Nonuniform distribution of normal pericardial fluid

Abstract

It has been suggested that pericardial fluid functions as a lubricant rather than a means of transmitting pericardial pressure from one region of the heart to another. Since the functional behavior of pericardial fluid depends on fluid thickness, we measured pericardial volume and fluid distribution. In seven animals, we found that the normal canine pericardium contains 0.25 +/- 0.15 ml of pericardial fluid per kg of body weight, resulting in an average pericardial fluid thickness of only 0.34 +/- 0.27 mm. We next determined the pericardial fluid distribution in eight anesthetized mongrel dogs (17-29 kg). Color video images were recorded, while green dye (0.1 ml) was injected into the pericardial space overlying the ventricular apex to allow visualization of the pericardial fluid distribution. Within 26 +/- 17 s (range 15-53 s), dye reached the base of the heart. After 15 min of equilibration, the dye distribution appeared very nonuniform with dye accumulation over the interventricular and atrioventricular grooves. Little or no dye was present over the right and left ventricular free walls. We conclude that pericardial fluid thickness over the interventricular and atrio-ventricular grooves is sufficient to allow fluid motion in these regions. In contrast, pericardial fluid thickness overlying the ventricular free walls is very thin. Thus, in these regions the pericardial fluid functions primarily as a lubricant; and regional variations in pericardial pressure may occur.

Pharmacokinetic Advantage of Intrapericardially Applied Substances in the Rat

“…These volumes probably represent plasma volumes and are well within the range of previously determined plasma volumes of male Wistar rats (Lee and Blaufox, 1985;Wauquier and Devynck, 1989). Given the almost instantaneous mixing of injected compounds in pericardial space (Santamore et al, 1990), it seems reasonable to assume that calculated V c values indicate pericardial fluid volume. Hence, pericardial fluid volumes of catheter-instrumented rats would be 0.5 to 0.9 ml/kg.…”

“…Since the catheter will create additional space in the pericardial cavity (estimated to be about 0.1 ml), which presumably is fully filled with fluid, "real" rat pericardial fluid volumes will probably be 0.25 to 0.35 ml/kg lower. Previous studies showed that mean pericardial fluid volumes are 0.23 ml/kg in greyhounds (Gibson and Segal, 1978) and 0.29 ml/kg in mongrel dogs (Santamore et al, 1990). In non-heart-diseased humans, pericardial fluid volume ranges between 15 and 50 ml (Spodick, 1992), which at a body weight of 75 kg would correspond to 0.2 to 0.67 ml/kg.…”

A Miniature Mobile Robot for Navigation and Positioning on the Beating Heart

“…2). This space is naturally filled with only a thin film of fluid and has a height of less than 1 mm in situ [35]. Accordingly, HeartLander must create its own clearance space by distending the pericardium.…”

Interventional Treatment of Pericardial Effusion

“…A small quantity of pericardial fluid (approximately 0.25 ± 0.15 mL/kg) is contained within the pericardial cavity in the healthy animal, creating a thin serous film which primarily serves a lubricatory function enabling the visceral and parietal layers of the pericardium minimal resistance motion during each cardiac cycle [1,2]. The pressure within the pericardial space may be inconsistent, since normal pericardial fluid thickness tends to be greater at the atrio-and interventricular grooves, allowing some fluid motion and thus transmission of intrapericardial pressure between different regions of the heart [2].…”

“…The pressure within the pericardial space may be inconsistent, since normal pericardial fluid thickness tends to be greater at the atrio-and interventricular grooves, allowing some fluid motion and thus transmission of intrapericardial pressure between different regions of the heart [2]. Accumulation of an abnormal fluid volume within the pericardial space is defined as pericardial effusion-a potential critical clinical condition.…”