Externally applied cardiac rhythm monitors are common tools used to diagnose symptoms that may or may not be related to cardiac rhythm abnormalities. Common problems that may lead to the use of cardiac rhythm monitors are syncope (loss of consciousness), near-syncope (near loss of consciousness), palpitations (the sensation of an abnormal heart beat), or monitoring of known cardiac rhythm problems like atrial fibrillation. The purpose of this research is to confirm the clinical value of a much easier-to-use cardiac rhythm monitoring system, hereafter referred to as the Investigational Monitoring System. Prior to discussing the investigational monitoring system, we will review standard electrocardiographic monitoring tools used to evaluate the heart's rhythm.