Association Of QT Dispersion And Tei Index In Hypertensive Patients With Left Ventricular Hypertrophy

Objective:Hypertension is a disease characterized by end-organ complications, leading to left ventricular hypertrophy (LVH) in about one third of hypertensive patients. LVH increases the risk of cardiovascular morbidity and mortality, and is an independent risk factor for sudden death, coronary heart disease, congestive heart failure. QT dispersion (QTd) is a marker of inhomogenenous ventricular repolarization and electrical instability, and therefore has the potential to predict ventricular arrhythmias and sudden death. Tei index measured with Doppler echocardiography reflects left ventricular systolic and diastolic function. The index is simple,noninvasive, easy to estimate and reproducible. The aim of this study was to investigate the correlation between QT dispersion and Tei Index in hypertensive patients.Methods:127 patients wiith hypertension (62 with LVH and 65 without LVH) and 76 normal control subjects were studied. The following parameters, including left atrial diameter (LAD), end-diastolic left ventricle diameter (LVD), interventricular septum thickness (IVST), left ventricle posterior wall diastolic thickness (LVPW) and left ventricular ejection fraction (LVEF%), were measured with echocardiogram. We measured peak E and A transmitral Doppler velocities, and estimated E/A ratio.Tei index and its components, isovolumetric relaxation time (IRT), isovolumetric contraction time (ICT), and the ejection time (ET), were measured from left ventricular outflow and mitral inflow Doppler velocity profiles. The dispersion of QT intervals was defined as the difference between the maximum and minimum of QT interval which could be measured in any of the electrocardiogram leads and was represented as QTd. Results:1.Compared with the control, both the LVH group and the non-LVH group had an significant increase in LAD,LVWI,Tei index and QTd.2. LAD,IVST,LVPWT,LVMI and E/A were significantly higher in the LVH group compared to the non-LVH group.3.Tei index and QTd were significantly increased in the LVH group compared to the non-LVH group.4. Tei index was positively correlated with ICT,IRT,LVMI,IVST,LVPWT and QTd, and negatively correlated with LVDd,E/A and EF in the LVH group.5.QTd was positively correlated with LVMI,Tei index,IVST,LVPW,LVDd,E/A, and negatively correlated with EF in the LVH group.Conclusions:Hypertension may lead to the Tei index and the QTd increasing and the LVEF decreasing. QTd was positively correlated with the left ventricular hypertrophy and Tei index, and was negatively correlated with the LVEF. The LVEF,Tei index and QTd are simple and reproducible methods for the assessment of left ventricular dysfunction in hypertensive patients with LVH. Therefore we should measure above-mentioned parameters as early as possible to prevent the development of arrhythmias and to guide the use of hypotensive drug.