Left Ventricle – Ventricular Septal Bulge (VSB)

Ventricular Septal Bulge

Normal vs Age Related Ventricular Septal Bulge vs  IHSS
This series of CTscans shows a normal Left ventricular outflow tract overlayed in bright red in a, with normal septum in green (c) contrasted to a patient with sigmoid shaped ,septum (green in b and bright red in d) with a thickened septum with overlay in green (d).                                               Courtesy Ashley DAvidoff MD 39208c01 code cardiac heart CTscan interventricular septum thickened IHSS imaging radiology CTscan

 

96 year old patient shows a symmetric asymmetrical thickening of the ventricular septum at the LVOT on a CTscan
Ashley Davidoff
tags asymmetric subaortic septum
96 year old patient shows asymmetric normal thickening of the ventricular septum at the LVOT on a CTscan At this level the septum measure 15.5 mms while the free wall measured 10.1mms The LA measured 39mms
Ashley Davidoff
tags asymmetric subaortic septum
96-LVH-002b

VSB

is an isolated hypertrophy of the basal segment of the interventricular septum protruding into the outflow tract of the left ventricle (LV),

  • common in elderly
    • 4% to 8% in individuals ≥60 years of age a
    • 10% in the eighth decade of life

Hypertension

and often difficult to distinguish from genetic hypertrophic cardiomyopathy

HCM is diagnosed less frequently than VSB at older ages, with a reversed female predominance. Most patients diagnosed with HCM at older ages suffer from hypertension, similar to those with VSB.

  • Criteria
    • isolated basal septal hypertrophy and a wall thickness >12–13 mm;
    • sometimes a proximal-to-mid/distal septal wall thickness ratio ≥1.3–1.5 is used as an additional criterion,
    • the presence of left ventricular outflow tract obstruction as an exclusion criterion, because considered diagnostic for HCM.
  • Most patients with VSB
    • Have a hx of hypertension
      •  between 50% and 80%
    • Usually asymptomatic
    • EKG
      • usually no LVH
    • maximal septal thickness is <15mm
    • posterior wall thickness <11mm
    • no mitral valve abnormalities
    • Rarely have SAM and LVOT obstruction
    • No LGE
From Canepa M et al Distinguishing ventricular septal bulge versus hypertrophic cardiomyopathy in the elderly Heart. 2016 Jul 15; 102(14): 1087–1094.

 

Links and References

Canepa, M et al Distinguishing ventricular septal bulge versus hypertrophic cardiomyopathy in the elderly Heart. 2016 Jul 15; 102(14): 1087–1094.