Fortunately, for both patients and thoracic surgeons coronary artery disease affects the first part, or proximal end, of the artery much more frequently and severely than the downstream portion of the artery. This allows for a surgical procedure that uses a portion of a vein or another artery to direct blood around the blockage. Doctors perform this procedure hundreds of times daily around the country - more than 500,000 times annually. If the bypass is successful, the individual should become free of the symptoms of coronary artery disease, and the heart muscle should receive normal blood flow and oxygen.
A less invasive procedure, coronary angioplasty, consists of placing a catheter with a balloon on its tip into the area of the blockage and inflating the balloon to open the artery. This may or may not include the placement of stents. This procedure does not require opening the chest and can be performed in an outpatient setting.
Fitness and Diving Issue
An individual who has undergone coronary artery bypass grafting or angioplasty (with or without stent placement) may have suffered significant cardiac damage prior to having the surgery. The post-operative cardiac function of individuals dictates their fitness for diving.
Anyone who has had open-chest surgery needs appropriate medical evaluation prior to scuba diving. After a period of stabilization and healing (6-12 months is usually recommended), the individual should have a thorough cardiovascular evaluation prior to being cleared to dive. He or she should be free of chest pain and have normal exercise tolerance, as evidenced by a normal stress EKG test (13 mets or stage 4 of the Bruce protocol - defined at the end of previous section on MI). If there is any doubt about the success of the procedure or how open the coronary arteries are, the individual should refrain from diving.
For more information on cardiovascular conditions, see the complete article by Dr. James L. Caruso on Cardiovascular Fitness and Diving from the July/August 1999 issue of Alert Diver.