Tissue Doppler imaging consistently detects myocardial abnormalities in patients with hypertrophic cardiomyopathy and provides a novel means for an early diagnosis before and independently of hypertrophy

Background-Left ventricular hypertrophy (LVH), the clinical hallmark of fam ilial hypertrophic cardiomyopathy (FHCM), is absent in a significant number of subjects with causal mutations. In transgenic rabbits that fully recapi tulate the FHCM phenotype, reduced myocardial tissue Doppler (TD) velocitie s accurately identified the mutant rabbits, even in the absence of LVH. We tested whether humans with FHCM also consistently showed reduced myocardial TD velocities, irrespective of LVH. Methods and Results-We performed 2D and Doppler echocardiography and TD ima ging in 30 subjects with FHCM, 13 subjects who were positive for various mu tations but did not have LVH, and 30 age- and sex-matched controls tall adu lts; 77% women). LV wall thickness and mass were significantly greater in F HCM subjects (P <0.01 versus those without LVH and controls). There were no significant differences in 2D echocardiographic, mitral, and pulmonary ven ous flow indices between mutation-positives without LVH and controls. In co ntrast, systolic and early diastolic TD velocities were significantly lower in both mutation-positives without LVH and in FHCM patients than in contro ls (P <0.001). Reduced TD velocities had a sensitivity of 100% and a specif icity of 93% for identifying mutation-positives without LVH. Conclusions Myocardial contraction and relaxation velocities, detected by T D imaging, are reduced in FHCM, including in those without LVH. Before and independently of LVH, TD imaging is an accurate and sensitive method for id entifying subjects who are positive for FHCM mutations.