Pericardial tamponade is a collection of pericardial fluid that accumulates around the heart. Tamponade occurs when enough fluid accumulates (pericardial effusion) to the point where intrapericardial pressure is greater than the intracardiac pressure, resulting in impaired cardiac filling
The most common pediatric etiologies include the following:
1) Following cardiac surgery (54%), most common after ASD repair (incidence as high as 28%)
The pericardium has limited stretch response to accommodate increased fluid. After this point, intrapericardial pressure begins to steeply rise. This will occur more quickly and with less volume in the setting of a rapidly accumulating effusion. When intrapericardial pressure becomes greater than intracardiac pressure the diastolic pressure among all 4 chambers equalizes. The result is a marked increase in ventricular interdependence with impaired cardiac filling and stroke volume. Conditions with reduced ventricular interdependence (pulmonary hypertension, hypertrophic cardiomyopathy) may mask findings of pericardardial tamponade.
Goals of Echocardiographic Exam
Measure the size and location of the pericardial effusion (at end diastole)
Trivial (seen only in systole)
Small (< 10 mm)
Moderate (10-20 mm)
Large (> 20 mm)
Localized versus circumferential
Assess for elelvated intrapericardial pressure
Right ventricular collapse in diastole (earliest sign)
Right atrial collapse in systole (late sign)
Inferior vena cava dilation with loss of respiratory variation
Markers of pulsus paradoxus
Increased tricuspid inflow variability on spectral Doppler (normal <40%)
Increased mitral inflow variability on spectral Doppler (normal <25%)
Increased tricuspid E wave and decreased mitral E wave
Exaggerated aortic outflow variability on spectral Doppler (note: patient must be spontaneously breathing and not on mechanical ventilation)
Armstrong, William F and Thomas Ryan. Feigenbaum’s Echocardiography. 7th ed. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins Health, 2010.
Baskar S, Ivan W. Pediatric Pericarditis. Latest in Cardiology from the American College of Cardiology 2016. Available at: http://www.acc.org/latest-in-cardiology/articles/2016/06/08/11/43/pediatric-pericarditis. Accessed January 17, 2017
Imazio M, Adler Y. Management of pericardial effusion. European Heart Journal. 2013;34(16):1186-1197.
Klein AL, Abbara S, Agler DA, et al. American Society of Echocardiography Clinical Recommendations for Multimodality Cardiovascular Imaging of Patients with Pericardial Disease. Journal of the American Society of Echocardiography. 2013;26(9):965–1012.e15.