How long does it take for adrenaline-induced tachycardia to resolve?

Resolution Time for Adrenaline-Induced Tachycardia

Adrenaline-induced tachycardia typically resolves within minutes to hours after the cessation of adrenaline exposure, with most cases returning to normal sinus rhythm within 6 hours. The exact timeline depends on the dose, route of administration, and individual patient factors.

Pathophysiology and Timeline

• Adrenaline (epinephrine) causes tachycardia through stimulation of beta-adrenergic receptors, which increases heart rate and contractility 1
• The half-life of circulating adrenaline is very short (approximately 2-3 minutes), which means its direct cardiovascular effects begin to diminish shortly after discontinuation 1, 2
• Most patients will experience normalization of heart rate within minutes to hours after adrenaline is discontinued 3
• In cases where tachycardia persists longer, resolution typically occurs within 6 hours of rate control interventions 1

Management Approaches

Immediate Interventions

• Vagal maneuvers (Valsalva, carotid sinus massage) can be attempted as first-line interventions for symptomatic tachycardia 1
• These should be performed with the patient in the supine position, with the Valsalva maneuver involving bearing down against a closed glottis for 10-30 seconds 1
• Applying an ice-cold, wet towel to the face (diving reflex) may also be effective in terminating tachycardia 1

Pharmacological Management

For persistent tachycardia requiring intervention:

• Beta-blockers (esmolol, metoprolol, propranolol) are first-line agents for adrenaline-induced tachycardia and can effectively counteract the beta-adrenergic stimulation 1, 2
• Non-dihydropyridine calcium channel antagonists (verapamil, diltiazem) may be used in hemodynamically stable patients without pre-excitation syndromes 1
• Adenosine (3-12 mg IV) can be effective for diagnostic purposes and may terminate certain forms of supraventricular tachycardia but has a very short half-life 1

Monitoring and Follow-up

• Heart rate should be monitored until it returns to normal range (60-80 beats per minute at rest) 1
• For patients with persistent tachycardia, 24-hour Holter monitoring may be useful to evaluate the heart rate response over time 1
• Criteria for adequate rate control typically involve achieving ventricular rates between 60-80 beats per minute at rest and between 90-115 beats per minute during moderate exercise 1

Special Considerations

• In patients with underlying heart conditions, resolution may take longer and require more aggressive interventions 1
• Sustained, uncontrolled tachycardia lasting more than 6 hours can lead to tachycardia-induced cardiomyopathy, which typically resolves within 6 months of achieving rate control 1
• If tachycardia recurs after initial resolution, it may develop over a shorter period and be associated with a poorer prognosis 1
• Beta-blockers may be more effective than beta-1-selective agents in controlling the electrocardiographic and metabolic effects of adrenaline 2

Pitfalls and Caveats

• Avoid using verapamil in patients who have received beta-blockers due to risk of profound bradycardia and hypotension 1
• Verapamil should not be used for SVTs associated with Wolff-Parkinson-White syndrome as it may precipitate ventricular tachycardia/fibrillation 1
• In patients with pre-excitation syndromes, avoid AV nodal blocking agents (beta-blockers, calcium channel blockers, digoxin) as they may paradoxically accelerate ventricular response 1
• For hemodynamically unstable patients, synchronized cardioversion should be performed promptly rather than waiting for pharmacological interventions to take effect 1