MedCourseFinder

Structure

Left ventricle

Source-checked · Content last updated · 2 min read ·

This is the date the draft was written, not a medical review date.

The left ventricle receives oxygenated blood from the left atrium and ejects it through the aortic valve into the systemic circulation. It has the thickest wall of the four chambers and forms the apex of the heart.

Terminologia Anatomica (Latin): Ventriculus sinister · Open in the 3D atlas

Location

Forms the apex and the left border of the heart; the apex lies behind the left fifth intercostal space near the midclavicular line.

Structure

The conical cavity has the thickest wall of the heart, fine trabeculae carneae and two large papillary muscles (anterolateral and posteromedial) tethering the mitral leaflets. A smooth aortic vestibule leads to the aortic valve. The interventricular septum is muscular, with a thin membranous part just below the aortic valve.

Blood supply

Left anterior descending artery (anterior wall, apex, anterior two thirds of the septum), left circumflex (lateral wall) and the posterior descending artery from the dominant coronary (inferior wall, posterior third of the septum). The left ventricle is perfused mainly in diastole.

Innervation

Mainly sympathetic from the cardiac plexus (beta-1 receptors increase contractility); vagal innervation of the ventricular myocardium is sparse.

Function

Generates systemic arterial pressure and a stroke volume of roughly 70 mL at rest (values vary with body size). Contraction involves twisting and longitudinal shortening that aid ejection and filling.

Clinical correlations

Most myocardial infarctions involve the left ventricle; complications include papillary muscle rupture, free wall rupture and ventricular septal rupture. Chronic pressure overload (hypertension, aortic stenosis) causes concentric hypertrophy, and dilated cardiomyopathy causes eccentric dilatation. Ejection fraction is the standard index of systolic function.

Common exam points

  • Wall much thicker than the right ventricular wall; two papillary muscles.
  • Muscular septum versus the small membranous septum under the aortic valve (usual site of perimembranous VSD).
  • Anterior wall and septum: LAD; lateral wall: circumflex; inferior wall: RCA or circumflex depending on dominance.
  • Left ventricular coronary flow occurs mainly in diastole, so aortic diastolic pressure and heart rate matter for perfusion.
  • Papillary muscle rupture after infarction causes acute mitral regurgitation; the posteromedial muscle has a single (often posterior descending) supply and ruptures more often.

References

  1. Drake RL, Vogl AW, Mitchell AWM. Gray's Anatomy for Students. Elsevier — Tier 3 (textbook)
  2. Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy. Wolters Kluwer, 8th edition (2018) — Tier 3 (textbook)
  3. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. Elsevier, 12th edition (2022) — Tier 3 (textbook)
  4. Fourth Universal Definition of Myocardial Infarction (2018). ESC / ACC / AHA / World Heart Federation (2018) — Tier 2 (guidelines / primary literature)

References are listed only where the article cites them. See the sources page for the full policy. How sources are chosen and credited

Back to the index