ABSTRACT
AIMS: Individuals with resistant arterial hypertension are particularly at risk of developing target organ damage and cardiovascular events. The advanced echocardiography technique called myocardial work (MW), through the analysis of the left ventricular pressure-strain loop, is among the possibilities for evaluating these individuals. Our study was designed to describe the behavior of MW indices in individuals with resistant arterial hypertension (RH), controlled hypertension (CH), and normal arterial pressure (N). METHODS AND RESULTS: Seventy-one patients underwent Ambulatory Blood Pressure Monitoring (ABPM) and were characterized into three groups after a medical consult: RH (subjects with hypertension on four or more antihypertensive medications despite having controlled blood pressure); CH (subjects with hypertension on up to two antihypertensive medications); and N (individuals with normal ABPM; not using any medications). Echocardiographic analysis was performed using the Vivid E95 ultrasound system and blood pressure was measured at the time of the examination and subsequently used to determine myocardial work indices. RH demonstrated lower global work efficiency (GWE, mean = .95%; p = .005) and higher global wasted work (GWW, mean = 114 mm Hg%; p = .011) compared to other groups. Left ventricular mass measured by three-dimensional echocardiography, systolic wall stress, relative wall thickness and peak systolic dispersion were inversely correlated to GWE. No difference was observed between CH and N groups regarding MW indices. On multivariate analysis, only systolic wall stress remained as an independent predictor of GWE, when controlled by 3D mass index, relative wall thickness, peak systolic dispersion, and the hypertension group. CONCLUSION: Individuals with resistant hypertension have lower global work efficiency and higher global wasted work, compared to individuals with controlled hypertension and without arterial hypertension.
Subject(s)
Blood Pressure Monitoring, Ambulatory , Hypertension , Humans , Antihypertensive Agents/therapeutic use , Hypertension/complications , Hypertension/diagnostic imaging , Hypertension/drug therapy , Blood Pressure/physiology , Echocardiography/methods , Ventricular Function, Left/physiology , Stroke VolumeABSTRACT
BACKGROUND: Hypertension is the most important and well established risk factor for atherosclerosis. The vascular and cardiac remodeling present in refractory hypertensive patients are related to endothelial dysfunction, a key factor in early atherogenesis and cardiovascular disease. However the mechanistic relationship among biochemical endothelial function markers, cardiovascular remodeling, and refractory hypertension is unknown. METHODS: We evaluated the left ventricular mass and function, carotid thickness, and plasma nitrate/nitrite (NO2/NO3), cyclic 3'-5'-guanosine monophosphate (cGMP), and thromboxane B2 (TXB2) levels in refractory hypertensive (RH; n = 20) and healthy (CONTROL; n = 20) subjects 22-65 years old. Carotid thickness, left ventricular mass index (LVMI), and left ventricular fraction ejection (LVFE) were estimated by duplex scan ultrasound. Nitrates/nitrites were assayed using the Griess reaction, and plasma cGMP and thromboxane B2 were determined by enzymatic immunoassay (EIA). RESULTS: Left ventricular mass index was higher in the RH group (138 +/- 20 vs. 108 +/-17 g/m2, p < 0.001) but there was no significant difference in the ejection fraction (67 +/- 5% vs. 69 +/- 4%). Pulse pressure (61 +/- 9 mmHg vs. 46 +/- 10 mmHg) and carotid thickness (1.59 +/- 0.22m vs. 1.04 +/- 0.14mm) were significantly higher (p < 0.001) in RH patients whereas NO2/NO3, cGMP, and thromboxane B2 plasma concentrations were similar in bot groups. CONCLUSION: There was no association between cardiovascular remodeling and the particular biochemical markers of endothelial function we assessed in refractory hypertensive patients.
