Cardiac Arrhythmia - Rapid or Irregular Heartbeat

When doctors speak of cardiac arrhythmia, they mean a category of conditions manifested by irregular heartbeat that is faster or slower than normal. Some forms of cardiac arrhythmia can be life threatening because they can lead to cardiac arrest and sudden death. Other forms of cardiac arrhythmia can bring about aggravating symptoms. These include an acute awareness of a different heartbeat, or the annoying condition of heart palpitation.

Sinus arrhythmia manifests itself with a moderately fast heartbeat, followed by slowing of the normal rhythm that comes with breathing. The normal adult heart rate ranges from 60 beats per minute to 100 beats per minute. A small area in the upper chamber of the heart, known as the sinoatrial node or sinus node, controls it.

Tachycardia, on the other hand, pertains to a fast heartbeat of above 100 beats per minute. The number of heartbeats changes with age, meaning that a younger person’s heartbeat is naturally faster than that of an older person's. The sinus node increases its rate of electrical activity to accelerate the heart rate during exercise. The normal fast rate resulting from exercise is sinus tachycardia. Cardiac arrhythmias caused by fast, abnormal electrical activity can result in dangerous tachycardia disorders.

There can be severe problems if the ventricles of the heart experience one of these tachycardia conditions for a prolonged period. Patients often perceive a tachycardia as a pounding sensation of the heart known as heart palpitation. If a tachycardia results in lowered blood pressure, it sometimes causes lightheadedness, dizziness or even fainting. Overly fast tachycardia can impede the pump function of the heart and this can cause sudden death.

Bradycardia is a slowed rhythm, meaning a heart rate of less than 60 beats per minute. This is usually not a life-threatening problem, but it can result in symptoms that may require implantation of a permanent pacemaker. Either type of cardiac arrhythmia calls for medical attention, since a doctor must evaluate the risks associated with them.

Fibrillation numbers among the more serious types of cardiac arrhythmias. In fibrillation, the heart’s muscle begins a quivering motion caused by a lack of coordination in contractile cell function. This type of cardiac arrhythmias can affect the atrium and cause atrial fibrillation. It can also affect the ventricle and cause ventricular fibrillation, which is imminently life threatening.

Doctors call a quivering, chaotic motion in the upper chambers of the heart atrial fibrillation. The causative factor for this type of cardiac arrhythmia is usually a serious underlying medical condition, which needs medical evaluation. However, it does not always qualify as a serious medical emergency. Another variant is ventricular fibrillation, which happens in the lower chambers (or ventricles) of the heart. Without timely administration of medical treatment, this kind of cardiac arrhythmia can lead to death within minutes. Effective pumping of blood stops when a heart goes into what doctors call ‘V-fib’, a condition considered as a form of cardiac arrest.

Patients suffering from it are unlikely to survive unless they receive cardiopulmonary resuscitation and defibrillation immediately. In the last minutes of life, almost all persons go into ventricular fibrillation because the heart muscle reacts to diminished oxygen or general blood flow, trauma, irritants, or depression of electrical impulses themselves from the brain.