What is cardiac arrhythmia?
Cardiac arrhythmia is a term that denotes a disturbance of the heart rhythm. Cardiac arrhythmias can range in severity from entirely benign to immediately life-threatening. If arrhythmia is suspected, a cardiologist should be consulted for confirmation. In addition, the use of natural substances for arrhythmia should always be supervised by a doctor. A cardiac
arrhythmia, also called cardiac dysrhythmia, is a disturbance in the regular rhythm of the heartbeat. Several forms of cardiac arrhythmia are life-threatening and a medical emergency.
A rhythm of the heart at a rate of more than 100 beats/minute is considered a tachycardia. If the ventricles of the heart sustain a tachycardia for a sustained period of time, there can be deleterious effects. Individuals may sense a tachycardia as a pounding sensation of the heart; this is known as "palpitations". However, strictly speaking, palpitations are any sensation of an individual's own heart beat, and can occur at rates less than 100 beats/minute. The causes of tachycardias are numerous, and include stress, ingested or injected substances (ie: caffeine, alcohol, hyperthyroidism, or various drugs). Individuals who have a tachycardia are often advised to limit or remove exposure to any causative agent. A slow rhythm, known as bradycardia (less than 60 beats/min), is usually not life threatening, but may cause symptoms. Either arrhythmia requires medical attention to evaluate the risks associated with the arrhythmia.
In normal adults, the heart beats regularly at a rate of 60 to 100 times per minute, and the pulse (felt at the wrist, neck or elsewhere) matches the contractions of the heart's ventricles (the heart's two powerful lower chambers). The heart's atria (two upper chambers) also contract to help fill the ventricles, but this milder contraction occurs just before the ventricles contract, and it is not reflected in the pulse. Under normal circumstances, the signal for a heartbeat comes from the heart's sinus node, the natural pacemaker located in the upper portion of the right atrium. From the sinus node, the heartbeat signal travels to the atrioventricular node, or "A-V node," (located between the atria) and through the bundle of His (pronounced HISS — a series of modified heart muscle fibers located between the ventricles) to the muscles of the ventricles. This triggers a contraction of the ventricles and produces a heartbeat.
Cardiac arrhythmias sometimes are classified according to their origin as either ventricular arrhythmias (originating in the ventricles) or supraventricular arrhythmias (originating in heart areas above the ventricles, typically the atria). They also can be classified according to their effect on the heart rate, with bradycardia indicating a heart rate of less than 60 beats per minute and tachycardia indicating a heart rate of more than 100 beats per minute.