From the Guidelines
Left ventricular hypertrophy (LVH) is diagnosed echocardiographically when the maximal end-diastolic wall thickness is ≥15 mm anywhere in the left ventricle in adults, as stated in the 2024 AHA/ACC/AMSSM/HRS/PACES/SCMR guideline 1. The diagnosis of LVH is crucial in identifying patients with hypertrophic cardiomyopathy (HCM) and other cardiac conditions. According to the guideline, a maximal end-diastolic wall thickness of ≥15 mm is considered diagnostic of HCM in adult patients, in the absence of another cause of hypertrophy 1.
- The guideline also notes that more limited hypertrophy (13-14 mm) can be diagnostic when present in family members of a patient with HCM or in conjunction with a positive genetic test identifying a pathogenic or likely pathogenic variant 1.
- In children, the diagnostic criteria for LVH are adjusted for body size and growth, with a body surface area-adjusted z-score of ≥2 standard deviations above the mean considered significant 1.
- The guideline proposes that a threshold of a z-score >2.5 may be appropriate to identify early HCM in asymptomatic children with no family history, whereas for children with a definitive family history or a positive genetic test, a threshold of a z-score >2 may suffice for early diagnosis 1. The accurate measurement of left ventricular wall thickness is essential for the diagnosis and management of patients with LVH and HCM, and echocardiography remains a critical tool in this assessment 1.
From the Research
Echo Criteria for LVH
The echo criteria for left ventricular hypertrophy (LVH) in terms of thickness are as follows:
- According to 2, the left ventricular posterior wall thickness and interventricular septal thickness were found to be increased (greater than or equal to 12 mm) in only 13 of 27 patients (48%) with LVH.
- The study 3 does not provide specific thickness criteria, but instead provides criteria based on left ventricular mass, with values of 294 g, 150 g/m2, and 163 g/m for men, and 198 g, 120 g/m2, and 121 g/m for women.
- The study 4 found that echo measurements of LV wall thickness were significantly correlated with anatomic measurements of compact zone thickness and total wall thickness including trabeculae.
Thickness Measurements
The thickness measurements for LVH are:
- Interventricular septal thickness: greater than or equal to 12 mm 2
- Left ventricular posterior wall thickness: greater than or equal to 12 mm 2
- Note that these values are not universally agreed upon and may vary depending on the study and population being examined.
Comparison of Measurement Methods
The comparison of measurement methods for LVH is as follows:
- Echocardiography typically measures greater wall thickness than cardiac magnetic resonance (CMR) imaging, with the largest differences in moderate to severe hypertrophy 5
- Contrast echocardiography more closely approximates CMR measurements of wall thickness than standard echocardiography 5
- Magnetic resonance imaging (MRI) can overestimate left ventricular wall thickness compared to digital subtraction angiography (DSA) and M-mode echocardiography 6