▌ Cardiac Codex
CARDIAC CODEX / GLOSSARY / RCIS

Left Anterior Descending (LAD) Artery

A Cath Lab Anatomy & Hemodynamics term on the RCIS exam blueprint, defined for cath lab and EP clinicians.

Courses down the anterior interventricular sulcus toward the cardiac apex, where it frequently branches in a characteristic "mustache" or "whale tail" sign. It gives off septal perforator branches, which arise at right angles and dive deep to supply the interventricular septum, and diagonal branches, which course diagonally across the anterolateral free wall of the left ventricle.

Anterior view of the heart with the left anterior descending artery highlighted running down the anterior interventricular sulcus toward the apex, labelling septal perforator branches, diagonal branches crossing the anterolateral left ventricular free wall, and the apical wrap known as the mustache or whale-tail sign.
The LAD’s course, its septal and diagonal branches, and the apical wrap.

Domain: Cath Lab Anatomy & Hemodynamics · Blueprint: RCIS exam guide

Related RCIS terms

Atrioventricular (AV) Node Bundle Branches Left Circumflex (LCX) Artery Left Main Coronary Artery (LMCA) Posterior Descending Artery (PDA)

Study RCIS terms in context

Cardiac Codex turns definitions like this into a full study system: 179 lessons, 2,198 practice questions with explanations, four blueprint-matched full-length mock exams, live and timed, and Cardiac Coach — an AI tutor grounded in this exact glossary you can ask from any lesson.

Start free Back to the glossary →
Written and reviewed by John-Philip (JP) Maarschalk, BSN, RN, CNML — a nurse manager who runs operations for the cardiac cath lab, electrophysiology, and interventional service lines at an academic health system in North Carolina. He hires and develops the staff who sit for these exams. More about JP and how this content is made →
Cardiac Codex is an independent study tool published by MdoubleA LLC, not affiliated with or endorsed by CCI or any certifying body. This glossary entry is exam-preparation information, not medical advice or a substitute for clinical judgment. Always verify current clinical practice against primary sources and institutional protocol.