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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Conventional ECG, Frank system VCG and the spatial velocity ECG were recorded in 42 cases of healthy adult men, 76 cases of hypertension and 26 cases of aortic insufficiency, and were studied qualitatively as well as quantitatively in order to clarify the characteristic changes in the spatial velocity ECG in the systolic and the diastolic overloadings of the left ventricle. Spatial velocity ECG were recorded by means of the spatial velocity electrocardiograph, leading three scalar ECG of Frank system (X, Y, and Z leads) into the differentiating, the squaring, the adding and the square root circuits in orders. Computations were performed automatically according to the following formula: see journal for formula. Spatial velocity ECG and three scalar ECG of Frank system were simultaneously recorded by the four channel heatwriting oscillograph with paper speed of 100 mm per second. The forty Hz and 4 Hz of the sinusoidal waves were introduced into the circuits for the calibrations of QRS and P and T waves respectively. P waves of the spatial velocity ECG in normal subjects showed 2-peaked (5%), 3-peaked (6%), and 4-peaked (26%) patterns exhibiting 3-peaked P waves as the basic pattern in normal. The three peaked and 4-peaked patterns were observed in 33% and 67% in hypertension, and in 35% and 65% in aortic insufficiency respectively. Two-peaked P wave was not observed and the incidence of the 4-peaked P waves of the spatial velocity ECG increased in the left ventricular overloadings..
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PMID:[Studies on the spatial velocity electrocardiogram in left ventricular overloadings]. 12 68

The Frank-Starling relationship of hearts from adult spontaneously hypertensive rats (SHR, Okamoto 1969), representing the established phase of hypertension, and of young SHR, representing the initial phase of hypertension, was investigated by using the isolated working heart preparation. In the "normal" diastolic pressure range (5 to 10 cm H2O), the left ventricle of both SHR groups displayed significantly reduced stroke volumes compared with hearts of normotensive controls (NCR); the degree of reduction being proportional to the left ventricular hypertrophy. This is suggested to be due to a reduced left ventricular diastolic compliance in SHR, as indicated by direct measurements of ventricular wall thickness and end-diastolic volumes in arrested hearts exposed to different end-diastolic filling pressures. Such a progressive shift of the Frank-Starling relationship to the right with duration of hypertension could, in combination with the gradual development of "structural autoregulation" of the precapillary resistance vessels, constitute dominating factors in shifting the hemodynamic situation in labile hypertension into that characterizing the established, or "fixed", state of hypertension.
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PMID:Consequences of myocardial structural adaptation on left ventricular compliance and the Frank-Starling relationship in spontaneously hypertensive rats. 12 25

Great ECG changes (Frank system) with age were found in normal men. ECG diagnostic criteria valid in Romania were studied by multivariate analyses in men aged 40--60 suffering from hypertension (Hyp) without cardiac congestive failure (CCF), out of which one group with left ventricular hypertrophy (LVH) and another one without it. Echocardiographic studies in normal and hypertensive men past forty, as well as studies in experimental Hyp with LVH and without CCF were carried out. Heart X-ray evaluation is not a functional one. Some non-invasive methods in men do not determine an accurate evaluation of LV performance. The increase of LV muscular mass alone cannot explain the ECG changes in LVH in Hyp without CCF. Two conditional adaptive mechanisms: the liberation of catecholamines from the myocardium storage, induced by the pressure overload stress, and the increase of intracellular Ca++ influx could contribute to the respective ECG changes.
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PMID:Studies concerning the significance of orthogonal ECG changes with age in normal men and in arterial hypertension without congestive cardiac failure in men past forty. 15 76

Cardiovascular 'reactivity' to graded splanchnic nerve stimulation was compared in adult spontaneously hypertensive rats (SHR) and normotensive controls (NCR), during abolished adrenal medullary secretion and neurogenic cardiac control and depressed reflex vascular adjustments. Arterial pressure, heart rate and cardiac output were measured, and total peripheral resistance (TPR) and stroke volume (SV) computed before, during and after nerve stimulation. The neurogenic resistance increases in the major gastrointestinal-renal-hepatic circuits expressed themselves as TPR elevations, which were much accentuated in SHR. This reflects an increased w/ri of SHR resistance vessels rather than any altered effector sensitivity, since the responses were particularly accentuated at high discharge rates when noradrenaline junction concentrations approach maximal levels. The splanchnic capacitance responses expressed themselves as SV increases, being the most relevant aspect of capacitance control. SV increased less in SHR, mainly reflecting the reduced diastolic compliance of the hypertrophied SHR left ventricle and the consequent rightward shift of its Frank-Starling curve. The results indicate that an elevated resistance may well be maintained by a normal sympathetic discharge in established SHR hypertension. There seems, however, to be an increasing need for accentuated discharge to the capacitance side to maintain proper cardiac filling of the hypertrophied left ventricle.
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PMID:Cardiovascular 'reactivity' to graded splanchnic nerve stimulation in spontaneously hypertensive and normotensive control rats. 15

Isolated hearts from adult spontaneously hypertensive rats (SHR; Okamoto 1969), with established hypertension, were investigated in an antegrade perfusion apparatus where preload and afterload could be varied independently. Frank-Starling curves were constructed at constant afterloads ranging from 50 mmHg to 150 mmHg. As earlier reported, the SHR hearts exhibited a rightward shift of their Frank-Startling relationships compared to those from the normotensive control hearts, though visible only at afterloads up to about 100 mmHg. At higher afterloads the SHR hearts performed significantly better then the NCR ones as their maximal stroke volume was significantly greater compared to that of controls. Thus, left ventricular hypertrophy obviously increases the work capacity of the heart, though at the cost of an altered Frank-Startling relation dependent on the reduced diastolic compliance. For such reasons the myocardial hypertrophy in established SHR hypertension must be considered a physiologic adaptation and not a degenerative phenomenon, though naturally degenerative processes may later become superimposed.
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PMID:Performance of the hypertrophied left ventricle in spontaneously hypertensive rat. Effects of changes in preload and afterload. 16 Jul 44

By means of a device system consisting of constituents of the SW-production and own developmental works in the factory Kombinat VEB Umformtechnik (combinate nationally owned enterprise transformation technology) for the first time ECG serial examinations were performed with the help of the mechanical ECG-analysis. The corrected orthogonal system of Frank with 3 leads served as deviation system. The ECG-registration was independently performed by function nurses. 1,720 male and female workers of this factory at the age of 21 to 59 years served as test persons. The ECG-registration lasted 20 sec., the whole time of examination including the changing of clothes and the way from the working place to the examination room did not last more than 4 to 8 min. As diagnosis programme served that one developed by Pipberger. The mechanical analysis resulted in 74.4% in a normal course of the electrocardiographic current curve. Among the pathological or abnormal ECGs (25.6%) prevailed the vegetative-functional heart diseases with 92%. Then followed the chronic ischaemic heart diseases with 7.9% and the hypertension with 5.1%. Diseases of the heart and the blood circulation established for the first time referred to 8.9%. Of them 5% needed control and 3.9% needed therapy.
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PMID:[1st experience on the use of an automatic ECG analysis in a large industrial plant in Erfurt]. 59 17

Central hemodynamics was studied by means of echocardiography in 7 patients suffering from neurocirculatory dystonia with a high cardiac index but normal arterial pressure, and in 41 patients with essential hypertension prior to, and after treatment. Two groups of patients suffering from essential hypertension were distinguished: with a hyperkinetic type of circulation and with a normal cardiac index. In the first group there was a statistically significant increase in the stroke index and the index of diastolic left ventricular diameter with a normal ejection fraction. The increase in the cardiac index in the hyperkinetic type of essential hypertension is caused by an increase in the stroke output according to the Frank--Starling law. The authors believe that the increase in peripheral resistance is the principal pathogenetic mechanism of hypertension with any level of the minute volume.
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PMID:[Hemodynamic types of hypertensive disease according to echocardiographic data]. 72 44

Studies were performed to assess clinical applicability and usefullness of several non-invasive indices of myocardial contractility, especially, ET/PEP, Pd/ICT and (Pd/ICT)(AO/EO). In dogs preload, afterload or myocardial contractility was altered by durgs. The ET/PEP was influenced by preload as well afterload and PdICT by afterload, respectively. A correction of Pd/ICT with preload, (Pd/ICT)/(AO/EO)showed a satisfactory correlation to Vmas even when the preload and/or afterload were altered. In clinical cases, ET/PEP, Pd/ICT and (Pd/ICT)/(AO/EO) all changed following administration of positive inotropic substances. Moreover, in azotemic cases with primary change in preload the gradient of the Frank-Sterling's curve increased progressively and the entire curve was located upwards with increase of (Pd/ICT)/(AO/EO) value. In case of high-resistance type hypertension, nevertheless, (Pd/ICT)/(AO/EO) showed a tendency to change in association with alteration of its constituent factor Pd. Since there exists no absolutely perfect non-invasive index of myocardial contractility available for clinical application as yet, it would be appropriate to make overall evaluation of myocardial contractility by combined use of several indices, with underlying pathological conditions and characteristics of individual parameters taken into consideration.
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PMID:Clinical evaluation of myocardial contractility and its problems. 87 31

The electrocardiography (ECG) contribution in the diagnosis of left ventricular hypertrophy (LVH) associated to arterial hypertension was evaluated in 54 hypertensive patients, 39 men and 15 women, with a mean age of 51.6 years, mean systolic and diastolic pressure 186 +/- 46 and 111 +/- 46 mmHg, respectively. The investigations included routine clinical and biologic tests as well as standard ECG in 12 derivations, Frank vectorial ECG and mono and bidimensional echocardiography (ECOCG). A correlative study of the ECG parameters demonstrated that the left ventricular mass index evaluated by ECOCG correlates best with Romhilt ECG index and with an LVH index elaborated by the authors of the present study, based on the Frank vectorial recordings (R wave amplitude in X and Z derivations; QRS duration in Z). These data were used in drawing linear regression equations for evaluation of the left ventricular mass, starting from the above-mentioned parameters. The results are discussed in comparison with those of other authors and their practical value is demonstrated.
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PMID:Evaluation of the electrocardiographic signs of left ventricular hypertrophy, using the echocardiography in patients with hypertensive cardiopathy. 147 96

Sixty four cases of retinal and vitreous hemorrhages are reported during a 15 months prospective study in Bamako. Main diseases associated with hemorrhages are high blood pressure (56% of cases), hemoglobinopathies (33%) and diabetes mellitus (23%). In 28% of cases several aetiologies are connected. SC hemoglobin is a frequent aetiology of vitreous hemorrhage (40%). Hemoglobin AS and AC, generally asymptomatic, are also liable to hemorrhages. Terson and Eales syndromes, Werlhof disease, hemophilia and AIDS are most uncommon. In 8% of cases there is not any aetiology.
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PMID:[General causes of retinal and vitreous hemorrhages in Mali]. 181 88


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