Treatment for Elevated Heart Rate in Adults Without Underlying Conditions
The primary treatment for tachycardia in adults without underlying conditions is to identify and treat the underlying cause rather than directly treating the heart rate itself, as the tachycardia is typically a physiologic response to an underlying stressor. 1
Initial Assessment and Stabilization
Immediately assess for hypoxemia and provide supplemental oxygen if needed, as hypoxemia is a common reversible cause of tachycardia. 1 Attach a cardiac monitor, evaluate blood pressure, and establish IV access while simultaneously investigating the underlying cause. 1
Obtain a 12-lead ECG to define the rhythm, but this should not delay treatment if the patient is unstable. 1 Evaluate for signs of increased work of breathing including tachypnea, intercostal retractions, and suprasternal retractions. 1
Determine if Tachycardia is Primary or Secondary
When heart rate is <150 bpm in the absence of ventricular dysfunction, the tachycardia is most likely secondary to an underlying condition rather than the primary cause of symptoms. 1 This is a critical decision point that determines your entire treatment approach.
Assess for Hemodynamic Instability
Look for rate-related cardiovascular compromise including: 1
- Acute altered mental status
- Ischemic chest discomfort
- Acute heart failure
- Hypotension or signs of shock
If the patient demonstrates these signs of instability AND heart rate >150 bpm, proceed to immediate synchronized cardioversion. 1
Identify and Treat Reversible Causes
For sinus tachycardia (heart rate >100 bpm with upright P waves in leads I, II, and aVF), no specific drug treatment is required. 1 Instead, therapy must be directed toward the underlying cause. 1
Common Reversible Causes to Evaluate:
Physiologic stressors: 1
- Fever or infection
- Dehydration
- Anemia
- Pain
- Hypotension/shock
Exogenous substances: 1
- Caffeine
- Beta-agonist medications (albuterol, salmeterol)
- Illicit stimulants (amphetamines, cocaine)
Medical conditions: 1
- Hyperthyroidism
- Heart failure
- Anxiety disorders
Critical Pitfall: Do Not Treat Compensatory Tachycardia
When cardiac function is poor, cardiac output can be dependent on a rapid heart rate. 1 In compensatory tachycardias where stroke volume is limited, "normalizing" the heart rate can be detrimental and potentially cause cardiovascular collapse. 1
Avoid rate-controlling medications (beta blockers, calcium channel blockers) when tachycardia is secondary to hypotension or shock, as the elevated heart rate is maintaining cardiac output. 2
Management of Inappropriate Sinus Tachycardia (IST)
If you have excluded all secondary causes and the patient has persistent symptomatic tachycardia (resting HR >100 bpm, average 24-hour HR >90 bpm) with debilitating symptoms like weakness, fatigue, or palpitations, consider IST. 1
Treatment Algorithm for IST:
First-line approach: 1
- Evaluation and treatment of any remaining reversible causes is mandatory (Class I recommendation)
- Recognize that lowering heart rate may not alleviate symptoms 1
Pharmacologic options (in order of preference): 1
- Ivabradine is reasonable for ongoing management (Class IIa recommendation) - this selectively reduces sinus node activity without other hemodynamic effects 1
- Beta blockers may be considered (Class IIb recommendation), though often ineffective or poorly tolerated due to hypotension 1
- Combination of beta blockers and ivabradine may be considered for refractory cases (Class IIb recommendation) 1
Non-pharmacologic approach: 1
- Exercise training may provide benefit, though unproven
- Because prognosis is generally benign, treatment may not be necessary if symptoms are tolerable 1
Important Caveats
Distinguish IST from postural orthostatic tachycardia syndrome, as treatment to suppress sinus rate in the latter may lead to severe orthostatic hypotension. 1 IST is a diagnosis of exclusion after ruling out all secondary causes. 1
IST predominantly affects females (90%) with mean age around 38 years, and anxiety is an important trigger that must be addressed. 1
Therapy with beta blockers or calcium channel blockers is often ineffective or not well tolerated in IST due to cardiovascular side effects like hypotension. 1