EKG Evaluation for Dizziness

Indications and Recommendations

The American College of Cardiology/American Heart Association (ACC/AHA) recommends obtaining a 12-lead EKG in all patients presenting with dizziness, regardless of whether cardiac disease is suspected 1, 2, 3
The ACC/AHA explicitly classifies dizziness as a Class I indication, meaning electrocardiography is the first choice for these patients 1, 2, 3
Even when dizziness appears to have a non-cardiac cause, the EKG may reveal asymptomatic but life-threatening conditions such as silent myocardial infarction, long QT syndrome, or severe conduction abnormalities 1, 3
The EKG is the only practical, noninvasive method for detecting cardiac arrhythmias that may cause dizziness 1, 2
Electrocardiographic abnormalities may be the first indicators of life-threatening drug effects, severe metabolic disturbances, or electrolyte abnormalities 1, 3
An abnormal initial EKG predicts adverse outcomes and increased all-cause mortality at 1 year in patients presenting with dizziness or near-syncope 4
The low cost of EKG justifies its use even when serious abnormalities are rare, as it can reveal potentially life-threatening but treatable disorders 5, 6

Patients with known heart disease, previously documented arrhythmia, or pacemaker dependency presenting with dizziness require immediate EKG 7
Conduction abnormalities (atrioventricular block, bundle branch blocks) that may progress to complete heart block are critical EKG findings to identify 4, 8
QT prolongation suggesting risk for torsades de pointes and sudden cardiac death is a critical EKG finding to identify 4, 7
Signs of structural heart disease (left ventricular hypertrophy, Q waves suggesting prior infarction) are important EKG findings to identify 4

Exercise electrocardiographic testing is reasonable in patients with exercise-related dizziness or suspected chronotropic incompetence 4
Echocardiography should be performed if structural heart disease is suspected based on history, physical examination, or EKG findings 6
Orthostatic vital signs should be obtained to assess for orthostatic hypotension 6
Carotid sinus massage may be appropriate for unexplained dizziness in patients >60 years old 6

The prognostic value of an abnormal EKG outweighs its modest diagnostic yield, as it identifies patients at increased risk for adverse outcomes who require urgent specialist evaluation 4, 5, 6
The initial EKG provides a specific diagnosis in only approximately 5% of patients with dizziness or syncope, but approximately 10% of dizziness/syncope can be attributed to bradycardia or conduction disorders, and an additional 18% to neurally mediated syncope (often with bradycardia) 4