Pseudo right atrial overloading pattern in complete defect of the left pericardium.

Two cases with complete defect of the left pericardium showing tall and peaked P waves in the right precordial leads are described. A review of the literature has yielded nine cases with uncomplicated complete defect of the left pericardium showing similar P wave changes. Right heart catheterization, performed in nine cases, including the present two cases, revealed no evidence of an intracardiac shunt in any case and normal intracardiac pressure in eight cases. Therefore, this P wave changes seems to be related to intrathoracic shift in cardiac position permitted by the absence of the restraining pericardium.