The heart is a strong, muscular pump. It moves blood, which carries oxygen and other nutrients, to the body's tissues and supports and assists in metabolic processes. According to the American Heart Association, the normal range for a resting heart is 60 to 80 beats per minute. The rate is determined by the body's need for oxygen and other nutrients and is controlled by a complicated system of nerves and hormones. There are many factors that can increase or decrease heart rate, and doctors pay close attention to this as it can be an indicator or warning sign of many different diseases or conditions.
Substances
There are a number of different substances that can either increase or decrease heart rate. Many over-the-counter and prescribed medications can have an effect on the heart, either temporarily or permanently. According to the University of Utah's College of Pharmacy, caffeine is a central nervous system stimulant that increases heart rate and contraction force. Millions of people use caffeine on a daily basis. Other stimulant drugs, including Ritalin, cocaine, methamphetamine and nicotine, also increase heart rate. On the other hand, drugs such as beta blockers, opioid medications, barbiturates and benzodiazepines decrease heart rate.
Emotion
An individual's emotions can cause the release of hormones that affect heart rate. Adrenaline, or epinephrine, is a hormone that is released by the adrenal glands in response to stress, according to MayoClinic.com. Adrenaline causes the heart rate to increase, the breathing to increase, the levels of energy-providing glucose to increase and prepares the body for a fight or flight response to external triggers of stress. Conversely, when a person feels emotionally calm and free of stress, the heart rate decreases and the heart beats slowly.
Heart Damage
The heart, under normal circumstances, beats regularly and smoothly. The actual muscular contraction that is the heartbeat is controlled by an electrical stimulation that originates in specialized tissue within the heart, called the sino-atrial node. These electrical impulses travel in an organized fashion through the heart and cause the heart muscle to contract, giving the heart a regular beat. When the heart becomes damaged through disease or a heart attack, these electrical impulses often cannot travel appropriately, which can lead to irregularity in the heartbeat or an inability of the heart to contract properly, according to the National Heart, Lung and Blood Institute.
Dehydration
Everyone loses significant amounts of water every day through perspiration and waste excretion, according to the University of Maryland Medical Center. Normally, these fluids are replaced through drinking and eating foods that contain water. Dehydration is a condition that occurs when individuals do not replace enough fluids to maintain proper balance within their bodies. Dehydration can be caused by illness or medications. One of the side effects of dehydration is an increased heart rate as the heart becomes stressed due to lack of fluid.
Member Comments