Hypertension & LVH

• LVH-Echo
  • Assessment
  • Example
  • LV Geometric Patterns
  • LV Geometric Patterns in the HOT Study
  • Impact on Prognosis
  • Impact of drugs on LVH

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• LVH-ECG
• Which ECG Criterion?
• Impact on Prognosis

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Left Ventricular Hypertrophy

Concentric LV remodelling or concentric LVH

Example: A 50-year old female had an echocardiogram and this was reported to show borderline left ventricular hypertrophy, presumably on the basis of wall thickness measurements.

The following measurements were obtained:
LVEDD 4.6cm (End-diastolic dimension of the LV)
IVS 1.1cm (thickness of the interventricular septum)
LVPW 1.2cm (thickness of the posterior wall)

The relative wall thickness can be calculated
=(2*LVPW)/LVEDD
=(2*1.2)/4.6
=2.4/4.6
=0.52

A relative wall thickness greater than 0.45 indicates the patient either has concentric LV hypertrophy or (if there is no LVH) concentric LV remodelling. In other words, the walls are relatively thick, the walls appear thick and the above ratio is a way to quantify this.

LV mass can be calculated (ASE formula and calculations not shown): 196g

This LV mass has to be indexed. One study used the following as normal, when LV mass was indexed to height^2.7: for men LV mass less than 49.2 and for women less than 46.7.

A female with a calculated LV mass of 196g that is shorter than 1.7m in height, would have LV hypertrophy by these criteria (calculations not shown) and if taller than 1.7m would be classified as having concentric left ventricular remodelling.

The patient is just under 1.7m in height, thus there is left ventricular hypertrophy and not "borderline left ventricular hypertrophy".

The patient was also reported to have early diastolic dysfunction based on a number of criteria consistent with underlying left ventricular hypertrophy, however, paradoxically, the left atrium was not enlarged (sometimes left atrial dimensions measured from the parasternal window can be normal).

On balance, I would recommend treatment for hypertension even if hypertension only seems to be "mild" and the patient's estimated cardiovascular risk assessment is below the threshold recommended for treatment by the the NZ guidelines.

Errors in measurement are a problem because the formula cubes the LVEDD and the sum of LVEDD+IVS+LVPW. Thus, there is the potential to easily under-estimate or over-estimate left ventricular mass but the potential advantages of this assessment should not be minimised. Several M-mode measurements should be made to try to increase the reliability of the measurements. If good quality M-mode measurements can not be made then LV mass can not be estimated using this method.

Incidentally, this patient had echocardiography to rule out obvious structural heart disease in the presence of very frequent symptomatic ventricular ectopy.