Acute breathing difficulty during swimming or diving may be associated with Immersion Pulmonary Edema (IPE). At SPUMS 2014, Peter Wilmshurst presented a summary of his rich clinical experience. In his opinion, IPE is an underestimated cause of fatalities. Problem with diagnosis of IPE in scuba diving is its rapid evolution. Divers may be overwhelmed with an internal lung flood before they realize the nature of their breathing difficulty and can safely exit the water.
cardiovascular
Primary Prevention of Cardiovascular Disease with a Mediterranean Diet
In a recent article published in New England Journal of Medicine, Ramón Estruch and his colleagues present results of a multicenter trial in Spain conducted to evaluate the effects of a Mediterranean diet on myocardial infarction, stroke or death from cardiovascular causes in subjects who were at high cardiovascular risk, but with no cardiovascular disease at enrollment. Participants were randomly assigned to one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet (advised to reduce dietary fat). The results of an interim analysis were so overwhelming that the trial was stopped after a median follow-up of 4.8 years.
Study enrolled 7,447 persons with an age range of 55 to 80. Severe cardiovascular events occurred in 288 participants. More severe events occurred in control group (109) then in the group assigned to a Mediterranean diet with extra virgin olive oil (96 events) and the group assigned to a Mediterranean diet with nuts (83 events), respectively. It represented a 30% reduction for the groups with Mediterranean diet in comparison to the control group.
Researchers concluded that “among persons at high cardiovascular risk, a Mediterranean diet supplemented with extra virgin olive oil or nuts reduced the incidence of major cardiovascular events.”
How your diet compares to Mediterranean-style diet? Check it here:
Estruch R, et al. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet. NEJM, 2013; 368 (14):1279-1290
Post written by: Petar Denoble, MD, D.Sc.
Obesity, The Heart & Diving
How does obesity affect your heart and why can obese divers develop heart trouble at apparently low level of exertion?
Obesity is an escalating problem and is linked to a spectrum of cardiac dysfunctions that affect feeling of wellbeing, physical fitness and longevity. In a recent review paper Rider O.J. et al, summarize current knowledge about how obesity affects the heart. The most notable fact is the change of source of the fuel from which the heart derives its energy. By excluding glucose and relying mostly on fatty acids, the energy process becomes less efficient and the heart needs more oxygen for the same level of work. In the long run, lipids become toxic for heart cells and lead to structural changes and weakening of the heart muscles, which is disabling and life threatening. In case of divers who feel fit enough to dive, however, the danger comes from the increased needs of heart for oxygen even at rest. In some cases, even a small increase in exercise level may cause a significant hypoxia of heart muscles which can lead to major troubles.
The good thing is that the problem can be improved by moderate weight loss. However, weight regulation should be started sooner rather than later when changes may become irreversible.
Learn more from DAN FAQs: Healthy But Overweight
Post written by: Petar Denoble, MD, D.Sc.
DAN Investigates Implanted Cardiac Devices: Volunteers Needed
In a recent divers’ health survey that DAN conducted, 25 participants, or one in 200, reported having an implanted pacemaker device. The median age of divers with implanted devices was 64 (39 to 90) years and 95% were male. We did not anticipate this and the survey did not ask about reasons for pacemaker implants, but we have learned something about their health status.
- About 64% active divers with pacemakers were either overweight or obese.
- 22 reported that they regularly participate in vigorous exercise such as running, biking, swimming, weightlifting, etc.
- Half were diagnosed with hypercholesterolemia, 9 with hypertension and 4 with diabetes.
- Few still indulge in some high risk habits such as heavy drinking and tobacco smoking.
- When asked to describe their general health, one participant answered it was excellent, 12 very good, 10 good, and one diver said that his health was fair or poor.
Five of the respondents with implanted pacemakers had basic certifications, 16 had advanced and four held instructor-level diving certifications. In terms of diving habits, the respondents with implanted pacemakers reported they:
- Perform about 30 dives per year (median)
- Have been active divers for an average of 20 years
- Have logged a median of 460 total lifetime dives per diver.
Divers with pacemakers don’t seem to be less active than other divers, but we did not explore the circumstances and severity of their dives. We did not ask about specific symptoms or manifestations related to underlying conditions for which they received the pacemaker nor about possible unwanted side effects of pacemakers.
Volunteers with Pacemakers Needed
This is why DAN designed a new study to learn about specific issues experienced by divers with pacemakers choosing to dive with or without medical clearance. DAN is looking for volunteers to participate in the “Diving Experience of Divers with Implanted Cardiac Devices” study, which consists of an online survey that takes approximately 10 minutes to complete, in addition to a possible follow-up interview if clarification is needed. If you would like to participate in this investigative study, ongoing through August* 2013, please contact DAN Research (919-684-2948 or research@dan.org). Participants will not be compensated for participation.
Post written by: Petar Denoble, MD, D.Sc.
*NOTE: This study has been extended through November 2013.
The Dive Lab 