Left Ventricular Torsion Changes Post Kidney Transplantation

BACKGROUND: To quantify changes of left ventricular (LV) torsion in patients' pre and post kidney transplantation. METHODS: A prospective study was conducted on 48 patients who received kidney transplantation for end stage renal disease and without myocardial infarction. The rotation, twist and torsion of LV were studied pre and post kidney transplantation (6 months post transplantation) using velocity vector imaging by echocardiography. The data is expressed as mean +/- standard deviation and compared by paired t-test at the p < 0.05 significance level. RESULTS: Six months post kidney transplantation, left ventricular ejection fraction (from 40.33 +/- 11.42 to 61.00 +/- 13.68%), ratio of mitral early and late diastolic filling velocity (from 1.04 +/- 0.57 to 1.21 +/- 0.52), rotation of basal LV (from 4.48 +/- 2.66 to 5.65 +/- 2.64 degree), rotation of apical LV (from 4.27 +/- 3.08 to 5.50 +/- 4.25 degree), LV twist (8.75 +/- 4.45 to 11.14 +/- 5.25 degree) and torsion (from 1.06 +/- 0.54 to 1.33 +/- 0.61 degree/cm) were increased significantly (p < 0.05). Interventricular septum thickness (from 11.67 +/- 2.39 to 9.67 +/- 0.48 mm), left ventricular mass index (from 104.00 +/- 16.47 to 95.50 +/- 21.44 g/m2), systolic blood pressure (from 143.50 +/- 34.99 to 121.50 +/- 7.09 mmHg), serum blood urea nitrogen (from 42.40 +/- 7.98 to 30.43 +/- 13.85 mg/dL) and creatinine (from 4.53 +/- 1.96 to 2.73 +/- 2.57 mg/dL) were decreased significantly (p < 0.05). CONCLUSION: Kidney transplantation in end stage renal disease without myocardial infarction results in improvement in left ventricular structure, function and myocardial mechanics as detected by echocardiography and velocity vector imaging. Velocity vector imaging provided valuable information for detection and follow-up of cardiac abnormalities in patients with end stage renal disease.

Left Ventricular Rotation and Twist: Why Should We Learn?

The left ventricle twists in systole storing potential energy and untwists (recoils) in diastole releasing the energy. Twist aids left ventricular ejection and untwist aids relaxation and ventricular filling. Therefore, rotation and torsion are important in cardiac mechanics. However, the methodology of their investigations is limited to invasive techniques or magnetic resonance imaging. With the advent of speckle tracking echocardiography, however, rotation and torsion (twist) become familiar to echocardiographers. In this review, I outline the mechanism and influencing factors of rotation and torsion with the anticipation of the routine use of these measurements in clinical practice.