ISSN:0009-7322    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Four completed prospective studies of drug-treated and control hypertensives utilizing double blind randomized protocols are reviewed for the purpose of evaluating the evidence on which the present therapeutic crusade is based. Patients studied were predominantly male, observed for short period, had complications or died at young age, had high incidence of previous target organ vascular disease, and did not include those whose blood pressure fell to normal with hospitalization alone. Incidence of complications associated with coronary artery disease was the same in control and treated patients. The rapidly progressive disease observed in these patients differs from that described in other natural history studies. Population screening for hypertension for the purpose of instituting drug therapy is premature because the value of antihypertensive drug treatment for the general hypertensive population has not been established.

ISSN:0009-7322    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Eight subjects with complete atrioventricular heart block were studied with simultaneous echocardiography and phonocardiography to investigate the role of the mitral and tricuspid valves in the genesis of the first heart sound (S1). Mitral valve motion was studied in all cases and tricuspid patterns in three. At P-R intervals less than 0.20 sec, mitral leaflet closure was completed by ventricular systole. Below P-R values of 0.20 sec there was an inverse relationship between P-R and S1amplitude. With P-R between 0.20 and 0.50 sec atrial systole closed the mitral valve without recordable sound. Beyond P-R intervals of 0.50 sec there was reopening of the mitral valve and secondary closure initiated by ventricular systole which was coincident with S1. The extent of mitral leaflet separation at the onset of ventricular systole correlated with S1amplitude. Pre-ejection period was not related to S1intensity. Over a wide range of P-R intervals in two subjects with a split S1, tricuspid valve closure was simultaneous with the second S1component. It was concluded that atrioventricular valve closure is a necessary event in the production of S1and that at least in some individuals tricuspid valve closure is related to its second high frequency component.

ISSN:0009-7322    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

A prototype multiple crystal echocardiographic system developed by Bom and associates was used to evaluate cross-sectional cardiac anatomy in real time in twenty infants and children with endocardial cushion defect (ECD). The findings were compared to fifty normal infants and children and nineteen patients with normal mitral valve anatomy but right ventricular enlargement (RVE). Three standard transducer positions for evaluation of sagittal and transverse cardiac cross-sections are outlined and the normal group and RVE subgroup described. Studies in patients with ECD demonstrated several distinctive abnormalities, consisting of multiple echoes in the mitral valve area, anterior mitral leaflet - septal apposition in diastole with reduced posterior motion in systole, and reduced excursion of the anterior mitral leaflet. In patients with complete atrioventricular (A-V) canal defects, the anterior leaflet was often observed passing across the plane of the ventricular septum into the right ventricle during diastole, and in some of these patients the anterior mitral leaflet was related to the tricuspid annulus. Multiple crystal cardiac ultrasonography allows a more precise determination of intra- and extracardiac spatial relationships and is easier to perform than single crystal echo. The new technique provides clinical information helpful in evaluating patients with possible ECD and gives some indication of the severity of the defect.

ISSN:0009-7322    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

The variety of echographic features associated with the mitral valve prolapse syndrome (MVPS) is not yet completely understood. Therefore, ultrasound recordings were obtained in 33 patients in whom mitral prolapse had been documented by biplane left ventricular cineangiography. Echographic abnormailities of the mitral leaflets during systole were recorded in 26/27 MVPS patients and 6/6 with ruptured chordae tendineae. In MVPS, the midsystolic mitral buckling, emphasized in early echocardiographic studies, was observed in only 12 patients. In our study, the most common aberrancy was abnormal pansystolic mitral motion in 14 patients, which in 12 was similar to the pansystolic bowing observed in all six patients with torn chordae. An additional echographic abnormality in MVPS was localized mitral collapse throughout systole in 10/14 patients with pansystolic prolapse; this finding was the most striking defect noted in five, in two of whom it was the only disturbance. Phonocardiography in MVPS showed typical midsystolic click and/or late systolic murmur in only 15/26 patients of whom ten had midsystolic mitral buckling. A variety of systolic clicks and/or murmurs occurred in the 14 patients with generalized bowing and/or localized collapse throughout systole on echocardiography. Thus, the mitral echographic spectrum of MVPS is comprised of three different abnormal patterns of systolic prolapse: buckling in midsystole, pansystolic bowing, and pansystolic collapse. These echocardiographic disorders commonly occur in the absence of classical auscultatory findings in MVPS and the most frequent abnormality on ultrasound is pansystolic bowing of both mitral leaflets.

ISSN:0009-7322    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

The concept of “normalized velocity’ has been applied in this study to the echocardiographic (echo) assessment of left ventricular (LV) function in 87 patients. The following normalized velocities were calculated from the ultrasound recording of LV wall motion: 1) the mean circumferential fiber shortening rate (mean VCF), 2) the mean normalized posterior wall velocity (VPW), and 3) the mean normalized interventricular septal velocity (VIVS). Systolic ejection fraction (SEF), and mean (non-normalized) posterior wall velocity (PWV) were also determined. There were 19 patients with normal LV function, 5 with atrial septal defect (mean VCF, VIVSand SEF were not calculated in these patients), 16 with LV volume overload, 29 with myocardial disease, 6 with hypertrophic cardiomyopathy and 12 with coronary artery disease (CAD). Single plane cineangiographic (angio) determinations of mean VCFand SEF were obtained in 50 of the 87 patients (including all 12 patients with CAD).Mean VCFand SEF done by echo correlated very well with mean VCFand SEF done by angio in the patients without CAD (r= 0.94 and 0.91, respectively). Mean VCF(by echo or by angio) adequately separated normal from abnormal LV function. Although correlation between mean VCFand SEF was good, mean VCFwas reduced while SEF was well preserved in several patients. In spite of LV asynergy, most of the patients with CAD had good correlation between echo and angio measurements of mean VCFand SEF. Although PWV correlated with echo and angio mean VCFin the patients without CAD, the overlap of normal and abnormal values made PWV an unreliable index of LV function. In contrast, VPWproved to be a reliable indicator of LV performance in patients without LV asynergy. Agreement between VPWand mean VCF(by echo or angio) was seen in 94% of the patients; in the presence of CAD, however, greater discrepancy was seen between these two measurements. Agreement between VIVSand VPWwas present in 90% of the patients without CAD, but in only 58% of the patients with CAD.The analysis of LV wall motion by echocardiography utilizing the “normalized velocity’ concept appears to be a rational and practical method for evaluation of LV performance. In the absence of asynergy, VPWprovides a reliable index of LV performance which may be of particular value when abnormal septal motion precludes the determination of SEF and mean VCF. In the presence of asynergy, however, mean VCF, VPWand VIVSmay reflect only the performance of the visualized segment of myocardium.

ISSN:0009-7322    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Thein vitroandin vivoechocardiographic characteristics of the Bjork-Shiley tilting disc prosthetic valve are described. Optimal position of transducer and valve for detecting maximal disc excursion occurs when the ultrasound beam is perpendicular to the maximally opened disc. This alignment may vary from patient to patient requiring individualization by the echocardiographer. Rotation of the inner valve annulus at the time of surgery, when physiologically feasible, can facilitate optimal valve and ultrasound transducer alignment for serial postoperative evaluations of valve function.

ISSN:0009-7322    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Echographic dimensions of the aortic root and left atrium were compared in 170 patients in order to assess dilation of the left atrium with reference to the relatively nondistensible fibrous aortic root. In 50 patients without cause for left atrial or aortic enlargement, the ratio of left atrial/aortic root dimension was 0.87-1.11. In 80 patients with known cause for left atrial enlargement, the left atrial/aortic root ratio was ≥ 1.17. In 40 patients with isolated aortic valve disease, dilation of both the aortic root and the left atrium resulted in a left atrial/aortic root dimension ratio < 1.17 in some patients. Despite this consideration, the comparison of left atrial and aortic root dimension appears to be as specific as, and more sensitive than, previously proposed methods for the evaluation of left atrial enlargement.

ISSN:0009-7322    

出版商:OVID    

年代:1974

数据来源: OVID