<unk>  is a hyperpolarization-activated cyclic nucleotide-gated channel blocker that is FDA approved for the prevention of hospitalization for worsening heart failure in patients with stable, symptomatic chronic heart failure with left ventricular ejection fraction ≤ 35%, who are in sinus rhythm with resting heart rate ≥ 70 beats per minute and either are on maximally tolerated doses of beta-blockers or have a contraindication to beta-blocker use.   Common adverse reactions include bradycardia, hypertension, atrial fibrillation and luminous phenomena (phosphenes) ( ≥ 1%).
Ivabradine
Dimetilan
Lofexidine
Propafenone
Maprotiline
Verapamil
Procainamide
Tocainide