LV Crypt (congenital)
  1. Definition*
    • Narrow V/U shaped fissure(s) confined to compacted myocardium and penetrating >50% of wall, perpendicular to LV long axis
  2. Contractility
    • Systolic obliteration
  3. Segment
    • Inferior / inferoseptal basal / mid wall
  4. LGE
    • No LGE
  5. Clinical relevance
    • Isolated clefts in normal hearts
    • Early biomarker in HCM mutation carriers without LV hypertrophy
 * Cleft, crypt, crevices and fissures are used interchangeably.

LV Non-Compaction (congenital)
  1. Definition*
    • Hypertrabeculated, non-compacted myocardium
    • Deep intertrabecular recesses
  2. Contractility
    • LV dilatation and dysfunction
  3. Segment
    • Apex, lateral wall, inferior wall
  4. LGE
    • LGE possible
  5. Clinical relevance
    • Very difficult diagnosis; may not be based on imaging criteria alone
    • Poor prognosis
    • Heart failure
    • Arrhythmias (SCD)
    • Thromboembolism
Diverticulum (congenital)
  1. Definition*
    • Narrow-necked saccular contractile outpouching of all layers of the myocardium beyond epicardial contour
  2. Contractility
    • Systolic contraction
  3. Segment
    • Apex (muscular diverticulum)
    • Sub-annular (fibrous divert)
  4. LGE
    • LGE in fibrous type
    • No LGE in muscular type
  5. Clinical relevance
    • Majority are asymptomatic
    • Heart failure, arrhythmias and thromboembolism occur
    • Fibrous type prone to valve regurgitation and rupture
True aneurysm (infarction, congenital)
  1. Definition*
    • Wide-necked, thin (scarred) outpouching of all layers of the myocardium beyond epicardial contour
  2. Contractility
    • Dyskinesia (systolic out-bulging) or akinesia
  3. Segment
    • Mainly LAD territory, particularly LV apex
  4. LGE
    • Transmural LGE in a coronary pattern
  5. Clinical relevance
    • Thrombus formation within true aneurysms
    • Heart failure
    • Arrhythmias
    • May be difficult to differentiate from pseudoaneurysm
Pseudoaneurysm (infarction, trauma)
  1. Definition*
    • Narrow-necked myocardial rupture contained by the pericardium
  2. Contractility
    • Dyskinesia (systolic out-bulging) or akinesia
  3. Segment
    • Mainly inferior (RCA) and lateral (CX) wall
  4. LGE
    • Perianeurysmal LGE in a coronary pattern but no LGE in the pericardial sac
    5. li>Clinical relevance
    • 30-45% risk of rupture with high mortality rate
    • May be difficult to differentiate from true aneurysm