摘要:

BackgroundHead-upright tilt (HUT) testing is valuable in evaluating syncope. Isoproterenol is used to increase sensitivity. However, isoproterenol is contraindicated or dangerous in undiagnosed heart disease and produces false-positives. We introduced esmolol withdrawal during esmolol HUT, hypothesizing that (1) acute withdrawal of the ultrashort-acting β-blocker induces (-adrenergic effects by unmasking endogenous catecholamines and may provoke syncope with fewer risks, and (2) response to esmolol/esmolol withdrawal may predict effective therapy.Methods and ResultsThirty-six patients with unexplained recurrent syncope/presyncope (7 to 35 years old, known heart disease or arrhythmia in 14) underwent 2 to 4 HUT tests (600, 49 minutes): (1) baseline, (2) esmolol (500 μg/kg plus 50 ug kg−1· min−1), (3) esmolol withdrawal (HUT continued after esmolol stopped), and (4) isoproterenol if tests 1 through 3 were negative and isoproterenol was not contraindicated. A positive test reproduced symptoms with hypotension or bradycardia, requiring recumbency for recovery. Twenty-five had positive tests, and 11 had negative tests. In 5, only the baseline test was positive; in 15, esmolol/esmolol withdrawal tests were also positive, with 3 in whom esmolol withdrawal was positive although negative at baseline. Two isoproterenol tilts were positive. Esmolol withdrawal and isoproterenol tilts had the highest initial heart rate and similar maximal heart rate increment. Only isoproterenol caused hypertension. One isoproterenol test was false-positive, with hypertension-induced arterial baroreflex. Treatment was p-blockers (8), Na/fludrocortisone (9), both (6), and DDD pacemakers (2). Esmolol/ esmolol withdrawal accurately predicted therapeutic response in 15; isoproterenol predicted therapeutic response in none.ConclusionsEsmolol withdrawal tilt testing is preferable to isoproterenol for provocative testing of syncope in the young, and it appears to be safer. Esmolol withdrawal testing has clinical utility before invasive testing as a first-line investigation for syncope in patients with or without heart disease.

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

BackgroundWe report an unusual type of residual interventricular communication in patients with conotruncal malformations in which the aorta is completely or partly aligned with the right ventricle (RV). Interventricular communications after surgical repair usually result from additional defects, patch dehiscence, or incomplete closure and lie in the septal plane. However, after a right ventricular aorta is baffled to the left ventricle, the ventricular septal defect (VSD) patch and RV free wall form part of the systemic outflow tract. This “neo-left ventricular” outflow tract may provide a location for residual interventricular communications out of the septal plane.Methods and ResultsWe reviewed echocardiographic, angiographic, and clinical records of patients who had one or more residual interventricular communications out of the plane of the ventricular septum after repair of a conotruncal anomaly. Between June 1990 and October 1992, we observed such defects in eight patients, 5 to 26 years old, after repair of double-outlet right ventricle (n=6), tetralogy of Fallot (n= 1), or truncus arteriosus (n=1). In each, the VSD patch was anchored to the RV free wall near the aortic root. Nonetheless, channels were observed around the edge of the patch, between the neo-systemic outflow tract and the right ventricle. All patients had right ventricular hypertension; in seven, the pulmonary-to-systemic flow ratio (Qp: Q8) was ≥2. At multiple unsuccessful reoperations (two to four per patient), the patch edges appeared securely attached to myocardium. Angiographic views profiling the septum failed to localize these defects, since they are not in the native septum. Echocardiographic detection of such anterior defects can be difficult. Transcatheter umbrella closure was attempted in the seven patients with large shunts; success was limited by the multiplicity of flow channels. Umbrella closure eliminated the need for further reoperation in four of seven patients, one patient died suddenly awaiting reoperation, and two deaths followed reoperation.Conclusions“Intramural” residual interventricular defects are difficult to diagnose by all modalities. Umbrella placement may reduce the left-to-right shunt. Successful surgical closure may require removal and reattachment of the anterior portion of the patch.

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

BackgroundMultistage surgery culminating in completed hemodynamic repair is now performed for pulmonary atresia with ventricular septal defect (PA-VSD). Justification for operation in patients with an adequate collateral pulmonary circulation is controversial. Data on natural adult survival are scant but are necessary to provide the rationale for multistage reconstructive procedures.Methods and ResultsAll cyanotic adults with PA-VSD in the UCLA Adult Congenital Heart Disease Center Registry from 1978 through 1992 formed the basis for this study. Registry data and echocardiographic, hemodynamic, and angiographic information were used to determine longevity, clinical course, and operative feasibility. Of 26 patients, 16 were unoperated when referred (group A), and 10 had been palliated before age 18 years (group B). Two thirds were 18 to 29 years old. Only 2 patients survived beyond age 40 years. Six died during follow-up at a mean age of 31 years (±12.1 SD). Eight group A patients were in New York Heart Association class II, and 8 were in class III. Of the 26 group A and B patients, 20 had aortic regurgitation, which was moderate or severe in 10. Eight had cardiac failure. Of 11 group A patients who remained unoperated, 5 died. Twelve patients were considered eligible for surgery at ≥18 years of age. Ten underwent completed hemodynamic repair with a mean postoperative right ventricular-to-left ventricular systolic pressure ratio of 0.45 (±0.16 SD), and there were no early or late deaths.ConclusionsEven when collateral blood flow permits adult survival, all such patients are symptomatic. Mean life expectancy without operation did not exceed three decades. Aortic regurgitation and cardiac failure are significant negative variables. Nearly half of unoperated adults died during follow-up. Staged hemodynamic repair can be performed with a low surgical risk in properly selected adults with PA/VSD.

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

BackgroundMyocardial damage in myocarditis is mediated, in part, by immunological mechanisms. High-dose intravenous γ-globulin (IVIG) is an immunomodulatory agent that is beneficial in myocarditis secondary to Kawasaki disease, as well as in murine myocarditis. Since 1990, the routine management of presumed acute myocarditis at Children's Hospital, Boston, and Children's Hospital, Los Angeles, has included administration of high-dose IVIG.Methods and ResultsWe treated 21 consecutive children presenting with presumed acute myocarditis with IVIG, 2 g/kg, over 24 hours, in addition to anticongestive therapies. A comparison group comprised 25 recent historical control patients meeting identical eligibility criteria but not receiving IVIG therapy. Left ventricular function was assessed during five time intervals: 0 to 7 days, 1 to 3 weeks, 3 weeks to 3 months, 3 to 6 months, and 6 to 12 months. At presentation, the IVIG and non-IVIG groups had comparable left ventricular enlargement and poor fractional shortening. Compared with the non-IVIG group, those treated with IVIG had a smaller mean adjusted left ventricular end-diastolic dimension and higher fractional shortening in the periods from 3 to 6 months (P= .008 andP= .033, respectively) and 6 to 12 months (P= .072 andP= .029, respectively). When adjusting for age, biopsy status, intravenous inotropic agents, and angiotensinconverting enzyme inhibitors, patients treated with IVIG were more likely to achieve normal left ventricular function during the first year after presentation (P= .03). By 1 year after presentation, the probability of survival tended to be higher among IVIG-treated patients (.84 versus .60,P= .069). We observed no adverse effects of IVIG administration.ConclusionsThese data suggest that use of high-dose IVIG for treatment of acute myocarditis is associated with improved recovery of left ventricular function and with a tendency to better survival during the first year after presentation.

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

BackgroundThe long-term clinical issue in Kawasaki disease (KD) concerns the coronary artery lesion. Two-dimensional echocardiography and coronary angiography are routine examinations to evaluate the coronary lesions; however, these are not adequate to assess the wall morphology of the coronary artery (CA). Intravascular ultrasound imaging (IVUS), a new technology for the evaluation of the coronary artery lumen and wall morphology in vivo, was performed for patients after KD in their long-term follow-up, and we examined the new insights it gave.Methods and ResultsIVUS was performed during cardiac catheterization in 20 subjects (10 patients after KD who still had coronary aneurysms or regressed coronary aneurysms, 2 after KD who had no coronary abnormal lesion, and 8 control patients with congenital heart disease and normal CA). We evaluated the wall structure at 10 to 15 sites of the CA in each patient. IVUS was performed with a commercially available ultrasound imaging catheter. Four sites of a CA aneurysm in KD demonstrated a markedly dilated lumen without thickened intima. One site of a CA aneurysm with calcification demonstrated an asymmetrical lumen by a dense echo with acoustic shadows. Twenty-two sites of a regressed CA aneurysm demonstrated a marked symmetrical or asymmetrical thickening of the intima with a dense echo, in which the size of the lumen was similar to that at a site near a regressed aneurysm. The sites of angiographically normal CA revealed normal structures and a thin intima in many instances. Nine of 28 sites in KD with a CA abnormal lesion, particularly near a coronary aneurysm or regressed aneurysm, demonstrated a mild thickening of the intima. All the 10 sites in KD without a CA abnormal lesion and all the 25 sites in patients with congenital heart disease with normal CA demonstrated a smooth intima.ConclusionsThis study demonstrated that the site of a regressed coronary aneurysm has a markedly thickened but smooth intima. The sites of angiographically normal CA after KD with or without a coronary lesion demonstrated normal IVUS findings in most instances but in some cases revealed a mild intimal thickening. IVUS is useful to evaluate the CA wall morphology and may contribute to the assessment of long-term CA sequelae and the possible development of arteriosclerotic changes in KD.

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

BackgroundThe outcome of the Fontan operation largely depends on patient selection because this procedure is a physiological correction. Among the several selection criteria for the Fontan operation, the importance of adequate size of the pulmonary artery remains controversial. To clarify whether or not pulmonary artery size is indispensable as one of the selection criteria for the Fontan operation, we considered the physiological importance of pulmonary artery size and investigated how pulmonary artery size influenced postoperative hemodynamics of the Fontan operation.Methods and ResultsIn congenital heart disease of decreasing pulmonary blood flow, 40 patients were examined for this analysis. Pulmonary artery indexes (cross-sectional area of the right and left pulmonary arteries divided by body surface area) were measured as the expression of pulmonary artery size, and the relations of pulmonary artery index (PAI) to pulmonary vascular resistance (Rp) and compliance (Cp) were studied. There was no significant correlation between PAI and Rp, whereas a significant correlation was found between PAI and Cp (r= .71,P= .001). Furthermore, Cp influenced postoperative hemodynamics of the Fontan operation by affecting peak central venous pressure and total impedance, which was the afterload to the ventricle. Impedance increased abruptly when PAI was less than =100 mm2/m2.ConclusionsThe smaller pulmonary artery size is hemodynamically disadvantageous after the Fontan operation, with resultant rise in peak centrol venous pressure and increased afterload to the single ventricle.

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

BackgroundThe diffuse nature of cardiac allograft vasculopathy makes early detection of the disease by traditional noninvasive methods or coronary angiography difficult. The aim of this study was to determine if there is a relation between abnormalities in vessel wall morphology, as assessed by intracoronary ultrasound, and a decreased vasodilatory response to the endothelium-dependent vasodilator papaverine hydrochloride and if cardiac allograft vasculopathy detected by coronary angiography is associated with specific intracoronary ultrasound findings.Methods and ResultsTwenty-three heart transplant recipients underwent 25 intracoronary ultrasound studies and 24 studies of coronary vasomotor tone 10 days to 8.3 years after surgery using a 20-mHz intracoronary ultrasound catheter. The studies were divided in two groups according to the presence (n=7, group 1) or absence (n= 18, group 2) of angiographically evident cardiac allograft vasculopathy. Qualitative assessment of vessel wall morphology and quantitative analysis of the vasodilator response to the injection of papaverine hydrochloride into the coronary artery distal to the imaging site were performed off-line, and results for the two study groups were compared. A significantly higher percentage of patients with than without angiographic evidence of cardiac allograft vasculopathy had a three-interface vessel wall morphology by intracoronary ultrasound (100% versus 11%,P< .001). In two recipients who underwent two serial studies, the appearance of three interfaces in the vessel wall or a progressive thickening of the inner interface of the vessel wall occurred in conjunction with the appearance of angiographic cardiac allograft vasculopathy. The vasodilator response to papaverine was less in patients with than in those without angiographically evident cardiac allograft vasculopathy both in terms of absolute and relative increases in lumen diameter (+0.1±0.12 mm versus +0.3±0.17 mm,P< .05, and +5.1±5.3% versus +8.2±5.3%,P= NS) and lumen crosssectional area (+0.5±0.6 mm2versus +1.7±1.1 mm2,P< .02, and +7.1±8.8% versus 16.6±11.0%,P= .055), respectively.ConclusionsIntracoronary ultrasound assessment of vessel wall morphology and evaluation of vascular response to endothelium- dependent vasodilators are useful techniques for detecting cardiac allograft vasculopathy.

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

BackgroundThe purpose of this investigation was to compare the magnitude of change in myocardial perfusion and function during exercise with that obtained during total coronary artery occlusion. Radionuclide studies are widely used for the diagnosis and determination of prognosis in patients with suspected or known coronary artery disease. These studies are based on the premise that the relative deficit of coronary blood flow, which is induced by exercise and recognized as increased demand, relates to the jeopardy experienced by the decrease or sudden absolute interruption of coronary blood flow that is recognized as decreased supply and is associated with coronary stenosis or total coronary artery occlusion. The magnitude of exercise-induced perfusion and function abnormalities compared with those induced by total coronary artery occlusion in humans has not been previously reported.Methods and ResultsWe prospectively studied 20 patients with ≥50% diameter stenosis documented by quantitative coronary angiography in at least one vessel. A same-day rest/exercise sestamibi myocardial function and perfusion study was performed within 24 hours before percutaneous transluminal coronary angioplasty. At 1 minute after balloon inflation, while the vessel was occluded, sestamibi was injected, and a myocardial perfusion and function study was performed. Perfusion defect size was greater during occlusion (28±3%) than during exercise (13±2%) (P< .01). Ejection fraction was greater during exercise (53±3%) compared with values measured during occlusion (41±2%) (P< .01).ConclusionsPhysiological abnormalities induced by coronary occlusion are greater than those that occur during exercise, thereby indicating that stress-induced ischemia may not reflect the total potential myocardium in jeopardy from a stenotic lesion, if sudden occlusion occurs.

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

BackgroundThe predominant cause of coronary artery calcification is atherosclerosis. Although fast x-ray computed tomography (CT) has been demonstrated to be a sensitive technique to detect coronary calcification, the increasing prevalence of calcification with age has been associated with a low specificity for identifying obstructive atherosclerosis. We hypothesized that the specificity of this test would be improved in a younger patient population, making it more useful in the diagnosis of coronary artery disease.Methods and ResultsWe compared fast CT-detected calcification with coronary angiography in 106 patients under the age of 50 years. Nonenhanced fast CT scans consisting of 20 contiguous 3-mm tomograms of the proximal coronary arteries were obtained during a single breath hold. A positive scan was defined as 4 contiguous voxels (≥1 mm2) of density >130 Hounsfield units in the region of the epicardial coronary arteries. Calcification detected by fast CT had an 85% sensitivity to predict patients with significant coronary artery disease (≥50% diameter stenosis), with a specificity of 45%. Although the sensitivity to detect multivessel disease was 94%, the sensitivity to detect single-vessel disease was 75%. Changing the threshold for defining a positive fast CT scan from 4 to 2 contiguous voxels produced a small improvement in sensitivity, to 88%, but reduced specificity to 36%.ConclusionsAlthough the specificity to detect angiographically significant coronary disease with fast CT improves in a younger patient population, it continues to be relatively low. In contrast to older patient populations, a small but significant number of patients <50 years old with angiographically significant coronary artery disease do not have coronary calcification demonstrated by fast CT. Thus, caution should be used in excluding significant coronary artery disease on the basis of a negative fast CT study.

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

BackgroundControversy exists as to whether low-osmolality radiographic contrast agents, which have less detrimental pharmacological effects but are considerably more expensive than high-osmolality agents, should be used universally or only for selected high-risk patients.Methods and ResultsA randomized, double-blind study was used to compare the frequency and severity of adverse events in 2245 consecutive patients undergoing diagnostic cardiac angiography. Two thousand one hundred sixty-six patients were successfully randomized to either iohexol, a low-osmolality contrast agent, or diatrizoate (as Hypaque 76), a highosmolality agent. The end point event included clinically important adverse events (which jeopardized the patient or required aggressive treatment), contrast agent-related procedure abbreviations, and conversion to open-label contrast agent. Clinically important end point events were associated with increased age, New York Heart Association functional class, left ventricular end-diastolic pressure, arteriovenous oxygen difference, severity of coronary artery disease, and history of a previous reaction to contrast agent. End point events were less frequent in patients receiving iohexol (2.6% versus 4.6%; adjusted odds ratio, 1.59; 95% confidence interval, 0.97-2.60;P= .07). The difference in event frequency between iohexol and diatrizoate was confined to the highestrisk quartile of the patient population. An algorithm was developed to classify patients as being at high or low risk for an event based on patient age, New York Heart Association class, history of a prior contrast reaction, and left ventricular enddiastolic pressure. Application of this algorithm for selective use of low-osmolality agents only for high-risk patients to a theoretical population of 1000 patients reduced contrast agent costs 66% without increasing the frequency of contrast agentrelated adverse events.ConclusionsThe advantages of low-osmolality contrast agents are clinically important in patients with severe heart disease but are not in less ill patients. Universal use of low-osmolality agents for cardiac angiography in an unselected population is not necessary. Appropriately guided selective use of low-osmolality contrast agents is feasible and has the potential to reduce cost substantially without compromising safety or effectiveness.

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID