Cardiac quandary

Among the specifically disqualifying medical conditions found in FAR Part 67, an “established medical history or clinical diagnosis” of any of the six cardiac pathologies requires an authorization for special issuance, which is a discretionary, time-limited medical certification. They include: myocardial infarction; angina pectoris (chest pain associated with underlying coronary heart disease); coronary heart disease that has required treatment, or, if untreated, that has been symptomatic or clinically significant; cardiac valve replacement; permanent cardiac pacemaker implantation; heart “replacement.”

The medical records and testing review for most of these cardiac histories require hospitalization records including admission history and physical exam, preoperative diagnostic testing results, imaging studies such as coronary angiography, any reports of surgical procedures, and the discharge summary. That is the historical information that doesn’t change.

The other important part is the current diagnostic testing conducted post-operatively to assess how you’re doing as a result of the corrective fixes. The FAA wants a “maximal” exercise stress test defined by reaching the maximum predicted heart rate (220 minus your age) or at least 85 percent of the predicted maximum calculation. Nine minutes is the standard protocol—a stress test of three stages of three minutes each, with an increasing treadmill speed and incline for each stage. (After age 70, the minimum duration is six minutes.) A 24-hour ambulatory heart monitor and an echocardiogram make up the baseline cardiac testing.

The FAA will pay attention to your stress test results. If the stress ECG is positive for a condition called ischemia, meaning the heart muscle isn’t getting an adequate blood flow during exercise stress, certification will likely be denied. The presence of arrhythmias—and there are all kinds of cardiac arrhythmias—may also be problematic.

An echocardiogram captures dimensional performance data on the heart, as well as structural viability of the heart valves that control the one-way flow of blood into the aorta. A key performance value is the ejection fraction (EF), the volume of blood that is pumped out of the left ventricle with each contraction. A normal EF is about 50 percent or more, and the FAA looks at a minimum of 40 percent as a base for medical certification purpose.