Asked by Sera
Verapamil is a non-DHP CCB which inhibits the entry of calcium ions into the slow L-type calcium channels in:
a. Myocardium: Negative chronotropic and inotropic effect
b. Coronary vascular smooth muscle: Coronary vasodilation and improved myocardial oxygen delivery
In patients with normal or mildly impaired left ventricular function, verapamil's vasodilator and negative inotropic effects are counterbalanced. With severe left ventricular dysfunction (LVEF <30%), however, treatment with verapamil can result in abrupt decompensation and development of overt pulmonary edema and hypotension.
References:
1. Fahie S, Cassagnol M. Verapamil. [Updated 2023 Feb 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538495/
2. Colucci WS, Fifer MA, Lorell BH, Wynne J. Calcium channel blockers in congestive heart failure: theoretic considerations and clinical experience. Am J Med. 1985 Feb 22;78(2B):9-17. doi: 10.1016/0002-9343(85)90164-0. PMID: 3976695.
