Associations of Hemodynamic Load and Ventricular Repolarization in Patients With Newly Diagnosed Essential Hypertension: A Long‐Term Follow‐Up Study

Abstract

The evolution of QT interval and its dispersion (QTd) were studied in 135 newly diagnosed nondiabetic patients, as well as the relationship between changes of these left ventricular (LV) repolarization parameters with blood pressure (BP) and LV mass changes, which were prospectively studied for a median period of 3.8 years. At baseline and at last follow-up visit, all patients underwent ambulatory BP monitoring, echocardiographic assessment, and 12-lead electrocardiography. At the end of follow-up, responders of antihypertensive treatment based on a reduced 24-hour systolic BP (n=122) exhibited a reduction in LV mass index (by 7.6 g/m 2 , P<.001) and corrected QT (by 4.3, P=.038), while corrected QTd was unchanged. In nonresponders (n=13), although no difference in LV mass index was observed, corrected QT increased by 12.4 ms (P=.048) and corrected QTd by 8.2 ms (P=.027). Changes in parameters of LV repolarization were related to BP changes but not to changes of myocardial size. J Clin Hypertens (Greenwich). 2014;16:219-224. ª2014 Wiley Periodicals, Inc.Parameters of left ventricular (LV) repolarization and its inhomogeneity, such as prolonged QT interval and its dispersion (QTd), are associated with an adverse prognosis in various clinical settings, including essential hypertension.1 Moreover, QT interval and QTd have been exhibited to be increased in diverse pathological conditions, such as myocardial ischemia and heart failure, as well as in diabetic and hypertensive patients and in those with the metabolic syndrome. 1-9Focusing on patients with hypertension, QT interval and QTd are increased in those with LV hypertrophy, whereas regression of LV hypertrophy decreases LV repolarization parameters. [10][11][12][13][14][15] Various types of antihypertensive treatment have been accompanied by significant changes in these parameters of LV repolarization after short periods of treatment. [15][16][17][18][19][20][21][22] The aim of the present study was to investigate the evolution of QT interval and QTd, as well as the relationship between changes of these LV repolarization parameters with blood pressure (BP) and LV mass changes in a cohort of patients with newly diagnosed hypertension after a long-term follow-up period. MATERIALS AND METHODS Study PopulationA total of 177 consecutive, white patients with untreated newly diagnosed stage I or II essential hypertension confirmed by ambulatory BP monitoring (daytime systolic/diastolic BP ≥135/85 mm Hg) were recruited between January 2004 and October 2008. We excluded patients with stage III hypertension or secondary hypertension (n=3); white-coat hypertension (n=14) (office BP >140/90 mm Hg and daytime BP <135/ 85 mm Hg); history of coronary artery disease, cerebrovascular disease, or congestive heart failure (n=2); atrial fibrillation; (n=2); diabetes mellitus (n=6); overt proteinuria (≥300 mg/g) or renal dysfunction (estimated glomerular filtration rate according to the Modification of Diet in Renal Disease formula <60 mL/min/1.73 m 2 ); and presence of neoplastic ...

Tp-e/QT ratio and QT dispersion with respect to blood pressure dipping pattern in prehypertension

“…Although there are studies that highlight increased QTd in hypertension especially in the presence of left ventricular hypertrophy and increased LVM [17], data on arrhythmogenic potential in prehypertensive patients are limited. Doğru et al [10] reported that QTd was prolonged in prehypertensives compared with normotensives and these changes were independent of LVM.…”

Modulation of the QT interval duration in hypertension with antihypertensive treatment

“…Following chronic antihypertensive drug therapy, subsequent decreases in BP may be more strongly associated with reductions in the QT interval, as well as small decreases in LV mass. 62 Given the controversy surrounding the experimental data, 58 the mechanism underlying changes in the duration of the QT interval secondary to alterations in BP remain to be elucidated.…”

Impact of blood pressure lowering on ventricular repolarization heterogeneity in patients with newly diagnosed hypertension

“…LVH is the most powerful predictor of adverse events in hypertensive patients, however, it is not a common ECG finding in hypertensive subjects and is generally considered as a sign of end-stage myocardial damage [4,6]. Importantly, increased BP levels and hemodynamic load seem to be also associated with repolarization abnormalities on ECG irrespective of LVH [17,18]. Moreover, the presence of repolarization abnormalities on ECG significantly predicts future adverse cardiovascular events in hypertensive patients [3,4,19].…”