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

Cardiovascular reflexes that are mediated by receptors in the heart and blood vessels control a variety of important hemodynamic and humoral functions. The action of these receptors can be shown to be abnormal in several pathologic states. Left atrial receptors exhibit a depressed discharge sensitivity in dogs with chronic congestive heart failure caused by an aortocaval fistula. The reflex effects of atrial receptor stimulation are also depressed in heart failure. Left ventricular receptor stimulation has been implicated in the abnormal vascular responses to exercise in patients with aortic stenosis. The arterial baroreflex control of heart rate is abnormal in animals and humans with various forms of hypertension. Arterial baroreceptors from hypertensive animals show a resetting of their pressure-discharge curve to higher pressures. The arterial baroreflex is also depressed in chronic heart failure. This effect may result from an abnormality of the efferent limb of the reflex arc or from changes in the interaction between baroreceptors and cardiac receptors centrally. A final possibility may be abnormal arterial baroreceptor discharge characteristics in heart failure.
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PMID:Aspects of cardiovascular reflexes in pathologic states. 388 28

To analyze whether atherosclerotic risk factors, including systemic hypertension, an elevated serum cholesterol level, smoking and diabetes, were associated with the presence of aortic stenosis (AS) in adults, 105 adults who had AS without coronary artery disease (CAD) were compared with 110 control subjects who had other types of valvular disease, 170 control subjects who underwent catheterization and had neither valvular disease nor CAD, and 269 matched control subjects who underwent general surgery. When using each control group separately or in combination, no risk factor showed consistent evidence of a significant association with the development of AS. If the true magnitudes of these associations are of the order previously reported for the development of CAD, the power of our study for detecting statistical significance ranges from 56 to 99%. In a supplemental analysis, 45 cases with both AS and CAD did not have a higher prevalence of risk factors than cases without CAD. Although a weak association between atherosclerotic risk factors and AS cannot be excluded, any such association is unlikely to be as strong as for predicting CAD.
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PMID:Case-control analysis of risk factors for presence of aortic stenosis in adults (age 50 years or older). 391 53

The clinical and electrophysiological features and the natural history of median intra-His block with a normal resting electrocardiogram were studied: 11 patients had a fixed split H1-H2 potential with a spontaneous or induced block between H1 and H2. The patients (5 men and 6 women) were aged 17 to 70 years (average 53 years). Associated pathology included 2 cases of aortic stenosis (1 severe), 1 case of ischaemic heart disease (effort angina), 1 case of mitral valve prolapse and 2 cases of hypertension. The presenting symptoms were syncope (4 cases), dizziness (2 cases), effort angina (1 case) and tiredness (3 cases); 1 patient was asymptomatic. Holter monitoring (24 hours) was performed in 8 patients and s-owed paroxysmal conduction defects in 6 cases; 4 Mobitz II 2nd degree AV block, 1 3rd degree AV block with narrow QRS complexes and 1 case of blocked atrial extrasystoles at coupling intervals longer than 480 ms and sinus cycle lengths of over 800 ms. Exercise testing by bicycle ergometry (4 patients) was normal in 1 case and revealed Mobitz II 2nd degree AV block in 3 cases. Baseline electrophysiological studies showed an A-H1 interval ranging from 60 to 100 ms (average 78 ms), a H1-H2 interval of 20 to 40 ms (average 31 ms) and a H2-V interval of 30 to 50 ms (average 32 ms). Block between H1 and H2 was observed: "spontaneously" during electrophysiological investigation in 6 cases, after IV atropine in 1 case, during overdrive atrial pacing at rates slower than 150/min in 7 cases, after atrial extrastimulus with a functional intra-His refractory period of over 420 ms in 7 cases, after ajmaline in 3 of the 4 cases in which this test was performed. A cardiac pacemaker was implanted in 10 patients in whom the initial symptoms have all regressed; the remaining patient considered to be "epileptic" had another syncopal attack under therapy and was finally paced. This series demonstrates that the diagnosis of median intra-His block depends on precise electrophysiological criteria and should be looked for even when the presenting symptoms are atypical; some of our patients complained only of tiredness. The value of Holter monitoring and careful endocavitary investigation is emphasised. Median intra-His block should be distinguished from longitudinal and functional His bundle dissociation.
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PMID:[Clinical and electrophysiological aspects of median intra-His bundle block with normal electrocardiogram at rest]. 392 29

One hundred fifty-three men (mean age 67.0 +/- 10.0 years) with basal systolic murmurs and aortic valve calcium on the echocardiogram (group II) were studied to assess the relationship between the grade of calcium and severity of aortic valve obstruction. Patients were subdivided into group IIA (hypertension, no coronary artery disease), group IIB (coronary artery disease, no hypertension), group IIC (hypertension and coronary artery disease) and group IID (neither hypertension nor coronary artery disease). Group I consisted of 21 normal age-matched men (mean age 60.5 +/- 10.9 years). Aortic valve calcium was graded as 1+ (63 patients), 2+ (54 patients), or 3+ (36 patients) according to the degree of involvement. Left ventricular wall thickness was greater in group II than in group I, and close correlation between wall thickness parameters and grade of aortic valve calcium was observed for group IID. Of 31 catheterized patients, none of seven with 1+ aortic calcium and 11 of 14 with 3+ calcium had gradients greater than or equal to 50 mm Hg. With 3+ calcium the valve area was 0.8 +/- 0.4 cm2, and with 1+ calcium it was 2.8 +/- 0.7 cm2 (f = 0.0006). The presence of 3+ calcium or grade 2+ calcium combined with a left ventricular ejection time index greater than 433 msec and a left ventricular mass greater than 300 gm was highly suggestive of severe aortic stenosis and could be used to separate patients to be considered for invasive studies from those with benign aortic valve sclerosis.
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PMID:The role of aortic valve calcium in the detection of aortic stenosis: an echocardiographic study. 399 15

Semantic difficulties arise when hypertrophic obstructive cardiomyopathy is seen without obstruction and with congestive failure, and also when congestive cardiomyopathy is seen with gross hypertrophy but without heart failure. Retention of a small left ventricular cavity and a normal ejection fraction characterizes hypertrophic cardiomyopathy at all stages of the disorder. Congestive cardiomyopathy is recognized by the presence of a dilated left ventricular cavity and reduced ejection fraction regardless of the amount of hypertrophy and the presence or not of heart failure. Longevity in congestive cardiomyopathy seems to be promoted when hypertrophy is great relative to the amount of pump failure as measured by increase in cavity size. Conversely, death in hypertrophic cardiomyopathy is most likely when hypertrophy is greatest at a time when outflow tract obstruction has been replaced by inflow restriction caused by diminishing ventricular distensibility. Hypertrophy is thus beneficial and compensatory in congestive cardiomyopathy, whereas it may be the primary disorder and eventual cause of death in hypertrophic cardiomyopathy. Reasons are given for believing that hypertension may have been the original cause of left ventricular dilatation in some case of congestive cardiomyopathy in which loss of stroke output thenceforward is followed by normotension. Development of severe hypertension in these patients after recovery from a prolonged period of left ventricular failure with normotension lends weight to this hypothesis. No fault has been found in the large or small coronary arteries in either hypertrophic cardiomyopathy or congestive cardiomyopathy when they have been examined in life by selective coronary angiography, or by histological methods in biopsy or post-mortem material. Coronary blood supply may be a limiting factor in the compensatory hypertrophy of congestive cardiomyopathy, and the ability to hypertrophy may explain the better prognosis of some patients. In hypertrophic cardiomyopathy excessive metabolic demand may not be met, and inadequacy of blood flow may contribute both to sudden death and to progressive replacement fibrosis in this disease. Histochemical and ultrastructural methods have failed to show any fundamental differences between hypertrophic cardiomyopathy and congestive cardiomyopathy, whereas conventional histology permits recognition of hypertrophic cardiomyopathy and distinction both from congestive cardiomyopathy and from ;normal' secondary hypertrophy in organic aortic stenosis.
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PMID:Ventricular hypertrophy in cardiomyopathy. 425 44

Aneurysm of the coronary artery associated with aortitis syndrome is extremely rare. This is a case report of a left coronary artery aneurysm associated with aortitis syndrome. The patient was a 47-year-old woman who complained of palpitation and dizziness on exertion. Aortogram revealed occlusion of the arch vessels, infrarenal aortic stenosis, and a fusiform aneurysm of the left coronary artery. There was neither an intraluminal thrombus nor occlusive changes in the coronary arteries. Severe systolic hypertension nearing 300 mmHg was present in the ascending aorta. Severe hypertension and direct extension of inflammation to the coronary artery seemed to be important factors for the formation of the aneurysm. To resolve the severe hypertension, a bypass operation between the ascending aorta and the abdominal aorta distal to the stenosis was performed. The postoperative course was uneventful and blood pressure was reduced.
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PMID:Coronary artery aneurysm associated with aortitis syndrome diagnosed pre- and intraoperatively. 614 72

Twelve normal subjects, 50 patients with valvular heart disease, and 14 with hypertension were studied. Those with valvular disease were divided into two groups: 28 with angiographically measured ejection fractions greater than or equal to 0.6 and 22 with ejection fractions less than 0.6. The echocardiographically measured ventricular thickness divided by radius ratio (t/r) was approximately proportional to peak systolic pressure (P) in all groups having ejection fractions greater than or equal to 0.6, so that the t/r divided by P ratios were nearly the same. Patients with ejection fractions less than 0.6 had significantly lower t/r divided by P values. No single component of the t/r divided by P ratio would identify the patients with lower ejection fractions. The t/r divided by P ratios in 14 hypertensive patients were nearly identical to the ratios in six patients with aortic stenosis and ejection fractions greater than or equal to 0.6, indicating that an aortic valve gradient does not cause a grossly abnormal form of pressure hypertrophy. The t/r ratio is thus a double sensitive, noninvasive index of dilation when correlated with systolic pressure.
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PMID:Dimensional correlates of left ventricular dilation in the presence of hypertrophy. 621 34

Assessment of left ventricular function may be of value in patients with pressure-loaded, hypertrophied left ventricles for the purpose of characterizing such patients as to prognostic risk. To determine whether left ventricular function is in part independent of loading stresses in such patients, and to assess the effects of removal of loading factors, we have reviewed preliminary data in 60 patients with essential hypertension and in 26 patients with aortic stenosis who were studied with radionuclide cineangiography. Patients with hypertension manifested a poor but statistically significant direct relationship between systolic arterial pressure and left ventricular ejection fraction at rest, and a poor but significant inverse relationship between systolic pressure and the magnitude of change in ejection fraction from rest to exercise. However, a strong correlation existed between echocardiographic systolic fractional shortening and end-systolic wall stress at rest. Nonetheless, many patients with normal fractional shortening-end-systolic wall stress relationships had subnormal ejection fraction responses during exercise; the two patients with subnormal fractional shortening-end-systolic wall stress relationships at rest also had subnormal fractional shortening-end-systolic wall stress relationships during exercise. Arterial pressure alone was not predictive of these functional responses. These data suggest that hypertensive patients can be categorized on the basis of left ventricular function at rest and during exercise, independent of arterial pressure. Among patients with aortic stenosis, ejection fraction at rest averaged 67 percent before valve replacement (normal = 57 percent, p less than 0.01), and changed little after operation (71 percent, not significant). However, potential functional benefits of afterload reduction in the patient with the chronically pressure-loaded, hypertrophied left ventricle was suggested by results during exercise: before surgery the ejection fraction during exercise averaged 56 percent (normal = 71 percent, p less than 0.01), but after valve replacement it rose to 72 percent (not significant versus normal). Thus, our data in patients with aortic stenosis supplement our data in patients with hypertension, indicating that myocardial functional improvement can be achieved by unloading therapy in patients with long-standing left ventricular pressure-loading and hypertrophy.
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PMID:Function of the hypertrophied left ventricle at rest and during exercise. Hypertension and aortic stenosis. 622 92

The left ventricular pressure-volume relationship is abnormal in left ventricular hypertrophy (LVH). As a result, the left atrium empties more slowly than normal during the rapid filling phase of diastole, producing a characteristic abnormality of diastolic aortic root motion. In order to determine whether this altered LV filling is accompanied by a derangement of diastolic LV wall motion which might be useful in identifying the presence of altered chamber compliance, the M-mode echocardiograms of 60 patients with LVH secondary to aortic stenosis, hypertrophic subaortic stenosis, or hypertension, and those of 36 normal individuals were evaluated. Patients with LVH demonstrated abnormal LV posterior wall motion manifested by prolonged phases of rapid ventricular filling and atrial contraction (p less than 0.01 and p less than 0.05, respectively). The early diastolic wall motion abnormality can be readily detected by visual inspection of the echocardiogram. These findings support the concept of diastolic dysfunction in LVH and represent another echocardiographic feature of that condition.
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PMID:Abnormal diastolic left ventricular posterior wall motion in left ventricular hypertrophy. 622 24

From 1965 to 1981, 27 patients over 35 years of age were operated for isthmic coarctation of the aorta. Surgery consisted of resection and direct suture in 16 cases, implantation of a Dacron prosthesis in 7 cases, isthmoplasty in 1 case, aortotomy-graft in 1 case, insertion of a Dacron tube between the left subclavian artery and the descending thoracic aorta in 1 case; finally, one patient presented with a rare form of coarctation in a double aortic arch and was treated by a bypass from the brachiocephalic trunk to the descending thoracic aorta. Ten patients had associated pathology. This was treated at the same time in 4 cases: closed heart mitral commissurotomy, cardiac plexectomy, section-suture of patent ductus arteriosus, and a resection of aneurysms of four intercostal arteries. A Bjork aortic valve prosthesis had been inserted nine months previously in a women with calcific aortic stenosis. There were 2 deaths (7,4%) in the immediate postoperative woman with calcific aortic stenosis. There were 2 deaths (7,4%) in the immediate postoperative period (one acute pulmonary oedema, one pulmonary embolism). There has been no operative mortality in the last 10 years. Twenty-three of the 25 survivors have been followed-up for an average period of 91,5 months (range 1 to 18 years). Two patients died of cardiovascular causes. Analysis of these results show: that the mortality rate is not prohibitive compared to that of the natural history of the condition (the average survival rate of unoperated patients is 35 years), good secondary results despite frequent technical difficulties, the possibility of residual hypertension (especially in older patients) which responds well to drug therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Isthmic coarctation of the aorta: characteristics and results of surgical treatment in subjects surgically-treated after 35 years of age]. 623 25


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