摘要:

An indirect estimate of the contractility index, max LV dP/dt/LVEDP, has been examined in 32 patients following acute myocardial infarction (AMI) and in three patients with acute coronary insufficiency (ACI). The index was derived from arterial diastolic pressure (DP) obtained by sphygmomanometer, left ventricular filling pressure (LVFP) obtained by pulmonary artery balloon catheter, and preejection period (PEP) determined from the phonocardiogram, carotid pulse, and ECG. These data were used in the relation (DP-LVFP)/PEP/LVFP (i.e., &Dgr;P/&Dgr;t/LVFP) as an approximation of the direct contractility index max dP/dt/LVEDP. While measurements of PEP, DP, and LVFP used independently were not useful in distinguishing patients grouped in surviving AMI, nonsurviving AMI, and ACI categories, the &Dgr;P/&Dgr;t/LVFP index showed marked separation of these groups. Because of the simplicity of measurement and minimal intravascular intervention, the index provides a safe and practical means of assessing the degree of left ventricular dysfunction in patients with AMI.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Among 124 consecutive patients undergoing operation for pure or predominant mitral stenosis between 1964 and 1969, closed commissurotomy was carried out in 53 (43%). There were no early or late deaths, and the hemodynamic and symptomatic results of operation were excellent. In 51 (41%) of the patients, valvular anatomy was such that valve replacement proved necessary. As a group, these patients were more severely symptomatic preoperatively and had worse hemodynamics than patients in the closed-commissurotomy group. With replacement, operative (24%) and late (12%) mortality were high, but surviving patients enjoyed hemodynamic and symptomatic benefits comparable to those of the patients undergoing closed commissurotomy. In 20 patients whose preoperative clinical and hemodynamic characteristics were intermediate between those of the closed-commissurotomy and valve-replacement groups, open commissurotomy was performed. Early (10%) and late (5%) mortality were less than with mitral replacement, but in general hemodynamic and symptomatic benefits were modest.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Twenty-five patients with discrete subaortic stenosis were reviewed. Twenty were operated on for severe obstruction. Review of available data suggests there is a wide spectrum of the disease which may be divided into two main types designated I and II. Type I is a thin discrete membrane immediately under the aortic valve obstructing the outflow but not associated with narrowing of it. Type II is situated about 1 cm below the valve and consists of a fibrous ring, thicker than type I, and associated with muscular hypertrophy which narrows the outflow tract, encroaches on the anterior leaflet of the mitral valve, and may extend 1-2 cm downward. Both have a characteristic angiographic appearance. Results of surgery are good for type I but not satisfactory for type II. Aortic incompetence is likely to increase or develop following operation in both types.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Bradycardia, with or without hypotension, frequently occurs in the early phases of acute myocardial infarction. To determine the relative effects of alterations in heart rate and blood pressure on the degree of ischemic injury, the left anterior descending coronary artery was occluded for 15-min periods in closed-chest conscious dogs by inflating a balloon cuff previously implanted around the artery. The degree of myocardial ischemia was estimated by summating the S-T elevation recorded from 12 myocardial electrodes. Heart rate was increased by atropine or pacing and decreased by electrical stimulation of the vagus nerve. Hypotension was produced by venesection (average decrease in mean BP, 56 mm Hg). At normal arterial pressures there was a positive correlation between percent change in heart rate (range 30-215 beats/min) and percent change in S-T elevation (y = 0.75 X + 30.2, r = 0.93,P< 0.01). When myocardial ischemia was induced during hypotension and bradycardia, S-T elevation totaled 68 mv at 15 min of ischemia. When heart rate was increased to control levels in the presence of hypotension S-T elevation during myocardial ischemia was greater (mean difference 29 mv,P< 0.05). In contrast, when blood pressure was increased to control in the presence of bradycardia, S-T elevation in seven of 10 dogs was less than during hypotension and bradycardia. Thus, during experimental acute myocardial ischemia, hypotension induced by hemorrhage increases ischemic injury, and bradycardia reduces it. It is concluded that in acute myocardial ischemia increases in heart rate, even from slow baseline rates; may be deleterious to the myocardium. It remains to be determined whether alterations in the degree of myocardial ischemia induced by hemorrhagic-hypotension are analogous to those caused by the type of hypotension that often accompanies bradycardia occurring during acute myocardial infarction in man.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Children with left-to-right shunt, with and without congestive heart failure, were found to have impaired glucose tolerance tests (GTT). In cyanotic children normal levels of glucose were found in association with abnormally high levels of insulin following oral GTT. Several possible mechanisms are proposed to explain the different glucose tolerance alterations: (1) Suppression of insulin release appeared to partially explain the low levels of insulin in congestive heart failure. This suppression may be related to the high levels of circulating norepinephrine found in these patients. (2) Excessive clearance of insulin by the lung may also be responsible for the reduced arterial insulin levels in patients with left-to-right shunt, and underclearance of insulin for the abnormally higher arterial insulin levels in patients with right-to-left shunts in whom a significant amount of venous blood has bypassed the lung. (3) Hypoxia of the pancreas and the liver in cyanotic patients and those with congestive heart failure may explain the reduction of insulin levels in the hepatic vein following i.v. glucose tolerance tests. An excess production of a glucagonlike gastrointestinal factor in cyanotic children may partially explain the abnormally high levels of insulin following oral GTT.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Thirty-seven infants with total anomalous pulmonary venous drainage have been operated upon at The Hospital for Sick Children, Great Ormond Street, London, with 13 survivors. Most were rapidly deteriorating when admitted. Cardiac catheterization, angiography, and operation were urgently undertaken to achieve the maximum salvage. Physical examination, plain radiography, and electrocardiography were insufficient for accurate diagnosis. Survival was closely related to the degree of pulmonary hypertension, which was dependent on the type of anomalous venous drainage and the presence of pulmonary venous obstruction. The prognosis was good for patients over 3 months of age, especially those without pulmonary venous obstruction, provided that they arrived in the hospital in reasonable condition. The best survival rate, nine of 11 cases, was achieved in those patients between 3 and 12 months of age with supracardiac drainage.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The spontaneous functional closure of the interatrial communication in total anomalous pulmonary venous drainage (TAPVD) subsequent to surgical correction of the TAPVD in infants is reported. Three cases are documented with descriptions of clinical features, cardiac catheterization data, thermodilution curves, and angiography. This evidence suggests that it might be unnecessary in infants to close the interatrial communication at the time of correction of the TAPVD. It also suggests that balloon atrial septostomy may sometimes be unwise before the first-stage correction.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Two cases of common pulmonary vein atresia (CPVA) are presented. In one, the diagnosis was suspected on clinical grounds, and in both it was c onfirmed by cardiac catheterization and angiocardiography. Surgical correction was attempted unsuccessfully in one. Prompt identification of the defect followed by immediate operation, using a technic of profound hypothermia and circulatory arrest, offers hope of successful correction in this rare anomaly.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The processes which are involved in the development of the normal outflow tracts of the ventricles are the following: The ostium bulbar torsion accounts for the concordant flow between the ventricles and the proximal conuses. The leftward shift of the ostium bulbi accounts for the partial overriding of the aorta over the left ventricle. The truncal rotation accounts for the twisted relationships of the great vessels and for the definitive interrelationships of the semilunar valves. The aortic conus absorption accounts for the aorticomitral fibrous continuity. These processes are not necessarily linked to each other. In the normal, mature heart the conus is represented by the subpulmonary portion of the right ventricular outflow tract.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

A primitive form of double-outlet right ventricle is described clinically and anatomically. A long tubular conus, arising exclusively from the right ventricle emptied into the transposed great vessels. Together with the presence of A-V canal malformation this heart represented a developmental arrest in the embryonic stage of the bulboventricular loop seen in horizon XV. Diagnosis is made on the basis of right ventricular angiography and theoretically, if this lesion is isolated, this conus malformation is surgically correctable.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID