Mechanics of pericardial effusion: a simulation study

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Computational Biology

Background:

• Pericardial effusion, fluid accumulation in the pericardial cavity, can cause hemodynamic impairment by compressing heart chambers.
• Understanding the mechanical basis of this impairment is crucial for predicting disease progression.

Purpose of the Study:

• To investigate the physiological mechanics of hemodynamic impairment in pericardial effusion using patient-specific computational modeling.
• To evaluate the impact of pericardial effusion on biventricular cardiac function and myocardial stress distribution.

Main Methods:

• Developed patient-specific computational models of the left and right ventricles using MRI data from patients with pericardial effusion and controls.
• Adjusted myocardial material parameters to match ventricular and effusion volumes.
• Determined pressure-volume relationships and stroke volume to assess cardiac function and analyzed myocardial fiber stress distributions.

Main Results:

• Pericardial effusion shifted pressure-volume relationships leftward, particularly restricting right ventricle diastolic filling.
• Left ventricle function, assessed via the Starling curve, was reduced.
• End-systolic left ventricle fiber stress decreased, while stress increased on the interventricular septum. Right ventricle stress was reduced due to pressure equalization.

Conclusions:

• Pericardial effusion significantly impairs biventricular cardiac mechanics, characterized by restricted diastolic filling and altered myocardial stress.
• Increased interventricular septum stress and pericardial extensibility contribute to diastolic right ventricle collapse.
• These mechanical alterations may indicate a progression towards cardiac tamponade.