A normal healthy heart beats 60 to 100 beats per minute. An irregular beat is known as cardiac arrhythmias. Heart rates that are above or below the normal range is not considered an arrhythmia.

Irregular heartbeat and heart rate are two independent conditions which may or may not manifest together. An arrhythmia which occurs with a low heart rate is known as bradyarrhythmia and with faster heart rate is called tachyarrhythmia.

Types of Cardiac Arrhythmias

Arrhythmias are classified into four types:

1. Premature Arrhythmias

The most common type of arrhythmias is premature in nature. These are mostly harmless and aren’t known for causing serious symptoms. When symptoms do occur, these are manifestations of fluttering sensation or a feeling similar to skipping a beat.

In healthy individuals, premature arrhythmias do not demand medical attention. Premature beats which occur in the upper chamber of the heart are known as premature atrial contractions (PAC) and in the ventricles, premature ventricular contractions (PAV). Premature beats can occur due to excess nicotine or caffeine consumption or by overexertion.

2. Ventricular Arrhythmias: A dangerous arrhythmia which requires immediate medical attention is ventricular arrhythmia. Included here are ventricular fibrillation (v-fib) and ventricular tachycardia. Ventricular arrhythmias are caused by heart attacks, coronary heart diseases and through weakened heart muscles.

• Ventricular Tachycardia: A regular heartbeat but at a quick pace which is short lived. A few increased beats are not of concern but when the incidents start to occur frequently, it is best to seek medical attention. Untreated ventricular arrhythmias can turn into a serious v-fib condition.

• Ventricular Fibrillation: V-fib is a condition where the electric signals in the heart are short-circuited. Instead of a regular movement of flap open and close, the flaps quiver because of an electric surge. When the ventricles don’t pump enough blood out of the heart, sudden death by cardiac arrest can occur. Treating v-fib is through defibrillation (electric shock directly to the heart).

3. Supraventricular Arrhythmias: These are primarily associated with tachycardia or fast heartbeats. Subtypes are:

• Atrial Fibrillation (AF): Irregular and fast contraction in the atria which has two major side effects being heart failure and stroke. Here, the electrical signal which regulates the heartbeat originates from the pulmonary vein instead of the SA node. AF becomes life-threatening when it induces ventricles to attain a fast beating pace. AF is generally caused when there is damage to the heart’s electrical system.

• Paroxysmal Supraventricular Tachycardia (PVST): Here, the heart starts to beat fast and ceases all of a sudden. PVST is a manifestation of an obstructed signal between the ventricles and atria. PVST is common in young children and young adults.

• Atrial Flutter: Similar to AF but the heartbeat is not irregular.

4. Bradyarrhythmias: When the heart rate is slower than the normal range, it is known as bradyarrhythmia. In some people, especially the ones who are physically fit, the normal heartbeat range is lower. In others, however, bradyarrhythmia is caused by heart attacks, beta blockers, digoxin, calcium channel blockers and a chemical imbalance in the blood.

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