How to manage a heart rate of 180 beats per minute, specifically tachycardia?

Management of Heart Rate of 180 Beats Per Minute

A heart rate of 180 bpm requires immediate assessment of hemodynamic stability—if the patient shows signs of shock, altered mental status, chest pain, acute heart failure, or hypotension attributable to the tachycardia, proceed directly to synchronized cardioversion. 1

Initial Stabilization and Assessment

Provide supplementary oxygen immediately if the patient shows signs of increased work of breathing (tachypnea, retractions, paradoxical abdominal breathing) or inadequate oxyhemogation, as hypoxemia is a common cause of tachycardia. 1

• Attach cardiac monitor, establish IV access, and evaluate blood pressure. 1
• Obtain a 12-lead ECG to define the rhythm, but do not delay cardioversion if the patient is unstable. 1
• Identify and treat reversible causes (fever, anemia, hypotension, dehydration) while initiating treatment. 1

Critical Decision Point: Stable vs. Unstable

If the patient demonstrates rate-related cardiovascular compromise (acute altered mental status, ischemic chest discomfort, acute heart failure, hypotension, or shock), proceed immediately to synchronized cardioversion. 1

Synchronized Cardioversion Protocol for Unstable Patients

• Establish IV access and administer sedation if the patient is conscious, but do not delay if extremely unstable. 1
• For narrow-complex SVT: Initial energy 50-100 J biphasic, increase stepwise if unsuccessful. 1
• For atrial fibrillation: Initial energy 120-200 J biphasic, increase stepwise if unsuccessful. 1
• For monomorphic VT with pulse: Initial energy 100 J, increase stepwise if unsuccessful. 1

Management of Stable Patients with HR 180 bpm

Determine Rhythm Type

Narrow-complex tachycardia (QRS <0.12 seconds) suggests supraventricular origin and includes sinus tachycardia, atrial fibrillation, atrial flutter, AV nodal reentry, or accessory pathway-mediated tachycardia. 1

Wide-complex tachycardia (QRS ≥0.12 seconds) is most likely ventricular tachycardia until proven otherwise. 1

If Regular Narrow-Complex SVT (Likely Reentry)

Adenosine is first-line therapy for stable patients with regular narrow-complex SVT while preparations are made for cardioversion if needed. 1

• First dose: 6 mg rapid IV push followed by NS flush. 1
• Second dose: 12 mg if required. 1
• Adenosine terminates most reentrant SVTs and aids diagnosis. 2, 3

If Sinus Tachycardia

Do not treat the heart rate directly—sinus tachycardia at 180 bpm is physiologic and requires identification and treatment of the underlying cause (fever, anemia, hypotension, dehydration, hypoxia). 1

• The upper limit of sinus tachycardia is approximately 220 minus the patient's age. 1
• Critical warning: When cardiac function is poor, cardiac output depends on rapid heart rate, and "normalizing" the rate can be detrimental. 1
• For dysautonomic patients specifically, heart rates <150 bpm rarely cause hemodynamic instability unless ventricular dysfunction is present, and aggressive rate control is not indicated. 4

If Atrial Fibrillation or Flutter

For hemodynamically stable patients, pharmacologic rate control is appropriate:

• Beta-blockers or nondihydropyridine calcium channel blockers (diltiazem, verapamil) are first-line for rate control. 1, 5
• Target resting heart rate <100 bpm for adequate rate control. 1, 5
• Esmolol may be used for rapid IV rate control: 500 mcg/kg bolus over 1 minute, followed by 50 mcg/kg/min infusion, titrating up to 200 mcg/kg/min as needed. 6
• Digoxin is not recommended as monotherapy for rate control in active patients. 5
• Cardioversion should be considered if symptomatic hypotension, angina, or heart failure is present. 1

If Ventricular Tachycardia (Monomorphic, Stable)

Amiodarone is first-line: 150 mg IV over 10 minutes, followed by maintenance infusion of 1 mg/min for first 6 hours. 1

• Procainamide alternative: 20-50 mg/min until arrhythmia suppressed, hypotension occurs, QRS widens >50%, or maximum 17 mg/kg given; avoid if prolonged QT or CHF. 1
• Differentiate from accelerated idioventricular rhythm (rate <120 bpm), which is usually harmless and requires no treatment. 1

Critical Pitfalls to Avoid

Never use AV nodal blocking agents (beta-blockers, calcium channel blockers, digoxin, adenosine) in patients with Wolff-Parkinson-White syndrome and wide-complex tachycardia, as they can accelerate ventricular rate and precipitate ventricular fibrillation. 1

Do not aggressively treat compensatory tachycardia in patients with poor cardiac function or shock, as stroke volume is limited and cardiac output depends on the elevated heart rate. 1, 4

Rates <150 bpm are unlikely to cause instability unless ventricular dysfunction is present, so the tachycardia is more likely secondary to an underlying condition rather than the primary problem. 1