Match the four surgical procedures that have been developed for the treatment of atrial fibrillation with the major detrimental sequela(e) of atrial fibrillation that each corrects

A. His bundle ablation.

1. Patient's sensation of irregular heart rhythm.

B. Left atrial isolation procedure.

1. Patient's sensation of irregular heart rhythm.

2. Hemodynamic compromise because of loss of AV synchrony.

C. Corridor procedure.

1. Patient's sensation of irregular heart rhythm.

D. Maze procedure.

1. Patient's sensation of irregular heart rhythm.

2. Hemodynamic compromise because of loss of AV synchrony.

3. Increased vulnerability to thromboembolism.

DISCUSSION: The surgical procedure most commonly employed for the treatment of atrial fibrillation is catheter ablation of the His bundle. The International Catheter Ablation Registry reveals that more than 60% of patients who undergo elective catheter ablation of the bundle of His do so for the treatment of atrial fibrillation. His bundle ablation is an isolation procedure, in that it confines the atrial fibrillation to the atria and protects the ventricles from the unpleasant sensation of an irregular heartbeat. Because the atria continue to fibrillate there is no restoration of AV synchrony, and therefore there is no improvement in cardiac hemodynamics. Moreover, the continuing fibrillation of the left atrium means that postoperatively the patient is still at the same risk for thromboembolism. Thus, His bundle ablation corrects only one of the three detrimental sequelae of atrial fibrillation, namely the arrhythmia problem.

The left atrial isolation procedure confines atrial fibrillation to the left atrium, allowing the sinus node to drive the remainder of the heart in a normal sinus rhythm. Thus, it alleviates the unpleasant sensation of an irregular heartbeat. In addition, because AV synchrony is re-established between the right atrium and right ventricle, right-sided cardiac output is restored to normal. This means that normal cardiac output is delivered through the lungs to the left side of the heart. In the presence of a normal left ventricle the left-sided cardiac output is also normal, despite the fact that left-sided AV synchrony is not present; however, because the left atrium is allowed to fibrillate, the vulnerability to thromboembolism remains unchanged postoperatively

The corridor procedure allows the sinus node to drive the heart in normal sinus rhythm, but because of the total isolation of the sinoatrial and AV nodes from the remainder of the atria, the atria may continue to fibrillate. Even if they do not, in effect they are isolated from their respective ventricles so that AV synchrony is lost on both sides of the heart. As a result, the corridor procedure alleviates the sensation of arrhythmia but does not restore normal hemodynamics, nor does it decrease vulnerability to thromboembolism. The maze procedure ablates the re-entrant circuits responsible for atrial fibrillation and restores the normal sinus rhythm. Thus, it alleviates the sensation of arrhythmia, restores normal hemodynamics, and alleviates the vulnerability to thromboembolism.