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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hypertrophic cardiomyopathy is a diverse clinical and pathophysiologic disorder of unknown cause that principally involves the left ventricle and is manifested as asymmetric or concentric hypertrophy. If asymmetric, the hypertrophy is usually greatest in the ventricular septum, but variations occur in which the hypertrophy may be maximal at the mid-ventricular level, at the apex, or rarely, in the free wall of the left ventricle. Right ventricular involvement is usually less evident. The principal abnormality in systole is the obstruction to left ventricular outflow caused by systolic anterior motion (SAM) of the anterior or posterior mitral leaflet(s) with mitral leaflet-septal contact. SAM occurs as the result of the Venturi forces created by the rapid ejection of blood through an outflow tract that is narrowed by upper septal hypertrophy, drawing the mitral leaflet(s) anteriorly. The time of onset and duration of mitral leaflet-septal contact determine the magnitude of the pressure gradient. Mitral regurgitation invariably accompanies the obstruction to outflow. Ventriculomyectomy surgery, by thinning the septum and widening the outflow tract, abolishes the abnormal mitral leaflet motion and, consequently, the obstruction to outflow and the mitral regurgitation. In symptomatic patients with resting obstruction this form of surgery more dramatically relieves the systolic abnormalities and the accompanying symptoms than any form of medical therapy currently available. The extent of hypertrophy is believed to be the principal determinant of impaired left ventricular relaxation and increased chamber stiffness that characterize diastole in hypertrophic cardiomyopathy. Diastolic dysfunction is common to most such patients irrespective of the presence or absence of outflow obstruction. Calcium entry blockers may improve the left ventricular relaxation process and relieve symptoms in patients with hypertrophic cardiomyopathy, particularly the subgroup with no obstruction to outflow. Atrial and ventricular arrhythmias are responsible for a significant proportion of the morbidity and mortality, and their prevalence appears to depend on the presence of obstruction and the extent of hypertrophy. Thus, the major manifestations of hypertrophic cardiomyopathy in systole and diastole, as well as the disturbances in rhythm, appear to be related to the site and/or extent of the hypertrophic process. We have learned much about hypertrophic cardiomyopathy in the 30 years since its modern description. The vast majority of symptomatic patients can now be improved with specific medical or surgical therapy.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Hypertrophic cardiomyopathy. 306 84

Hypertrophic cardiomyopathy is a diverse clinical and pathophysiologic entity that involves principally the left ventricle and is caused by asymmetric or concentric hypertrophy of unknown cause. If asymmetric, the hypertrophy is usually greatest in the ventricular septum, but variations occur in which the hypertrophy may be maximal at the apex, at the midventricular level, or, rarely, in the free wall of the left ventricle. Right ventricular involvement is usually less evident. The principal abnormality in systole is the obstruction to left ventricular outflow caused by upper septal hypertrophy narrowing the outflow tract and setting the stage for Venturi forces to cause systolic anterior motion of the anterior or posterior mitral leaflets. The time of onset and duration of mitral leaflet-septal contact determine the magnitude of the pressure gradient. Mitral regurgitation invariably accompanies the obstruction to outflow. Ventriculomyotomy-myectomy surgery, by thinning the septum and widening the outflow tract, abolishes the abnormal mitral leaflet motion and, consequently, the obstruction to outflow and the mitral regurgitation. This form of surgery more dramatically relieves the systolic abnormalities and the accompanying symptoms than any form of medical therapy available today. The extent of hypertrophy is believed to be the principal determinant of the impaired left ventricular relaxation and increased chambers stiffness (decreased compliance) that characterize diastole in hypertrophic cardiomyopathy. Relaxation is impaired by the contraction load (the obstruction), by a decrease in the principal relaxation loads, by a pathologic degree of nonuniformity of contraction and relaxation, and in all likelihood, by impaired inactivation of the biochemical processes responsible for contraction (? due to primary or ischemia-induced calcium overload). Calcium channel-blocking agents may dramatically improve left ventricular relaxation by speeding up the inactivation process, by decreasing the degree of nonuniformity, or by altering the contraction and relaxation loads in a favorable manner. Atrial and ventricular arrhythmias are responsible for a significant proportion of the morbidity and mortality, and their occurrence also appears to depend on the extent of hypertrophy. Thus, the major manifestations of hypertrophic cardiomyopathy in systole and diastole as well as the disturbances of rhythm appear to be related to the site and/or extent of the hypertrophic process.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Hypertrophic cardiomyopathy. The importance of the site and the extent of hypertrophy. A review. 316 67

In view of the paucity of reports describing symptoms of increased degree, and deterioration of left ventricular systolic function in patients with apical hypertrophic cardiomyopathy (apical HCM), two cases with congestive heart failure and progressive thinning of previously hypertrophied apical portions of the left ventricle are reported. These were among 13 patients observed from eight to 10 years. Case 1: A 56-year-old man was diagnosed as having apical HCM at the age of 49 years. Severe left ventricular hypertrophy and prominent ST-T changes were observed on ECG during his first admission. His left ventricular end-diastolic pressure (LVEDP) was 24 mmHg and a left ventriculo-gram revealed a decrease in the left ventricular cavity in the apex and marked hypertrophy of the apical wall. Moderate interstitial fibrosis without hypertrophy or disarray of myocytes was observed in a left ventricular endomyocardial biopsy specimen. In two episodes of cardiac arrest he was successfully resuscitated at the age of 50 years. At the age of 55 years, two-dimensional echocardiography revealed thinning and abnormal motion in the apical wall, and a defect in 201T1 accumulation was observed in the same region by perfusion scintigraphy. This patient was readmitted with a diagnosis of cerebral embolism at the age of 56 years. Cardiac catheterization revealed normal LVEDP (8 mmHg), and a left ventriculogram revealed an aneurysm in the left ventricular apex with normal major epicardial coronary arteries. He has been under treatment with antiarrhythmic medications, calcium antagonists and anticoagulants, and has become relatively asymptomatic. Case 2: A 69-year-old-man was diagnosed as having apical HCM after a complete evaluation, including cardiac catheterization, at the age of 59 years. His LVEDP was elevated (17 mmHg), and a left ventricular angiogram revealed marked hypertrophy localized to the apex. Ejection fraction was 64%. A left ventricular endomyocardial biopsy revealed interstitial fibrosis without hypertrophy of myocytes. Thereafter, he has been followed as a New York Heart Association functional class III to IV with occasional elevation of cardiac enzymes but without chest pain or acute changes in his ECGs. However, atrial fibrillation with complete right bundle branch block developed at the age of 60 years. Apical wall thinning and dyskinesis were diagnosed by 2D echocardiography and a defect in the 201T1 accumulation was observed at about 65 years of age. He was readmitted in severe cardiac failure at the age of 69 years, and he was diagnosed as having cardiac asthma with pulmonary capillary wedge pressure of 35 mmHg.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Advanced sequelae of apical hypertrophic cardiomyopathy: report of two cases with wall motion abnormalities]. 322 16

Gated magnetic resonance imaging (MRI) was performed in 6 patients with familial hypertrophic cardiomyopathy associated with abnormal thallium perfusion, and 12 patients with ordinary hypertrophic cardiomyopathy. The patients with ordinary hypertrophic cardiomyopathy and abnormal thickening of the septal wall and normal left ventricular dimensions, while the patients with familial hypertrophic cardiomyopathy had focal wall thinning (usually involving the apical-septal wall) and dilated left ventricle in addition to hypertrophied heart. The quantitative measurement for cardiac dimensions using MRI was similar to that found on echocardiography in all cases. In addition, inhomogeneous signal intensities at left ventricular wall were observed in 3 cases of familial hypertrophic cardiomyopathy, which may suggest the existence of myocardial fibrosis. Gated MRI should be performed for early detection and follow-up of hypertrophic cardiomyopathy, since some patients will progress from hypertrophic cardiomyopathy to dilated cardiomyopathy.
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PMID:Magnetic resonance imaging in familial hypertrophic cardiomyopathy associated with abnormal thallium perfusion and cardiac enzymes. 341 62

Positron emission computed tomography (PET) is regarded an excellent technique for quantitative measurements. However, its accuracy is related to the spatial resolution of the system. The relation between myocardial wall thicknesses as measured by X-ray CT or MRI and the radioactivity as measured using PET was studied in 37 patients. 1. In patients with transmural infarction, the infarcted myocardium was imaged as a region of low radioactivity. However, the myocardium usually exhibited wall thinning, so that partial volume effects must be taken into account in evaluating the radioactivity. 2. In the infarcted regions, the regions of the low radioactivity tended to be larger than those of wall thinning. 3. There were cases with the regional low radioactivity without wall thinning in myocardial infarction and in hypertrophic cardiomyopathy. Because patients with myocardial infarction frequently had regional wall thinning, it seems necessary to correct partial volume effects for the infarcted regions which differ from the normal. It was concluded that, to estimate regional myocardial blood flow or metabolism using PET, it is necessary to supplement another morphological diagnostic method to evaluate myocardial wall thickness.
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PMID:[Problems related to tracer concentration and wall thickness: pitfalls in positron CT diagnosis]. 350 33

This investigation was undertaken to assess the prevalence of systolic dysfunction, left ventricular (LV) wall thinning and cavity enlargement in a large population of patients with hypertrophic cardiomyopathy (HC), and to determine the role of these conditions in the natural history of this disease. Of 217 consecutively studied patients with HC, most of whom were severely symptomatic, 197 (91%) had an LV ejection fraction of 50% or more and 20 (9%) had an ejection fraction of less than 50% as assessed with radionuclide angiography. Changes in LV wall thickness and cavity dimension were evaluated using serial M-mode and 2-dimensional echocardiography over an average follow-up of 3.6 years in 67 of the 217 patients (54 with ejection fraction of greater than or equal to 50% and 13 with ejection fraction less than 50%). A substantial decrease (at least 5 mm) in LV wall thickness was seen in 8 of the 13 patients (62%) with an ejection fraction greater than or equal to 50%, but in only 2 of the 54 patients (4%) with an ejection fraction greater than or equal to 50% (p less than 0.001). LV cavity dimension increased significantly over the period of follow-up in the 13 patients with depressed ejection fraction (from 44 +/- 5 to 49 +/- 7 mm, p less than 0.005); however, absolute cavity size remained normal (less than or equal to 52 mm or less) in 10 of these 13 patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Occurrence and significance of progressive left ventricular wall thinning and relative cavity dilatation in hypertrophic cardiomyopathy. 360 25

Nine patients with hypertrophic cardiomyopathy associated with Friedreich's ataxia were treated with the calcium antagonist verapamil, which is known to reduce myocardial hypertrophy and improve diastolic function in patients with idiopathic hypertrophic cardiomyopathy. Daily oral doses of 7 mg/kg were given for a mean (SD) of 24 (8) months. M mode echocardiography performed at the start of the study and at the end of follow up showed no significant difference between the treated group and an untreated control group of nine patients. Verapamil produced no changes in left ventricular wall thickness, mass index, left ventricular internal diameter, fractional shortening, peak normalised lengthening rate, peak rate of septal and posterior wall thinning, and time from minimum ventricular cavity dimension to mitral valve opening. Myocardial calcium overload has been suggested as a cause of cardiac disease in Friedreich's ataxia; however, verapamil had no beneficial effect on these patients with established myocardial hypertrophy.
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PMID:Echocardiographic evaluation of verapamil in Friedreich's ataxia. 396 8

Digitised M-mode echocardiography was used to study the changes in left ventricular diastolic function over a 3-year period in 11 patients with hypertrophic cardiomyopathy an 14 normals. Compared to normal, in hypertrophic cardiomyopathy, isovolumic relaxation was prolonged (P less than 0.001) and mitral valve opening delayed relative to minimum dimension (P less than 0.001). There was a wide range of values for the peak rates of dimension increase and wall thinning, and although the means were normal, 6 and 8 patients respectively were outside the normal range. There were no significant mean changes in function during the 3.4 +/- 0.3 years of follow-up, but, in 3 patients, marked alterations in relaxation were observed. They showed a gross reduction in the delay in mitral valve opening (125 to 55 125 to 35 and 110 to 75 msec). There was little overall change in isovolumic relaxation in two, but in one patient it reduced from 95 to 50 msec. In most patients with hypertrophic cardiomyopathy, relaxation and diastolic function appear to remain stable over a period of 3 years, and none had an apparent deterioration. Some patients may have an apparently spontaneous "improvement" in function similar in extent to that described due to the therapeutic action of calcium antagonists.
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PMID:Longitudinal changes in left ventricular diastolic function in hypertrophic cardiomyopathy. 404 Apr 99

An autopsy case of an advanced form of hypertrophic cardiomyopathy (HCM) showing marked fibrosis with intramural small arterial abnormalities is presented in this report. A 52-year-old woman, who had a positive family history of HCM, was admitted because of palpitations. The chest roentgenogram showed a mildly enlarged cardiac silhouette and the electrocardiogram revealed abnormal Q waves and R wave and T wave abnormalities. The echocardiogram revealed hypokinesis with thinning of the interventricular septum and the anterior wall of the left ventricle. Percutaneous right ventricular endomyocardial biopsies demonstrated moderate interstitial fibrosis with small arterial thickening. At necropsy, the anterior and posterior walls of the left ventricle and the interventricular septum were markedly thinned and showed a massive transmural fibrosis. Moreover, the intramural small arteries, 50-300 microns in diameter, showed marked intimal and medial hypertrophy with proliferation of elastic fibers and smooth muscle cells. From these findings, it is suggested that this was originally a case of HCM which progressed to a decompensated stage because of the abnormal intramural small arteries. The significance of small arterial lesions in HCM is discussed.
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PMID:An advanced form of familial hypertrophic cardiomyopathy showing massive myocardial fibrosis with intramural small arterial thickening. An autopsy case. 408 79

In order to determine the relation between three manifestations of left ventricular hypertrophy--ST-T wave changes on the electrocardiogram, diastolic disturbances, and increased myocardial echo intensity--M mode and cross sectional echocardiograms were recorded in 12 normal subjects, 15 athletes, 16 patients with hypertrophic cardiomyopathy, and 42 patients with secondary left ventricular hypertrophy due to aortic stenosis (20), severe essential hypertension (8), coarctation (7), or subaortic stenosis (7). M mode echocardiograms were digitised and cross sectional echocardiograms were analysed for regional echo intensity. In patients with hypertrophy regional echo amplitude was significantly increased in mid and basal septum and posterior left ventricular wall. Patients with increased echo amplitude in any region showed a higher incidence of ST-T wave abnormalities than those without and of diastolic abnormalities--including prolongation of isovolumic relaxation time, delay in mitral valve opening with respect to minimum cavity dimension, and a reduction in peak rate of posterior wall thinning and dimension increase. There was a significant rank order correlation between median pixel count and these diastolic abnormalities. No significant differences were demonstrable in these relations between the diagnostic groups. By contrast, electrocardiographic findings, diastolic function, and pixel count were uniformly normal in athletes, although the increase in left ventricular mass was similar to that in the patients. Thus an increase in left ventricular mass alone is not responsible for repolarisation or wall motion abnormalities occurring in pathological left ventricular hypertrophy. These latter changes are, however, strongly associated with the change in myocardial properties detected as an increase in echo intensity and may be due to increased interstitial fibrosis.
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PMID:Relation of regional echo amplitude to left ventricular function and the electrocardiogram in left ventricular hypertrophy. 623 8


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