Pericardial Effusion/Tamponade

A pericardial effusion is viewed as an echo free space surrounding the heart,most commonly seen posteriorly. Echocardiography provides a semiquantitative assessment of pericardial efision and a qualitative description of its distribution.It can be quantified into small, moderate and large pericardial effusion. A small pericardial effusion is defined as less than 5mm in maximum dimension.Moderate pericardial effusion typically are 10-15mm in dimension and tends to be more circumferential. Large effusions are defined as more than 15mm.

When amount of pericardial efision is massive, the heart may have "swinging" motion in pericardial cavity.

It is important to differentiate between pericardial and pleural efision differences are tabulated below

Plax view-large PE 1.9 cm posteriorly

SAX view-PE present all around

Four chamber view-PE around lateral wall, apex

(Two-dimensional echocardiographic views showing large PE but no evidence of tamionade)

Cardiac Tamponade

Cardiac tamponade is1 failure of adequate cardiac output as a result of a pericardial effusion idterfering with right and left ventricular filling.

Two Dimensional ech~cardiographic Plax and four C view in-patient with
~nassive pericardial effusion with evidence of diastolic LV collapse

M-Mode and 2D Ech~cardiography signs are:

1) Early diastolic collkapse of the RV.(most specific) [Fig. 3.2 (a) and (b)]

2) Late diastolic RA collapse. (Most sensitive)

3) Abnormal ventricular septa1 motion.

4)Respiratory variation in ventricular chamber size.

5) Dilated Inferior vena cava (>2 cm) with inspiratory collapse of < 50 per cent.

M-Made across &C showing dilatation and decreased inspiratory collapse

Doppler Echocardiographic Features
Doppler findings of cardiac tarnponade are based on the following characteristic respiratory variations in intrathoracic and intracardiac hemodynamics.

1) The normal respiratory variation of the tricuspid valve is 25 per cent, with a greater velocity in inspiration than expiration; and the normal mitral valve shows the opposite pattern with a variation of approximately 15 per cent. In hernodynamically significant effusion, there is greater than usual variation in the respiratory pattern (> 25 per cent in mitral position and > 40 per cent in
tricuspid position.)

Fig. 3.4 (a): Pulse wave Doppler across mitral valve in-patient with tamponade showing respiratory variation. Mitral inflow velocity decreases with inspiration and increases with expiration.

Fig. Pulse wave Doppler across tricuspid valve showing respiratory variation.
Tricuspid inflow velocity has opposite changes in inspiration.
 

Pulse wave Doppler across hepatic vein showing increased expiratory flow
reversal in diastole.

2) Inspiratory decrease and expiratory increase in pulmonary vein diastolic forward flow and expiratory decrease in hepatic vein forward flow and increase in expiratory reversal flow.

Other Important Observations are:

1) Is the left ventricdlar function poor? (Pericardiocentesis may cause circulatory collapsk).

2) If the effusion is $mall, but respiratory variability of the left sided velocities is present or the patient is significantly breathless, consider effusive-constrictive pericalrditis.

Reporting Pericardiai Effusion
1) Size and distribution.

2) Evidence of tampbnade.

3) Is there enough fliuid in the direction of proposed drainage?

4) Left ventricular fulnction.