Syncope, i.e., passing out, is a rare, but documented, potential adverse occurrence of treadmill stress testing. It is usually listed as such in the informed consent that the patient signs prior to the test. Its mere occurrence, therefore, would not be a deviation from the standard of care. Of course, this assumes informed consent was obtained and, also, that the patient passed out.
The overwhelming majority of such instances of syncope have a vasovagal etiology (that is, when blood pressure and/or heart rate abruptly fall) and occur in the recovery period, i.e., the period following cessation of exercise. In a rare instances, a patient can pass out during exercise, but this would have to be secondary to a serious cardiac condition such as severe aortic stenosis, severe coronary artery disease, or a malignant arrhythmia.
What is overwhelmingly more likely is that a patient may experience some dizziness during exercise causing an inability to continue exercising. However, this would not cause a patient to pass out because undergoing a stress test would actually produce a higher heart rate and higher blood pressure which, in turn, would actually reduce or eliminate the possibility of “passing out.” What you would need to have is medical evidence to substantiate a cardiac abnormality (as noted above) which, in turn, would support your claim.
Syncope during treadmill testing medical expert witness specialties include cardiology, emergency medicine, interventional cardiology, heart failure cardiology, and cardiac electrophysiology.