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

2. 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  , 62-66DOI: ( /chest )
Copyright © 1968 The American College of Chest Physicians Terms and Conditions

3. 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 Control trace (top) shows 2:1 ventricular alternation which diminishes as fluid is withdrawn, disappearing after removal of 130 ml.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  , 62-66DOI: ( /chest )
Copyright © 1968 The American College of Chest Physicians Terms and Conditions

4. 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  , 62-66DOI: ( /chest )
Copyright © 1968 The American College of Chest Physicians Terms and Conditions

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

6. 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  , 62-66DOI: ( /chest )
Copyright © 1968 The American College of Chest Physicians Terms and Conditions