Do I need to order an echocardiogram (echo) for patients with recurrent syncope and bradycardia?

From the Guidelines

Yes, you should order an echocardiogram for patients with recurrent syncope and bradycardia. This recommendation is based on the latest guidelines from the American College of Cardiology, American Heart Association, and Heart Rhythm Society, as outlined in the 2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1. An echocardiogram is essential to evaluate cardiac structure and function, which may reveal underlying causes such as valvular disease, cardiomyopathy, or wall motion abnormalities that could contribute to the patient's symptoms.

The yield of echocardiography is higher when there are clinical indications of structural disease, including in patients with syncope who manifest signs or symptoms of cardiac disease, such as bradycardia or conduction disorders 1. Furthermore, echocardiographic parameters like left ventricular end-diastolic diameter and ejection fraction can predict adverse cardiac events, such as syncope, heart failure, and atrial tachyarrhythmias, in patients with symptomatic sinoatrial node dysfunction (SND) 1.

In addition to the echocardiogram, other evaluations such as 12-lead ECG, Holter monitoring, and possibly tilt-table testing should be performed to comprehensively assess the patient's condition. The results of these tests will guide further management decisions, including medication adjustments, pacemaker consideration, or other interventions. Early identification of structural heart disease is crucial as it significantly impacts treatment approach and prognosis in patients with recurrent syncope and bradycardia.

Key points to consider when evaluating patients with recurrent syncope and bradycardia include:

• The importance of transthoracic echocardiography in identifying structural cardiac abnormalities underlying bradycardia or conduction disturbance 1
• The role of ambulatory electrocardiographic monitoring in symptomatic patients with conduction system disease 1
• The consideration of advanced imaging, such as cardiac MRI, computed tomography, or nuclear studies, in selected patients with suspected structural heart disease and unrevealing echocardiogram 1

From the Research

Ordering an Echocardiogram for Recurrent Syncope and Bradycardia

• The decision to order an echocardiogram (echo) for patients with recurrent syncope and bradycardia depends on various factors, including the patient's history, physical examination, and electrocardiogram (ECG) results 2.
• According to a study published in the Journal of Hospital Medicine, the diagnostic yield of echocardiogram for detecting clinically important abnormalities in patients with a normal history, physical examination, and ECG is extremely low 2.
• However, echocardiograms performed on patients with syncope and a positive cardiac history, abnormal examination, and/or ECG can identify an abnormality in up to 29% of cases 2.
• A study published in the American Journal of Cardiology found that bradycardia causing syncope was found in 8 out of 17 patients with recurrent presyncope or syncope, and a bundle branch block at the initial evaluation predicted the occurrence of bradycardia at follow-up 3.
• The role of echocardiography in the evaluation of syncope was studied in a prospective study published in the journal Heart, which found that echocardiography was most useful for assessing the severity of the underlying cardiac disease and for risk stratification in patients with unexplained syncope but with a positive cardiac history or an abnormal ECG 4.
• Another study published in the journal Pacing and Clinical Electrophysiology found that implanted devices with monitoring functions can be used to diagnose syncope in patients with infrequent recurrent syncope undiagnosed after extensive noninvasive and invasive testing 5.
• The American College of Cardiology recommends echocardiogram only if initial history or examination suggests a cardiac etiology, or ECG is abnormal 2.
• In patients with recurrent syncope and bradycardia, an echocardiogram may be ordered if the patient has a positive cardiac history, abnormal examination, and/or ECG, or if the patient has a high risk of cardiac complications 3, 2, 4.