PFO: Is It Time to Change the Course?

wooden pointerPresentations at SPUMS continue…

Peter Wilmshurst’s series of cases shows that 79% of all skin DCS have PFO, 10% lung disease and only remaining cases occur in divers with closed PFO due to severe dive exposure. Similar statistics were provided for inner ear DCS and neurological DCS. Other authors dispute association of PFO with spinal form of DCS  and say only cerebral DCS appears to be associated. Nevertheless, a large number of DCS cases could be avoided if the diver was aware of PFO and exercised caution.

How safe is the option of transcatheter closure?

Mark Turner, another cardiologist from the United Kingdom, provided a detailed presentation of the procedure, pitfalls and outcomes. The overall outcome: Successful with very low rate of adverse events.


Deep Vein Thrombosis (DVT)

blood clotDeep vein thrombosis (DVT) is a condition in which a blood clot (thrombus) forms in one or more of the deep veins, usually in the legs. Blood clots can break free and travel with blood causing life-threatening condition like pulmonary embolism (PE) or a stroke due to paradoxical embolism in people with patent foramen ovale (PFO). DVT is not related to diving, but divers often travel and thus are exposed to risk of DVT. In case of acute DVT, divers must not dive.


Exercise and Acute Cardiovascular Events: Placing the Risks Into Perspective


Do not ignore possible warning symptoms!

The American Heart Association’s Scientific Statement published in 2007 is still valid when it comes to exercise and acute cardiovascular events. While many sudden cardiac deaths related to exercise occur in subjects without obvious symptoms of heart disease, in many cases warning symptoms preceded death but were ignored by victims or their physician. Specifically, 50% of joggers, 75% of squash players, and 81% of distance runners who died during exercise had probable cardiac symptoms before death. Most reported these symptoms only to relatives and few sought medical attention. We have seen this also in scuba divers although not in such high percentages. Recommendation is that exercising adults should be aware of the nature of warning cardiac symptoms and the need for prompt medical attention.

 The most commons warning symptoms are:

  • Chest pain/angina                                                                        
  • Increasing fatigue                                                         
  • Indigestion/heartburn/gastrointestinal symptoms        
  • Excessive breathlessness                                           
  • Ear or neck pain                                                                         
  • Vague malaise                                                                                  
  • Upper respiratory tract infection                                         
  • Dizziness/palpitations                                                                     
  • Severe headache                                                                              

Suggestions for prudent risk mitigation measures brought forth in the same article could be modified and applied to diving as follows:

  • If your health changed recently, you are healthy and over 45, or you have two or more risks for heart disease, take your annual medical exam before resuming physical activities in preparation for diving.
  • If you have a known cardiac condition, you should be evaluated for diving according to published guidelines
  • Prepare physically for your dive trip by gradually increasing your exercise level and refreshing your skills in preceding months.
  • Know the nature of warning symptoms for heart disease and seek prompt medical care if such symptoms develop.
  • Modify your dive plan in response to variations in the environmental and general diving conditions. Learn to when to call a dive (this may be even before the dive starts).
  • Ask your dive provider where their staff is trained and equipped for resuscitation and if they conduct periodic drills.

Post written by: Petar Denoble, MD, D.Sc.