Dominant EEG frequencies of patients undergoing dobutamine stress test

Abstract

There has been considerable research and speculation that if the brain is under stress then it could affect the heart and lead to heart disease. The purpose of the present research was to examine the inverse problem of whether the heart could potentially cause undesirable reactions in the brain. One method to evaluate for underlying coronary artery disease is to perform stress testing. Often, myocardial stress is achieved by the patient walking on a treadmill while being monitored. In patients who are unable to exercise, pharmacologic stress testing is performed, either with vasodilatory agents (e.g. adenosine) or dobutamine, which is a pro-inotropic and chronotropic drug. During dobutamine infusion, the heart rate increases, but there is a negligible increase in blood pressure. Five patients who were undergoing dobutamine stress testing were instrumented with the standard 19 electrode EEG sensors to record brain activity. It was found that all patients showed resonance in the brain activity at frequencies around 10Hz. The signal strengths and the electrode locations where a resonance varied between patients. The one location where all of the patients showed resonance was at T5-O1; towards the back of the head and for this location, all patients showed an EEG resonance frequency at approximately 10Hz. Further analysis of the EEG data is needed to appreciate the consequences of this neurocardilogical phenomenon.