Background. Myocardial fibrosis occurs in the subepicardial myocardium of the left ventricular posterior wall in patients with Duchenne Muscular Dystrophy (DMD). The aim of this study was to clarify how these regional myocardial lesions might influence the focal cardiac movement using two-dimensional speckle tracking echocardiography and to investigate whether this new method is useful for the early detection of cardiac involvement in DMD patients. Methods and Results. Twelve DMD patients with a normal fractional shortening (FS) of the left ventricle and twelve healthy age-matched control subjects were enrolled in this study. The segmental radial strain of the left ventricle was recorded using the two-dimensional tissue tracking echocardiography, and the systolic maximal strain was measured. Thereafter, the peak systolic maximal strain was separately measured in the inner-half and outer-half of the left ventricular posterior wall. In DMD patients, the systolic maximal radial strain of the septum, posterior, and inferior walls were significantly lower than those in normal subjects. In particular, the systolic maximal radial strain of the posterior wall in the DMD patients was the most significantly decreased (P<0.0001). Six of the DMD patients had postsystolic shortening in the inner-half, and four of the DMD patients had systolic thinning in the outer-half of the posterior wall. Conclusions. Even if the FS is normal, the left ventricular posterior wall of DMD patients often showed an abnormal strain pattern. A segmental myocardial strain analysis might be useful for the early detection of cardiac involvement in DMD patients.
Background. The assessment of left ventricular (LV) dyssynchrony is increasingly important in clinical cardiology. Methods. The aim of this study was to evaluate LV dyssynchrony in patients with myocardial infarction (MI) using 2D speckle tracking imaging. Basal, middle and apical 2D LV short-axis images were acquired in 41 patients with MI and in 15 age-matched controls. Using 2D strain software, radial strain, circumferential strain, time interval from the R wave on the electrocardiogram to peak radial strain (Trs), and time to peak circumferential strain (Tcs) were measured in 6 segments at each level. To assess LV dyssynchrony, the following dyssynchrony indices were calculated: Trs(cs)-18SD: the standard deviation (SD) of Trs(cs) in all 18 segments, Trs(cs)-12SD: the SD of Trs(cs) in 6 basal and 6 mid segments, Trs(cs)-6SD: the SD of Trs(cs) in 6 basal segments. Results. Trs(cs)-18SD was significantly prolonged in the MI group when compared to age-matched controls. Trs(cs)-18SD was significantly longer compared to Trs(cs)-12SD or Trs(cs)-6SD in patients with anterior wall MI. Trs(cs)-18SD was significantly longer in patients with anterior wall MI compared to those with inferior wall MI. Conclusions. Myocardial infarction has results in the development of LV dyssynchrony. Both the size and the location of MI affect the extent of LV mechanical dyssynchrony. 2D speckle tracking imaging has a potential for accurate assessment of LV dyssynchrony in the LV short-axis views.
Segmental left ventricular (LV) dysfunction associated with subarachnoid hemorrhage usually develops in the apex. We encountered a patient with subarachnoid hemorrhage associated with transient LV basal dysfunction and functional mitral regurgitation. Echocardiography showed akinesis in the whole basal LV and hyperkinesis in the apex with significant mitral regurgitation without organic leaflet lesion. The LV wall motion abnormality as well as mitral regurgitation disappeared 22 days later. Subarachnoid hemorrhage can occasionally cause atypical segmental basal LV dysfunction associated with functional mitral regurgitation.