What is the treatment for tachycardia using ivabradine?

Treatment of Tachycardia with Ivabradine

Ivabradine is FDA-approved and guideline-recommended for heart rate reduction in specific tachycardia conditions, with the strongest evidence supporting its use in heart failure with reduced ejection fraction (HFrEF), inappropriate sinus tachycardia (IST), and postural orthostatic tachycardia syndrome (POTS). 1

Primary Indication: Heart Failure with Reduced Ejection Fraction

For patients with HFrEF (LVEF ≤35%) in sinus rhythm with resting heart rate ≥70 bpm on maximally tolerated beta-blockers, ivabradine reduces hospitalization risk and is a Class IIa recommendation. 2

Dosing Strategy for HFrEF:

• Start with 5 mg twice daily with meals for most patients 2, 1
• Start with 2.5 mg twice daily for patients with history of conduction defects or age ≥75 years 2
• Assess after 2 weeks and titrate based on resting heart rate 1:
  • If HR >60 bpm: increase by 2.5 mg twice daily (maximum 7.5 mg twice daily)
  • If HR 50-60 bpm: maintain current dose
  • If HR <50 bpm or symptomatic bradycardia: decrease by 2.5 mg twice daily or discontinue 1

Critical Prerequisites:

• Patient must be in sinus rhythm (not persistent/chronic atrial fibrillation or 100% atrial pacing) 2
• Beta-blocker must be optimized to maximum tolerated dose first 2
• History of paroxysmal atrial fibrillation is acceptable if sinus rhythm present ≥40% of time 2

Inappropriate Sinus Tachycardia (IST)

Ivabradine is a Class IIa recommendation for symptomatic IST, particularly when beta-blockers are not tolerated or fail to control symptoms. 2, 3

Evidence for IST:

• Reduces daytime heart rate from 98±11 bpm to 85±9 bpm (p<0.001) 2
• More effective than metoprolol alone in one observational study 2
• Improves exercise tolerance and quality of life scores significantly 4, 5
• Persistent benefit observed in 80% of patients even after discontinuation 4

Dosing for IST:

• Start 2.5-5 mg twice daily 2
• Titrate to 5-7.5 mg twice daily based on response 2, 5
• Can be combined with beta-blockers for refractory cases, though monitor closely for excessive bradycardia 2

Postural Orthostatic Tachycardia Syndrome (POTS)

Ivabradine is recommended by the American College of Cardiology as a reasonable option for POTS, especially when beta-blockers cause intolerable fatigue or are contraindicated. 3

POTS-Specific Considerations:

• Particularly effective for patients with severe fatigue exacerbated by beta-blockers 3
• Quality of life improvements documented after one month of treatment 3
• Dose range: 2.5-7.5 mg twice daily 3
• Does not lower blood pressure, making it advantageous in hypotension-prone POTS patients 3

Vasovagal Syncope with Sinus Tachycardia

For the subset of vasovagal syncope patients demonstrating sinus tachycardia before collapse on tilt testing, ivabradine shows promise with 72% reporting marked benefit or complete symptom resolution 6. Doses of 5-20 mg/day (mean 10.7 mg) were used 6.

Absolute Contraindications

Do not use ivabradine in patients with: 1

• Acute decompensated heart failure
• Blood pressure <90/50 mmHg
• Sick sinus syndrome, sinoatrial block, or 3rd-degree AV block (without pacemaker)
• Severe hepatic impairment (Child-Pugh C)
• Pacemaker dependence
• Concomitant strong CYP3A4 inhibitors (clarithromycin, itraconazole, ketoconazole, ritonavir, etc.) 2, 1
• Avoid with diltiazem or verapamil 2

Common Pitfalls and Safety Monitoring

Atrial Fibrillation Risk:

• Increases atrial fibrillation incidence by 0.7% absolute risk 2
• Regularly monitor cardiac rhythm and discontinue if atrial fibrillation develops 1

Phosphenes (Visual Phenomena):

• Occur in 3-15% of patients 2, 3
• Described as transient enhanced brightness in visual field 1
• Usually mild, transitory, and rarely require discontinuation (<1%) 2

Bradycardia:

• Monitor closely when combining with other negative chronotropes (digoxin, amiodarone) 1
• Risk factors include sinus node dysfunction, conduction defects, and ventricular dyssynchrony 1
• Symptomatic bradycardia occurred in 2.7% per patient-year in SHIFT trial 1

NOT Indicated For:

Ivabradine should NOT be used for: 2

• Acute treatment of focal atrial tachycardia (use IV beta-blockers, diltiazem, or verapamil instead) 2
• Patients with stable coronary artery disease and preserved left ventricular function (SIGNIFY trial showed potential harm in this population) 2
• Supraventricular tachycardia requiring acute cardioversion 2

Duration of Treatment

Continue ivabradine as long-term therapy for chronic conditions like HFrEF and IST, with regular heart rate monitoring. 7 Some IST patients maintain benefit even after discontinuation, suggesting potential disease-modifying effects 4.