Management of Sinus Tachycardia

Diagnosis and Classification

• The American College of Cardiology defines physiological sinus tachycardia as heart rate >100 bpm in response to appropriate physical, emotional, pathological, or pharmacologic stimuli 3, 2
• Physiological sinus tachycardia can be caused by emotional stress or anxiety 4, hypovolemia or anemia 5, medications such as caffeine, nicotine, salbutamol, atropine, catecholamines 5, and recreational drugs like amphetamines, cocaine, ecstasy, cannabis 5
• Inappropriate sinus tachycardia (IST) is characterized by persistent elevation in resting heart rate (>100 bpm) unrelated to or disproportionate to physical, emotional, or pharmacologic stress 4
• IST predominantly affects healthcare professionals and females (90%) with a mean age of presentation around 38 years 6
• Symptoms of IST include palpitations, chest pain, shortness of breath, dizziness, and pre-syncope 6

Diagnostic Approach

• A 12-lead ECG showing P waves positive in leads I, II, and aVF; negative in aVR is indicative of sinus tachycardia 5
• The P wave axis in the frontal plane should be between 0° and 90° 2
• P waves may be peaked but with normal contour 2, 7
• Nocturnal normalization of rate on 24-hour Holter monitoring is a characteristic feature of IST 2

Management

• The American College of Cardiology recommends beta blockers as the first-line pharmacological therapy for symptomatic sinus tachycardia 1, 2
• Beta blockers are effective for emotional stress and anxiety-related tachycardia 4 and provide prognostic benefit after myocardial infarction 1
• Non-dihydropyridine calcium channel blockers like diltiazem or verapamil can be used as an alternative to beta blockers 6
• Sinus node modification by catheter ablation can be considered for refractory cases of IST 3
• The American College of Cardiology suggests that beta blockers provide symptomatic and prognostic benefits in heart failure patients, but monitoring for worsening heart failure is necessary 1