Thick Walls, Thin Data
Measuring Left Ventricular Wall Thickness With MRI Versus Echocardiography
This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
“Baseball is a game of inches.”
If baseball is a game of inches, then modern cardiology is a discipline of millimeters. Just over 3 millimeters separates abnormal from normal myocardial thickness in any of the myocardial segments. An end-diastolic myocardial wall thickness of 15 mm may lead to the diagnosis of hypertrophic cardiomyopathy (HCM); in relatives of a proband, this threshold drops to only 13 mm1 on a background of 11.8 mm as the upper limit of normal.2 Even these seemingly simple thresholds are not sufficient in the case of apical HCM, where the only image-based clue to diagnosis may be failure of the normal tapering of left ventricular wall thickness from base to apex, thus allowing for the diagnosis of HCM even in the absence of crossing the thresholds. Although the clinician making the diagnosis of HCM must incorporate clinical, electrocardiographic, and laboratory parameters to distinguish HCM from other causes of left ventricular hypertrophy, visualization with echocardiography or MRI is usually pivotal in this endeavor. The pattern and degree of myocardial thickening, often supported by other morphological features (eg, crypts and papillary muscle anomalies), offer critical diagnostic data.1,3,4
See Article by Hindieh et al
Accurate measurement of left ventricular wall thickness is essential to the management in addition to the diagnosis of patients with HCM. The likelihood of success of alcohol septal ablation for HCM patients with left ventricular outflow tract obstruction can be predicted by echocardiographic and MRI wall thickness,5–7 whereas creation of a ventricular septal defect is a concern in patients with only modest septal hypertrophy undergoing either septal myectomy or …