Cardiac rotation and relaxation in patients with aortic valve stenosis

Background Diastolic dysfunction with delayed relaxation and abnormal passi ve elastic properties has been described in patients with seven pressure ov erload hypertrophy. The purpose of this study was to evaluate the time cour se of rotational motion of the left ventricle in patients with aortic valve stenosis using myocardial tagging. Methods Myocardial tagging is a non-invasive method based on magnetic reson ance which makes it possible to label ('tag') specific myocardial regions. From the motion of the tag's cardiac rotation, radial displacement and tran slational motion can be determined. In 12 controls and 13 patients with sev ere aortic valve stenosis systolic and diastolic wall motion was assessed i n an apical and basal short axis plane. Results The normal left ventricle performs a systolic wringing motion aroun d the ventricular long axis with clockwise rotation at the base (- 4.4 +/- 1.6 degrees) and counterclockwise rotation at the apex (+ 6.8 +/- 2.5 degre es) when viewed from the apex. During early diastole an untwisting motion c an be observed which precedes diastolic filling. In patients with aortic va lve stenosis systolic rotation is reduced at the base (- 2.4 +/- 2.0 degree s; P<0.01) but increased at the apex (+ 12.0 +/- 6.0 degrees; P<0.05). Dias tolic untwisting is delayed and prolonged with a decrease in normalized rot ation velocity (- 6.9 +/- 1.1 s(-1)) when compared to controls (- 10.7 +/- 2.2 s(-1); P<0.001). Maximal systolic torsion is 8.0 +/- 2.1 degrees in con trols and 14.1 +/- 6.4 degrees (P<0.01) in patients with aortic valve steno sis. Conclusions Left ventricular pressure overload hypertrophy is associated wi th a reduction in basal and an increase in apical rotation resulting in inc reased torsion of the ventricle. Diastolic untwisting is delayed and prolon ged. This may explain the occurrence of diastolic dysfunction in patients w ith severe pressure overload hypertrophy.