Located in southeastern New Mexico, Carlsbad Caverns lie beneath the Earth's surface and were formed when limestone was dissolved by sulfuric acid during the last ice age.
There are three types of rate control medications: Beta Blockers, which slow the heart rate and relax the blood vessels. Examples include Atenolol (TenorminÂ®), Carvedilol (Coregâ¢), Metoprolol (Toprol XLâ¢, LopressorÂ®), and Sotalol (BetapaceÂ®)
1 These medicines can slow your heartbeat too much.  You faint or have other symptoms of a slow heartbeat. For example, this may happen if the main artery in your neck that supplies your brain with blood is sensitive to pressure. Just quickly turning your neck can cause your heart to beat slower than normal.