Abstract
To eliminate abnormal electrical activity in the posterior wall of the left atrium, extensive pulmonary vein isolation is performed to treat symptomatic, drug-refractory atrial fibrillation. In addition to clinical visual information, detailed anatomical knowledge of the left atrium is necessary to create an effective ablation line. We studied the dimensions and histological properties of the anatomical obstacles surrounding the pulmonary vein in human heart autopsy specimens. Specimens were obtained from 23 individuals (median age: 63 years); none showed a clinical history of tachyarrhythmia or major cardiac abnormalities. Distances between the following structures were measured: right superior pulmonary vein – fossa ovalis, right inferior pulmonary vein – fossa ovalis, fossa ovalis – mitral annulus, left superior pulmonary vein – left atrial appendage, left atrial appendage – mitral annulus, left inferior pulmonary vein – mitral annulus, and left superior pulmonary vein – left inferior pulmonary vein. Among the obstacles of the left atrium, the narrowest isthmus encircling the pulmonary vein was the ridge between the left superior pulmonary vein and left atrial appendage with a median width of 8.4 mm, minimum and maximum values varied as much as four fold. No correlation between the heart weight and distances between obstacles was found. A detailed understanding of the precise anatomy of the left atrium and its individual diversity seems helpful for the determination of the ablation line.
