Assessment of left ventricular twist mechanics by speckle tracking echocardiography reveals association between LV twist and myocardial fibrosis in patients with hypertrophic cardiomyopathy.

We aimed to investigate whether left ventricular (LV) twist analysis can detect the extent of myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM). This prospective case-control study recruited 81 consecutive patients with HCM examined between January 2012 and April 2013. Data of 76 patients were analyzed after excluding 5 patients whose echocardiographic images were of poor quality. Healthy volunteers (n = 46) served as controls. Both groups underwent comprehensive echocardiographic examination (i.e., Bas-Rotation, AP-Rotation, LVEF, LADs, IVST, LAVi, E/Em, LVMI, advanced LV-twist analysis by speckle tracking echocardiography) and magnetic resonance imaging. Between-group differences were analyzed by independent t test; logistic regression analysis was performed to identify effect factors. No significant differences were found between baseline characteristics of HCM and control groups (all p > 0.05). HCM patients had significantly higher Bas-Rotation, AP-Rotation, LV Twist, LVEF, LADs, IVST, LAVi, E/Em and LVMI than controls (all p < 0.0001) and significantly lower LVDd and E/A (both p < 0.001). Bas-Rotation, AP-Rotation, LV-Twist, LADs, IVST, LAVi, E/Em and LVMI were significantly higher in HCM patients with fibrosis than in those without fibrosis (p < 0.001), but no significant differences in other echocardiographic parameters were found between those with and without fibrosis. Age, Bas-Rotation, AP-Rotation, LV twist, LADs, IVST, LAVi, E/A, E/Em, and LVMI were significant effect factors for fibrosis. AUROC analysis showed that LV twist had high discriminatory power to detect extent of myocardial fibrosis (AUC 0.996, 95 % CI 0.989-1.004, p < 0.001). Left ventricular twist mechanics are associated with the extent of myocardial fibrosis. LV-twist assessment by STE may be clinically useful.

Left atrial minimum volume by real-time three-dimensional echocardiography as an indicator of diastolic dysfunction.

BACKGROUND: Left atrial (LA) maximum volume is becoming a prognostic biomarker for left ventricular (LV) diastolic dysfunction. However, we assessed LV diastolic function by measuring LA phasic volumes using real-time threedimensional echocardiography (RT3DE) in patients with stable coronary artery disease (CAD). METHODS: Sixty-five stable CAD patients with normal LV ejection fraction (LVEF) were divided into three groups according to degree of coronary stenosis: control (n = 15) with <50% stenosis as control group, mildS (n = 25) with mild stenosis (50%-70%) and severeS (n = 25) with >70% stenosis. LA phasic volumes and function were evaluated and compared using RT3DE and two dimensional echocardiography (2DE). N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were examined. The correlations of RT3DE-derived parameters with other conventional indices were analyzed. RESULTS: Significant correlations between RT3DE and 2DE for LA volume measurements were: control, r = 0.93; mildS, r = 0.94; severeS, r = 0.90 (all P < 0.05). Patients with severe coronary stenosis presented higher NT-proBNP level, indices of LA minimum volume and volume before atrial contraction, but lower LA total emptying fraction (LAEF) and LAEFpassive. Significant correlations of RT3DE derived LA volume indices with E/E' (r = 0.695) and NF-proBNP (r = 0.630) level were found. CONCLUSIONS: RT3DE derived, LA indices correlate well with NT-proBNP level and may be superior to 2DE measurements for the evaluation of LV diastolic dysfunction. Enlargement of LA minimum volume in stable CAD patients without systolic dysfunction appears earlier and may be better correlated with LV diastolic function than that of LA maximum volume.