Exercise echocardiography for the prognostic stratification of patients with low pretest probability of coronary artery disease.

PURPOSE: The aim of this study was to determine whether exercise echocardiography provides incremental data for risk stratification of patients with a low pretest probability of coronary artery disease. PATIENTS AND METHODS: The study included patients referred for exercise echocardiography whose probability of coronary artery disease was 25% or less. We calculated an exercise wall motion score index (on a 1-5 scale), an indicator of the extent and severity of exercise-induced abnormalities. The primary outcomes of the study were subsequent cardiac events (cardiac death and nonfatal myocardial infarction). RESULTS: We studied 571 men and 1047 women; their mean (+/- SD) age was 55 +/- 13 years. During a median follow-up of 3 years, there were 19 cardiac events (6 cardiac deaths and 13 nonfatal myocardial infarctions); an additional 37 patients underwent coronary revascularization. In a multivariate analysis of clinical, exercise electrocardiographic, and echocardiographic parameters, exercise wall motion score index (hazard ratio [HR] = 2.1 per 0.5 units; 95% confidence interval [CI]: 1.3 to 3.4), and age (HR = 2.0 per decade; 95% CI: 1.2-2.8) were independently associated with the risk of cardiac events. Although exercise echocardiographic variables contributed significantly (P = 0.01) to a model of the risk of adverse events, only 9 (47%) of the 19 patients with cardiac events were identified by an abnormal exercise echocardiogram. CONCLUSION: Among patients with low pretest probability of coronary artery disease by clinical criteria, exercise echocardiography identifies some, but not all, patients at risk of future events. Because of the low event rate, routine application of exercise echocardiography in a patient with a low pretest probability does not appear to be cost-effective and therefore cannot be recommended.

Contrast dobutamine stress echocardiography: clinical practice assessment in 300 consecutive patients.

In this study we compared non-contrast imaging with contrast imaging of the left ventricle during dobutamine stress echocardiography (DSE). Wall segment visualization, image quality, and confidence of interpretation were determined with and without the use of intravenous Optison, a second-generation echocardiographic contrast agent, in 300 consecutive patients undergoing rest and peak DSE. At rest and at peak stress, the percentage of wall segments visualized, image quality, and confidence of interpretation were better with contrast compared with non-contrast imaging. No significant decrease was seen in wall segment visualization, image quality, or confidence of interpretation from rest to peak stress in images obtained with contrast, unlike the images obtained without contrast from rest to peak stress. The use of the intravenous echocardiographic contrast agent Optison during DSE significantly improved wall segment visualization and image quality at rest and at peak stress, resulting in improved confidence of interpretation.

Radiographic measurements of cardiac size as predictors of outcome in patients with dilated cardiomyopathy.

BACKGROUND: Cardiac dilatation is a predictor of poor outcome in patients with dilated cardiomyopathy. Whereas cardiac chamber dimensions or volumes can be assessed by various noninvasive and invasive techniques, simple chest radiography also may provide a valuable assessment of cardiac size. METHODS AND RESULTS: To determine the relative power of radiographic heart measurements for predicting outcome in dilated cardiomyopathy, we retrospectively studied 88 adult patients with chest radiographs obtained within 35 days of echocardiography. Standard radiographic variables were measured for each patient, and the cardiothoracic (CT) ratio, frontal cardiac area, and volume were calculated. During a mean 4.1-year follow-up, 62 of the 88 (71%) patients died. CT ratio was the best predictor of mortality among the radiographic cardiac measurements. By multivariate analysis, a model including echocardiographic ejection fraction, New York Heart Association (NYHA) functional class, and history of heart failure was highly predictive of survival. When added to this model, CT ratio also was independently associated with mortality, but not radiographic cardiac area or volume. When radiographic variables were each added to CT ratio, they did not add incremental predictive value to the model that included CT ratio alone. Echocardiographic measurement of left ventricular (LV) size, especially when indexed for body size, was independently predictive of outcome, but it did not supersede the predictive power of CT ratio. CONCLUSION: The simply derived radiographic CT ratio is a useful predictor of outcome in patients with dilated cardiomyopathy and compares favorably with other clinical and selected echocardiographic variables.

Identification of a locus for autosomal dominant polycystic liver disease, on chromosome 19p13.2-13.1.

Polycystic liver disease (PCLD) is characterized by the growth of fluid-filled cysts of biliary epithelial origin in the liver. Although the disease is often asymptomatic, it can, when severe, lead to complications requiring surgical therapy. PCLD is most often associated with autosomal dominant polycystic kidney disease (ADPKD); however, families with an isolated polycystic liver phenotype without kidney involvement have been described. The clinical presentation and histological features of polycystic liver disease in the presence or absence of ADPKD are indistinguishable, raising the possibility that the pathogenetic mechanisms in the diseases are interrelated. We ascertained two large families with polycystic liver disease without kidney cysts and performed a genomewide scan for genetic linkage. A causative gene, PCLD, was mapped to chromosome 19p13.2-13.1, with a maximum LOD score of 10.3. Haplotype analysis refined the PCLD interval to 12.5 cM flanked by D19S586/D19S583 and D19S593/D19S579. The discovery of genetic linkage will facilitate diagnosis and study of this underdiagnosed disease entity. Identification of PCLD will be instrumental to an understanding of the pathogenesis of cyst formation in the liver in isolated PCLD and in ADPKD.

The Mayo Clinic's Clinician-Educator Award: A program to encourage educational innovation and scholarship.

In 1998, the Board of Governors of the Mayo Clinic requested that the Education Committee design and implement a program to grant time and resources to clinical faculty to support the development of educational projects. The essence of the resulting Clinician-Educator Award Program is the concept of using funding to award time and resources for educational projects judged to be meritorious by an impartial, peer-review-based faculty mentoring process. The authors report early experiences with the program, which was enthusiastically accepted by faculty, to provide a model to help other academic health centers, especially those with salary-based faculty, to facilitate educational innovation and scholarship despite the growing constraints on academic clinicians' time and resources.

Risk of patients with severe aortic stenosis undergoing noncardiac surgery.

Aortic stenosis (AS) is a major risk factor for perioperative cardiac events in patients undergoing noncardiac surgery. We previously showed that selected patients with AS who were not candidates for, or refused, aortic valve replacement could undergo noncardiac surgery with acceptable risk. We extended our previous experience over a subsequent 5-year period by retrospectively analyzing the perioperative course of all patients with severe AS (aortic valve area index < 0.5 cm2/m2 or mean gradient > 50 mm Hg), determined with Doppler echocardiography or cardiac catheterization, who underwent noncardiac surgery. Nineteen patients underwent 28 surgical procedures: 22 elective and 6 emergency. The types of these procedures were 12 orthopedic, 6 intraabdominal, 4 vascular, 4 urologic, 1 otolaryngologic, and 1 thoracic. Mean age was 75 +/- 8 years. Of the 19 patients, 16 (84%) had > or = 1 symptom: dyspnea, angina, syncope, or presyncope. Mean left ventricular ejection fraction was 61 +/- 11%. The type of anesthesia was general in 26 procedures and continuous spinal in 2. Intraarterial monitoring of blood pressure was used in 20 of the 28 surgical procedures. Intraoperative hypotensive events were treated promptly, primarily with phenylephrine. In all cases the anesthesia team was aware of the severity of the AS and integrated this into the anesthetic plan. Two patients (elective operation in 1 and emergency in 1) had complicated postoperative courses and died. There were no other intraoperative or postoperative events in any of the other patients. Although aortic valve replacement remains the primary treatment for patients with severe AS, selected patients with severe AS, who are otherwise not candidates for aortic valve replacement, can undergo noncardiac surgery with acceptable risk when appropriate intraoperative and postoperative management is used.

Hypertensive response during dobutamine stress echocardiography.

Among 3,129 dobutamine stress echocardiographic studies, a hypertensive response, defined as systolic blood pressure (BP) > or = 220 mm Hg and/or diastolic BP > or = 110 mm Hg, occurred in 30 patients (1%). Patients with this response more often had a history of hypertension and had higher resting systolic and diastolic BP before dobutamine infusion.

Is review of videotape necessary after review of digitized cine-loop images in stress echocardiography? A prospective study in 306 patients.

The interpretation of stress echocardiography has been made easier by the comparison of digitized prestress and poststress frame-grabbed images (cine-loops), each representing a portion of a single cardiac cycle. Often, review of these digitized images is substituted for review of the complete videotape record of the examination. An alternative is to review both the digitized images as well as the videotape record of the rest and stress images. To date, there has been insufficient documentation of whether these options (cine-loop images alone versus cine-loop images plus videotape) provide comparable or additive information. Therefore, we prospectively evaluated information obtained from review of cine-loop images versus combined review of cine-loop images and videotape records in 306 consecutive patients undergoing treadmill (213 patients, 70%) or dobutamine (93 patients, 30%) stress echocardiography. An experienced echocardiologist first reviewed the cine-loop images and scored the wall motion in 16 segments at rest and with stress. Next, the complete videotape record was reviewed with repeated wall motion scoring. A questionnaire comparing cine-loop and videotape images was completed at the end of each review. Digitization of images was technically inadequate in 14 patients (4%). In 116 (40%) of the other 292 patients, the regional wall motion assessment, after relying solely on cine-loop images, was modified with subsequent videotape review. In 40 patients (14%), these modifications resulted in a change in the final impression regarding whether the study result was normal or abnormal. In a multivariate analysis, age, gender, and type of stress echocardiography had no significant influence on discordance of the cine-loop image and combined cine-loop and video information. Stepwise logistic regression analysis identified poorer image quality (p < 0.0001) and regional wall motion abnormalities (p < 0.0001) as predictors of discordance between cine-loop and combined review. We conclude that relying solely on digitized cine-loop images representing a single cardiac cycle is not optimal, especially if the quality of the digitized images is suboptimal and if regional wall motion abnormalities are present. Thus we recommend a combined review of both cine-loop images and videotape images in the interpretation of stress echocardiography.

Two-dimensional echocardiographic calculation of left ventricular mass as recommended by the American Society of Echocardiography: correlation with autopsy and M-mode echocardiography.

The American Society of Echocardiography (ASE) has recommended diastolic area length and truncated ellipsoid methods for estimating left ventricular (LV) mass by two-dimensional (2D) echocardiography. The major goals of this retrospective study were to (1) assess the correlation between ASE-recommended 2D and M-mode echo-derived measurements of LV mass, (2) compare the two ASE-recommended 2D echocardiography methods, and (3) compare the echo-derived LV mass with anatomic LV mass. The study included 2D echocardiograms obtained within 30 days of death from 34 patients who subsequently underwent autopsy and 2D echocardiograms of 56 normal subjects. The formula used for measurement of M-mode echo-derived LV mass was LV mass = 0.8 (ASE-cube LV mass) + 0.6 gm. For 2D echo-derived LV mass, the ASE-recommended area length and truncated ellipsoid methods in systole and diastole were used, with and without incorporating the papillary muscles into the myocardial shell. LV mass derived by M-mode echocardiography was comparable to that derived by 2D methods, and it is reasonable to use this technique for normally shaped ventricles. When the papillary muscles were included into the myocardial shell, diastolic 2D methods overestimated autopsy LV mass. Both diastolic area length and truncated ellipsoid methods were comparable to autopsy LV mass. When the papillary muscles were excluded, the systolic area length method showed the best agreement with autopsy LV mass.

The value of two-dimensional echocardiography and Doppler examination in the assessment of hypertensive patients: a pilot study.

There has been hesitation in accepting the routine use of echocardiography in patients with hypertension. The concept of "limited" or "focused" echocardiography has been introduced but incompletely evaluated. In this prospective observational cohort study, 100 consecutive hypertensive adults underwent comprehensive two-dimensional echocardiography and Doppler assessment regardless of referral question. Patients were categorized on the basis of echocardiographic referral questions into two groups: (1) determination of left ventricular mass only (limited echocardiography) and (2) determination of left ventricular mass and associated cardiac problems. In group 1, missed diagnoses were rare (5%). Additional, clinically relevant information was provided by comprehensive echocardiography in 9% of patients. Doppler echocardiography did not provide any additional useful information in group 1 but was useful in group 2. In both groups, echocardiography affected clinical management. In patients referred for determination of left ventricular mass only, the equivalent of limited echocardiography, missed diagnoses are rare. Additional, clinically relevant information is provided in only a small number of patients by comprehensive two-dimensional echocardiography. Comprehensive two-dimensional echocardiography, including Doppler echocardiography, was useful in selected patients referred with hypertension and other cardiac problems and should be part of the echocardiographic assessment of such patients. With careful selection of hypertensive patients, limited echocardiography can be a cost-effective strategy.

Determination of left ventricular mass by echocardiography in a normal population: effect of age and sex in addition to body size.

OBJECTIVE: In this study, we determined the effect of age, sex, and body size on left ventricular mass. DESIGN: Two-dimensional-guided M-mode echocardiography was used in an assessment of 111 healthy, normal adults. MATERIAL AND METHODS: Left ventricular mass was calculated with the cube function formula corrected by a regression equation to agree with autopsy estimates of left ventricular mass. Calculated left ventricular mass, indexed by body surface area and by height, was analyzed on the basis of sex and age of the study participants. Age was analyzed as a dichotomous, trichotomous, and continuous variable. The effects of age, sex, and obesity, as well as interactions, were tested within a multiple linear regression model framework. RESULTS: Left ventricular mass, when indexed for either body surface area or height, was greater in men than in women. For women, but not men, we found a small but significant increase in left ventricular mass with advancing age. Body mass index, an indicator of obesity, increased with aging in women but not in men and affected left ventricular mass. No significant changes were noted in left ventricular cavity size with advancing age, and the increase in left ventricular mass in women was due to increased ventricular wall thickness. CONCLUSION: The findings in this study suggest that left ventricular mass, as assessed by two-dimensional-guided M-mode echocardiography, is affected not only by sex and body size but also by age in women. This phenomenon may be related to an increase in body mass index with advancing age in women. In clinical studies that use echocardiographic left ventricular mass to diagnose left ventricular hypertrophy, these observations should be considered.

Influence of prosthesis size on change in left ventricular mass following aortic valve replacement.

Current surgical practice regarding valve replacement has as its primary concern the appropriateness of tissue versus mechanical prostheses and perhaps lesser emphasis has been placed on the size of the device. Despite technical advances, which provide maximal valve orifice area in valve substitutes, small device implantation may be accomplished in the aortic root but not effectively relieve the obstructive nature of the original disease. We reviewed 39 patients who had undergone aortic valve replacement (AVR) for aortic stenosis (AS) and had preoperative and postoperative (6 months-3 years) echo measurements which permitted calculation of the left ventricular mass (LVM) and mass index (LVMI). The mean age for the 32 women and 7 men was 67.4 years (22-83). There were four groups as determined by prosthetic size and aortic root enlargement (ARE) or not. The majority of the prostheses were heterografts (26), and the others were tilting discs or bileaflet. There was no difference (P = ns) in preoperative NYHA class, cardiopulmonary bypass (CPB) time, cross-clamp time, associated procedures or complications among the four groups. Although all groups demonstrated a reduction in LVM and LVMI, there was a greater and equal mass and mass index reduction in patients receiving a 21 mm prosthesis or larger. Despite the refinements in artificial valve designs, the 19 mm size valves may not provide comparable reduction in LVM and LVMI following AVR for AS, and the aortic root enlargement permits a larger prosthetic implantation and greater potential for reduction in LVM and LVMI without an increase in the operative time or postoperative complications.

Primary cardiac angiosarcoma: a clinicopathologic study of six cases.

Autopsy or surgical specimens from six patients with primary cardiac angiosarcoma seen at the Mayo Clinic (all in men) between 1939 and 1988 were studied (patients' ages, 31 to 80 years; mean 50 years). The symptoms were nonspecific and included dyspnea and thoracoabdominal pain in six; anorexia in five; fatigue, hemoptysis, or orthopnea in four; nausea and vomiting, fever, or weight loss in three; and night sweats in two. Cardiomegaly was present in five, and a pericardial effusion or density, a mass adjacent to the heart, or nonspecific ST-T wave changes were present in three. All six neoplasms arose from the right atrium and exhibited epicardial or endocardial extension; three produced obstructive intracavitary right atrial masses. Pulmonary metastatic lesions were noted in five patients. The cardiac neoplasm was diagnosed by computed tomography or magnetic resonance imaging in the three most recent patients, and surgical resection was performed in two of them. Mean survival was 6 months after presentation. Causes of death were pulmonary hemorrhage in three, thoracic metastasis in two, and hemopericardium in one. The diagnosis of primary cardiac angiosarcoma was established at operation in two patients and at autopsy in four. Despite diagnosis by noninvasive imaging procedures and aggressive early surgical intervention, survival was less than 6 months. Thus optimal therapy is unclear.

Significance of mildly elevated creatine kinase (myocardial band) activity after elective abdominal aortic aneurysmectomy.

The clinical significance of mildly elevated creatine kinase (CK) myocardial band (MB) enzyme levels in patients undergoing elective repair of an abdominal aortic aneurysm was evaluated retrospectively in 348 patients. For each patient, preoperative and postoperative electrocardiograms (ECGs) were interpreted blindly for left ventricular hypertrophy, ST segment abnormality, left bundle branch block, right bundle branch block, left axis deviation, atrial fibrillation, T wave abnormality, and Q waves. A total of 107 patients (31%) had postoperative CK-MB elevations of trace or greater; 37 had trace, 35 had 1% to 4%, and 35 had greater than or equal to 5% elevation. There was no difference in survival between those with trace and no CK-MB elevation. Patients with increased CK-MB (greater than or equal to 1%) values were more likely to have ECG abnormalities. The following ECG (either preoperative or postoperative) abnormalities were univariately related to decreased postoperative survival: left ventricular hypertrophy (P less than 0.001), ST segment abnormalities (P less than 0.001), left bundle branch block (P less than 0.001), the combination of right bundle branch block and left axis deviation (P = 0.006), Q wave infarction (P less than 0.001), and atrial fibrillation (P less than 0.001). There were 15 in-hospital deaths, and 333 patients were discharged and followed-up for a median of 4.6 years. There were 97 posthospitalization deaths, 61% of which were due to cardiac causes. Overall survival was associated with the degree of CK-MB elevation; the higher the CK-MB, the worse the survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Can anatomical left ventricular mass be estimated reliably by M-mode echocardiography? A clinicopathological study of ninety-three patients.

To evaluate the accuracy of M-mode echocardiography in the assessment of left ventricular mass, we compared various echocardiography-derived regression equations for left ventricular mass to postmortem left ventricular weights in 93 patients (mean age 68 +/- 11 years) who had autopsy within 30 days of technically adequate two-dimensional guided M-mode echocardiography and who had normal left ventricular shape. The left ventricle was enlarged in 36 patients (39%) and was involved by chronic ischemic disease in 48 patients (52%). Only a modest correlation was found between M-mode echocardiography and anatomical left ventricular mass (range of correlation coefficients, 0.58 to 0.67). Each echocardiographic formula demonstrated increasing deviations as left ventricular mass increased. A previously suggested correction formula lessened overestimation, but considerable data dispersion remained. Regional wall-motion abnormalities, present in 22%, did not affect the correlation. We conclude that M-mode echocardiography, performed with standard methods, does not reliably estimate anatomical left ventricular mass, especially in patients with large hearts.

Cardiology patient simulator and computer-assisted instruction technologies in bedside teaching.

The design and uses of an innovative technology-based approach which addresses critical problems with bedside teaching during ward rounds in the current health care situation are described. A cardiology patient simulator (HARVEY) and an accompanying computer-based interactive laserdisk system provide medical students, house officers and other health professionals with the opportunity to encounter a wide variety of clinical problems for learning and assessment. A group of cardiologists and medical educators from a consortium of US medical schools has guided the development and formal assessment of the entire system over the past 10 years. The system and simulator can be configured and programmed to provide appropriate heart sounds, laboratory data, and test results upon request; hands-on experience to practise examination skills is also available. The system, whole or in part, can be used in a variety of instructional modes from self-instruction to demonstration teaching, and from self-assessment to the final clinical examination. The system's effectiveness for teaching medical clerks is summarized, as is its use in providing continuing education for primary care doctors in rural practice.

Doppler echocardiography in aortic stenosis: feasibility and clinical impact.

The clinical utility of Doppler echocardiography for the assessment of aortic stenosis was prospectively studied in 425 consecutive patients referred to the echocardiography laboratory over 1 year with the clinical diagnosis of aortic stenosis. Optimal peak Doppler velocities were obtained in 405 (95%) patients of all ages. In 108 patients, the severity of aortic stenosis as determined by subsequent cardiac catheterization was compared with that found by Doppler assessment. Categorization of severity was concordant in 8 (89%) of 9 cases of mild aortic stenosis and in 28 (78%) of 36 cases of severe aortic stenosis, but there was considerable diagnostic overlap in cases of moderate stenosis. Forty-nine patients with mild aortic stenosis as determined clinically had moderate or severe stenosis as assessed by Doppler; 7 (14%) of these patients underwent subsequent replacement of the aortic valve. Increased aortic velocity, as determined by Doppler, was associated with a significant incidence of subsequent (mean follow-up period, 22 months) cardiac events (cardiac death, aortic valvar replacement, New York Heart Association functional class III or IV). Patients with mild aortic stenosis as assessed by Doppler (peak aortic velocity less than 2.5 m/sec) had greater than 95% event-free survival at 1 year and rarely required cardiac catheterization. Conversely, only 45% of patients with severe aortic stenosis as determined by Doppler were free of a cardiovascular event at 1 year. Although the noninvasive assessment of aortic stenosis should ideally include determination of the area of the aortic valve and the mean aortic gradient by Doppler echocardiography, this is not always possible. Prognostic information derived from peak aortic velocity alone is clinically useful. It has the additional advantage that it is much less laborious and time-consuming to obtain and is obtainable in almost all (99%) patients.

Imaging techniques for assessing pulmonary artery hypertension and right ventricular performance with special reference to COPD.

Several imaging techniques, both noninvasive and minimally invasive, have now been applied widely for determining cardiovascular performance in patients with chronic respiratory disease, particularly COPD. Moreover, some of these techniques are useful for evaluating response to therapeutic intervention in these patients. The plain chest radiograph is useful primarily for detecting the presence of pulmonary artery hypertension in patients with COPD. Radionuclide angiocardiography, using either first-pass techniques or the gated equilibrium technique, is particularly useful for determining right and left ventricular ejection fraction. Echocardiography has evolved as a technique for assessing right ventricular size and function and, in some cases, the degree of pulmonary artery hypertension.

Stable angina pectoris: 1. Clinical patterns.

The symptoms of angina pectoris reflect transient inadequacy of myocardial oxygen supply as a consequence of decreased myocardial blood flow, increased myocardial oxygen demand, or both. The prognosis for patients with angina depends on the extent and severity of coronary artery disease, on left ventricular systolic function, and on the presence and severity of ischemia on exercise testing. The characteristics of angina may be variable, but certain clinical patterns are consistent and are helpful for diagnosis. Angina must be distinguished from various noncardiovascular and cardiovascular conditions; in most cases, the differences can be established by careful clinical assessment.

Stable angina pectoris: 2. Cardiac evaluation and diagnostic testing.

The examination of a patient with angina pectoris begins with clinical assessment. Certain clinical findings that are present only during angina, such as mitral regurgitation due to ischemia-induced papillary muscle dysfunction, may clarify an otherwise uncertain diagnosis. Electrocardiography is a useful and relatively inexpensive test for detecting evidence of ischemia in patients with suspected angina. The presence of cardiomegaly on the chest roentgenogram has adverse prognostic implications. Exercise stress testing is important in the diagnosis of coronary artery disease and also provides prognostic information. Patients should be classified into high-, intermediate-, or low-risk subsets by noninvasive techniques. Although relatively easy and inexpensive, treadmill exercise stress testing cannot be performed in all patients, and sometimes it will yield equivocal results. In these cases, radionuclide testing (with thallium scintigraphy or radionuclide angiography) can be helpful and also can identify high-risk patients. Some patients will require coronary angiography.