Is a heart rate of 138 beats per minute (bpm) significant enough to warrant emergency room (ER) evaluation for tachycardia?

From the Guidelines

A heart rate of 138 beats per minute (bpm) is not typically considered significant enough to warrant emergency room evaluation on its own, unless accompanied by other symptoms or underlying conditions, as suggested by the 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1. When evaluating the significance of a heart rate of 138 bpm, several factors must be considered, including:

• The presence of symptoms such as chest pain, shortness of breath, dizziness, or fainting
• The persistence of the rapid heart rate at rest
• The presence of underlying heart conditions
• The patient's age and overall health status According to the guidelines, a tachycardia rate of 150 beats per minute is considered more likely to be attributable to an arrhythmia, and many experts suggest that a heart rate below 150 bpm is unlikely to cause symptoms of instability unless there is impaired ventricular function 1. In general, for healthy individuals, a temporary elevation to 138 bpm during exercise, stress, or anxiety is normal and typically does not require emergency care. However, if the elevated heart rate is causing distress or if the patient is unsure about the cause, it is better to err on the side of caution and seek medical evaluation, as tachycardia can sometimes indicate serious underlying conditions that require prompt treatment. The evaluation and management of tachyarrhythmias, as depicted in the ACLS Tachycardia With Pulse Algorithm, emphasize the importance of determining whether the tachycardia is the primary cause of the presenting symptoms or secondary to an underlying condition 1. It is essential to note that the 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care do not provide new recommendations specifically addressing the significance of a heart rate of 138 bpm 1. Additionally, the 2003 ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias emphasize the importance of diagnostic evaluation, including a 12-lead ECG, but do not provide specific guidance on the significance of a heart rate of 138 bpm 1.

From the Research

Tachycardia Treatment and ER Evaluation

• A heart rate of 138 beats per minute (bpm) is considered significant and falls under the category of tachycardia, as it exceeds the normal heart rate of 100/min 2.
• Tachycardia can be further classified into different types, including supraventricular tachycardias (SVTs) and ventricular tachycardia (VT), each requiring distinct treatment approaches 2.
• The decision to send a patient to the emergency room (ER) for tachycardia evaluation depends on various factors, including the severity of symptoms, underlying medical conditions, and the presence of other concerning signs or symptoms.

Treatment Options for Tachycardia

• Adenosine, adrenaline, ajmaline, amiodarone, and atropine are commonly used medications for treating tachycardia, with the specific choice depending on the type and severity of the arrhythmia 2.
• Beta-blockers, such as metoprolol and propranolol, may also be used to control heart rate and prevent arrhythmic events in patients with tachycardia 3, 4, 5.
• Amiodarone has been shown to be effective in treating stable ventricular tachycardia in the prehospital setting, with a moderate success rate and relatively low risk of adverse events 6.

ER Evaluation Criteria

• Patients with tachycardia who exhibit severe symptoms, such as chest pain, shortness of breath, or syncope, should be evaluated in the ER 2.
• Those with underlying medical conditions, such as heart failure or coronary artery disease, may also require ER evaluation to rule out potential complications 3, 4.
• The presence of broad QRS complexes or other abnormal electrocardiogram findings may indicate a more serious arrhythmia, such as ventricular tachycardia, and warrant ER evaluation 2.