ISSN:0009-7322    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

Intracardiac blood oxygen saturation was determined in 31 patients, at cardiac catheterization, by means of a fiberoptic in vivo hemoreflection system, giving an immediate report. When compared to in vitro spectrophotometric analysis of samples obtained through a second catheter, a standard error of estimate of only 1.99-per cent saturation (r = 0.966) was found for the higher speed instrument (response time 0.07 second) and 1.13-per cent saturation (r = 0.992) for the slower instrument (response time 1.5 seconds).The average of the standard deviations of saturation values in cardiac chambers in which no primary mixing occurred, was only 0.88-per cent saturation. The continuous recording of oxygen saturation while moving the catheter, permits measurements at multiple sites within a brief period of time (14 to 26 seconds through the right side of the heart). Oxygen saturation changes can be continuously monitored under changing conditions, such as exercise. Finally, the higher speed instrument permits investigation of changes in oxygen saturation in patients with congenital heart disease within portions of the cardiac cycle.

ISSN:0009-7322    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

The fiberoptic instrument and catheters described in the preceding study were employed in the measurement of indocyanine-green concentrations in the circulatory system by a simple change of filters.Cardiac output was calculated from the recorded curves in 19 instances. In 13 of these, the results were compared with cardiac output determinations simultaneously obtained by a conventional method. There was good agreement for each of the values obtained (range 2.37 to 7.32L./min., r = 0.985). The only blood withdrawn in each patient was the 8 ml. needed for calibration.Distinct step-function was seen in the descending as well as the ascending portions of the curves. In three instances left ventricular injections were done and end-diastolic and end-systolic volumes calculated. The results are similar to those reported for thermodilution methods.From the rapidly changing concentration of dye within one cardiac cycle in the presence of aortic regurgitation, a formula was derived by which the amount of regurgitation could be calculated. This method was tested in a model where regurgitation varied up to twice the forward stroke volume by means of a ther-modilution method. Good agreement between measured and calculated degrees of regurgitation (r = 0.928) in 26 observations is shown. The application of the formula to a patient with proven aortic regurgitation is demonstrated.

ISSN:0009-7322    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

Hemodynamic studies, including cardiac output, arterial blood pressure, run-off index, flow cessation pressure, and blood volume, were performed in 20 normotensive control subjects, 17 labile hypertensive patients and 20 patients with fixed hypertension, 10 of them with a mild elevation of the diastolic pressure and 10 classified as severe because of a diastolic blood pressure above 110 mm. Hg.In labile hypertension cardiac output was elevated, whereas blood volume, peripheral resistance, run-off index and flow cessation pressure were normal when blood pressure was high. This hemodynamic pattern was interpreted as due to an enhanced myocardial contractile energy or a restriction of the capacity vascular bed.In mild fixed hypertension total peripheral resistance and flow cessation pressure were uniformly increased, but cardiac output and run-off index were normal. This pattern may be explained by the influence of flow autoregulation and the barostatic mechanism.In severe fixed hypertension blood volume, cardiac output, and peripheral resistance were found to be high. Renal ischemia and secondary hyperaldosteronism may determine the development of this last stage of hypertension.

ISSN:0009-7322    

出版商:OVID    

年代:1965

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

The effect of valvular insufficiency on left ventricular volumes was studied by an angiographic method in 37 patients. Ejection of the additional volume load imposed by valvular insufficiency was achieved by an increase in end-diastolic volume and not by increasing the proportion of end-diastolic volume ejected. Of the 37 patients, 16 (43 per cent) had a significant reduction in the fraction of end-diastolic volume ejected per beat. These patients performed significantly less stroke work from a given end-diastolic fiber length (end-diastolic volume) than did the others and evidence is presented that they had impaired myocardial function. An index of myocardial contractility is derived which relates stroke work to end-diastolic volume.The magnitude of left ventricular volumes is determined in part by the severity of the volume load but a further increase in volume without necessarily a further increase in ejection occurs in those patients with impaired myocardial function. Valvular insufficiency is quantitated from the difference between left ventricular ejection volume determined angiographically and forward stroke volume determined from indicator-dilution curves. The results show good agreement with subsequent surgical findings in the 15 patients who underwent operation.

ISSN:0009-7322    

出版商:OVID    

年代:1965

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

The material comprised the data of 146 patients with tetralogy of Fallot treated by corrective intracardiac surgery. Electrocardiograms were recorded in all cases before and in 108 cases after operation. The majority of the patients were between 5 and 20 years of age at the time of surgery and have been followed for an average of 1.5 years.Arrhythmias, mostly extrasystoles, were recorded in eight cases before operation and in 14 cases on the last follow-up examination. The amplitude of the P wave in lead II decreased by 1 mm. or more after surgery in one third of the cases.Seventeen patients developed complete AV block postoperatively, seven died; of the 10 who survived operation, in all but two the electrocardiogram reverted to normal sinus rhythm.The electrocardiogram showed right axis deviation and right ventricular hypertrophy in the majority of cases. A balanced axis and signs of combined ventricular hypertrophy were commonest in acyanotic patients and more common in cyanotic patients who had had previous shunt procedures than in cyanotic patients who had had no previous shunt. Two patients showed electrocardiographic signs of left ventricular hypertrophy. After corrective cardiac surgery, the mean electrical axis and the pattern of the QRS complex in V1and V6changed toward normal in the eight patients in whom intraventricular conduction defects did not appear and in the 26 patients with incomplete right bundle-branch block.Two of nine surviving patients in whom a small coronary artery was divided at surgery developed the pattern of myocardial infarction in the postoperative electrocardiogram.Conduction disturbances frequently appeared during operation; they were considered to be caused mainly by direct trauma to the conduction system during closure of the ventricular septal defect or during infundibulum resection. Complete right bundle-branch block appeared in 74 (69 per cent) and incomplete right bundle-branch block developed in 20 (19 per cent) of surviving patients. Only eight patients showed no disturbances of conduction after surgery. The right bundle-branch blocks persisted throughout the follow-up period. The conduction disturbances have not adversely affected the postoperative course, nor have they caused any discomfort to the patients.

ISSN:0009-7322    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

Detailed analysis for the presence and type of heart disease was made in 96 deceased patients who had electrocardiographic “peri-infarction block.” Evidence for disease of the left ventricle was found in 80 per cent of these patients. Left ventricular hypertrophy and diffuse scarring of the left ventricle were the most common abnormalities on pathologic examination. Definite myocardial infarction was found in only 12 of the 55 patients (22 per cent) subjected to postmortem examination. Electrocardiographic “peri-infarction block” was therefore not specific for myocardial infarction although it was often associated with it. Use of the term should be restricted to left intraventricular conduction defect of the “peri-infarction block type.”In spite of the nonspecificity of this type of intraventricular conduction defect, it can be a useful clinical sign. If chronic obstructive airway disease and emphysema can be excluded, the presence of some type of left ventricular disease is almost assured.

ISSN:0009-7322    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

Sixteen patients developed angina pectoris during cardiac catheterization.During an anginal attack, left ventricular end-diastolic pressure did not uniformly rise. When it did occur, it seemed to be more closely related to acute left ventricular hypertension.During a stress-induced anginal attack, the rise, if any, in systolic ejection rate of the left ventricle, was markedly decreased below that achieved in normal subjects or in subjects with coronary artery disease without angina. The impaired augmentation in systolic ejection rate was associated with subnormal increases in cardiac output as well as in stroke volume during the anginal state. Average heart rate and systolic ejection period were no different from the nonanginal patients.Myocardial excess lactate was found in the vast majority of cases during an anginal episode, and actual myocardial lactate production was seen in one half of the patients during angina.The abnormalities in left ventricular function may be related to abnormalities in oxygen supply to the myocardium.

ISSN:0009-7322    

出版商:OVID    

年代:1965

数据来源: OVID