Figure 20-1 Atrial fibrillation.
© Jones & Bartlett Learning.
Atrial fibrillation (Afib) is one of the most common arrhythmias you will run across in your clinical practice. Afib affects millions of people. In addition to the hemodynamic consequences of the arrhythmia, atrial fibrillation is a leading cause of debilitating and deadly strokes. The prevalence in our society increases with age, making Afib even more of a health concern as the “baby boomer” generation continues to age.
Atrial fibrillation is an irregularly irregular rhythm that is marked by an absence of observable P waves (Figure 20-1). Atrial activity in atrial fibrillation is electrocardiographically represented by a continuous, randomly occurring series of oscillations known as fibrillatory or f waves. These waves are best seen in lead V1. The f wave rates are typically between 400 and 600 beats per minute (BPM), and the ventricular response can be variable, involving the entire spectrum from bradycardia to very fast tachycardias. Clinically, atrial fibrillation is characterized by a lack of organized atrial activity and the accompanying loss of the atrial kick. The arrhythmia can be further classified as either paroxysmal, persistent, or permanent.
Figure 20-1 Atrial fibrillation.
© Jones & Bartlett Learning.
NOTE
It is important to make a distinction between F waves and f waves. F waves are the flutter waves seen in atrial flutter. The f waves we are talking about in this chapter refer to fibrillatory waves that are found in atrial fibrillation.
Paroxysmal atrial fibrillation occurs acutely. The patient’s episodes are usually very short lived, lasting anywhere from a few seconds to a few days. In many cases, the rhythm may actually spontaneously convert back and forth between atrial fibrillation and sinus rhythm. The symptoms of paroxysmal atrial fibrillation are usually more pronounced, compared with the persistent or permanent subtypes, because compensatory mechanisms are usually not in play during acute episodes. The sudden hemodynamic compromise and rapid pulmonary fluid buildup associated with paroxysmal episodes cause the patient to experience acute shortness of breath, congestive heart failure, light-headedness, palpitations, syncope, and other disabling complications. In many cases, these symptoms spontaneously resolve with termination of the arrhythmia.
Persistent atrial fibrillation refers to a chronic form of the arrhythmia, but one that can still be converted using either pharmacologic means or cardioversion. Permanent atrial fibrillation, on the other hand, is a chronic, stable form of the arrhythmia that does not lend itself to conversion by any means, or once converted, spontaneously reverts back to a fibrillatory pattern.