Arrhythmia : DEFINITION Arrhythmia is defined as loss of cardiac rhythm, especially irregularity of heart-beat and is an abnormal cardiac rhythm, usually involving the change in rate or regularity and is monitored by using Electrocardiograph (ECG). PATHOPHYSIOLOGY The blood pushed from ventricles in a controlled sequence of muscle contraction. In cardiac arrhythmia, there will be disturbed in the sequence and in electrical conductivity. Arrhythmias are classified in to differentkinds depending upon the disorders of impulse generation and includes, Premature contraction - Common arrhythmia, which affect large number of people. Caffeine and stress increases the occurrence of premature beats. Tachycardia - An abnormally fast heart beats (more than 100beats/min) ,this can also lead to insufficient blood circulation. Bradycardia- An abnormally fast heart beats (more than 100beats/min). This can also lead to insufficient blood circulation. Atrial fibrillation- A rapid, irregular heart rhythm caused by abnormal electrical impulses that begins in the upper chambers of the heart.In atrial fibrillation the heart rate is even higher i.e. 500 beats/min. Atrial flutter - In atrial flutter the heart rate is 250-350 beats/min, associated with tachycardia.Commonly seen in hyperthyroidism and heart failure. Ventricular fibrillation - Life threatening condition in which the heartquivers very rapidly about 350times/min or more.This leads to rapidly fatal if not reversed by defibrillation.


Wolff-Parkinson-White syndrome : Wolff-Parkinson-White syndrome is a heart condition in which there is an abnormal extra electrical pathway of the heart. The condition can lead to episodes of rapid heart rate (tachycardia). Wolff-Parkinson-White syndrome is one of the most common causes of fast heart rate disorders in infants and children. Normally, electrical signals in the heart go through a certain pathway that helps the heart beat regularly. The wiring of the heart prevents extra beats from occurring and keeps the next beat from happening too soon. In people with Wolff-Parkinson-White syndrome, some of the heart's electrical signal goes down an extra (accessory) pathway. This may cause a very rapid heart rate called supraventricular tachycardia. A person with this syndrome may have: • Chest pain or chest tightness • Dizziness • Light-headedness • Fainting • Palpitations (a sensation of feeling your heart beat) • Shortness of breath Medication • Medicine such as adenosine, antiarrhythmic drugs, and amiodarone may be used to control or prevent a rapid heartbeat.


Atrial fibrillation : The ventricular rate in atrial fibrillation can be controlled with a beta-blocker or diltiazem.or verapamil. Digoxin is usually effective for controlling the rate at rest; it is also appropriate if atrial fibrillation is accompanied by congestive heart failure. If the rate at rest or during exercise cannot be controlled, diltiazem or verapamil may be combined with digoxin, but care is required if the ventricular function is diminished. In some cases, e.g. acute atrial fibrillation or paroxysmal atrial fibrillation, diltiazem or verapamil or a beta-blocker may be more appropriate than digoxin (see also Paroxysmal Supraventricular Tachycardia and Supraventricular Arrhythmias below). Anticoagulants are indicated especially in valvular or myocardial disease, and in the elderly; in the very elderly the overall benefit and risk needs careful assessment. Younger patients with lone atrial fibrillation in the absence of heart disease probably do not need anticoagulation. Aspirin is less effect than warfarin at preventing emboli but may be appropriate if there are no other risk factors for stroke; aspirin 75 mg may be used.


Atrial flutter : The ventricular rate at rest can sometimes be controlled with digoxin. Reversion to sinus rhythm (if indicated) may be achieved by appropriately synchronised d.c. shock. Alternatively, amiodarone may be used to restore sinus rhythm, and amiodarone or sotalol to maintain it. If the arrhythmia is long-standing a period of treatment with anticoagulants should be considered before cardioversion to avoid the complication of emboli. Drugs used - Digoxin, Amiodarone and Sotalol