L-type calcium channel
L-type calcium channel blocker drugs are used as cardiac antiarrhythmics or antihypertensives , depending on whether the drugs have higher affinity for the heart ( the phenylalkylamines , like verapamil ) , or for the blood vessels ( the dihydropyridines , like nifedipine ) . 
<triplet> calcium channel blocker <subj> antihypertensives <obj> subclass of <triplet> verapamil <subj> calcium channel blocker <obj> subclass of <subj> antiarrhythmics <obj> subject has role <triplet> dihydropyridines <subj> calcium channel blocker <obj> subject has role <triplet> nifedipine <subj> calcium channel blocker <obj> subclass of