What Are Heart Ventricles?

Heart ventricles are the two lower muscular chambers of the heart that generate the pressure driving blood through the pulmonary and systemic circulations. The right ventricle receives deoxygenated blood from the right atrium and pumps it at relatively low pressure into the pulmonary artery for oxygenation in the lungs; the left ventricle receives oxygenated blood from the left atrium and pumps it at high pressure into the aorta for distribution to the body. Because the systemic circuit has a higher vascular resistance than the pulmonary circuit, the left ventricular wall is substantially thicker and generates pressures roughly five times greater than those of the right ventricle.

In biomedical engineering, the ventricles are studied as pressure-generating mechanical structures, as electrophysiological substrates for arrhythmias, and as the primary targets of heart failure therapies. The performance of each ventricle is characterized by indices such as ejection fraction, end-diastolic volume, stroke volume, and wall motion scores, all of which are derived from cardiac imaging and used to guide clinical decisions about surgery, device implantation, and pharmacological management.

Ventricular Mechanics and the Cardiac Cycle

During systole, the ventricular myocardium contracts in a coordinated twisting pattern driven by helically arranged muscle fibers, generating the pressure rise that opens the outflow valves and expels the stroke volume. The pressure-volume loop, which plots ventricular pressure against volume through one complete cardiac cycle, is the standard tool for quantifying ventricular work and contractile function. The slope of the end-systolic pressure-volume relationship (Ees) is a load-independent index of contractility used in research and clinical hemodynamic assessment. During diastole, the ventricle relaxes actively and passively refills; diastolic dysfunction, in which impaired relaxation limits filling and raises filling pressures, is the dominant form of heart failure in older adults.

Computational Modeling of Ventricular Function

Patient-specific finite element models of ventricular mechanics are constructed from MRI or CT imaging data and used to simulate myocardial deformation, wall stress, and blood flow through the chamber. These models are validated against hemodynamic measurements and imaging-derived strain maps. Research on computational cardiology and visualization of cardiac anatomy from CT imaging demonstrates how three-dimensional reconstructions of the ventricles are used to plan ablation procedures, optimize pacing lead placement, and predict the response to cardiac resynchronization therapy. The bioengineering field has also used computational models to understand how mechanical forces on ventricular cardiomyocytes regulate gene expression and hypertrophic remodeling.

Ventricular Disease and Therapeutic Engineering

Ventricular disease encompasses heart failure with reduced ejection fraction, hypertrophic cardiomyopathy, dilated cardiomyopathy, and the sequelae of myocardial infarction. Mechanical circulatory support devices, including ventricular assist devices (VADs) and total artificial hearts, are implanted to supplement or replace ventricular function in end-stage disease. The field of cardiovascular tissue engineering is developing engineered myocardial patches and injectable cell therapies to regenerate infarcted ventricular wall. A review of bioengineering and the cardiovascular system situates ventricular research within the broader history of cardiovascular bioengineering, tracing how understanding of hemodynamic loading has shaped both surgical approaches and device design.

Applications

Heart ventricles, as the primary pumping chambers, are the focus of application in a wide range of fields, including:

• Ventricular assist device design and clinical implantation
• Cardiac resynchronization therapy and implantable defibrillator programming
• Surgical repair of congenital ventricular septal and wall defects
• Patient-specific computational modeling for pre-operative planning
• Tissue engineering for myocardial repair after infarction