LEFT VENTRICULAR HYPERTROPHY

I.. Definitions/epidemiology

  1. Defined in terms of "LV mass index":
  1. > 134g/m2 in men
  2. > 110g/m2 in women
  1. Prevalence increases with age, HTN (esp. systolic), obesity, tall build, high salt intake, male sex, EtOH; more common in black than in white hypertensives

II. Pathogenesis:

  1. Increased preload: hyperthyroidism, ESRD, AR, MR
  2. Increased afterload: HTN, AS, obesity
  3. Impaired LV fn: CAD, cardiomyopathies
  4. Idiopathic

III. Consequences:

  1. Unlike exercise-induced LVH, in LVH due to to press. overload, myocardial vasc. supply doesn't increase proportionately, i.e. you get relative decrease in myocard. vasc. reserve. & dependence on high perfusion pressures.; higher incidence of ischemia than with just HTN
  2. Reduced LV complicance-->diastolic dysfn, low LVEF
  3. At higher risk for CVA, CHF, PVD (Framingham)
  4. Complex ventricular arrhythmias
  5. Independently ass'd with increased mortality in pts with and without CAD (RR 4.1 and 2.1, respectively; Ann Int. Med 117:831, 1992-AFP)

IV. Dx

  1. ECG and CXR are very insensitive (12-29% for ECG)
  2. Echo is more accurate
  3. Types of LVH (only distinguishable on echo):
  1. Concentric--occurrs with increased afterload; more ass'd with MI
  2. Eccentric--occurrs with increased preload

V. Tx:

  1. Tx of underlying disorder
  2. Best Tx for HTN with LVH: see under "Consideration of Coexisting Conditions in the Tx of Hypertension"