Asian Cardiovasc Thorac Ann 2002;10:198
© 2002 Asia Publishing EXchange Pte Ltd
Left Atrial Reduction: Isolation of the Pulmonary Veins
Ovidio A García-Villarreal, MD
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Department of Cardiothoracic Surgery Hospital of Cardiovascular Diseases and the Chest No. 34 Instituto Mexicano del Seguro Social Monterrey, Nuevo León 67130, Mexico
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I have read with attention the article of Erdo
an and colleagues1 regarding left atrial reduction. This procedure is increasingly used during mitral valve (MV) surgery, with the dual objectives of downsizing the left atrium (LA) and reestablishing sinus rhythm.2,3 This surgical technique includes extirpation of the base of the left atrial appendage, which is the major source of embolus in patients with MV disease and atrial fibrillation (AF), as well as resection of the LA in a circumferential band or half-moon fashion, and isolation of the pulmonary veins. The fundamental objective of this procedure should be analyzed. A giant LA is defined as greater than 8 cm in diameter. Nevertheless, AF is frequently present when the LA diameter is less than 8 cm; one of the most important factors in the origin and maintenance of AF is LA diameter greater than 4.5 cm.4 Haissaguerre and colleagues5 demonstrated that the ectopic electrical stimuli that trigger and produce AF are located in the pulmonary veins in up to 96% of cases. Elimination of AF and restoration of sinus rhythm must be the priority, rather than reduction of left atrial diameter, except in cases of giant LA. Therefore, the crucial step in this surgical technique is total isolation of the pulmonary veins by means of surgical incisions. In this way, the chaotic electrical stimuli that produce AF are isolated, preventing their passage from the pulmonary veins to the interior of the LA.
I have performed left atrial reduction in 25 cases of MV disease, with successful elimination of AF in 92% (23/25). All patients were restored to normal sinus rhythm. Two patients showed recurrence of AF within the first postoperative week, but they reverted on antiarrhythmic medication. In 3 redo MV cases, it was not possible to reduce the size of the LA, due to the existence of strong adhesions between the base of the left atrial appendage and the pericardium. Nevertheless, the results were excellent in terms of eliminating AF.
In my view, the utility of the left atrial reduction procedure is multiple: elimination of the highly frequent AF by isolation of the pulmonary veins, reduction in the size of the LA, and amputation of the left atrial appendage. However, it must be emphasized that the greatest benefit of this technique derives from surgical isolation of the pulmonary veins, thereby restoring normal sinus rhythm in most of the patients undergoing this procedure.
REFERENCES
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Erdoan HB,
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2001;9:171–5.[Abstract/Free Full Text]
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García-Villarreal OA, Rodríguez H, Treviño A, Gouveia AB, Argüero R. Left atrial reduction and mitral valve surgery: the "functional-anatomic unit" concept. Ann Thorac Surg
2001;71:1044–5.[Abstract/Free Full Text]
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Sankar NM, Farnsworth AE. Left atrial reduction for chronic atrial fibrillation associated with mitral valve disease. Ann Thorac Surg
1998;66:254–6.[Abstract/Free Full Text]
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Ortiz de Murúa JA, del Carmen Avila M, Ochoa C, de la Fuente L, Moreno de Vega JC, del Campo F, et al. Independent predictive factors of acute and first year success after electrical cardioversion in patients with chronic atrial fibrillation [Spanish]. Rev Esp Cardiol
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Haissaguerre M, Jais P, Shah DC, Takahashi A, Hocini M, Quiniou G, et al. Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med
1998;339:659–66.[Abstract/Free Full Text]
