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    From Cardiovascular System

    Circumflex Branch
    Curves around to the posterior heart.
    Right Coronary Artery
    Supplies blood to right side of heart.
    Pulmonary Valve
    Valve between right ventricle and pulmonary trunk.
    Aortic Arch
    Curved portion of the aorta giving rise to major arteries.
    Ulnar Arteries
    Supply the medial aspect of the forearm and hand.
    External Carotid Artery
    Supplies blood to the face and scalp.
    Aortic Valve
    Valve between left ventricle and aorta.
    Thoracic Aorta
    Part of descending aorta within the chest.
    Crista Terminalis
    Smooth muscular ridge in the right atrium.
    External Iliac Veins
    Drain lower limbs and join internal iliac veins.
    Fibrous Pericardium
    Outer layer of the pericardium made of dense connective tissue.
    Common Iliac Arteries
    Branch from abdominal aorta to supply the lower limbs.
    Anterior Cardiac Veins
    Drain directly into the right atrium.
    Brachial Arteries
    Major artery of the upper arm.
    Subclavian Arteries
    Supply blood to the arms and part of the brain.
    Cephalic Veins
    Superficial veins of the lateral upper limb.
    Dorsal Venous Arch
    Superficial venous network on the dorsum of the foot.
    Visceral Layer (Epicardium)
    Covers the external surface of the heart.
    Descending Aorta
    Portion of the aorta descending through thorax and abdomen.
    Moderator Band
    Muscular band of heart tissue found in the right ventricle.
    Left Subclavian Artery
    Supplies the left upper limb.
    Fossa Ovalis
    Remnant of the fetal foramen ovale.
    Brachiocephalic Veins
    Formed by the union of subclavian and internal jugular veins.
    Right Inferior Pulmonary Vein
    Returns oxygenated blood from right lung.
    Great Saphenous Vein
    Longest vein in the body, running along the leg.

    Marginal Branch

    Reviewed by our medical team

    Supplies right ventricle along the margin.

    Overview

    The marginal branch, commonly referring to the right marginal branch of the right coronary artery (RCA), is an important arterial vessel that supplies blood to the right ventricle of the heart. It is one of the key branches of the RCA and plays a significant role in maintaining adequate perfusion to the anterior portion of the right heart. Occasionally, the term "marginal branch" may also refer to the obtuse marginal branches of the left circumflex artery (LCx), which supply the lateral wall of the left ventricle. However, unless otherwise specified, "marginal branch" typically refers to the right marginal artery.

    Location

    The right marginal branch originates from the right coronary artery as it courses along the right atrioventricular (coronary) sulcus. The branch emerges near the inferior border (acute margin) of the heart and runs toward the apex. It travels along the anterior surface of the right ventricle, often visible on the external surface of the heart during dissection or imaging.

    In contrast, obtuse marginal branches (OM1, OM2, etc.) arise from the LCx and run along the left lateral margin of the heart, supplying the lateral wall of the left ventricle.

    Structure

    The right marginal branch is a relatively large artery that travels superficially along the right border of the heart. It is often accompanied by a marginal vein, which drains into the small cardiac vein. The artery itself is a muscular, medium-caliber vessel and follows a relatively straight course toward the apex of the heart.

    Its origin and branching pattern may vary slightly between individuals, but it typically branches off from the mid-portion of the right coronary artery.

    Function

    The primary function of the right marginal branch is to supply oxygenated blood to the:

    • Anterior portion of the right ventricle

    • Right border of the heart (acute margin)

    • Occasionally the apex of the heart, through collateral supply

    This perfusion is crucial to maintain contractility and electrical activity of the right ventricular free wall.

    Physiological Role(s)

    The marginal branch supports several key physiological roles in cardiovascular function:

    • Ventricular contraction: By perfusing the right ventricular myocardium, it ensures proper contraction during systole, essential for pulmonary circulation.

    • Electrophysiological stability: The artery indirectly supports the electrical conduction system by maintaining viable myocardium in areas near conduction pathways.

    • Collateral circulation: In cases of partial coronary occlusion, the marginal artery may contribute to collateral flow to the left or posterior heart regions.

    Clinical Significance

    The right marginal branch has considerable clinical importance in both ischemic and interventional cardiology:

    • Coronary Artery Disease (CAD): Atherosclerosis can affect the right marginal branch, leading to ischemia of the right ventricle. Symptoms may include chest pain, arrhythmias, or right-sided heart failure.

    • Myocardial Infarction: Occlusion of the right coronary artery proximal to the marginal branch can cause infarction in the right ventricular free wall. This is often identified on ECG with ST elevation in right-sided chest leads.

    • Percutaneous Coronary Intervention (PCI): The marginal branch is frequently visualized and sometimes stented during right coronary angioplasty if significant stenosis is present.

    • Bypass Surgery: In cases of multivessel coronary disease, the marginal branch may be bypassed using a graft, especially if it supplies a large territory of viable myocardium.

    • Imaging: Coronary angiography and CT angiography help visualize the marginal branch for diagnosis and surgical planning.

    • Anatomical Variants: The number and size of marginal branches can vary; some individuals may have multiple right marginal arteries, while others have a dominant single vessel.

    Proper understanding of the marginal branch's anatomy and variability is essential during cardiac catheterization, coronary surgery, and in the management of right ventricular infarctions.

    Did you know? The human circulatory system is about 60,000 miles long.