either exam but I will ask next time. The cardiologist has stated that the PFO is very small and I have previously assumed that PFO size is a risk factor so small = better.

I will get the lungs checked by a GP and also mention it when my next cardiology exam is due (2012). I will then make a decision on whether to resume diving, possibly with the added precaution of diving nitrox on air tables. I won't be exceeding 30m as I'm not qualified to go below that anyway.

One final question, is there any evidence that the presence of both MR and a PFO can lead to greater risk of problems than just summing the individual risks associated with either condition?

 

[Duke Dive Medicine]

One final question, is there any evidence that the presence of both MR and a PFO can lead to greater risk of problems than just summing the individual risks associated with either condition?

Possibly, depending on the relative severity of each. This is another question that's tough to answer without seeing you so is probably better addressed by your cardiologist. Best of luck!

 

[DryFish]

Possibly, depending on the relative severity of each. This is another question that's tough to answer without seeing you so is probably better addressed by your cardiologist. Best of luck!

Thanks for your comments, very helpful.

 

[Dr. Doug Ebersole]

As a tech diver/instructor and interventional cardiologist, I agree completely with the staff at Duke Dive Medicine above. Mitral regurgitation is not a contraindication to diving as long as you have normal heart muscle function and adequate exercise tolerance. As mentioned, the main reommendation for diving with a PFO is to dive conservatively and limit your venous bubble load -- avoid decompression diving, long safety stops, nitrox, etc.

By the way, I am doing a research study in conjuction with Divers Alert Network (DAN) looking at divers with PFO. All of the information is available at DAN: Divers Alert Network - Scuba Diving and Dive Safety Association.