Monday, July 19, 2010

EDITORIAL, AUGUST 2010: CANDY COATED DIVERS?

By Cathryn Castle Whitman  

I got an e-mail from a reader recently, expressing her concern over a photograph that appeared in a recent issue of Dive Training. Every now and then a “no-no” photo slips past us — maybe the diver is wearing his snorkel on the right side of the mask instead of the left or a way-too-long weight belt is shown dangling. It happens sometimes. And readers take us to task. But this time, rather than point out the problem, the reader simply asked, “What’s wrong with this picture?”

I scanned it carefully, looking for the glaring error that got overlooked. The photo was of a group of wet-suit-clad divers preparing to gear up for a dive. In it, no one had a snorkel attached to a mask incorrectly, or a too-long belt. The scuba units were stowed properly and no one, heaven forbid, had their mask perched on top of their head, or some other obvious “no-no” likely to set off a letter to the editor.

I didn’t get it.

So, I offered to discuss the reader’s concern in a phone conversation. She e-mailed her phone number, I called, and after we exchanged a few polite greetings she asked, “So, what’s wrong with this picture? Do you get it yet?”
I stared harder. Still, nothing jumped out.

“They’re all obese. Or at least overweight.

NO DUMB QUESTIONS, AUGUST 2010: Pacemakers and Diving, Advanced Training, The Effect of Crude Oil on Corals

Q:Thomas McGill had a follow-up question regarding a feature article I did a few months ago called “The Telltale Heart” (April 2010). Could you expand on some information on diving with pacemakers for me? The article states, in part, ‘there is no reason why a pacemaker should automatically disqualify anyone from recreational diving.’ I and the pacemaker manufacturers seem to agree with this. The article goes on, ‘the real issue is why the patient needs a pacemaker. If the device was implanted solely to correct a problem with the rhythm of the heart, then the candidate can dive. If, however, the heart showed other problems or disease, then the pacemaker candidate should not dive.’ Could you expand on that last sentence for me? My pacemaker was installed because of a slow heart rate. Otherwise, I have no heart difficulties, and I do maintain myself in reasonable physical condition for diving.”

A:Thomas, sorry I wasn’t able to answer your question fully in my earlier feature. The issue is not one of technology but the same concern we have with any medical condition: Might the underlying problem for which the pacemaker was installed affect one’s fitness to participate in scuba diving? 

Pacemakers are installed to address abnormalities in the heart’s electrical conduction system. Often, though not always, patients with such abnormalities have some form of cardiac disease as the underlying cause of their abnormality. For example, congenital heart disease, certain valvular heart diseases (aortic stenosis with valvular and AV-ring calcification), cardiomyopathy and coronary heart disease all may be associated with chronic conduction system abnormalities. Any of these conditions can mean that an individual may lack the cardiovascular fitness required to safely participate in diving. In fact, according to the Divers Alert Network, the most common reason for a pacemaker is underlying ischemic heart disease. This is a huge concern in diving because an increasing number of recreational diving fatalities each year are attributable to coronary artery disease. Another complicating factor is that diving often takes place in remote locations far from facilities that provide emergency cardiac care.

In your case, it appears that there was no underlying heart disease, and the pacemaker was installed solely to correct an arrhythmia problem. Assuming you have sufficient exercise tolerance, you are exactly the type of individual who need not be disqualified from diving.

One other issue I also failed to address in the feature involves the pacemaker itself. Any device used while diving must be up to functioning in the underwater environment. Therefore, the pacemaker must be rated to perform at least to a depth of 130 feet (39 m), and must operate satisfactorily during conditions of wide pressure changes, such as during ascent and descent.

BUDDY LINES: LETTERS TO THE EDITOR, AUGUST 2010

Thoughts and feedback on what constitutes a safe diver, tipping your dive crew, adaptive scuba diving, and remembering Andy Letourneau, all in this month's edition of "Buddy Lines."