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. Author manuscript; available in PMC: 2007 Aug 24.
Published in final edited form as: J Am Soc Echocardiogr. 2007 May;20(5):539–551. doi: 10.1016/j.echo.2006.10.013

Figure 3.

Figure 3

Transmural sequence of deformation in the left ventricle using sonomicrometry. During isovolumic contraction, shortening is initiated along the subendocardial (right-handed helical) fiber direction (A). Onset of shortening in the subepicardial (left-handed helical) fiber direction is delayed and coincides with the onset of left ventricular ejection (B). The tissue specimens on the right show the corresponding subendocardial and subepicardial fiber arrangements, the position of sonomicrometry crystals (orange markers), and pairs of crystals used to determine deformation along the fiber direction (yellow arrows). Phase 1, preejection; 2, ejection; 3, isovolumic relaxation; 4, early diastole; 5, late diastole. Ao, aorta (red tracing); ECG, electrocardiogram; LA, left atrium (gray tracing); LV, left ventricle (blue tracing).