ISSN:0009-7322    

出版商:OVID    

年代:1967

数据来源: OVID

摘要:

A developmental anomaly in the form of occlusive fibroelastosis of the proximal segments of both coronary arteries, leading to progressive myocardial infarction and death, was found in the course of an autopsy on a 6-week-old infant. Congenital malformations of the coronary arteries are not uncommon, but a report of one such as this has not been found in the literature.

ISSN:0009-7322    

出版商:OVID    

年代:1967

数据来源: OVID

摘要:

The atrial rhythm was studied in 38 patients during runs of tachycardia of five or more beats in sequence which occurred during cardiac catheterization and whose ventricular site of origin could be established with considerable confidence. Simultaneous esophageal and other leads were recorded. The most frequent mechanism was retrograde conduction to the atria with varying degrees of V-A (ventriculo-atrial) block which occurred in 26 of the 38 patients. Runs of ventricular tachycardia with one-to-one V-A conduction occurred in 13 patients. Runs with an independent atrial rhythm (A-V dissociation) occurred in nine patients. Varying atrial mechanisms during different runs of tachycardia occurred in 11 patients. The minimum QRS-to-retrograde P intervals in 24 of 35 patients with V-A conduction were within 0.03 sec of P-R interval. The briefest QRS-to-retrograde P interval observed was 0.09 sec. Reciprocal beats occurred in eight of 35 patients with V-A conduction.

ISSN:0009-7322    

出版商:OVID    

年代:1967

数据来源: OVID

摘要:

Epicardial excitation was explored by means of an exploring electrode during operation on a patient with a large atrial septal defect of the secundum type, whose ECG indicated a Wolff-Parkinson-White syndrome of type B. Very early excitation occurred, 10 msec after the end of the P wave, at the right lateral border, near the atrioventricular sulcus, an area which is located a relatively large distance from the atrioventricular node. Because the epicardial region closest to this node did not show early excitation, it was concluded that in this heart the node was not involved, but that a muscular bypass between the right atrial muscle and the closely adjacent right ventricular surface was responsible. The location corresponds with that described in several extensive anatomic studies of hearts with a WPW syndrome. The right ventricle was activated predominantly or completely by an excitation wave originating in this area; the excitation pattern of the left ventricle did not differ significantly from the normal.

ISSN:0009-7322    

出版商:OVID    

年代:1967

数据来源: OVID

摘要:

In 25 cases at open heart surgery, atrial and ventricular close bipolar electrograms, an atrial unipolar electrogram, and a lead-II electrocardiogram were simultaneously monitored throughout each procedure. In six cases the ventricles or atria, or both, were paced by electrical stimulation. Although atrial activity could frequently not be clearly delineated on the lead II electrocardiogram, the time relationship between atrial and ventricular depolarization could at all times be determined from the electrograms.During ventricular premature beats and ventricular rhythms, retrograde A-V conduction and retrograde activation of the atria were common, and unidirectional retrograde A-V block was infrequent. In spontaneous and induced cardiac arrhythmias the fastest pacemaker of the heart, atrial, His bundle, or ventricular, usually activated the entire heart.

ISSN:0009-7322    

出版商:OVID    

年代:1967

数据来源: OVID

摘要:

Instantaneous ascending aortic blood flow and left ventricular and central aortic pressure were determined at the time of operation in nine patients with severe aortic regurgitation. In six, the heart rate was controlled and increased by electrical stimulation between 50 and 170 beats/min. The relative duration of diastole decreased, and that of systole increased at faster heart rates. The mean systolic ejection rate fell, and regurgitant flow rates remained relatively constant. Thus, the per cent regurgitation was not reduced at faster rates. Following isoproterenol administration, the faster heart rate lengthened the relative duration of systole, abbreviated that of diastole, and increased the systolic ejection rate. Net result was an increased total forward flow and a reduced per cent regurgitation, but when the heart rate was held constant, the total forward stroke volume was ejected more rapidly, but the total forward and regurgitant flows per beat and per minute, and consequently the per cent regurgitation did not change. Assessments of left venticular function also were made in two patients.

ISSN:0009-7322    

出版商:OVID    

年代:1967

数据来源: OVID

摘要:

Twenty-three patients exhibiting coronary insufficiency on exercise have been studied at rest and at exercise prior to and following sublingual administration of nitroglycerin. The most consistent and marked effect of nitroglycerin was the reduction in pulmonary artery pressure, total pulmonary resistance, and right ventricular work at rest and during exercise. Our patients were grouped according to the degree of left ventricular failure as indicated by the abnormality of rise in pulmonary artery pressure during exercise. It became evident that nitroglycerin improved left ventricular function in terms of increased output and lessened pulmonary artery pressure in cases in which failure was most severe.

ISSN:0009-7322    

出版商:OVID    

年代:1967

数据来源: OVID

摘要:

A miniature scintillation detector recently designed and constructed in this laboratory can be inserted into the esophagus and under fluoroscopic vision positioned so that radioactivity emitted from the blood in the descending aorta can be detected and a time-concentration curve recorded from which cardiac output can be determined. Twenty simultaneous determinations of cardiac output by the isotope-dilution method with the esophageal scintillation counter probe and the dye-dilution technique were done in 10 dogs. There was a good correlation between the two methods. Among the technical advantages of the isotope-dilution method over the dye-dilution method are avoidance of arterial puncture, only one sample of venous blood required, an easily performed procedure, and ability to permit repeated determinations of cardiac output with a minimum of manipulation and trauma.

ISSN:0009-7322    

出版商:OVID    

年代:1967

数据来源: OVID

摘要:

One-plane cineangiographic measurement of left ventricular volume uses angiocardiograms taken in the right anterior oblique view. Its basic assumption is that the third (unvisualized) dimension, depth from septum to free wall, is of the same magnitude and behaves in the same way as the visualized short axis. Examination of this assumption with biplane x-ray equipment revealed that the unmeasured length averages 7% less and varies directly with the length of the measured short axis. Volumes measured correlate well with consecutive studies using serial biplane x-rays and are systematically somewhat larger than volumes obtained in autopsy specimens injected with barium sulfate paste. The method is tolerant of variations in positioning of the patient, is convenient, yields repeatable analyses from one experienced observer to another, allows 60 volume measurements per second so that rapid cardiac events can be studied, and the small doses of x-rays and contrast medium permit several observations at one catheterization session. This means that effects of drugs and other interventions can be studied by the informative techniques of semi-continuous volume measurement and pressure-volume analysis.

ISSN:0009-7322    

出版商:OVID    

年代:1967

数据来源: OVID

摘要:

Ventricular performance was assessed before and after angiocardiography in 22 patients with normal left ventricle, mitral stenosis, aortic stenosis, and myocardial disease. The increased circulating blood volume known to occur after angiocardiography is a determinant of the increased ventricular pre-load. The after-load is unchanged. Patients with normal left ventricle and some patients with valve stenosis responded by an increase in the work performed and some had only a minimal or no increase. A group of patients with serious heart disease performed less work. If the ventricular response can be considered on the basis of the Frank-Starling principle, then the abnormal response of such patients is due to an altered length-tension relationship.

ISSN:0009-7322    

出版商:OVID    

年代:1967

数据来源: OVID