Ivabradine in acute care: Revisiting the funny current in critical care context

Table 2 Comparison of ivabradine and beta-blockers

Variable	Ivabradine	Beta-blockers
Mechanism	Blocks If channels in SA node (reduces HR only)	Block β1/β2-adrenergic receptors (reduces HR + BP)
Common side effects	Luminous phenomena (visual brightness). Bradycardia. Headache. Rare: Atrial fibrillation	Fatigue. Cold. hands/feet. Bronchospasm (worsens COPD/asthma) Erectile dysfunction. Sleep disturbances. Depression
Metabolic effects	Neutral (no impact on glucose/Lipids)	May worsen: Insulin resistance. Triglycerides (↑). HDL (↓)
Contraindications	HR < 60 bpm. Acute heart failure. Pacemaker-dependent	Asthma/COPD. Severe bradycardia. Heart block (2nd/3rd degree)
Advantages	Pure HR control. Safe in lung diseases. No sexual dysfunction. No metabolic interference	Broader benefits (angina, HTN, post-MI). Lower cost
Uses	COPD/asthma patients. Diabetes patients. HR reduction without BP effects	Hypertension. Post-heart attack. Arrhythmias

HR: Heart rate; BP: Blood pressure; HDL: High-Density Lipoprotein; COPD: Chronic obstructive pulmonary disease; HTN: Hypertension, MI: Myocardial infarction; SA: Sinoatrial; If: Funny current.