Dear Barbara, thank you for your question. Lithium can cause slow heart rhythms (termed bradycardias) to occur. If you were having bradycardia, then your heart may not have been beating fast enough to supply your brain with nutrients and oxygen. Thus, you had fainting spells. A pacemaker automatically causes a heartbeat if the heart rhythm is too slow and prevents fainting spells. From what you write, it sounds like you do need a pacemaker so I would not recommend any additional tests.
I hope you find this information useful. Information provided in the heart forum is for general purposes only. Only your physician can provide specific diagnoses and therapies. Please feel free to write back with additional questions. Good luck!
If you would like to make an appointment at the Cleveland Clinic Heart Center, please call 1-800-CCF-CARE or inquire online by using the Heart Center website at www.ccf.org/heartcenter. The Heart
Center website contains a directory of the cardiology staff that can be used to select the physician best suited to address your cardiac problem.