摘要:

Cholestyramine (12 g/day) was administered to four subjects with familial hyperchloesterolemia (type II) for 12 to 15 days. Plasma cholesterol values fell by 24 to 28% in all subjects. Total endogenous fecal steroids increased from 2.0 to 2.5 times over the control values. This increment was mainly in the acidic fraction which increased from 1.4 to 6.5 times during treatment. The neutral steroid fraction showed a slight increase (nonsignificant) in two subjects and a significant increase (P< 0.05) in one subject. The total fecal steroid increment was considerably in excess of the decrement in plasma cholesterol, thus indicating either (a) a substantial increase in cholesterol synthesis, (b) a transfer of cholesterol from depots, or (c) both. Plasma cholesterol specific activity time curves showed a sharp increase in the slope immediately after the commencement of treatment, reflecting an increase in the rate of entry of unlabeled cholesterol into the readily miscible pool. Since cholestyramine did not change the absorption of the dietary cholesterol, the increase in the contribution of unlabeled cholesterol could only be from an increase in endogenous synthesis. In accordance with previous findings from this laboratory, no evidence of degradation of the steroid nucleus was detected during its passage through the gastrointestinal tract.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

This study evaluates interrelationships between carbohydrate and lipid metabolism during oral glucose tolerance tests (GTT) in 65 ischemic heart disease (IHD) males and 69 age-matched healthy controls (age range 45 to 69 years). The frequency of abnormal GTT, usually accompanied by type IV hyperlipoproteinemia, was significantly higher in IHD (37%) than in controls (19%). The mean immunoreactive insulin (IRI) response curve of IHD patients with abnormal GTT showed an elevated and delayed peak at 2 hours. The mean free fatty acid response curve of IHD patients had a significantly lower rebound at 3 hours. IHD patients and controls with abnormal GTT showed significantly higher and lagging lactate levels at 2 and 3 hours. Incidence of abnormal GTT was neither related to relative weight nor to elapsed time from onset of IHD to time of examination. Canonical correlations revealed that IRI is the common denominator in both carbohydrate and lipid abnormalities in IHD.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

A thin-walled Silverman needle has been used for 254 percutaneous punch biopsies of the left ventricle in 198 patients with closed chests at the Cleveland Clinic. The technic is described. The biopsy specimens were adequate for diagnosis in 192 patients. In all but three patients (who had lupus erythematosus, scleroderma, and chronic glomerulonephritis with congestive heart failure) cardiac catheterization and selective cardioangiographic studies were performed. There was angiographic evidence of primary myocardial disease, coronary atherosclerosis, or both, or rheumatic valvular disease in 175 patients. Cardiac catheterization and angiographic studies demonstrated no evidence of organic heart disease in 20 patients.Cardiac tamponade was a complication of myocardial biopsy in eight patients. Post-pericardiotomy syndrome occurred in four patients and ventricular fibrillation in one patient.Myocardium with no pathologic diagnosis and interstitial fibrosis or myocardial hypertrophy or both were the light microscopic findings in 165 patients. Representative sections of the biopsy in 27 patients demonstrated small-vessel disease, basophilic degeneration, focal interstitial myocarditis, amyloidosis, Aschoff's nodules, or vacuolar degeneration. The current experience suggests that myocardial biopsy combined with selective cardioangiography is of experimental value, improves the accuracy of diagnosis, and plays a role in the management of some patients.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Entrance block of an atrial premature beat (APB) into the atrioventricular node is demonstrated by its lack of effect on the A-V nodal conduction of a subsequent beat which is introduced before the full recovery time of the A-V node. This phenomenon was demonstrated in five patients by using programmed atrial stimulation and His bundle recordings. Entrance block into the A-V node occurred in a narrow range (28-33%) of the basic cycle length and concealed conduction occurred at coupling intervals longer than this range. It appears that entrance block of these early APBs is due to a “functional block’ between the atrium and the A-V node. The concept of an entrance block into the A-V node is useful in explaining some forms of the supernormal phase of A-V conduction as well as in the interpretation of complex arrhythmias.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

In nine patients with left bundle-branch block (LBBB), normal QRS axis, and normal P-R interval, atrial, His bundle, and ventricular electrograms were recorded. The extrastimulus method was utilized to determine the relative refractoriness of the various components of the atrioventricular conducting system.The functional refractory period (FRP) of the A-V node was normal in all but one patient. In six patients, the effective refractory period (ERP) of the ventricular specialized conducting system (VSCS) was greater than the FRP of the A-V node. The differential refractoriness within the three components of the VSCS was determined. Before the ERP of the VSCS was reached, a leftward shift in the mean QRS axis was noted in all six patients, thus documenting participation of the left anterior division of the LBB in ventricular depolarization. We found no evidence that the left posterior division participated in ventricular activation and conclude that it is functionally silent in LBBB. Conduction abnormalities in the right bundle branch were demonstrated both by long H-V intervals and the fact that its ERP was prolonged.The increased refractoriness of all three divisions of the VSCS suggests that the conduction abnormalities producing evidence of LBBB on the surface are trifascicular in nature.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The left ventricular papillary muscles appear to be the last portions of the heart to be perfused by coronary arterial blood. As a consequence they are sensitive anatomic markers of myocardial ischemia. Foci of necrosis or fibrosis therefore are commonly seen in these structures, particularly the posteromedial papillary muscle, which has a poorer blood supply than does the anterolateral muscle. Coronary arterial luminal narrowing is the most common cause of necrosis or fibrosis of the left ventricular papillary muscles. Other conditions, all associated with inadequate cardiac output, which may produce these lesions include left ventricular outflow tract obstruction, especially that resulting from congenitally malformed aortic valves, acute valvular regurgitation (infective endocarditis), various cardiomyopathies, and primary endocardial fibroelastosis with or without anomalous origin of one or both coronary arteries from the pulmonary trunk. Various infiltrative diseases, including inflammation (Aschoff bodies, sarcoid, abscesses), amyloid, iron, and neoplasms, also may involve the papillary muscles. Their most common congenital malformation is the parachute or single papillary muscle. Fibrosis or necrosis of adjacent left ventricle free wall without involvement of the papillary muscles themselves may simulate clinically “papillary muscle dysfunction.’ The anterior papillary muscle of the right ventricle is frequently affected by conditions which also affect the left ventricular papillary muscles. Whether or not necrosis or fibrosis of the right ventricular papillary muscle causes tricuspid regurgitation, however, is unknown at present.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Ebstein's anomaly represents an anatomic, pathologic, and physiologic spectrum. There have been few hemodynamic correlates for the observed auscultatory events. Multiple components of the first sound and “ejection’ sounds are frequently described.Cardiac catheterization, intracardiac sound-pressure studies (Telco), and cineangiograms were performed in three patients with Ebstein's anomaly who had a prominent early systolic sound.The right ventricular pressure pulse was abnormal in all; an initial delta-wave configuration, followed by a more rapid pressure rise, produced a prolonged rise to peak pressure. The right ventricular pressure pulse is not that of a conduction defect alone; rather it suggests that the altered pattern of ventricular contraction and abnormal leaflet placement are contributing factors.The early systolic sound was recorded in the atrialized right ventricle or right ventricle in all. It occurred just after the peak of the c wave in the atrialized right ventricle. In the right ventricle the sound occurred at the point where initial slow delta portion of right ventricular pressure pulse gave rise to rapid upstroke. The early systolic sound most likely occurs when the large, sail-like tricuspid valve reaches the limit of systolic excursion. The sound has been designated as the “sail sound,’ and may be the most specific auscultatory event in Ebstein's anomaly.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Patients with the third and fourth pharyngeal pouch syndrome, thymic and parathyroid aplasia or hypoplasia, have a very high incidence of aortic arch anomalies and congenital heart disease. These patients present with a unique syndrome characterized by profound hypocalcemia, defective thymic-mediated cellular immune function, and cardiovascular anomalies. The cardiac abnormalities most frequently are conotruncal malformations of the tetralogy of Fallot or truncus arteriosus types and are often the cause of death. Patients with profound neonatal hypocalcemia should be screened for evidence of normal thymic function and congenital heart disease.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

In the case described anatomically corrected transposition of the great vessels is associated with situs inversus. Anatomically corrected transposition is extremely rare, and has not been previously reported with situs inversus. This type of transposition should not be confused with classical corrected transposition. Thus the case examined exhibited a D-bulboventricular loop with L-transposition and atrial inversion, so that blood flow was physiologically incorrect as in classical complete transposition. In the case examined, it was also found that bulbar musculature was present between the aorta and the mitral valve.Additional study of the conducting tissue revealed inversion of the sinoatrial node with the atria, and also of the atrial portion of the atrioventricular node. The atrioventricular bundle and its branches were in expected positions in relation to a large ventricular septal defect. These results are discussed with regard to previous reports and to the embryology of the conducting tissue.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Prior to consideration of the effects of digitalis compounds on ionic exchange the basic mechanisms of active Na+and K+transport are discussed. It is generally accepted that digitalis is a specific inhibitor of the Na+-K+activated ATPase located primarily in the sarcolemmal membrane. Present evidence supports the concept that positive inotropic effects of digitalis are not seen unless evidence of inhibition of the enzyme and, therefore, of the “Na pump’ leads to a small increase of intracellular Na+. This leads to augmented activity of a Na+transport system which is coupled, not to K+, but to Ca+ +. Evidence for the existence of Na+-Ca+ +coupling at excitable membranes is accumulating, and this is reviewed. The possibility that administration of digitalis, through its inhibition of the Na+-K+coupled system produces an increase in Na+- Ca+ +coupled transport and thereby an increase of influx of Ca+ +to the myofilaments is discussed and is presented as a possible basis for the mechanism of digitalis action. The toxic electrophysiologic effects of digitalis are discussed in terms of the effects on K+exchange induced by the drug.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID