Calcium Channel Blockers: Action: Block calcium access to the cells, causing decreased heart contractility and conductivity and leading to a decreased demand for oxygen Uses: Angina HTN Dysrhythmias (verapamil and diltiazem) Contraindications: Nifedipine: hypersensitivity Verapamil: severe left ventricular dysfunction, decreased BP, cardiogenic shock, or heart block diltiazem: sick sinus syndrome, heart block, decreased BP, acute MI, or pulmonary congestion Precautions: Renal or hepat...