No abstract

In hypertrophic cardiomyopathy patients without significant LV hypertrophy, in addition to basal septal thickness, anterior MV length, abnormal chordal attachment, and bifid PM mobility are associated with LVOT obstruction. In such patients, additional procedures on MV and PM (±myectomy) could be considered.

Hypertrophic cardiomyopathy is a complex genetic cardiovascular disorder with substantial variability in phenotypic expression and natural progression. Recent research demonstrates the incremental utility of cardiac magnetic resonance in the diagnosis, therapeutic planning, and prognostication of this disease. The increasing incorporation of multimodality imaging of hypertrophic cardiomyopathy in clinical practice will continue to improve our understanding of the subtle morphologic differences and their prognostic implications.

In patients with obstructive HCM, despite a wide range of expected 5-year primary event rate, the observed primary events were similar across the 3 ESC SCD risk categories, with myectomy mitigating SCD risk. In patients with obstructive HCM, SCD risk may need to be refined for patients following myectomy.

BackgroundHypertrophic cardiomyopathy (HCM) is a primary myopathic process in which regional left ventricular dysfunction may exist without overt global left ventricular dysfunction. In obstructive HCM patients who underwent surgical myectomy (SM), we sought to determine if there is a significant association between echocardiographic longitudinal strain, histopathology, and in vitro myocardial performance (resting tension and developed tension) of the surgical specimen.Methods and ResultsHCM patients (n=122, 54±14 years, 54% men) undergoing SM were prospectively recruited. Longitudinal systolic strain and diastolic strain rates were measured at that basal septum (partially removed at SM) by using velocity vector imaging on preoperative echocardiography. Semiquantitative histopathologic grading of myocyte disarray and fibrosis and in vitro measurements of resting tension and developed tension were made in septal tissue obtained at SM. Mean basal septal systolic strain and diastolic strain rate were −8.3±5% and 0.62±0.4/s, while mild or greater degree of myocyte disarray and interstitial fibrosis were present in 85% and 87%, respectively. Mean resting tension and developed tension were 2.8±1 and 1.4±0.8 g/mm2. On regression analysis, basal septal systolic strain, diastolic strain rate, disarray, and fibrosis were associated with developed tension (β=0.19, 0.20, −0.33, and −0.40, respectively, all P<0.01) and resting tension (β=0.21, 0.22, −0.25, and −0.28, respectively, all P<0.01).ConclusionIn obstructive HCM patients who underwent SM, left ventricular mechanics (echocardiographic longitudinal systolic strain and diastolic strain rates), assessed at the basal septum (myocardium removed during myectomy) and histopathologic findings characteristic for HCM (disarray and fibrosis) were significantly associated with in vitro myocardial resting and developed contractile performance.