Focal Atrial Tachycardia
A cardiac arrhythmia characterized by a regular rhythm greater than 100 beats per minute originating from a single site in the left or right atrium outside the sinus node due to a mechanism of enhanced automaticity or microreentry. Electrocardiographically, there is generally a single P wave morphology that is distinct from the sinus P wave. Patients generally present with palpitations or, in rare cases, syncope. Underlying causes include hypertension, cardiomyopathy, myocardial infarction, infection, hypokalemia, hypoxia, theophylline, cocaine, or other stimulants. Many cases are idiopathic.
Multifocal Atrial Tachycardia
A cardiac arrhythmia characterized by an irregular rhythm greater than 100 beats per minute originating from multiple sites in the left and right atria, resulting in at least three distinct P wave morphologies. Underlying pulmonary disease (most commonly chronic obstructive pulmonary disease) is present in the majority of cases, although decompensated heart failure is also present in many patients. The arrhythmia is often an incidental finding with symptoms of underlying pulmonary disease or congestive heart failure (ie, shortness of breath, cough, fatigue) predominating, although palpitations may be present.
I49.8 – Other specified cardiac arrhythmias
276796006 – Atrial tachycardia