Editing Palpitations (section)

===Evaluation===

Most patients who experience palpitations have harmless underlying causes.<ref name="Robinson Sanchack 2019" /> The main purpose of further testing is to identify individuals with higher risk of serious arrhythmia.<ref name="Robinson Sanchack 2019" /> 

A 12-lead electrocardiogram must be performed on every patient complaining of palpitations.<ref name="Robinson Sanchack 2019"/>  The presence of a short PR interval and a delta wave ([[Wolff-Parkinson-White syndrome]]) is an indication of the existence of ventricular pre-excitation.<ref name="Robinson Sanchack 2019"/>  Significant left ventricular hypertrophy with deep septal Q waves in I, L, and V4 through V6 may indicate [[hypertrophic obstructive cardiomyopathy]].<ref name="Robinson Sanchack 2019"/>  The presence of Q waves may indicate a prior [[myocardial infarction]] as the etiology of the palpitations, and a prolonged QT interval may indicate the presence of the long QT syndrome.<ref name="Robinson Sanchack 2019"/>

Laboratory studies should be limited initially.<ref name="Robinson Sanchack 2019"/>  A [[complete blood count]] can assess for anemia and [[infection]].<ref name="Robinson Sanchack 2019"/>  Serum [[urea]], [[creatinine]] and [[electrolyte]]s assess for [[electrolyte imbalance]]s and [[renal dysfunction]].<ref name="Robinson Sanchack 2019"/>  [[Thyroid function test]]s may reveal hyperthyroidism.<ref name="Robinson Sanchack 2019"/>

Further diagnostic testing is recommended for those in whom the initial diagnostic evaluation (history, physical examination, and EKG) suggest an arrhythmia, those who are at high risk for an arrhythmia, and those who remain anxious to have a specific explanation of their symptoms.<ref name="Robinson Sanchack 2019"/>  People considered to be at high risk for an arrhythmia include those with organic heart disease or any myocardial abnormality that may lead to serious arrhythmias.<ref name="Robinson Sanchack 2019"/>  These conditions include a [[scar]] from myocardial infarction, [[Cardiomyopathy|idiopathic dilated cardiomyopathy]], clinically significant valvular regurgitant, or stenotic lesions and hypertrophic cardiomyopathies.<ref name="Robinson Sanchack 2019"/>

An aggressive diagnostic approach is recommended for those at high risk and can include ambulatory monitoring or electrophysiologic studies.<ref name="Robinson Sanchack 2019"/> There are three types of ambulatory EKG monitoring devices: [[Holter monitor]]s, continuous-loop event recorders, and an [[implantable loop recorder]]s.<ref name="Robinson Sanchack 2019"/> Patients should be made aware of the properties of the device and the accompanying course of examination.<ref name="Robinson Sanchack 2019"/> The Holter monitor is a 24-hour monitoring system that is worn by exam takers themselves and records and continuously saves data.<ref name="Robinson Sanchack 2019"/>  Holter monitors are typically worn for a few days.<ref name="Robinson Sanchack 2019"/>  The continuous-loop event recorders are also worn by the exam taker and continuously record data, but the data is saved only when someone manually activates the monitor.<ref name="Robinson Sanchack 2019"/>  The continuous-loop recorders can be long worn for longer periods of time than the Holter monitors and therefore have been proven to be more cost-effective and efficacious than Holter monitors.<ref name="Robinson Sanchack 2019"/>  Also, because the person triggers the device when he/she feel the symptoms, they are more likely to record data during palpitations.<ref name="Robinson Sanchack 2019"/>  An implantable loop recorder is a device that is placed subcutaneously and continuously monitors for cardiac arrhythmias.<ref name="Robinson Sanchack 2019"/>  These are most often used in those with unexplained syncope and can be used for longer periods of time than the continuous loop event recorders. An implantable loop recorder is a device that is placed subcutaneously and continuously monitors for the detection of cardiac arrhythmias.<ref name="Robinson Sanchack 2019"/>  These are most often used in those with unexplained syncope and are a used for longer periods of time than the continuous loop event recorders.<ref name="Robinson Sanchack 2019"/>  Electrophysiology testing enables a detailed analysis of the underlying mechanism of the cardiac arrhythmia as well as the site of origin.<ref name="Robinson Sanchack 2019"/>  EPS studies are usually indicated in those with a high pretest likelihood of a serious arrhythmia.<ref name="Robinson Sanchack 2019"/> The level of evidence for evaluation techniques is based upon consensus expert opinion.<ref name="Robinson Sanchack 2019"/>

Most people with palpitations display normal heart structure, but valvular defects are possible. In these cases, a doctor may hear a murmur and perform an [[echocardiogram]].