Noninvasive measurement and clinical relevance of myocardial twist and torsion

Left ventricular (LV) torsion (twisting) and untwisting results in equalization of wall stress and augmentation of pressure generated for a given shortening of sarcomere during the systolic contraction and aids early diastolic relaxation. This is attributed to the dynamic interaction of epicardial and endocardial helical myocardial fibers. Recent advances in noninvasive imaging techniques have enabled us to quantify torsion accurately and reliably in health and disease. LV torsional mechanics are altered in range of clinical conditions from those that cause minimal cardiac architectural changes as seen in hypertension, diabetes mellitus or older age to advanced cardiac remodeling as seen dilated or hypertrophic cardiomyopathy. Therefore, assessment of LV rotational mechanics may be a potentially sensitive marker of cardiac dysfunction and may provide important insights into the pathophysiology of heart failure.