A 4-tiered classification of left ventricular hypertrophy based on left ventricular geometry: the Dallas heart study

Abstract

Background: Left ventricular hypertrophy (LVH) is traditionally classified as concentric or eccentric, based on the ratio of LV wall thickness to chamber dimension. We propose a 4-tiered LVH classification based on LV concentricity(0.67) (mass/end-diastolic volume(0.67)) and indexed LV end-diastolic volume (EDV).

Methods and results: Cardiac MRI was performed in 2803 subjects and LVH (n=895) was defined by increased LV mass/height(2.7). Increased concentricity(0.67) and indexed EDV were defined at the 97.5th percentile of a healthy subpopulation. Four geometric patterns resulted: increased concentricity without increased EDV ("thick hypertrophy," n=361); increased EDV without increased concentricity ("dilated hypertrophy," n=53); increased concentricity with increased EDV ("both thick and dilated hypertrophy," n=13); and neither increased concentricity nor increased EDV ("indeterminate hypertrophy," n=468). Compared with subjects with isolated thick hypertrophy, those with both thick and dilated hypertrophy had a lower LV ejection fraction and higher NT-pro-BNP and BNP levels (P</=0.001 for all). Subjects with dilated hypertrophy had a lower LV ejection fraction and higher troponin T, NT-pro-BNP, and BNP levels versus those with indeterminate hypertrophy (P<0.001 for all). Subjects with indeterminate LVH versus those without LVH had increased LV mass (by definition) but also a higher LV ejection fraction and no increase in troponin or natriuretic peptide levels.

Conclusions: Concentric or eccentric LVH can each be subclassified into 2 subgroups, yielding 4 distinct geometric patterns. Many subjects currently classified with eccentric LVH can be reclassified into an indeterminate subgroup that has better LV function and comparable levels of biomarkers reflecting cardiac stress as compared with those without LVH.