Search

Epigenetics refers to functional alterations in gene expression or phenotype without any change of the underlying DNA sequence. It is the study of the potential of a cell or organism to express different traits through functional regulation of its gene transcription. Though it is met as a necessary process in biology, epigenetics may often play a crucial part in the development of specific pathologic conditions, including cardiovascular diseases and hypertension., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: The appearance of a discrete upward deflection of the ST segment, termed the ST hump sign during exercise testing has been associated with resting hypertension and exaggerated blood pressure response to exercise., Objective: We investigated the correlation between the presence of hump sign during exercise testing with coexisting impaired diastolic function of the left ventricle (LV) at these patients., Methods: We formed a cohort of 237 nonconsecutive patients (140 males, 41 +/- 5 years old) having undergone a treadmill test, according to the Bruce protocol, which divided into 2 groups: group A, including 130 patients which presented ST-segment hump sign at any of the leads of the electrocardiograms recorded during exercise, and group B, including 107 patients that didn't. All patients subsequently underwent an echocardiographic estimation of the LV diastolic function, using conventional and Tissue Doppler Imaging techniques., Results: From 237 patients included in our study, 106 had echocardiographic signs of diastolic LV dysfunction. Among them, the appearance of ST hump sign at the peak of exercise testing was observed in 93 patients (88%), particularly in the inferior and lateral leads, while no ST hump sign was observed only in 13 patients (12%) with impaired diastolic LV function., Conclusions: The appearance of ST segment hump sign during exercise testing is strongly correlated with diastolic LV dysfunction and can be used as an exercise electrocardiographic index of diastolic LV dysfunction, independently from the echocardiographic study., (2010 Elsevier Inc. All rights reserved.)

Purpose: It is well known that patients with arterial hypertension frequently present with ischemic electrocardiographic changes during exercise testing without actually having coronary artery disease (CAD). The purpose of this study was to establish additional electrocardiographic criteria during exercise testing for detecting CAD in hypertensive patients with ischemic ST-segment response., Methods: Three hundred eighty-two consecutive hypertensive patients (224 males, 58 +/- 8 years) who presented with ischemic electrocardiographic changes during exercise testing and agreed to undergo coronary arteriography were included in the study., Results: From 382 hypertensive patients undergoing coronary angiography, only 76 (20%) had significant coronary stenosis, whereas 306 (80%) had normal coronary arteries. From 382 patients, 287 (75%) (group A) presented with ST-segment depression during exercise in leads II-III-aVF-V(6), 271 (94%) of which had normal arteries at the angiography. The remaining 95 patients (25%) (group B) of the studied patients presented with ST-segment depression in II-III-aVF and/or V(4) through V(6), 60 (63%) of which had CAD. Furthermore, 251 patients of group A presented with ST-segment depression during the fourth to sixth minute of the recovery period in V(4) through V(6), 247 (98%) of which had normal arteries. Another 28 patients from group B presented with ST-segment depression during the fourth to eighth minute of the recovery period in V(4) through V(6), 22 (79%) of which had significant coronary artery stenosis., Conclusions: Hypertensive patients who present with ST-segment depression during exercise in leads II-III-aVF and/or V(4) through V(6) and with a prolonged duration of this depression at the recovery phase (fourth to eighth minute) are more likely to have CAD. Absence of ST-segment depression in V(4) and V(5) at the end of exercise or during the seventh and eighth minute of recovery favors a false-positive result.