Statistics from Altmetric.com
One of the most important objectives in cardiology is to gain knowledge about the function of the left ventricle (LV). The patient's prognosis is closely related to LV function in nearly all cardiac diseases affecting myocardial function. The ventricular mechanics are complicated. LV mechanics consist of longitudinal and circumferential shortening and lengthening, radial thickening and thinning and twist. This means that every attempt to assess LV function by cardiac imaging will be a simplification of true LV deformation.1 The most recent imaging techniques from echocardiography have improved diagnostics considerably and will give the cardiologist valuable information on the diagnosis and prognosis of the patient.
This article describes the assessment of ventricular mechanics by echocardiographic techniques which are widely available to all cardiologists. The different deformation patterns and how the assessment of these can be used in the clinical setting are discussed.
Left ventricular anatomy
LV myocardial fibres are oriented mainly in three layers. Myocardial fibres in the mid LV wall are oriented mainly in the circumferential direction (0°). The fibres in the subendocardium have an approximately longitudinal orientation of about 80° to the circumferential direction. Fibres in the sub-epicardium are oriented in an oblique way of around 60° to the circumferential direction and rotated in the opposite direction from the subendocardial fibres. The subepicardial fibres form a left handed helix and subendocardial fibres form a right handed helix, which is essential for the development of ventricular torsion.w1–w5
Right ventricular anatomy
The normal right ventricle (RV) is relatively thin-walled compared to the LV. The RV has normally low pressures, but RV function will adapt quickly to changes in pre- and afterload due to the thin walls. Longitudinal function is a major contributor to RV performance.2
Techniques to assess detailed ventricular deformation
Established echocardiographic techniques such as M mode, colour Doppler, pulsed Doppler, two dimensional greyscale loops and two dimensional colour …