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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Among hypertensive patients, blacks are more likely than whites to have ischemia by electrocardiographic and 201Tl-myocardial stress imaging, possibly due to racial differences in the regulation of coronary blood flow or velocity. This investigation was undertaken to determine whether intensive antihypertensive therapy with two or more drugs can correct or reduce ischemia in black hypertensive patients. Thallium myocardial stress imaging and electrocardiographic and echocardiographic studies were performed on 13 black patients with essential hypertension and ischemic heart disease due to hypertensive heart disease (without significant obstructive epicardial coronary artery disease). The studies were made at baseline and after 4 to 48 months of intensive treatment, with a calcium antagonist and an angiotensin converting enzyme (ACE) inhibitor as the main components of the antihypertensive drug regimen. The majority of the patients with abolition or reversal of myocardial ischemia documented by 201Tl-myocardial imaging also had a significant reduction in left ventricular mass (LVM). However, some patients either did not have LV hypertrophy at baseline or had changes in LVM beyond the precision of the echocardiographic M-mode mass calculations. The finding indicated that factors other than reduction of LVM were involved in the reversal of the ischemia. The most likely factor was a change in the regulation of coronary blood flow. Reduction in LVM and reversal of myocardial ischemia determined either by electrocardiography or by thallium myocardial imaging studies may be considered indicators of the effectiveness of treatment.
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PMID:Correction of left ventricular ischemia in blacks with hypertensive heart disease. 839 11

We describe the case of a 73-year-old man with cardiac failure due to hypertensive heart disease, chronic atrial fibrillation, prior ischemic stroke and acute ischemia of the left leg probably embolic in nature, in whom transthoracic echocardiography (TTE) detected a large left atrial mass compatible with thrombus. Transesophageal echocardiography (TEE) was performed to better evaluate the atrial mass. TTE showed a mass that was firmly attached to the wall of the left atrium, compact, homogeneous and stationary, indicating a relatively low embolic risk. On the other hand TEE clearly detected a marked motility and echographic unhomogeneity of the atrial mass, suggesting a poorer prognosis and urgent surgical referral due to high impending embolik risk. This case further supports the superiority of TEE to TTE in the assessment of intracardiac masses and, in particular, of embolik risk in a patient with left atrial thrombosis.
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PMID:[Role of transesophageal echocardiography in the evaluation of the potential embolic risk in left atrial thrombosis. Report of a clinical case]. 853 6

Control of hypertension and treatment of concomitant pathophysiologic conditions require use of multiple drugs. Unfortunately, most studies regarding hypertensive disease have focused on monotherapy. Thus, our knowledge of combination therapy in the treatment of hypertension is, to a great extent, extrapolation from monotherapy. Angiotensin converting enzyme (ACE) inhibitors in combination with calcium antagonists should be particularly efficacious in reducing left ventricular hypertrophy (LVH). Drug classes that either stimulate the renin-angiotensin system or the sympathetic nervous system are less likely to reduce LVH and should be avoided. In hypertensive patients with congestive heart failure, amlodipine should be added to triple therapy with an ACE inhibitor, whereas in the postmyocardial ischemia patient, verapamil may exert some additional beneficial effects with regard to reinfarction rates. Given that two drugs when used separately are beneficial in a disorder does not necessarily mean that their combination is equally or even more beneficial. Thus, combination therapy should primarily be used for lowering arterial pressure and only secondarily to possibly improve concomitant pathophysiologic conditions associated with hypertensive heart disease.
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PMID:Cardiac effects of combination therapy. 923 91

Assessment of regional left ventricular (LV) function in patients with asymmetric LV hypertrophy is difficult with two-dimensional echocardiography mainly because of factors such as LV geometry, structure, regional wall stress, and ischemia. Multiplane transesophageal echocardiography with three-dimensional reconstruction of cross-sectional images was used for quantitative evaluation of regional wall thickness and fractional thickening. Fifteen patients (56 +/- 13 years old) with hypertrophic cardiomyopathy (LV ejection fraction 71% +/- 4%), 15 (62 +/- 13 years) with hypertensive heart disease (ejection fraction 66% +/- 8%) and 15 (53 +/- 11 years) healthy control subjects (ejection fraction 61% +/- 5%) were included in the analysis. Regional function was studied in four parallel equidistant short-axis cross sections from base to apex of the reconstructed left ventricle. In 15 degree intervals, 24 wall thickness measurements in each cross section were made at end-diastole and end-systole after endocardial and epicardial border tracing. A total of 192 measurements were obtained in each patient, and absolute wall thickening and fractional thickening were calculated. Absolute and fractional wall thickening showed a significant inverse relation to end-diastolic wall thickness in all heart conditions (r = 0.71, p < 0.0001). Regions of normal wall thickness in diseased patients were not hyperdynamic when compared with normal control subjects. Significant impairment in fractional thickening at identical end-diastolic thickness was observed in the septum compared with the lateral free wall in both hypertrophic cardiomyopathy and hypertensive heart disease. Thus regional systolic function is inversely related to end-diastolic wall thickness. The decrease in regional systolic function with increasing LV hypertrophy was similar in idiopathic and hypertensive cardiomyopathy. In both types of hypertrophy, significant differences in systolic function were observed in septal and lateral wall segments of similar wall thickness. This indicates that factors other than end-diastolic wall thickness influence myocardial thickening in patients with hypertrophy and preserved global function.
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PMID:Evaluation of regional systolic function in hypertrophic cardiomyopathy and hypertensive heart disease: a three-dimensional echocardiographic study. 971 89

Hypertension is a well-known risk factor that predisposes to the development of left ventricular hypertrophy, coronary flow abnormalities, and systolic and diastolic dysfunction. This complex of abnormalities is known as hypertensive heart disease and eventually leads to heart failure. Structural lesions underlying this process include excess deposition of collagens and cellular infiltration, with an increase in the size of cardiac myocytes (remodeling). The occurrence of arteriolar lesions may lead to impediments of flow. Clinically, hypertensive heart disease manifests itself by anginal complaints and sometimes by silent ischemia, arrhythmias, and sudden death. Alterations in systolic and/or diastolic function may be associated with symptoms of heart failure. Although successful treatment of hypertension can probably retard the process of cardiac impairment, there is as yet no evidence that heart failure can be prevented.
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PMID:Hypertension and the development of heart failure. 973 90

MRI myocardial tagging is now a well-developed method for evaluation of regional myocardial contraction. A series of progressively more refined imaging strategies, combined with advances in analytic strategies have provided a strong armamentarium of methods. Important insights into normal human physiology of left ventricular systolic and diastolic function have been developed using one-dimensional, two-dimensional and three-dimensional analyses of myocardial deformation. In disease states, improved understanding and detection of early alterations in myocardial function in hypertensive heart disease has been possible. In addition, improved understanding of effects of ischemia and infarction on regional function has been possible. Further, after acute myocardial infarction, clearer definition of the natural history of contractile dysfunction in the infarct region and the zone adjacent to the infarct have been possible. Similarly, effects on regional function of a number of important pharmacologic agents used for treatment, such as angiotensin converting enzyme inhibitors, beta blockers and angiotensin receptor blockers have been characterized. In the cardiomyopathies, myocardial tagging has permitted more reliable assessment of heterogeneity of segmental function, especially in hypertrophic cardiomyopathy. Finally, initial applications of myocardial tagging to assessment of right ventricular regional function in hypertrophied hearts with and without major congenital abnormalities have generated advances in understanding of effects of hypertrophy on right ventricular function.J. Magn. Reson. Imaging 1999;10:609-616.
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PMID:MRI myocardial tagging. 1054 69

Primary diastolic failure is typically seen in patients with hypertensive or valvular heart disease as well as in hypertrophic or restrictive cardiomyopathy but can also occur in a variety of clinical disorders, especially tachycardia and ischemia. Diastolic dysfunction has a particularly high prevalence in elderly patients and is generally associated, with low mortality but high morbidity. The pathophysiology of diastolic dysfunction includes delayed relaxation, impaired LV filling and/or increased stiffness. These conditions result typically in an upward displacement of the diastolic pressure-volume relationship with increased end-diastolic, left atrial and pulmo-capillary wedge pressure leading to symptoms of pulmonary congestion. Diagnosis of diastolic heart failure requires three conditions: (1) presence of signs or symptoms of heart failure; (2) presence of normal or slightly reduced LV ejection fraction (EF > 50%) and (3) presence of increased diastolic filling pressure. Assessment of diastolic function can be performed with several non-invasive (2D- and Doppler-echocardiography, color Doppler M-mode, Doppler tissue imaging, MR-myocardial tagging, radionuclide ventriculography) and invasive techniques (micromanometry, angiography, conductance method). Doppler-echocardiography is the most useful tool to routinely measure diastolic function. Different techniques can be used alone or in combination to assess LV diastolic function, but most of them are dependent on heart rate, pre- and afterload. The transmitral flow pattern remains the starting point, since it is easy to acquire and rapidly categorizes patients into normal (E > A), delayed relaxation (E < A), and restrictive (E >> A) filling patterns. Invasive assessment of diastolic function allows determination of the time constant of relaxation from the exponential pressure decay during isovolumic relaxation, and the evaluation of the passive elastic properties from the slope of the diastolic pressure-volume (= constant of chamber stiffness) and stress-strain relationship (= constant of myocardial stiffness). The prognosis of diastolic heart failure is usually better than for systolic dysfunction. Diastolic heart failure is associated with a lower annual mortality rate of approximately 8% as compared to annual mortality of 19% in heart failure with systolic dysfunction, however, morbidity rate can be substantial. Thus, diastolic heart failure is an important clinical disorder mainly seen in the elderly patients with hypertensive heart disease. Early recognition and appropriate therapy of diastolic dysfunction is advisable to prevent further progression to diastolic heart failure and death. There is no specific therapy to improve LV diastolic function directly. Medical therapy of diastolic dysfunction is often empirical and lacks clear-cut pathophysiologic concepts. Nevertheless, there is growing evidence that calcium channel blockers, beta-blockers, ACE-inhibitors and AT2-blockers as well as nitric oxide donors can be beneficial. Treatment of the underlying disease is currently the most important therapeutic approach.
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PMID:Diastolic heart failure. 1072 7

The echocardiographic examination is generally performed in patients with heart failure and it often gives a significant contribution to the differential diagnosis. Firstly, the evaluation of left ventricular pump function by measuring the ejection fraction (EF) can distinguish patients with heart failure into two different groups, with depressed or preserved EF. The most frequent causes of heart failure and depressed EF are coronary artery disease, idiopathic dilated cardiomyopathy (DCM) and hypertensive heart disease. Although the echocardiographic features of coronary artery disease versus idiopathic DCM may be similar, the demonstration of inducible ischemia at dobutamine echocardiographic test suggests the presence of significant coronary artery disease and may be useful in the selection of cases for coronary arteriography. The association of left ventricular hypertrophy, hypokinesis and, sometimes, significant dilation is compatible with hypertensive heart disease or end-stage hypertrophic cardiomyopathy. No useful echocardiographic findings can identify the patients with genetic DCM or affected by myocarditis from other cases with idiopathic DCM. Some advanced cases of right ventricular dysplasia/cardiomyopathy may show a biventricular involvement and mimic DCM; these patients are usually characterized at echo by predominant right ventricular dilation and multiple a-dyskinetic bulges in the absence of pulmonary hypertension. Very difficult to manage are the patients with significant left ventricular dysfunction and severe valvular heart disease (such as aortic stenosis or mitral regurgitation). According to the literature, the left ventricular systolic function is relatively preserved (EF > 40%) in 30-40% of patients with heart failure. In these cases a diastolic dysfunction may be hypothesized. Echo-Doppler evaluation can be helpful in the recognition of signs of increased left ventricular stiffness ("restrictive filling pattern") and of increased filling pressures. In the differential diagnosis one must first consider the most frequent heart disorders that may present with this clinical syndrome, coronary artery disease and hypertensive heart disease. Furthermore, other less common diseases characterized by heart failure due to predominant diastolic dysfunction are the following: hypertrophic and restrictive cardiomyopathies, infiltrative heart diseases, such as amyloidosis, and constrictive pericarditis. Restrictive cardiomyopathy is characterized by heart failure and preserved left ventricular EF in the absence of significant ventricular dilation and hypertrophy; typical, although not pathognomonic, echocardiographic features are atrial enlargement ad restrictive filling pattern. In distinguishing constrictive pericarditis from restrictive cardiomyopathy useful Doppler signs are the wide respiratory variability in flow velocities at mitral and tricuspid levels, due to increased ventricular interdependence caused by the presence of an abnormally rigid pericardium.
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PMID:[Contribution of echocardiography to the diagnosis of patients with chronic heart failure]. 1106 13

The increased cardiovascular morbidity and mortality in hypertension are related to the target organs (ie, heart, brain, kidneys) involvement from vascular disease. Left ventricular hypertrophy (LVH), the major expression of cardiac involvement, is both a structural and functional adaptation to the afterload imposed by the vascular disease. Without this adaptation, cardiac failure would result much earlier in the natural history of hypertensive heart disease (HHD). However, LVH imposes an independent risk that is even greater than the risk associated with the height of systolic or diastolic pressure. The mechanisms that explain this risk have not been defined precisely; several have been postulated. Among these are the following: 1) coronary hemodynamic alterations associated with HHD (ie, increased coronary vascular and minimal vascular resistance, reduced coronary blood flow and flow reserve, and increased blood viscosity); 2) enhanced predisposition for lethal cardiac arrhythmias, cardiac failure, and accelerated atherosclerosis of the coronary arteries (with exacerbation of the ischemia); and 3) collagen deposition and ventricular fibrosis. From the earliest controlled therapeutic trials, deaths from stroke and coronary heart disease were significantly reduced. However, more recent data have indicated that the prevalence of cardiac failure (CHF) continues to rise progressively. The nature of the CHF is no longer primarily from systolic dysfunction, but is now chiefly from diastolic dysfunction. Diastolic dysfunction occurs primarily in the elderly hypertensive patient or in the patient with ischemic heart disease, both of which are associated with increased collagen deposition. Indeed, these effects continue to be suggested by the data from the Framingham Heart Study as well as NHANES-III that indicate CHF is the most common diagnosis occurring in hospitalized patients over 65 years of age. In this report, both experimental and clinical evidence demonstrating that increased ventricular fibrosis occurs in the spontaneously hypertensive rats and in hypertensive patients are provided, and that treatment with the newer antihypertensive agents reduce ventricular hydroxyproline (ie, collagen) content while, at the same time, improve coronary hemodynamics.
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PMID:Fibrosis and ischemia: the real risks in hypertensive heart disease. 1141 56

Complete atrioventricular block occurred during spinal and subsequent general anaesthesia in a 74-year-old patient with known arterial hypertension but without heart conduction abnormality. Drug therapy and intermittent transcutaneous pacing was successful. A decrease of arterial pressure by more than 40% preceded the heart blockade in the course of both events. Subsequent cardiologic examination revealed evidence of a discrete hypertensive heart disease. Relative ischemia of the atrioventricular region during anaesthesia was suggested as an aetiology. When the patient presented for the next operation, again general anaesthesia was applied, and invasive arterial blood pressure monitoring as well as catecholamine support were used and no further atrioventricular blockade occurred. The case demonstrates the possible recurrence of an intraoperative complete atrioventricular blockade in an older patient without pre-existing conduction abnormalities and only minor signs of heart disease, irrespective of the anaesthesia technique. Under these circumstances transcutaneous pacing should always be in place. Maintenance of coronary perfusion pressure is essential and invasive blood pressure monitoring is recommended.
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PMID:[Complete heart block after spinal and general anaesthesia]. 1271 35


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