afib aflutter svt

A Fib is uncoordinated firing of the Atria cells, creating a fibrillation pattern on ECG. The atria is unable to contract while in fibrillation, which puts the patient at risk for blood pooling within the atria and developing into a clot. Flutter is coordinated depolarization of the atria, producing a saw tooth pattern on ECG. The rate of depolarization of the atria contraction is usually 250-450. The atria do contract, but don't contract well; therefore, these patients are also at risk for developing a clot and embolism, but not as much as the fib patients. The term supraventricular tachycardia is a broad term encompassing all conditions in which the ventricle is tachycardic and the electrical origin of tachycardia is above the ventricle (eg in the AV node, or atria). It can be sinus tachycardia, A Fib or A flutter (when the electrical impulses are transmitted through to the ventricles), etc. It can be distinguished from Ventricular tachycardia on ECG because you normally see narrow QRS waves (V tach produces wide QRS waves because the electrical depolarization of the heart does not use the conduction system (bundle of His, purkinje fibers, etc, which allow for coordinated depolarization of the heart), whereas SVT does.