Any disorder of heart rate or rhythm. Causes and Risks Arrhythmias are caused by a disruption of the normal electrical conduction system of the heart. The signal then travelsthrough the 2 atria and stimulates them to contract.
Problems can occur anywhere along the conduction system, causing various arrhythmias.
There can be a problem in the heart muscle itself, causing it to respond differently to the signal, or causing the ventricles to contract independently of the normal conduction system. Arrhythmias are classified as lethal if they cause a severe decrease in the pumping function of the heart. People who have a history of coronary artery disease , heart valve disorders, or other cardiac disorders, and people with imbalances of blood chemistries , are at higher risk for arrhythmias and complications from arrhythmias. Arrhythmias are also caused by some drugs. These include anti-arrhythmics, beta blockers, caffeine , cocaine, psychotropics, and sympathomimetics.