Subacute Constrictive Pericarditis with Cardiac Tamponade David H. Spodick, M.D., Sudarshan Kumar, M.B.  Diseases of the Chest  Volume 54, Issue 1, Pages 62-66 (July 1968) DOI: 10.1378/chest.54.1.62 Copyright © 1968 The American College of Chest Physicians Terms and Conditions

Figure 1 Initial ECG showing 2:1 ventricular electric alternation. This is seen in all lead tracings, but is most striking in V5. Diseases of the Chest 1968 54, 62-66DOI: (10.1378/chest.54.1.62) Copyright © 1968 The American College of Chest Physicians Terms and Conditions

Figure 2 Sequential ECG tracings obtained from precordial monitoring electrodes during pericardiocentesis. Control trace (top) shows 2:1 ventricular alternation which diminishes as fluid is withdrawn, disappearing after removal of 130 ml. Diseases of the Chest 1968 54, 62-66DOI: (10.1378/chest.54.1.62) Copyright © 1968 The American College of Chest Physicians Terms and Conditions

Figure 3 Induced pneumopericardium following pericardi-centesis. Polyethylene catheter outlined by diatrizoate (Hypaque) (dash-like interruptions of contrast medium are due to air in the tubing). A small pericardial cavity is disclosed by the air with haziness and a “cut-off” appearance superiorly. Diseases of the Chest 1968 54, 62-66DOI: (10.1378/chest.54.1.62) Copyright © 1968 The American College of Chest Physicians Terms and Conditions

Figure 4A Frontal plane vectrocardiographic loops showing the two types observed during electric alternation. Diseases of the Chest 1968 54, 62-66DOI: (10.1378/chest.54.1.62) Copyright © 1968 The American College of Chest Physicians Terms and Conditions

Figure 4b Horizontal plant loops similarly recorded to A. Alternation was not as striking as in scalar traces (Fig 1). (Technical imperfections were tolerated because VCGs were recorded while awaiting emergency equipment.) Diseases of the Chest 1968 54, 62-66DOI: (10.1378/chest.54.1.62) Copyright © 1968 The American College of Chest Physicians Terms and Conditions