NucMed Boards Prep
IMAGE INTERPRETATION · CARDIAC IMAGING

Inferior Wall Ischemia: Right Coronary Artery Territory

Myocardial perfusion SPECT — inferior wall defect
Myocardial perfusion SPECT — inferior wall defect

CC BY-SA 4.0 · Wikimedia Commons · source file

Question

A reversible (stress-induced) inferior wall perfusion defect is identified on MPI. The inferior and inferolateral walls of the left ventricle are supplied primarily by which coronary artery in a right-dominant coronary system?

  1. ALeft anterior descending artery (LAD)
  2. BRight coronary artery (RCA) — supplies the inferior wall via the posterior descending artery
  3. CLeft circumflex artery (LCX)
  4. DLeft main coronary artery
Show the answer and explanation

B. Right coronary artery (RCA) — supplies the inferior wall via the posterior descending artery

In a right-dominant coronary system (present in ~85% of individuals), the right coronary artery (RCA) gives rise to the posterior descending artery (PDA), which supplies the inferior wall of the left ventricle, the posterior interventricular septum, and the inferior septum. A reversible inferior wall defect on MPI therefore indicates RCA territory ischemia. In a left-dominant system, the LCX gives rise to the PDA. The inferior wall is the most common territory for attenuation artifact (diaphragm in men, inferior portion in women), so gated SPECT and prone imaging help distinguish artifact from true RCA ischemia.

More cardiac imaging images

Myocardial perfusion SPECT — pharmacologic stress studyVasodilator Stress Contraindications: Caffeine and Bronchospasm Gated myocardial perfusion SPECT — cardiac function assessmentGated SPECT: Ejection Fraction and Ventricular Volumes Myocardial perfusion SPECT — anterior and apical defectLAD Territory Perfusion Defect on SPECT Myocardial perfusion SPECT — multiple territory defectsMultivessel Coronary Disease on Stress MPI Cardiac SPECT — supine vs. prone imaging comparisonProne Imaging in Cardiac SPECT Myocardial perfusion SPECT — right ventricle visualizationProminent Right Ventricle on MPI: RV Hypertrophy
← FDG PET Viability: Hibernating MyocardiumVasodilator Stress Contraindications: Caffeine and Bronchospasm →

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