Left atrial dilatation in constrictive pericarditis: a pre and post-operative echocardiographic study.

Thirty-three surgically proven cases of constrictive pericarditis were studied pre-operatively by echocardiography for left atrial dilatation and 18 of them underwent post-operative study at a mean follow-up period of 229 +/- 105 days. The degree of left atrial dilatation in these patients was compared with patients of restrictive cardiomyopathy (n = 8) and sex matched controls of similar age (n = 33). Significant left atrial dilatation was present in patients of constrictive pericarditis compared to controls and it was of a similar or greater degree compared to patients of restrictive cardiomyopathy (the left atrium to aorta ratio was 1.7 +/- 0.31, 1.53 +/- 0.18 and 1.07 +/- 0.1, in constrictive pericarditis, restrictive cardiomyopathy and controls, respectively, P = NS for constrictive pericarditis vs. restrictive cardiomyopathy and P < 0.001 for constrictive pericarditis vs. controls). There was no correlation of degree of left atrial dilatation with clinical and hemodynamic variables. Postoperatively, there was regression of left atrial size in patients with normal hemodynamics (n = 12, pre- vs. post-operative left atrium to aorta ratio 1.65 +/- 0.23 vs. 1.32 +/- 0.14, P < or = 0.001) and persisting or increasing left atrial dilatation in patients with persisting hemodynamic abnormality (n = 6, left atrium to aorta ratio 1.66 +/- 0.23 vs. 1.82 +/- 0.15, P = NS). We conclude that significant left atrial dilatation is a consistent echocardiographic feature of constrictive pericarditis. Hemodynamic normalization following successful pericardiectomy is associated with regression of atrial size.