Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ultrasoundcardiograms (UCG) and radiocardiograms (RCG) were obtained from 50 patients with essential hypertension. They were classified into four groups according to the severity index of Veterans Administration Hospital. These echocardiograms were compared with those obtained from 20 normal individuals. Of the 50 patients with hypertension, ten had abnormal patterns of mitral valve echogram: two had shoulder formation of the A wave (A-A'), three had increased amplitude of the A wave (A greater than E), and five had systolic anterior movement (SAM) of the anterior mitral leaflet toward the ventricular septum. The former two groups were considered to have impairment of left ventricular (LV) function proven by UCG and RCG, however, the SAM group was considered to have hyperfunction with concentric hypertrophy of the left ventricle with thickened ventricular septum simulating that of idiopathic hypertrophic subaortic stenosis (IHSS). This was supported by the fact that SAM increased after inhalation of amyl nitrite and decreased after injection of propranolol. The descent rate of the anterior mitral valve decreased and the thickness of the ventricular septum increased with the severity of hypertension, indicating the LV compliance decreases as the severity of hypertension advances. A significant positive correlation was noted between stroke index (SI) obtained by UCG and RCG. There were no significant differences of LV dimensions and function indices measured by UCG and RCG among the groups classified according to the severity index of hypertension. This suggests that such factors as myocardial ischemia might play an important role in LV function as well as the grade of afterload due to hypertension.
 ...
PMID:Echocardiographic observations in hypertension. 12 50

Seventeen patients with labile hypertension received nitroglycerin and 18 received amyl nitrite. Twelve patients with established essential hypertension received nitroglycerin and 12 received amyl nitrite. Nitroglycerin reduced the systolic and mean arterial pressures and cardiac output in both groups, but had no effect on diastolic pressure and total peripheral resistance. Amyl nitrite decreased systolic, diastolic, and mean arterial pressures and peripheral vascular resistance and increased heart rate and cardiac output in labile hypertensives. In established hypertensive patients, amyl nitrite decreased systolic, diastolic, and mean arterial pressures and cardiac output, and had little effect on peripheral vascular resistance. Nitroglycerin reduced arterial pressure in labile and established hypertensives through venodilation and peripheral venous pooling. Amyl nitrite and effects similar to nitroglycerin in established hypertensives; in labile hypertensives it reduced arterial pressure through arterial dilation and a decrease in peripheral vascular resistance.
 ...
PMID:Action of Nitroglycerin and amyl nitrite in labile and essential hypertension: hemodynamic differences. 41 75

Human hypertension has been related to abnormalities of autonomic blood pressure regulation. In order to characterize a possible defect, we have studied several aspects of reflex autonomic circulatory control in normal subjects, patients with primary hypertension, and two types of subjects with uremia and elevated blood pressure. Phenylephrine infusion (a measurement of baroreceptor response to high pressure stimulus) resulted in similar hemodynamic changes in all types of subjects. However, all groups of patients exhibited significantly different hemodynamic responses to amyl nitrite inhalation (an index of baroreceptor response to low pressure stimulus). These results suggest that patients with uremia and those with primary hypertension differ from each other and normal subjects regarding baroreceptor reflex function. Furthermore, one type of uremic patient may have a neurogenic component to their hypertension similar to experimental animals following surgical section of afferent baroreceptor nerves.
 ...
PMID:Baroreflex function in uremic and hypertensive man. 72 17

To investigate the predisposing factors and the clinical significance of the musical aortic component of the second heart sound (musical S2), 18 patients with musical S2 (musical group) among the consecutive 2,000 patients with phonocardiographic examination were noninvasively studied by analyzing underlying diseases, phonocardiographic findings, organic changes of the aortic valve, severity of aortic regurgitation and left ventricular dysfunction. Organic changes of the aortic valve were assessed by two-dimensional echocardiography, and aortic regurgitation was assessed by color Doppler flow imaging. Twenty-two normal subjects (normal group) and 17 patients with essential hypertension (hypertensive group) served as controls. Mean ages were matched among the three groups. 1. Left ventricular dilatation (seven patients) and hypertension (six patients) were the dominant part of underlying disease in the musical group. 2. Musical S2 was classified in the following two types based on the phonocardiographic characteristics; musical vibrations followed immediately after the accentuated S2, and the S2 which was replaced by regular vibratory waves. 3. Frequency of the musical vibrations ranged from 120 to 200 Hz, and its duration ranged from 60 to 120 msec. Amplitude of the musical vibrations decreased by inhalation of amyl nitrite, but increased by infusion of methoxamine. In a case with mild rheumatic valve disease, methoxamine induced marked intensification of the amplitude and prolongation of the duration of the musical vibrations, finally giving a typical cooing murmur. 4. Echo intensity of the aortic valve tended to be higher in the musical group than in the other two groups. 5. Echocardiographically, aortic regurgitation appeared more frequently in the musical group (88%) than in the normal (36%) and hypertensive (41%) groups. Area of the aortic regurgitant signal was significantly larger in the musical group (4.1 +/- 1.4 cm2) than in the normal (1.2 +/- 0.8 cm2) and hypertensive (2.3 +/- 1.2 cm2) groups. 6. Left ventricular end-diastolic dimension was significantly larger in the musical group (5.8 +/- 0.6 cm) than in the normal (4.7 +/- 0.5 cm) and hypertensive (4.8 +/- 0.7 cm) groups. Fractional shortening of the left ventricle was significantly smaller in the musical group (26 +/- 10%) than in the normal (37 +/- 5%) and hypertensive (37 +/- 8%) groups. In a case of the musical group, musical vibrations following the S2, which was large in amplitude at the state of heart failure, decreased markedly after the recovery from heart failure.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:[Possible mechanism of production of the musical second heart sound and its clinical significance]. 188 56

Previous biochemical assessment of sympathetic nervous system activity including plasma catecholamines, plasma renin activity, and plasma dopamine-beta-hydroxylase levels has suggested racial differences in the contribution of the sympathetic nervous system to the pathogenesis or maintenance of hypertension. We, therefore, performed physiological and pharmacological studies in white and black subjects with essential hypertension and their age-matched normotensive counterparts to assess autonomic and sympathetic nervous system function. One hundred one male subjects (47 white hypertensive, 17 black hypertensive, 22 white normotensive, and 15 black normotensive subjects) were evaluated for baroreceptor reflex sensitivity to low-pressure (amyl nitrite inhalation) and high-pressure (phenylephrine infusion) stimuli; cold pressor test heart rate and blood pressure responses; and blood pressure response to phentolamine alpha-adrenergic blockade. Hypertensive subjects exhibited an increase in resting heart rate, a decrease in baroreceptor reflex sensitivity, and an exaggerated decline in mean arterial pressure in response to phentolamine. These abnormalities were present to a comparable degree in black and white hypertensive subjects. Cold pressor testing revealed greater increases in heart rate in blacks as compared with whites; however, this racial difference was present regardless of blood pressure status, occurring in black normotensive and black hypertensive subjects to a comparable degree. Cold pressor test blood pressure increments were similar in the four groups. We conclude that both white hypertensive and black hypertensive subjects demonstrate similar abnormalities in autonomic and sympathetic nervous system function including blunting of baroreceptor reflex sensitivity and an increased alpha-adrenergic receptor participation in blood pressure maintenance. The results do not suggest major racial differences in autonomic pathogenetic mechanisms in hypertension.
 ...
PMID:Autonomic function in hypertension. Are there racial differences? 196 34

Ten patients with adult-onset diabetes in whom diabetes antedated the appearance of hypertension were evaluated. These patients had evidence of diabetic autonomic neuropathy, including significant orthostatic hypotension (four patients), impotence (three patients), and evidence of diabetic peripheral sensorimotor neuropathy (nine patients) in clinical testing and nerve conduction study results. Baroreflex function was evaluated by multiple hemodynamic tests, including inhalation of amyl nitrite and intravenous administration of phenylephrine, before and after parasympathetic blockade with atropine, and the cold pressor test; results were compared with results in normal control subjects, patients with essential hypertension, and two subgroups of uremic patients undergoing maintenance hemodialysis. Baroreflex function was significantly abnormal in the diabetic patients and was consistent with combined parasympathetic and sympathetic motor nerve (efferent) dysfunction in the baroreflex arc. There was a significant inverse correlation between the degree of orthostatic hypotension in the diabetic patients and their baroreflex response to phenylephrine (r = -0.680, p less than 0.05). There was no significant correlation between supine hypertension in the patients with diabetes and any of the hemodynamic or biochemical parameters examined. The results suggest that orthostatic hypotension in these patients is related to baroreflex dysfunction. However, baroreflex dysfunction does not appear to be a factor in the development of hypertension in these patients, although more studies with normotensive diabetic patients are needed to confirm this point.
 ...
PMID:Baroreflex dysfunction in patients with adult-onset diabetes and hypertension. 613 Jul 1