摘要:

The echocardiographic features of the enlarged coronary sinus are described in eight patients with a left superior vena cava draining to the coronary sinus and two patients with total anomalous pulmonary venous connection to the coronary sinus. The diagnosis was confirmed in each patient by cardiac catheterization and surgery. On the M-mode echocardiogram, a dense echo was present posterior to the mitral valve at the level of the atrioventricular junction. The clear space immediately behind this echo represented the enlarged coronary sinus. On the two-dimensional echocardiographic examination, the enlarged coronary sinus was seen in several planes; however, the structure was imaged best with the parasternal long-axis view. In the long-axis plane in the eight patients with a left superior vena cava, the coronary sinus was visualized as a distinct circular structure lying posteriorly in the atrioventricular junction. In the two patients with total anomalous pulmonary venous connection, the confluence of the pulmonary veins and its connection to the coronary sinus were imaged in the long-axis plane. These findings were substantiated by contrast M-mode and two-dimensional echocardiograms in five patients. The M-mode and two-dimensional echocardiographic examinations allowed detection of the enlarged coronary sinus and diagnosis of certain venous anomalies that caused increased coronary sinus blood flow. The two-dimensional echocardiographic examination easily distinguished the enlarged coronary sinus from other congenital lesions that cause anomalous echoes behind the anterior mitral valve leaflet on M-mode echocardiographic examination.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Cross-sectional and M-mode echocardiograms were performed on 23 consecutive patients with infective endocarditis. Both M-mode and cross-sectional echocardiography identified vegetations in 18 patients, 10 of whom required valve replacement within 1 month of presentation. Cross-sectional echocardiography alone identified a vegetation in one patient with a prosthetic valve. Neither technique identified vegetations in five instances. The size and shape of a vegetation on cross-sectional echocardiography did not accurately predict the need for early valve replacement or the incidence of major peripheral emboli.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

The purpose of this study was to determine if respiratory variation and/or absolute size of echocardiographically measured right or left ventricular internal dimension at end-diastole (RVIDd or LVIDd) are accurate indicators of the presence or severity of cardiac tamponade. We measured RVIDd or LVIDd by echocardiography in nine closed-chest, spontaneously breathing dogs in control and during hypotensive tamponade. With tamponade, the end-expiratory RVIDd and LVIDd were significantly smaller than control. Inspiratory increases in RVIDd and decreases in LVIDd were exaggerated during tamponade. Because of the wide range and overlap of RVIDd and LVIDd, no single expiratory value or amount of respiratory change indicated the presence or severity of tamponade. We conclude that if serial echocardiograms show a pericardial effusion, a decreasing end-expiratory RVIDd and LVIDd and an increasing percentage change in ventricular diameter with inspiration, a progressive degree of tamponade should be suspected. However, a single echocardiogram cannot accurately predict the presence or severity of tamponade.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

To evaluate left ventricular (LV) reserve, we developed a method of dynamic exercise echocardiography (DEE). Forty-six healthy persons and 47 cardiac patients performed bicycle ergometer exercise in the supine position. A special table was used on which the subjects could be firmly attached at shoulder level to prevent bodily movements which might disturb the recordings. In 83% of the subjects in whom a clear echocardiogram was obtained at rest, a clear echocardiogram was also obtained during dynamic exercise. During exercise, cardiac output estimated from the echocardiogram and that from the dye-dilution method showed an excellent correlation. The changes of the mean velocity of LV circumferential shortening during exercise permitted discrimination between older and younger healthy men, and also between healthy subjects and those with either mild or severe LV dysfunction. We conclude that DEE is useful for evaluating LV reserve.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Sixteen healthy subjects, ages 18-35 years, were studied in the supine position by means of systolic time intervals and echocardiography before and after smoking a high-nicotine cigarette (2.5 mg nicotine) and a tobacco cigarette of very low nicotine content (⩽ 0.02 mg nicotine) to assess and compare the immediate effects upon left ventricular function.Smokers (n = 12) and nonsmokers (n = 4) behaved alike. High- and low-nicotine cigarettes both caused significant increases in heart rate, systolic and diastolic blood pressure and the triple product (systolic blood pressure X left ventricular ejection (LVET) X heart rate), prolonged LVETc and decreased the preejection period (PEP) and PEP/LVET. In addition, smoking a nicotine reference cigarette increased the echocardiographically derived LV end-diastolic volume by 7.5%, augmented ejection fraction by 4%, while significantly enhancing mean normalized circumferential fiber shortening by 12.5% and mean normalized posterior wall velocity by 9%. Smoking a tobacco cigarette of ultra-low nicotine content resulted in comparable increases in ejection fraction and mean circumferential fiber shortening, albeit on the basis of a significant decrease in end-systolic volume without alteration in end-diastolic volume.These data suggest that in the supine position smoking a high-nicotine cigarette acutely increases venous return and augments the principal determinants of myocardial oxygen consumption heart rate, contractility, preload and afterload and that cigarette smoke may contain inotropic and chronotropic substances other than nicotine.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Five different algorithms for determining left ventricular (LV) ejection fraction (EF) and volumes from two-dimensional echocardiographic examination (TDE) were compared with standard methods for obtaining EF and volume from x-ray cineangiography (cine) and EF from radionuclide ventriculography (RVG) in 35 patients. Although all methods correlated positively, the degree of correlation varied with the algorithm used. For EF determination, TDE algorithms (especially those using multiple planes of section) were superior to unidimensional algorithms commonly used with M-mode echocardiography. The best algorithm (modified Simpson's rule) correlated well enough with cine EF (r = 0.78; SEE 0.097) and RVG EF (r = 0.75; SEE 0.087) to make clinically useful estimates. TDE volumes also correlated meaningfully with cine end-diastolic and end-systolic volumes (r = 0.84; n = 70) but were associated with a large standard error of the estimate (43 ml) and offered less advantage over unidimensional volume estimations. Quantitative application of TDE appears to be a useful noninvasive method of evaluating LVEF, but is not as useful for estimating LV volumes.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

The ability of cardiac scintigraphy with indium-lll ('1l1n)-labeled platelets to detect coronary artery thrombosis (CAT) was assessed in a canine model. Cardiac imaging and tissue distribution studies were performed shortly after administering "11In-labeled platelets to 12 dogs (group 1) with acute CAT. Four dogs (group 2) with acute CAT were studied 2 and 22 hours after administering "'In platelets. In addition, four dogs (group 3) with 24-hour-old CAT were similarly evaluated. In all group 1 animals, in vivo imaging 1-2 hours after. In platelet administration revealed intense uptake in the region of thrombus-containing left anterior descending arteries that was readily discernible from background blood pool activity. Sequential imaging of the four group 2 animals over a 22-hour period revealed no change in the scintigraphic pattern of the thrombosed arteries. In contrast, "'In platelet imaging in the four group 3 animals with 24-hour-old CAT failed to reveal enhanced activity within the region of the thrombus-containing coronary artery. In the 12 group 1 animals, the CAT accumulated 69 ± 10 (mean ± SEM) times greater activity than present in blood and 651 ± 135 times greater activity than normal left ventricular myocardium. There was 24 ± 7 times greater "'In activity in the damaged left anterior descending arteries compared with normal circumflex arteries. Similar uptake ratios were seen in group 2 animals. The 24-hour-old thrombi from group 3 animals showed no enhanced "'In uptake.This study demonstrates that experimental acute CAT can be detected readily with "'In platelet cardiac scintigraphy. Acutely formed thrombi accumulate labeled platelets, but 24-hour thrombi do not. Serial imaging of acutely formed thrombi over 22 hours after the administration of "'In platelets shows no significant change in the scintigraphic appearance. This technique may provide a better understanding of the role of thrombosis in myocardial infarction.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Myocardial and blood kinetics of thallium-201 (201T1) and potassium42 (42K) were studied in five patients with normal coronary angiography. A mixture of 400 oCi of 201TI, 400 μCi of 42K, 50 μCi ofiodine-125 radioiodinated human serum albumin as intravascular indicator, and 400 μCi of tritiated water (THO) as extravascular indicator was injected as a bolus into the pulmonary artery, and blood timeconcentration curves were obtained from the aortic root and coronary sinus. These curves were numerically deconvoluted to obtain the frequency function of transit times (FFTT) of the four isotopes through the coronary system.Initial maximal myocardial extraction of the two tracers were similar. The net maximal myocardial uptake of 201TI per 100 g of tissue ranged from 1.0-2.7% of the injected dose and was positively related to myocardial blood flow (MBF) calculated from THO and to the ratio MBF/cardiac output (CO), while net uptake of 42K ranged from 1.4-2.4%, but was not correlated with MBF nor with MBF/CO.The analysis of the FFTT indicates that 42K, but not 201TI, is washed out from the myocardium more rapidly when MBF and the heart rate are higher. Thus, thallium appears to be a much more suitable agent than potassium isotopes for myocardial perfusion studies.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Using a quantitative, computer-aided circumferential profile technique, we have shown that thallium-201 scintigrams with large defects can identify a group of patients with a high mortality after acute myocardial infarction. To determine whether high-risk thallium scintigrams predict poor survival because of a critical loss of myocardium, we correlated infarct size in 24 autopsied patients with the extent of thallium defect in three views. Of 13 patients with large defects (computer score 7.0) eight (62%) had > 25% loss of left ventricular (LV) myocardium, but five (38%) had smaller infarcts (4-24% of LV myocardium), suggesting that part of the scintigraphic defect was related to ischemia without necrosis. Eight of nine patients with loss > 25% LV myocardium had large defects. In 10 of 11 patients with small defects (computer score < 7.0), infarcts involved < 20% of LV myocardium. Although scintigrams with large defects predicted a critical loss of myocardium in over 60% of our patients, they included an important second group, in which the scintigraphic defect appeared to reflect a small infarct and a large surrounding area of reversibly ischemic myocardium.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID