摘要:

To evaluate the short-term results of percutaneous aortic balloon valvuloplasty, 55 consecutive elderly patients with symptomatic, severe aortic stenosis who were at high risk for surgical intervention underwent the procedure, with follow-up by clinical evaluation and Doppler echocardiography. Over a mean follow-up of 6.2 months, there were three early deaths (< 30 days) and eight late deaths. Nine patients underwent subsequent aortic valve surgery, and four had repeat balloon valvuloplasty. Doppler echocardiography revealed a reduction in aortic valve mean gradient from 48 ± 18 to 33 ± 12 mm Hg after the procedure (p< 0.0001) but a return to 46 ± 16 mm Hg at follow-up (p< 0.05). The aortic valve area increased from 0.54 ± 0.15 to 0.85 ± 0.23 cm2after the procedure (p< 0.0001), but there was a significant decrease to 0.67 ± 0.19 cm2at follow-up (p< 0.05). Of patients free of aortic valve operation or death after 30 days after the procedure, 76% were severely symptomatic before the procedure as compared with 38% at follow-up. In patients undergoing percutaneous aortic balloon valvuloplasty, there is a continued high short-term mortality and a significant incidence of restenosis over short-term follow-up. Nonetheless, a subset of patients do experience sustained clinical improvement from this procedure.

ISSN:0009-7322    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Thirty-five consecutive patients with an overt accessory pathway, all but two suffering from arrhythmia (atrial fibrillation, reciprocating tachycardia, or both), underwent attempted transcatheter ablation (fulguration) of their accessory pathway. Thirty-three patients had been treated with a mean of 2.3 ± 1.4 antiarrhythmic drugs. A standard bipolar catheter was positioned on the internal surface of the right or left atrioventricular anulus with 1) a subclavian approach of the right cardiac cavities in 29 patients with right-sided accessory pathway (n= 27) or left posteroseptal accessory pathway (n= 2), 2) a patent foramen ovale in five patients (two with a left posterolateral accessory pathway and three with a left parietal accessory pathway), and a transseptal catheterism (one patient with a left parietal accessory pathway). Cathodic shocks (mean, 4.3 shocks/patient) with a mean cumulative energy of 690 J enabled the ablation (disappearance of both anterograde and retrograde conduction) of the accessory pathway in 32 patients with a follow-up ranging from 1 to 32 months (mean, 10 ± 8 months). Two of the remaining three accessory pathways were impaired: one pathway became intermittent, the anterograde effective refractory period of the second pathway increased from 260 to 410 msec, and the third pathway was slightly impaired. This latter patient is the only one who still requires therapy, with a single antiarrhythmic drug. All others are free of arrhythmias and require no therapy. Not using coronary sinus catheterism inclusive of its os has led to only a few, benign side effects. Only one third-degree atrioventricular block occurred in a posteroseptal accessory pathway ablation. Three cases of patients with incessant reciprocating tachycardia involving a further successful ablation occurred at the beginning of our experience. The best area for ablation is, in our opinion, the recording site for the Kent-bundle activity (18 of 35 patients), but a meticulous mapping of the atrioventricular anulus during orthodromic reciprocating tachycardia makes ablation possible when the shortest ventriculoatrial time (V-A′) can be recorded with reliability (mean, 85 ± 18 msec). Such a procedure is an alternative to surgical ablation regardless of the location of the accessory pathway—not only posteroseptally.

ISSN:0009-7322    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Experimental studies have shown that among dogs with a healed myocardial infarction, depressed baroreflex sensitivity (BRS) identifies a subgroup at higher risk for sudden death. We have examined the relation among BRS, several clinical cardiovascular variables, and subsequent mortality in 78 patients below the age of 65 years who have had a first myocardial infarction. BRS was assessed by calculating the regression line relating phenylephrine-induced increases in systolic blood pressure to the attendant changes in the RR interval. A reduced BRS primarily reflects an impairment in the vagal efferent component of the baroreceptor reflexes. The BRS of the entire population was 7.8 ± 4.9 msec/mm Hg. BRS was lower among patients with an inferior myocardial infarction (6.1 ± 3.3 vs. 8.9 ± 5.8 msec/mm Hg,p= 0.03), with a three-versus a one-vessel disease (4.8 ± 2.7 vs. 7.1 ± 3.1 msec/mm Hg,p= 0.04), and with episodes of ventricular tachycardia (5.1 ± 3.0 vs. 8.3 ± 5.1,p= 0.03). There was no correlation between BRS and left ventricular ejection fraction or with mean pulmonary capillary wedge pressure at peak exercise, but a correlation (r = 0.35,p< 0.001) was present with exercise tolerance. During the 24 months mean follow-up period, there were six cardiovascular deaths (7.6%), and four were sudden. The BRS of the deceased patients were strikingly lower than those of the survivors (2.4 ± 1.7 vs. 8.2 ± 4.8 msec/nun Hg,p= 0.004), and mortality dramatically increased from 2.9% (two of 68) to 40% (four of 10) (p< 0.001) in the presence of a markedly depressed BRS (< 3.0 msec/mm Hg). Even among patients with depressed left ventricular function, mortality was associated with reduced BRS. This clinical prospective study suggests that analysis of baroreflex sensitivity in patients after myocardial infarction provides novel information on cardiovascular pathophysiology and may contribute to more accurate identification of individuals at high risk for subsequent mortality.

ISSN:0009-7322    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

To improve the performance of exercise stress testing in the diagnosis of effort angina while minimizing risks of serious complications, we evaluated an impulse response of ST changes, which is a transient ST response resulting from a hypothetical, strenuous-impulselike exercise, without actually imposing the strenuous load. To obtain the impulse response, subjects walked intermittently according to a computer-generated random binary sequence on a treadmill for 20 minutes (with a constant speed of 1.7 mph and a slope of 10%). We used Fourier transform for beat-to-beat changes in ST level and the binary sequence of exercise. We then determined the transfer function by taking the ratio of Fourier transformed ST level to exercise over the frequency range of 0.5 through 5.0 cycles/min. Converting the transfer function to the time domain yielded the impulse response of ST change. The subjects consisted of 49 patients (60 ± 9 years) with effort angina, 13 patients with atypical chest pain (56 ± 9 years), and 30 healthy, male volunteers (23 ± 7 years). In 82 subjects (89%), the ST impulse response showed an initial depression followed by a smooth, gradual restoration toward the preexercise ST level (type I response). The average duration of the initial depression was 8 ± 3 seconds in the healthy volunteers, whereas it was significantly prolonged to 23 ± 14 seconds in effort angina (p< 0.05). The depression in patients with atypical chest pain was not significantly different from that in the healthy volunteers. Although the level of exercise was milder in the proposed exercise test than in the conventional treadmill exercise test, the sensitivity and the specificity were significantly better in the proposed exercise test than in the conventional one in the same population. We conclude that this random exercise test is a sensitive, safe tool and is very accurate for the diagnosis of effort angina.

ISSN:0009-7322    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

We prospectively investigated whether201T1 single-photon emission computed tomography (SPECT) could accurately diagnose the presence and quantify the extent of acute myocardial infarction when compared with infarct size assessed by plasma MB-creatine kinase activity. Thirty patients with enzymatic evidence of infarction were imaged within 12–36 hours of chest pain (mean, 23.4 hours). No patient had a previous infarction, and none underwent intervention seeking to restore coronary patency. Infarct size was quantified with computer-generated polar maps of the myocardial radioactivity and expressed as a percentage of the total left ventricular volume. To assess left and right ventricular performance, blood-pool gated radionuclide angiography was performed immediately after SPECT. All 30 patients had perfusion defects consistent with myocardial infarction. Scintigraphic and enzymatic estimates of infarct size correlated well for the group as a whole (r= 0.78,p< 0.001, SEE = 9.1) but especially for those patients with anterior infarction (r= 0.91,p< 0.001, SEE = 7.9). The poor correlation observed in patients with inferior infarction (r= 0.50,p< 0.05, SEE = 10.0) was believed to be related to the frequent occurrence of right ventricular involvement because SPECT assessed only left ventricular damage, whereas the enzymatic method estimated the myocardial injury in both ventricles. A quantitative index of right ventricular infarct size, derived from the relation between the scintigraphic and enzymatic estimates, had a strong inverse correlation with right ventricular ejection fraction (r= −0.89,p< 0.001, SEE = 3.6). Therefore,201T1 SPECT is highly sensitive for detecting the myocardial perfusion deficit during acute infarction in humans and can accurately quantify left ventricular infarct size. The comparison of infarct size by SPECT to the enzymatic estimate may provide a means to assess the extent of right ventricular involvement in patients with inferior infarction.

ISSN:0009-7322    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

To determine prospectively the prevalence of mitral, aortic, tricuspid, and pulmonary regurgitation in normal persons, 211 consecutive, apparently healthy volunteers were examined with a color Doppler flow imaging system. The subjects were divided into five age groups (group 1, 6–9 years old; group 2, 10–19 years old, group 3, 20–29 years old, group 4, 30–39 years old, and group 5, 40–49 years old). The prevalence rate of mitral regurgitation in the normal subjects was 38–45% in each group. The mitral regurgitant jets came from the posteromedial commissure in all but two subjects. No aortic regurgitant flow signals were detected in the normal subjects. Tricuspid regurgitation was detected in 15–77% in each group, and pulmonary regurgitation was detected in 28–88%. Regarding the tricuspid and pulmonic valves, the prevalence rate of regurgitation is age dependent (p< 0.01) and tends toward the lower rate in groups over the age of 30 years. The tricuspid and pulmonary regurgitant jets came from the center of the coaptation of each valve. The area of the regurgitant jet signals in normal persons was significantly smaller (p< 0.001) than that obtained from patients with organic valve disease. Our study shows that in a large proportion of normal persons under the age of 50 years color Doppler echocardiography permits recording of regurgitant signals behind all valves except the aortic. In conclusion, one should be aware of the existence and characteristics of regurgitation in normal persons when evaluating valvular regurgitation by Doppler techniques.

ISSN:0009-7322    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

To determine the value of transesophageal ultrasound in the assessment of cardiac valve prostheses, 14 patients with clinically suspected mitral prosthesis malfunction were studied by transthoracic and transesophageal two-dimensional imaging as well as by color Doppler flow velocity mapping (color Doppler). Patients underwent left ventricular angiography (n= 13), surgery (n= 11), or both angiography and surgery (n= 10). Nine patients had only mitral valve replacement, four patients had both mitral and aortic valve replacement, and one patient had mitral, aortic, and tricuspid valve replacement. There were 16 biological and four mechanical prostheses. The degree of mitral regurgitation was graded by both transthoracic and transesophageal color Doppler according to the area of the regurgitant jet visualized and was compared with a three-point classification of mitral regurgitation by left ventricular angiography judged by observers blinded to the echocardiographic results. All transesophageal studies were performed without complication and were well tolerated. The pathological morphology of the mitral prosthesis was additionally or more clearly visualized by transesophageal two-dimensional imaging and subsequently proven at surgery in three patients with flail leaflets and one patient with a vegetation compared with images obtained by the transthoracic approach. Valvular regurgitation was graded by the transthoracic approach as absent in four patients, mild in two patients, moderate in five patients, and severe in only three patients. The transesophageal assessment showed absence of mitral regurgitation in two patients, moderate regurgitation in two patients, and severe regurgitation in 10 patients. Left ventricular angiography done in 13 of the 14 patients revealed no regurgitation in two patients, mild regurgitation in one patient, moderate regurgitation in one patient, and severe mitral regurgitation in nine patients. This corresponded to the grading by transesophageal echocar-diography in 12 of the 13 patients with the 13th patient graded as mild regurgitation by angiography and moderate regurgitation by transesophageal echocardiography. We conclude that in patients with biological mitral prosthesis malfunction, transesophageal two-dimensional imaging, as well as color Doppler, can provide reliable diagnostic information beyond that available from the transthoracic approach with the degree of mitral regurgitation corresponding to that found on left ventricular angiography.

ISSN:0009-7322    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Left ventricular aneurysm (LVA) remains a poorly understood entity, often resulting in congestive failure that is not consistently improved by standard resection with linear closure. Although other surgical approaches have been proposed, current methods to assess their effect on left ventricular function are not adequate. The purpose of the present study was to quantitatively define regional systolic function in patients with LVA and to assess acute changes in regional function after standard repair. Seven patients underwent resection of an anteroapical LVA. Intraoperative two-dimensional echocardiography was performed off cardiopulmonary bypass immediately before and after resection. In all patients, short-axis views at the papillary muscle (apex) level showed anteroseptal paradox and distorted geometry, whereas at the mitral valve (base), symmetric wall motion and geometry were preserved. Videotaped echo images were divided into octants by a floating axis fitted to internal landmarks. Myocardial area and midwall perimeter were obtained for each octant, and wall thickness was calculated at end diastole (ED), isovolumetric systole (IS), and end systole (ES). Wall thickening (Δ t) for each segment was calculated as the percent increase in thickness from ED and averaged for all seven patients. At the apex level before resection, isovolumetric thinning occurred in the aneurysm as well as bordering segments, with Δ t ranging from −17 ± 5% (± SEM) in the anteroseptal segment to 12 ± 6% posterolaterally (p< 0.05). The isovolumetric bulge was followed by late-systolic thickening, however, with Δ t ranging from 13 ± 7% to 27 ± 8% (NS). Systolic function at the base was symmetric, with Δ t ranging from 12 ± 3% to 18 ± 3% at IS (NS) and from 20 ± 6% to 26 ± 6% (NS) at ES. After resection, isovolumetric function at the apex improved significantly, with thickening present in all segments. In the posteroseptal segment, Δ t improved from −6 ± 3% before repair to 11 ± 6% after repair (p< 0.05) and improved in the septal segment from −8 ± 4% to 9 ± 5% (p< 0.05). End-systolic thickening was not significantly changed from prerepair values at either the apex or base. These data define the nature of regional systolic function with anteroapical LVA. Paradoxic wall thinning occurs not only in the aneurysm itself but in border zones as well. Thinning is maximal at isovolumetric systole and is followed by net end-systolic thickening. Normal systolic function is maintained in posterior segments and at the base of the heart. LVA resection eliminates the aneurysm itself and normalizes isovolumetric function of the border segments. This method of analysis will allow objective assessment of newer forms of LVA repair.

ISSN:0009-7322    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Twenty-four patients aged 10.1 ± 4.5 (mean ± SD) years with recurrent paroxysmal supraventricular tachycardia underwent an electrophysiological study. Eleven patients had an overt and seven had a concealed accessory connection; six patients had no accessory connection. An orthodromic reciprocating tachycardia was inducible in 17 of 18 patients with an accessory connection, and an atrioventricular nodal reentrant tachycardia was inducible in four of six patients without accessory connection. After administration of propafenone, the sinus cycle length decreased. Intra-arterial, intranodal, and His-ventricle intervals and QRS duration increased. The atrial and ventricular effective refractory periods and anterograde and retrograde effective refractory periods of the atrioventricular node increased. The cycle length at which nodal second-degree block occurred increased. Of 18 patients with accessory connection, propafenone prolonged retrograde conduction in all, blocked anterograde conduction in five, and prolonged it in six. The drug terminated the orthodromic reciprocating tachycardia in all 17 patients and the atrioventricular nodal reentrant tachycardia in three of four patients. In three of four patients with atrioventricular nodal reentrant tachycardia and in 15 of 17 patients with orthodromic reciprocating tachycardia, the tachycardia was no longer inducible or norisustained after propafenone. A follow-up of 26 ± 10 months revealed that the drug when orally administered to all patients prevented recurrences of tachycardia in 15 of 18 patients with and in four of six patients without accessory connection. The results of short-term drug testing with propafenone predict the response to long-term oral therapy with this drug.

ISSN:0009-7322    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

From April 1984 to April 1987, surgical anatomic correction was performed in 86 newborn infants, 2–23 days old (6.8 ± 3.6 days, mean ± SD) with simple transposition of the great arteries. In all patients, the pulmonary artery was reconstructed by end-to-end anastomosis according to the Lecompte maneuver, including eight patients with side-by-side position of the great arteries. Three different approaches were used. In the first 10 patients (group 1, six survivors), two separate patches of preserved tanned pericardium were used to reconstruct the pulmonary artery, whereas in the next 15 patients (group 2, 13 survivors), a single patch of the same material was used, and in the last 61 patients (group 3, 56 survivors), surgery was performed with a single patch of fresh autologous pericardium. Among the 75 survivors, 68 (including six in group 1, 12 in group 2, and 50 in group 3) were followed serially for at least 6 months (6–48 months, 26 ± 9 months) with sequential noninvasive evaluations. At follow-up, all were asymptomatic with normal growth. Two patients with severe pulmonary artery stenosis (group 1) were successfully reoperated on. Four infants with moderate pulmonary artery stenosis have been followed medically and have had stable right ventricular pressures. The last 62 patients have normal or near-normal right ventricular pressures. The spatial relation of the great arteries did not affect the quality of the results. Group 1 had clearly the worst results. Although there were no statistically significant differences between the results in groups 2 and 3, the best results, judged clinically, were obtained with the last surgical approach (group 3). With this current technique, there have only been two moderate pulmonary artery stenoses, both localized at the pulmonary artery branches, and 46 of the 50 patients have right ventricular pressures less than 40 mm Hg. With this technique, the pulmonary arteries grow satisfactorily, and the right ventricular pressure does not increase.

ISSN:0009-7322    

出版商:OVID    

年代:1988

数据来源: OVID