A Fast Heart Rate And Dizziness

Dizziness is one of the most common reasons people visit the doctor. It can involve a variety of sensations, including light-headedness. Feeling light-headed or dizzy is often a precursor to fainting. According to the Merck Manual, fainting is usually associated with a reduction in blood flow to the brain. Under certain conditions, a fast heart rate not only causes the loss of blood flow that contributes to dizziness, but also creates a life-threatening situation that requires immediate attention. Not all situations where dizziness and a fast heart rate coincide are life-threatening, however. Identifying circumstances and clarifying symptoms during an event can give insight into distinguishing the difference.

Symptom Identification

In August 2010 the "American Family Physician" reported that dizziness, as a symptom, often fits into one of four categories: vertigo, loss of balance, feeling faint, or light-headedness. Vertigo and loss of balance are often associated with inner ear conditions, whereas light-headedness and feeling faint are representative of cardiovascular conditions. However, if there is concern in the event of a fast heart rate and dizziness --- of any kind --- always seek medical attention immediately.

Role of Cardiovascular System

Dizziness occurs from a lack of oxygen supplied to the brain, according to the Mayo Clinic. Since oxygen is carried via the blood, and the cardiovascular system controls the circulation of the blood, the heart rate may play a significant role during episodes of dizziness. A brief overview of the cardiovascular system helps to explain dizziness and a fast heart rate. It includes the heart, which pumps blood into circulation, and the vessels, which permeate nearly every tissue in the body. Blood is pumped out of the heart with coordinated, synchronized contractions; it moves through the vessels with balanced, steady pressure. A lack of oxygen to the brain occurs either when blood-oxygen levels are poor or when circulation is poor. In both cases, the heart typically responds by increasing its rate to deliver more oxygen. Dizziness and a fast heart rate may occur because of situational circumstances, or it may have a sudden onset for no apparent reason.

Situational Explanations

Many people have experienced dizziness resulting from orthostatic hypotension. Orthostatic hypotension is the medical term for the abrupt, yet brief loss of blood pressure that occurs when standing up to fast. Whenever blood pressure falls, the heart typically responds by increasing its rate. Going from sitting to standing, however, would hardly create a noticeable fast heart rate; but, there are other reasons blood pressure drops. According to the National Heart Lung and Blood Institute, dehydration is the most common cause of orthostatic hypotension. Dehydration can occur if fluids are not replenished during physical activity. Other situations to be aware of that cause a fast heart rate and dizziness include beginning a new prescription or over-the-counter medication, as well as anxiety or panic attacks.

Significance in Unexplained Circumstances

An arrhythmia is a heart rhythm that affects the heart's ability to pump blood into circulation. To understand rhythmic versus arrhythmic heartbeats, consider the following: a single heart contraction is similar to the events taking place when a series of dominoes falls down. As long as everything is set up and aligned, a single tap of the appropriate domino initiates a smooth cascade, knocking down each domino in sequence. The heart performs this setting-up and knocking-down task about 60 to 100 times per minute. This rhythmic sequence underlies the heart's vigor to pump efficiently; however, disruption results when the chain of events is initiated in the lower chambers of the heart, called the ventricles. The contractions may increase in speed and become chaotic. If sustained, the heart loses all ability to maintain circulation. Ventricular arrhythmias can occur suddenly and without warning or cause, according to the Heart Rhythm Society.

Assessing the Situation

Identifying stressors, knowing exercise limitations, and consulting with your physician or pharmacist on medications are all important to assessing concerns that arise regarding a rapid heart rate and sensations of dizziness. Considering the situation surrounding an event is a sound means for deciding whether the event was normal or abnormal. It allows you to act sooner when warranted, and it alleviates anxiety when unwarranted.