Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Echocardiography is an extremely useful noninvasive technic in the differential diagnosis of a large heart. It may show whether a large heart is due to left ventricular hypertrophy or dilatation, or if it is due to a pericardial effusion. The hypertrophied heart may be further characterized by determining whether it is symmetrical, as caused by aortic stenosis or hypertension, or whether it is assymmetrical, which is characteristic of hypertrophic cardiomyopathy. Similarly, dilatation of the heart may be due to volume overload of the left ventricle secondary to valvular insufficiency, congestive cardiomyopathy or ischemic heart disease; these can be distinguished by echocardiography. As certain types of mitral insufficiency are associated with specific valvular dysfunction, the possible etiology of the mitral insufficiency and therefore of the volume overload of the left ventricle may be determined using echocardiography. Finally, mediastinal tumors may simulate a large heart, and demonstration of normal cardiac dimensions and wall motion can exclude a cardiac etiology for the "large heart."
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PMID:Echocardiography in the differential diagnosis of the large heart. 13 5

A total of 4,000 consecutive electrocardiograms covering an 8-yr period was studied and all cases with pure left anterior hemiblock reviewed on the basis of clinical diagnosis and subsequent follow-ups. There were 66 cases in all, representing 1.6% of the total series with an age range of 30--81 and a mean of 53.4 yr; 43 males to 23 females--a ratio of approximately 2 : 1. 34 cases (51.5%) were hypertensives all with a minimum diastolic pressure of 120 mm Hg before treatment. Congestive cardiomyopathy accounted for 16 cases (24.3%) and diabetes mellitus unassociated with other ailments for another 6 cases (9.1%). Other causes included mixed aortic valve disease with 2 cases (3%), endomyocardial fibrosis with 2 cases (3%). In 6 patients (9.1%), all above the age of 70, who had been admitted for minor surgical operations, no cause could be found. This etiological pattern differs from that seen in white populations where ischemic heart disease is by far the commonest cause. The extreme rarity to left anterior hemiblock in rheumatic mitral valve disease is considered of help in separating cases of lone rheumatic regurgitation from those of mitral regurgitation complicating congestive cardiomyopathy if and when diagnostic difficulty arises.
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PMID:Left anterior hemiblock in adult Africans. 64 77

Coronary artery disease patients frequently have left ventricular wall motion abnormalities. Though nitroglycerin is commonly used in ischemic heart disease, its effects on wall motion abnormalities is unknown. In this study we have evaluated the effects of nitroglycerin on wall motion abnormalities and on ejection fraction in 25 patients. Sixteen had coronary artery disease (greater than 70% luminal narrowing). Six had no evidence of heart disease and three had congestive cardiomyopathies with normal coronary arteries. Left ventricular angiography was performed prior to and six minutes after administration of 0.4 mg of sublingual nitroglycerin. Twelve of the 16 coronary artery disease patients had wall motion abnormalities, and in seven of these, segmental wall motion improved after nitroglycerin. In five, all motion did not change. The initial heart rate, left ventricular systolic and end-diastolic pressure, and left ventricular end-diastolic volumes were not different for those whose wall motion improved versus those whose did not. The increase in the former and fall in the latter three hemodynamic parameters were significant (P less than 0.01) and similar for the two groups. In those whose wall motion abnormalities improved after nitroglycerin, ejection fraction (mean plus or minus se) increased significantly (P less than 0.05), from 0.47 plus or minus 0.025 to 0.62 plus or minus 0.046. In those without improvement, the ejection fraction went from 0.55 plus or minus 0.056 to 0.58 plus or minus 0.051 (NS). Three patients with congestive cardiomyopathy showed no improvement in ventricular wall motion or ejection fraction after nitroglycerin. Left ventricular wall motion abnormalities and ejection fraction improved in some coronary artery disease patients following nitroglycerin. The mechanism for this is unknown; however, ventriculography before and after nitroglycerin may be of potential usefulness for identifying areas of reversible wall motion abnormalities.
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PMID:Improvement in left ventricular wall motion following nitroglycerin. 80 32

The current methods for estimating isometric contraction time were discussed. Ultrasonically derived isometric contraction time, using external carotid pulse tracing, phonocardiogram, and the B-point of the mitral echogram was also measured. Recordings were performed in 10 normal subjects, and 15 patients. Hypertrophic cardiomyopathy (5), congestive cardiomyopathy (6), and ischemic heart disease (4). In 11 patients, the results were correlated with the internal isometric contraction time. The ultrasound isometric contraction time showed good correlation with the internal isometric contraction time (r equals 0.92, P less than 0.01). The external isometric contraction time showed less correlation with the internal isometric contraction time and was significantly shorter (P less than 0.01). The ultrasound isometric contraction time showed a superior discriminating value to the external isometric contraction time for differentiation the normal subjects from the patients' group.
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PMID:The use of echocardiography to measure isometric contraction time. 109 Jan 34

The purpose of the study was to evaluate the effect of enalapril on the frequency of ventricular premature beats in patients with congestive heart failure. The study group consisted of 30 patients with a mean age of 47 +/- 0.6 years with chronic congestive heart failure (NYHA classes III and IV) due to primary dilated cardiomyopathy and cardiomyopathy in the course of ischaemic heart disease. Initial therapy with digitalis and diuretics was supplemented with enalapril at a dose of 5-20 mg daily. Initially and at three months after enalapril, the following parameters were evaluated: NYHA functional class, the presence of premature ventricular beats in 24-hour ECG recording and left ventricular function by echocardiography. The scheduled therapy was completed by 23 patients; in 5 patients, the intake was discontinued because of hypotension, one patient died after 14 days due to worsening heart failure, and one patient was submitted for pacemaker implantation. Clinical improvement manifesting itself by a shift to lower NYHA classes was found in 20 patients. A reduced number of premature ventricular beats was observed in 52% of the patients. Termination of cardiac arrhythmias, especially of complex beats, was parallel to the circulatory improvement.
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PMID:The effect of enalapril on cardiac arrhythmias in patients with congestive heart failure. 128 55

The aim of this study was to assess the diurnal variability of heart rate during VT. For the purpose of this investigation VT was considered to be a minimum of 3 consecutive ventricular beats in duration at a rate more than 100 bpm. From the group of 287 patients with VT during 24-hour ECG monitoring, a selection was made of 52 patients in whom episodes of monomorphic VT occurred in the day-time and night-time without any changes of the QRS morphology. Thirty one patients had ischemic heart disease, 10--dilated cardiomyopathy, 2--mitral valve prolapse and 10 patients had no evidence of heart disease. In these patients the rate of VT (HR-V), basic heart rate (HR-S) before VT, and coupling interval (CI) of VT initiating beat were measured during day-time and night-time. The mean VT rate was 170 +/- 34 bpm during day-time and 149 +/- 36 bpm during night-time (p < 0.001). The mean sinus rhythm rate was significantly (p < 0.001) greater during day-time (88 +/- 16 bpm) than at night (78 +/- 19 bpm). There was significant difference in the mean values of the CI between day-time and night-time (504 +/- 122 vs 589 +/- 181 ms). A significant correlation was noted between HR-V and HR-S at night (r = 0.73; p < 0.001) but not during day-time (r = 0.38). Thus, HR-V similarly as HR-S is greater during day-time than during night-time. Diurnal variability of HR-V may be related to changes in autonomic nervous system tone.
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PMID:[Diurnal variability of heart rate during paroxysmal ventricular tachycardia]. 128 89

We studied whether cardiac abnormalities contribute to the increased risk of stroke in patients with nonvalvular atrial fibrillation (NVAF). M-mode and 2D echocardiography were performed in four age- and gender-matched groups: 20 stroke patients with NVAF, 20 patients with NVAF who had not suffered a previous stroke, 20 stroke patients with sinus rhythm, and 40 healthy controls. Their mean age was 77 years. The two groups with atrial fibrillation differed from healthy controls in that they had more 2D-echocardiographic findings of severe left-ventricular-wall-motion abnormalities (p < 0.05) and tended more often to have enlarged left ventricles, and hypertrophic and congestive cardiomyopathy. Left atrial diameter was 47 mm compared to 41 and 39 mm in the two groups with sinus rhythm (p < 0.001). Intracardiac thrombi were only found in the two atrial-fibrillation groups (with stroke: 15% without stroke: 5%). Aortic sclerosis was common in all groups (30-60%), as was mitral annulus calcification (10-20%). The only significant difference between the two atrial-fibrillation groups was a higher frequency of earlier ischemic heart disease in the stroke group. Both atrial-fibrillation groups had cardiac abnormalities predisposing for embolic as well as thrombotic stroke.
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PMID:Echocardiographic findings and the increased risk of stroke in nonvalvular atrial fibrillation. 130 Dec 43

To evaluate the usefulness of gated blood pool single photon emission computed tomography with 99mTc (gated SPECT) for assessing left ventricular function, we performed gated SPECT in 2 normal subjects and 18 patients including 13 with ischemic heart disease, 3 with hypertrophic cardiomyopathy and 2 with dilated cardiomyopathy. Left ventricular end-diastolic volume (LVEDV), left ventricular ejection fraction (LVEF) and regional wall motion obtained by gated SPECT were compared with the results of contrast left ventriculography (contrast LVG), echocardiography and planar multigated blood pool imaging (planar blood pool). After the patients' red blood cells were labelled with 30 mCi (1,110 MBq) 99mTc in vivo, gated SPECT was performed in each of 32 projections through a 360 degree arc for each of the cardiac cycle divided into 16. From these images, the left ventricular vertical long-axis image, the horizontal long-axis and short-axis images were reconstructed. To calculate LVEDV, we used serial short-axis images which were composed of the left ventricle. To define left ventricular and left atrial borders, we used amplitude images and cinematic displays of the vertical long-axis image. The level of the optimal cut for delineating the left ventricular border was determined from the volume-cut-level-graph at each background activity, which was constructed by a phantom study. Left ventricular wall motion by gated SPECT was compared with the results of contrast LVG according to segmental analysis. LVEDV obtained by gated SPECT showed an excellent linear correlation with LVEDV calculated by echocardiography (r = 0.98, p < 0.01) and by contrast LVG (r = 0.89, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Left ventricular function assessed by multigated blood pool single photon emission computed tomography with 99mTc]. 130 71

Single cardiac myocytes were isolated from the ventricles of failing and non-failing human hearts. The contraction amplitude, time-to-peak shortening and time to 50% and 90% relaxation were measured in cells stimulated at 0.2 Hz at 32 degrees C. The effects of increasing extracellular calcium and isoproterenol were investigated using cumulative concentration/response curves. Maximum contraction amplitude in high calcium or velocities of contraction or relaxation were not impaired in cells from failing hearts. Beta-adrenoceptor function in a single cell was assessed by the maximum contraction amplitude in the presence of isoproterenol relative to that with high calcium in the same cell (isoproterenol/calcium ratio). A decrease in the isoproterenol/calcium ratio correlated positively with an increase in the isoproterenol EC50 (concentration for half-maximal effect) for a cell (P less than 0.02, n = 39). The isoproterenol/calcium ratio in left ventricular myocytes decreased with increasing severity of disease, correlating with failure as defined by New York Heart Association class (P less than 0.001, n = 26 patients), left ventricular ejection fraction (P less than 0.001, n = 24), left ventricular end diastolic pressure (P less than 0.05, n = 21) and amount of diuretics prescribed (P less than 0.001, n = 26). In right ventricular myocytes, only increasing NYHA class correlated with decreasing isoproterenol/calcium ratios. There was a correlation of the isoproterenol/calcium ratio between right and left ventricular cells from patients with ischemic heart disease (P less than 0.05), n = 11). Beta-adrenoceptor subsensitivity occurred in mitral valve disease, ischemic heart disease, congenital abnormalities and congestive cardiomyopathy, but not in the right ventricle of patients with myocarditis. The isoproterenol/calcium ratio correlated negatively with the age of the patient (P less than 0.001, n = 26, left ventricle). Multiple regression indicated that the maximum contraction amplitudes in either high isoproterenol or high calcium declined significantly with age only, but that both age and severity of disease contributed to the decrease in isoproterenol/calcium ratio. Time-to-peak tension in isoproterenol, as well as relaxation times in high calcium also decreased with the age of the patient. Analysis of variance showed that between-patient variation was significantly greater than between-cell for most of the parameters measured. Beta-adrenoceptor desensitisation may be detected in individual myocytes from failing hearts, and this relates more to the severity of disease and the age of the patient rather than the etiology of heart failure. A decline in absolute contractility of muscle cells with age was detected.
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PMID:Isolated ventricular myocytes from failing and non-failing human heart; the relation of age and clinical status of patients to isoproterenol response. 132 14

Patients with different heart diseases, dilated cardiomyopathy, valvular heart disease, hypertension, ischemic heart disease or myocarditis showed manifestations of autoimmunity and down-regulation of beta-adrenergic receptors. Autoantibodies against beta-adrenergic receptors in these patients were detected with radioligand binding inhibition assay. The results suggested that the down-regulation of cardiac beta-adrenergic receptors in these patients may be mediated by autoimmunity. Autoantibodies against beta-adrenergic receptor were not related to any specific heart diseases, but to the severity of heart failure irrespective of its etiology. The significance of these autoantibodies in heart failure was discussed.
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PMID:[Circulating autoantibodies against beta-adrenergic receptors in patients with heart diseases]. 133 2


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