Cardiac arrhythmia is a group of conditions in which the electrical activity of the heart is irregular or is faster or slower than normal.

Cardiac arrhythmias comprise any abnormality or perturbation in the normal activation sequence of the myocardium. Arrhythmias stem from several causes. The heart's natural timekeeper - a small mass of special cells called the sinus node - can malfunction and develop an abnormal electrical impulse rate. CPR can prolong the survival of the brain in the lack of a normal pulse, but defibrillation is the intervention which is most likely to restore a more healthy heart rhythm. A slow rhythm, known as bradycardia (less than 60 beats/min), is usually not life threatening, but may cause symptoms. When it causes symptoms implantation of a permanent pacemaker may be needed. Either dysrhythmia requires medical attention to evaluate the risks associated with the arrhythmia. The signs and symptoms of cardiac arrhythmias can range from completely asymptomatic to loss of consciousness or sudden cardiac death.

Complaints such as:

• lightheadedness
• dizziness
• quivering
• shortness of breath
• chest discomfort
• heart fluttering or pounding
• and forceful or painful extra beats are commonly reported with a variety of arrhythmias

Beats are generated by electrical impulses in the atria (top chambers of the heart) and are then conducted to the ventricles, where they produce the powerful muscle contraction that pumps blood. People may have allergies or idiosyncratic reactions to many other foods and beverages that cause transitory arrhythmias. Long-term nicotine exposure and any cocaine exposure can cause much more serious arrhythmias. Oxidative stress is a common feature of ischemic-reperfusion injuries, which occur when the heart is temporarily deprived of oxygenated blood (a state known as ischemia), followed by the reintroduction of oxygenated blood (reperfusion). The development of arrhythmias includes congenital heart defects, coronary artery disease, high blood pressure (hypertension).

Advances in medicine and technology have created new treatment options for cardiac arrhythmia (commonly known as heart rhythm disturbances).

• Cardioversion is the application of electrical current across the chest wall to the heart and it is used for treatment of supraventricular or pulsed ventricular tachycardia.
• Defibrillation differs in that it is used for ventricular fibrillation and pulseless ventricular tachycardia, and more electricity is delivered with defibrillation than with cardioversion.
• Arrhythmias may involve medications (anti-arrhythmic therapy), catheter ablations, and implantation of pacemakers or implantable cardioverter defibrillators (ICD).
• Cardiac resynchronization therapy (CRT) or CRT-D (CRT with defibrillator therapy) is an innovative therapeutic option for patients with refractory HF.
• Antiarrhythmic medications help to change the electrical signals within the heart to suppress or prevent the arrhythmia.

Treatment for Cardiac Arrhythmias

• Using a small, battery-powered generator to deliver timed, electrical impulses to the heart muscle through tiny wire leads.
• The treatment for some patients is a technique called cardiac ablation.
• Magnetic guidance in the heart while transcatheter ablation is very effective, it can be difficult.
• Stereotaxis Niobe Magnetic Navigation System uses two superconductive magnets, a magnetic-tipped guide wire and advanced computer imaging techniques.
• Atrial fibrillation can also be treated through a procedure, e.g. pulmonary vein isolation.
• Fibrillation differs in that it is used for ventricular fibrillation and pulseless ventricular tachycardia.