We appreciate Dr Kern's interest and thoughtful remarks regarding our case of loculated pericardial effusion. 1 First, we would like to address the issue of the reliability of the recordings presented. The published tracings of pericardial pressure were obtained via a pigtail catheter, which was positioned in the pericardial cavity over the wire, after injection of echo-contrast through the needle confirmed the intrapericardial position of the needle. Thus, we are completely certain that the

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... ves correctly demonstrate intrapericardial pressure tracings; multiple subsequent recordings were obtained as the effusion was drained, with a corresponding decline of the pressure. We agree that in a case of free-flowing pericardial effusions, leftand right atrial and ventricular diastolic pressures rise with subsequent equalization. As Dr Kern points out, compression of right chambers leads to hemodynamic compromise. However, loculated pericardial effusions may cause a different hemodynamic situation. Loculated pericardial effusions may be associated with regional cardiac tamponade, which occurs when any of the cardiac chambers may be compressed by the loculated effusion. 2 They also usually are accompanied by localized pericardial adhesions, which may protect other chambers from the effect of elevated intrapericardial pressure, especially after cardiac surgery, as in our case. 3 In our patient the ventricularized tracing of the pericardial effusion was due to the transmission of pressure from the left ventricle to the pericardial effusion caused by the outward movement of the free wall of the left ventricle in systole. This pressure was not transmitted uniformly to the right atrium or right ventricle to cause the hemodynamic sequelae described by Dr Kern; right atrial and right ventricular pressures were elevated, but complete collapse could not ensue due to adhesions, which were holding these chambers open. Partial collapse was seen on echocardiograms. Space constraints and the format of the case presentation prevented us from demonstrating all relevant images. It is well described that regional tamponade may cause atypical hemodynamic findings and reduced cardiac output with unilateral filling pressure elevation. 2 We agree with Dr Kern that our case is particularly interesting and a striking example of atypical hemodynamic behavior of a loculated pericardial effusion. Disclosures None. References 1. Syros G, Maysky M. High-pressure loculated pericardial effusion in postpericardiotomy syndrome.