Atrial fibrillation (AF) is the most common arrhythmia in the world. It is associated with significant morbidity and mortality secondary to its detrimental sequelae: (1) palpitations resulting in patient discomfort and anxiety; (2) loss of atrioventricular (AV) synchrony, which can compromise cardiac hemodynamics, resulting in various degrees of ventricular dysfunction or congestive heart failure; (3) stasis of blood flow in the left atrium, increasing the risk of thromboembolism and stroke.1–10
Medical treatment of AF has many shortcomings. Because of this, interest in nonpharmacologic treatment approaches led to the development of catheter-based and surgical techniques beginning in the 1980s. Initial attempts aimed at providing rate control failed to address the detrimental hemodynamic and thromboembolic sequelae of atrial fibrillation. The early attempts at finding a surgical treatment culminated in the introduction of the Maze procedure in 1987, which became the gold standard for many years.
The following sections describe the historical aspects of surgery for AF, and the current state of surgical ablation for the treatment of AF, including recent minimally invasive techniques.
The Left Atrial Isolation Procedure
The first surgery designed specifically to eliminate AF, the left atrial isolation procedure, was described in 1980 in the laboratory of Dr. James Cox at Duke University. This approach confined AF to the left atrium, and restored the remainder of the heart to sinus rhythm (Fig. 58-1).11 This procedure reestablished a regular ventricular rate without requiring a permanent pacemaker. Isolating the left atrium allowed the right atrium and the right ventricle to contract in synchrony, providing a normal right-sided cardiac output. This effectively restored normal cardiac hemodynamics.
Standard left atriotomy, demonstrating incisions to the mitral valve annulus at both the 10 and 2 o'clock positions. The superior and inferior vena cavae are seen with tourniquets, and the pulmonary vein orifices are seen inferiorly. Cryoablation is used to complete the line of conduction block at the valve annuli. (Adapted from Williams JM, Ungerleider RM, Lofland GK, Cox JL: Left atrial isolation: new technique for the treatment of supraventricular arrhythmias. J Thorac Cardiovasc Surg 1980; 80(3):373-380.)
By confining AF to the left atrium, the left atrial isolation procedure only eliminated two of the three detrimental sequelae of AF: an irregular heartbeat and compromised cardiac hemodynamics. It did not eliminate the thromboembolic risk because the left atrium usually remained in fibrillation. This procedure never achieved clinical acceptance, although it was performed by Dr. Cox in a single patient.
Catheter Ablation of the Atrioventricular Node–His Bundle Complex
In 1982, Scheinman and coworkers introduced catheter fulguration of the His bundle, a procedure that controlled the irregular cardiac rhythm associated with AF and other refractory supraventricular arrhythmias.12 This procedure electrically isolated the fibrillation to the atria. Unfortunately, ablating ...