ACC/AHA guidelines for the clinical application of echocardiography. A report of the American College of Cardiology/American Heart Association Task Force on Assessment of Diagnostic and Therapeutic Cardiovascular Procedures (Subcommittee to Develop Guidelines for the Clinical Application of Echocardiography)

Echocardiographic Assessment of the Left Ventricle in Young Prehypertensive Nigerians

BACKGROUND

 Prehypertension is associated with an increased risk of cardiovascular morbidity and mortality. This risk could partly be explained by the early compromise in left ventricular (LV) structure and function. This study investigated the LV geometry and function in young black prehypertensive subjects.

METHODS AND RESULTS

This cross-sectional descriptive study was conducted at the Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria. Echocardiography-derived LV geometry and function were assessed using standardized methods. Prehypertensive subjects had higher mean systolic blood pressure (BP) (130.78 ± 3.57 mmHg vs 111.42 ± 3.54 mmHg, P<0.001), diastolic BP (79.32 ± 4.13 mmHg vs 66.39 ± 4.42 mmHg, P<0.001), body mass index (BMI) (26.24 ± 3.45 kg/m2 vs 22.20 ± 2.21 kg/m2, P<0.001), waist circumference (WC) (86.93 ± 8.73 cm vs 76.73 ± 6.66 cm, P<0.001), fasting blood glucose (FBG) (93.84 ± 7.28 mg/dl vs 90.08 ± 6.26 mg/dl, P<0.001), and dyslipidemia (21.5% vs 6%. P<0.001) compared to normotensive subjects. LV mass index (LVMI) was greater in prehypertensive subjects compared to normotensive subjects {male (106.84 ± 12.34 g/m2 vs 76.07 ± 10.25 g/m2, P<0.001); female (92.06 ± 8.80 g/m2 vs 66.53 ± 7.21 g/m2, P<0.001)}, with abnormal LV geometry recorded in 17.5%. Linear regression analysis showed that waist circumference, systolic BP, serum creatinine level, and urea level were determinants of LVMI. The prevalence of LV diastolic dysfunction was higher in prehypertensive subjects than in normotensive subjects (14.5% vs. 0.5%, P<0.001), with systolic BP {odds ratio (OR) 0.928, confidence interval (CI) 0.834 - 0.969; P=0.016)} and diastolic BP (OR 0.832, CI 0.722 - 0.958; P=0.011) being independent predictors.

CONCLUSION

 This study showed that prehypertension in young Black subjects was associated with altered LV geometry and impaired diastolic function, and these changes demonstrated linear progression with increasing systolic BP.

Initial Right Ventricular Dysfunction Severity Identifies Severe Peripartum Cardiomyopathy Phenotype With Worse Early and Overall Outcomes: A 24-Year Cohort Study

BACKGROUND

Outcomes in peripartum cardiomyopathy (PPCM) vary. We sought to determine whether severity of left or right ventricular dysfunction (RVD) at PPCM diagnosis differentially associates with adverse outcomes.

METHODS AND RESULTS

We conducted a single-center retrospective cohort study of 53 patients with PPCM. The primary outcome was a composite of left ventricular assist device implantation, cardiac transplantation, or death. We used Kaplan-Meier curves to examine event-free survival and Cox proportional hazards models to examine associations of left ventricular (LV) ejection fraction <30%, LV end-diastolic diameter ≥60 mm, and moderate-to-severe RVD at PPCM diagnosis with the primary outcome. Median (interquartile range) follow-up time was 3.6 (1.4-7.3) years. Seventeen patients (32%) experienced the primary outcome, of whom 11 had moderate-to-severe RVD at time of PPCM diagnosis. Overall event-free survival differed by initial RVD severity and LV ejection fraction <30%, but not by LV end-diastolic diameter ≥60 mm. In univariable analyses, LV ejection fraction <30% and moderate-to-severe RVD were associated with the outcome (hazard ratios [95% confidence intervals] of 4.85 [1.11-21.3] and 4.26 [1.47-11.6], respectively). In a multivariable model with LV ejection fraction <30%, LV end-diastolic diameter ≥60 mm, and moderate-to-severe RVD, only moderate-to-severe RVD was independently associated with the outcome (hazard ratio [95% confidence interval], 3.21 [1.13-9.10]). Although most outcomes occurred within the first year, nearly a third occurred years after PPCM diagnosis.

CONCLUSIONS

Initial moderate-to-severe RVD is associated with a more advanced cardiomyopathy phenotype and increased risk of adverse outcomes in PPCM, within and beyond the first year of diagnosis. By identifying a worse PPCM phenotype, initial moderate-to-severe RVD may prompt earlier consideration of advanced heart replacement therapies.

Assessing the appropriateness of coronary revascularization: the University of Maryland Revascularization Appropriateness Score (RAS) and its comparison to RAND expert panel ratings and American College of Cardiology/American Heart Association guidelines with regard to assigned appropriateness rating and ability to predict outcome

BACKGROUND

Significant regional variation in procedural frequencies has led to the development of the RAND and American College of Cardiology/American Heart Association (ACC/AHA) guidelines; however, they may be difficult to apply in clinical practice. The University of Maryland Revascularization Appropriateness Score (RAS) was created to address the need for a simplified point scoring system.

HYPOTHESIS

The study was undertaken to compare revascularization appropriateness ratings yielded by the RAND Expert Panel Ratings, ACC/AHA guidelines, and the University of Maryland RAS.

METHODS

We applied these three revascularization appropriateness scoring systems to 153 catheterization laboratory patients with a variety of cardiac diagnoses and treatments. For each patient, appropriateness scores assigned by each of the three systems were compared with each other and with the actual treatment delivered. Concordance of care with appropriateness score was then correlated with outcome.

RESULTS

There were significant differences among all three scoring systems in their ratings and in the concordance of treatment with appropriateness rating. When treatment provided was concordant with RAND ratings, there was a lower occurrence of subsequent coronary artery bypass grafting (CABG), the composite end point of either CABG or percutaneous transluminal coronary angioplasty (PTCA), and the composite end point of death, myocardial infarction (MI), or revascularization. When treatment was concordant with the ACC/AHA guidelines, there was lower occurrence of all-cause mortality, PTCA, the composite end point of either CABG or PTCA, and the composite end point of death, MI, or revascularization. When treatment provided was concordant with the RAS, there was lower occurrence of cardiac death, all-cause death, CABG, the composite end point of either CABG or PTCA, and the composite end point of death, MI, or revascularization.

CONCLUSIONS

The RAS is a simple scoring system to assess revascularization appropriateness. When the RAND, ACC/AHA, and RAS systems are compared in a catheterization laboratory population, they rate the same patient differently and vary in their correlation of appropriateness rating with outcome.

Nonmyocardial production of ST2 protein in human hypertrophy and failure is related to diastolic load

OBJECTIVES

This study was designed to investigate: 1) relationships between serum ST2 levels and hemodynamic/neurohormonal variables; 2) myocardial ST2 production; and the 3) expression of ST2, membrane-anchored ST2L, and its ligand, interleukin (IL)-33, in myocardium, endothelium, and leukocytes from patients with left ventricular (LV) pressure overload and congestive cardiomyopathy.

BACKGROUND

Serum levels of ST2 are elevated in heart failure. The relationship of ST2 to hemodynamic variables, source of ST2, and expression of ST2L and IL-33 in the cardiovascular system are unknown.

METHODS

Serum ST2 (pg/ml; median [25th, 75th percentile]) was measured in patients with LV hypertrophy (aortic stenosis) (n = 45), congestive cardiomyopathy (n = 53), and controls (n = 23). ST2 was correlated to N-terminal pro-brain natriuretic peptide, C-reactive protein, and hemodynamic variables. Coronary sinus and arterial blood sampling determined myocardial gradient (production) of ST2. The levels of ST2, ST2L, and IL-33 were measured (reverse transcriptase-polymerase chain reaction) in myocardial biopsies and leukocytes. The ST2 protein production was evaluated in human endothelial cells. The IL-33 protein expression was determined (immunohistochemistry) in coronary artery endothelium.

RESULTS

The ST2 protein was elevated in aortic stenosis (103 [65, 165] pg/ml, p < 0.05) and congestive cardiomyopathy (194 [69, 551] pg/ml, p < 0.01) versus controls (49 [4, 89] pg/ml) and correlated with B-type natriuretic peptide (r = 0.5, p < 0.05), C-reactive protein (r = 0.6, p < 0.01), and LV end-diastolic pressure (r = 0.38, p < 0.03). The LV ST2 messenger ribonucleic acid was similar in aortic stenosis and congestive cardiomyopathy versus control (p = NS). No myocardial ST2 protein gradient was observed. Endothelial cells secreted ST2. The IL-33 protein was expressed in coronary artery endothelium. Leukocyte ST2L and IL-33 levels were highly correlated (r = 0.97, p < 0.001).

CONCLUSIONS

In human hypertrophy and failure, serum ST2 correlates with the diastolic load. Though the heart, endothelium, and leukocytes express components of ST2/ST2L/IL-33 pathway, the source of circulating serum ST2 is extra-myocardial.

Early Detection of Left Ventricular Dysfunction by Doppler Tissue Imaging and N-terminal Pro-B-type Natriuretic Peptide in Patients with Symptomatic Severe Aortic Stenosis

BACKGROUND

Patients with severe aortic stenosis (AS) require valve replacement before development of irreversible left ventricular (LV) dysfunction. It has been postulated that Doppler tissue imaging (DTI) parameters are more sensitive to detect subtle LV dysfunction compared with conventional echocardiographic parameters.

OBJECTIVE

We sought to assess early LV dysfunction with DTI-derived echocardiographic parameters and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with severe AS and normal LV ejection fraction.

METHODS

A total of 29 patients (mean age 65 +/- 12 years, 15 male) with symptomatic severe AS and 17 control subjects were included in the study. DTI was performed at the level of the mitral lateral (m(lat)) and septal (m(sep)) annulus. Systolic (Sm), early (Em), and late (Am) diastolic velocities were measured, and E/Em ratio was calculated. NT-proBNP was determined by an electrochemiluminescence immunoassay.

RESULTS

Baseline characteristics between patients and control subjects were similar regarding LV ejection fraction and mitral inflow E/A ratio. However, patients with AS had significantly lower DTI values (Sm, Em, Am) compared with control subjects. Moreover, LV filling pressures, expressed by the E/Em ratio, were significantly higher in patients. Correlation analysis showed a relationship between the natural logarithm of NT-proBNP and aortic valve area, Sm(lat), and E/Em((sep)) ratio. Using stepwise multiple linear regression, Sm(lat) was found to be independently related to NT-proBNP.

CONCLUSIONS

In patients with severe AS and normal LV ejection fraction, DTI showed LV systolic and diastolic dysfunction compared with control subjects. DTI-derived variables, and especially Sm(lat), were correlated with NT-proBNP levels.

Cardiomyocyte apoptosis is related to left ventricular dysfunction and remodelling in dilated cardiomyopathy, but is not affected by growth hormone treatment

BACKGROUND AND AIMS

Cardiomyocyte apoptosis (CA) is a common feature of end-stage heart failure. We examined whether CA is associated with cardiac dysfunction and remodelling in heart failure due to dilated cardiomyopathy and studied the effect of human growth hormone (hGH) on CA.

METHODS AND RESULTS

We studied 38 patients, included in a phase III multi-center, randomised, double-blind and placebo-controlled trial of biosynthetic hGH treatment in dilated cardiomyopathy, at baseline and after 14 weeks treatment. Twenty-six patients received hGH and 12 received placebo. CA was quantified in endomyocardial biopsies using the TUNEL assay. CA correlated with left ventricular size (r=0.43, p=0.007). Compared to patients with CA below the median of 0.53%, patients with CA above the median had significantly larger left ventricular volumes and lower ejection fractions (EF) by echocardiography (median (interquartile range)) 200 ml (84) vs. 257 ml (134) and 27% (11) vs. 23% (9). Expression of the Fas receptor was associated with a high rate of CA. hGH treatment significantly increased serum IGF-1 levels, but it had no effect on CA or cardiac structure and function.

CONCLUSION

CA is related to left ventricular enlargement and dysfunction in dilated cardiomyopathy. CA is not affected by short-term treatment with hGH.

A Pilot Study of the Clinical Impact of Hand-Carried Cardiac Ultrasound in the Medical Clinic

BACKGROUND

Small, hand-carried ultrasound devices have become widely available, making point-of-care echocardiograms (echos) accessible to all medical personnel as a means to augment and improve the increasingly inefficient physical examination. This study was designed to determine the clinical utility of hand-carried echo by medical residents in clinical decision making.

METHODS

Nine residents underwent brief, practical echo training to perform and interpret a limited hand-carried echo as an integral component of their office examination. The residents' hand-carried echo consisting of four basic views to define left ventricular (LV) function and wall thickness, valvular disease, and any pericardial effusions was compared to one performed by a level III echocardiographer.

RESULTS

Seventy-two consecutive medical clinic patients were enrolled with an average image acquisition time of 4.45 minutes. Residents obtained diagnostic images in 94% of the cases and interpreted them correctly 93% of the time. They correctly identified 92% of the major echo findings and 78% of the minor findings. Their diagnosis of LV dysfunction, valvular disease, and LV hypertrophy improved by 19%, 39%, and 14% with hand-carried echo compared to history and physical alone. Management decisions were reinforced in 76% and changed in 40% of patients with the use of hand-carried echo.

CONCLUSION

This study demonstrates that it is possible to train medical residents to perform an effective and reasonably accurate hand-carried echo during their physical examination, which can impact clinical management.

Cardiac Resynchronization Therapy Delays Heart Transplantation in Patients With End-stage Heart Failure and Mechanical Dyssynchrony

BACKGROUND

Cardiac dyssynchrony is frequent in advanced heart failure, and cardiac resynchronization therapy (CRT) may offer an alternative to heart transplantation. We aimed to investigate the impact of CRT on freedom from Tx and death in transplant candidates with end-stage heart failure.

METHODS

Over a period of 2 years, 46 consecutive patients with refractory congestive heart failure due to dilated cardiomyopathy were referred for heart transplant evaluation. Patients with cardiac dyssynchrony > 107 milliseconds according to tissue Doppler imaging (TDI) or QRS duration > 150 milliseconds were treated with CRT (CRT group, n = 24), whereas patients without dyssynchrony were not treated (non-CRT group, n = 22).

RESULTS

At baseline, both groups showed similar hemodynamic and functional parameters, including ejection fraction (19 +/- 10% vs 21 +/- 12%, not statistically significant [NS]) and Vo2max (11.9 +/- 2.0 vs 12.0 +/- 1.8 ml/kg/min, NS). After a follow-up of 488 +/- 346 days, cumulative survival with freedom from transplantation and death was higher in CRT vs non-CRT patients (92% vs 39%; p < 0.001). CRT patients showed a decrease in New York Heart Association (NYHA) class from 3.2 +/- 1.1 to 2.2 +/- 0.9 (p = 0.003) and an increase in Vo2max from 11.9 +/- 2.0 to 13.1 +/- 1.8 ml/kg/min (p = 0.02), and 71% (17 of 24) of these patients were successfully removed from the waiting list.

CONCLUSIONS

In heart transplant candidates with significant dyssynchrony, CRT delays heart transplantation and improves NYHA class and exercise capacity. For these patients, CRT should be considered before heart transplantation.

Immediate and late outcomes of patients undergoing transseptal left-sided heart catheterization for symptomatic valvular and arrhythmic diseases

BACKGROUND

The transseptal technique has been widely used for diagnostic and therapeutic left-sided heart catheterization. However, its differential immediate and late outcomes among patients with various valvular and arrhythmic diseases are not yet determined.

METHODS

Beginning from 1993, all patients undergoing transseptal procedures were screened and categorized into diagnosis, arrhythmia, and valvuloplasty groups according to the purposes of the catheterization. Incidences of transseptum-related acute major events (cardiac perforation, embolic stroke, and bradyarrhythmia during the procedure) and late complications (residual atrial septal defect [ASD], embolic stroke, bradyarrhythmia, and death up to 18 months) were analyzed and compared between groups.

RESULTS

From January 1993 to May 2003, a total of 176 patients underwent 184 transseptal procedures for diagnosis of valvular heart diseases (n = 8), catheter ablation of arrhythmogenic foci (n = 29), and mitral valvuloplasty (n = 147). The immediate outcome was similar among the 3 groups, with an overall acute complication incidence of 3.8%. At follow-up, the incidences of bradyarrhythmia, embolic stroke, and death were not different among the 3 groups. Patients undergoing valvuloplasty had a significantly higher prevalence of residual ASD, especially for those with more severe mitral stenosis and less valvuloplasty success. However, presence of ASD did not impose disadvantage over the 1.5-year prognosis.

CONCLUSION

Transseptal left-sided heart catheterization can be safely applied to patients with different categories of cardiac diseases with comparably good immediate and late outcomes. Although patients undergoing percutaneous valvuloplasty have a higher chance of permanent ASD creation, their prognosis is not influenced.

Transesophageal echocardiography discloses unexpected cardiac sources of embolus in stroke patients aged more than 45 years

Cerebral embolism from cardiac source is an important cause of stroke, specially in patients younger than 45 years old. OBJECTIVE: To describe the transesophageal echocardiography (TEE) findings in young and non-young stroke patients without any prior evidence of cardiac source for cerebral embolism. METHOD: Transversal study: 523 patients (267 men and 256 women) with ischemic stroke, without any evidence of cardiac abnormality, underwent to TEE. RESULTS: Ten percent were aged 45 years; or less. Left ventricle hypertrophy, left atrial enlargement, spontaneous contrast in aorta, interatrial septum aneurysm, mitral and aortic valve calcification, aortic valve regurgitation, and atherosclerotic plaques in aorta were significantly more frequent in patients aged more than 45 years; 2.8% of non-young patients had thrombus in left heart. CONCLUSION: TEE is widely used to diagnose cardiac source of cerebral embolism in young patients, but it seems to be as useful for older ones, in whom cerebral embolism risk is underestimated; atherogenic and cardioembolic causes may actually coexist, and both should be treated.

Wall stress modulates brain natriuretic peptide production in pressure overload cardiomyopathy

OBJECTIVES

We postulated that both diastolic and systolic load modulate B-type natriuretic peptide (BNP) production in human pressure overload hypertrophy/failure.

BACKGROUND

In isolated myocytes, diastolic stretch induces BNP messenger ribonucleic acid expression. However, the mechanism of the BNP release in human hypertrophy remains controversial.

METHODS

In 40 patients with symptomatic aortic stenosis (AS), left ventricular (LV) performance and systolic and diastolic wall stress were calculated from combined invasive and echocardiographic data. Plasma BNP was determined by the rapid point-of-care bedside analyzer (Biosite Triage, Biosite Diagnostics Inc., San Diego, California).

RESULTS

A significant relationship was observed between plasma BNP and pulmonary capillary wedge pressure (p < 0.001), fractional shortening (p = 0.001), and aortic valve area (p = 0.006). Furthermore, a significant correlation was noted between BNP and LV mass index (p = 0.005) as well as between BNP and markers of diastolic load such as LV end-diastolic wall stress (p = 0.011), indexed LV end-diastolic volume (p < 0.001), and isovolumic relaxation time (p = 0.02). Preoperative BNP levels were elevated in patients with AS compared with patients without AS. Plasma BNP was higher in AS patients with impaired versus normal preload reserve (297 +/- 56 pg/ml vs. 168 +/- 44 pg/ml; p = 0.017) and in AS patients with clinical deterioration after valve replacement compared with those without (399 +/- 82 pg/ml vs. 124 +/- 41 pg/ml; p = 0.011).

CONCLUSIONS

In patients with AS, BNP appears to be regulated not only by systolic but also by diastolic load. This supports the hypothesis that myocardial stretch modulates BNP production in human pressure overload hypertrophy/failure.

Hemodynamic effects of inducible nitric oxide synthase and nitrotyrosine generation in heart failure

OBJECTIVES

The hemodynamic effects of cardiac inducible nitric oxide synthase (iNOS) and of iNOS-mediated peroxynitrite in patients with left ventricular (LV) dysfunction are unclear. The present study investigates the incidence and functional significance of iNOS expression and nitrotyrosine formation in patients with heart failure.

METHODS

LV endomyocardial biopsies obtained from 24 patients with heart failure due to idiopathic dilated cardiomyopathy (ejection fraction [EF] <45% and left ventricular end-diastolic volume index [LVEDVI] >102 ml/m2) were analyzed for iNOS and nitrotyrosine. LV contractile performance was assessed by left ventricular ejection fraction (LVEF) and stroke work normalized for end-diastolic pressure (SW/EDP). LV filling pattern was assessed by Doppler E/A wave ratio, deceleration time (DT) of early LV filling and indexed LV end-diastolic volume normalized for EDP as a marker of diastolic distensibility.

RESULTS

iNOS immunostaining correlated significantly with nitrotyrosine formation (r = 0.86, p < 0.001). In the whole study group, patients expressing iNOS (n = 13) showed larger LV end-diastolic (173 +/-16 vs 128 +/- 9 ml/m2, p = 0.031) and end-systolic volume indices (110 +/- 16 vs 61 +/- 9 ml/m2, p = 0.018) and similar LVEDP (18 +/- 2 vs 21 +/- 2 mm Hg, p = 0.227). In patients with advanced heart failure and reduced pre-load reserve (LVEDP > 16 mm Hg, n = 18), iNOS protein and nitrotyrosine formation correlated positively with LVSW/EDP (r = 0.65, p = 0.03 and r = 0.64, p = 0.04, respectively), DT (r = 0.96, p < 0.01 and r = 0.88, p < 0.01, respectively) and inversely with E/A (r = -0.82, p < 0.01 and r = -0.88, p < 0.01, respectively). In addition, nitrotyrosine formation correlated positively with LVEDVI/EDP (r = 0.64, p = 0.02). Advanced iNOS-positive heart failure patients had a higher LVEDVI/EDP compared with iNOS-negative patients (5.30 +/- 0.64 vs 3.13 +/- 0.34 ml/mm Hg x m2, p = 0.02).

CONCLUSIONS

In heart failure, iNOS protein expression is associated with nitrotyrosine formation. Although iNOS-positive patients are generally characterized by larger LV volume and depressed function, the preserved NO generation appears to be associated with higher cardiac work due to the preserved Frank-Starling relationship in end-stage heart failure.

Can hand-carried ultrasound devices be extended for use by the noncardiology medical community?

Echocardiography (echo) is a powerful, noninvasive, inexpensive diagnostic imaging technique that provides important information in a variety of cardiovascular diseases. Echo provides rapid information regarding ventricular and valvular function in the clinical management of patients. Smaller, relatively inexpensive hand-carried cardiac ultrasound (HCU) devices have become commercially available, which can be used for diagnostic cardiac imaging. Because of their relative ease of use, portability, and affordable cost, these new hand-held systems have made point-of-care (bedside) echocardiography available to all medical personnel. The rate-limiting step to the widespread use of this technology is the lack of personnel with echo training at the immediate contact point with patients. Although extensive training and experience are needed to acquire and interpret a complete echo, training medical personnel to perform and interpret a limited echo (defined as a brief, diagnosis focused exam) may fully exploit the potential of echo as a point-of-care diagnostic tool and may be accomplished in a short period of time. Presently there are guidelines for independent competency in echocardiography and HCU echo established by several professional organizations and as a result of these rigorous guidelines, other noncardiology medical professionals who could practically derive the greatest benefit are discouraged and virtually precluded from utilizing echo during the initial encounter with the patient. However, there is now a growing body of literature in a diverse group of noncardiology medical personnel that demonstrates that it is possible to quickly and effectively train them to perform and interpret limited echocardiograms. Medical students, medical residents, cardiology fellows with limited experience, emergency department physicians, and surgical intensive care unit staff have all been evaluated after only brief, focused training periods, and investigators found that HCU echo provided important new information, changed therapeutic management, and was vastly superior to the physical exam alone with an acceptable overall level of accuracy. The contribution of echocardiography to the field of cardiovascular disease since its invention has been significant and the newer compact, portable, ultrasound systems have the potential to revolutionize the utilization and availability of echocardiography. To maximize integration of echo into medical practice, physicians and physician extenders could be trained to perform and interpret limited echo to complement their clinical examination and improve their diagnostic skills. The challenge is to provide practical training programs to assure competency in performing point of care echocardiograms.

Hand-carried cardiac ultrasound (HCU) device: recommendations regarding new technology. A report from the Echocardiography Task Force on New Technology of the Nomenclature and Standards Committee of the American Society of Echocardiography

The newest introduction to echocardiography is a hand-carried ultrasound (HCU) device. It is a small echocardiographic machine that typically weighs less than 6 lb and can obtain echocardiographic images and data. However, neither the device nor the context of the examination fulfills the criteria for a comprehensive or complete echocardiographic examination. The American Society of Echocardiography believes that HCU will extend the concept of the "complete physical examination," allowing more rapid assessment of cardiovascular anatomy, function, and physiology. However, appropriate user-specific training (Level 1 at a minimum) and assumption of responsibility are essential to ensure the most accurate acquisition, interpretation, and use of the data.

Role of echocardiography in the evaluation and management of atrial fibrillation

This article reviews the utility of transthoracic echocardiography and transesophageal echocardiography for patients with atrial fibrillation and focuses on evidence that these diagnostic techniques can aid in the achievement of these goals. Following a brief review of common findings from each of these techniques, the relevance of specific results to the management of atrial fibrillation is assessed.

Where Does Ultrasound Stand in Technology Assessment and Outcomes Research

Although diagnostic ultrasound has been widely applied for various clinical conditions and diseases, its clinical effectiveness remains less well defined. Technology assessment can be applied to ultrasound and includes several criteria such as techologic capability, range of possible uses, diagnostic accuracy, impact on health care providers, therapeutic impact, and patient outcome. A review of each of these criteria is provided to raise sonographer awareness as to the need for further reserch in this area.

Echocardiography in the evaluation of patients with syncope

OBJECTIVE

Echocardiography is frequently used as a screening test for cardiac disease in patients with syncope despite the lack of published data describing its utility in this regard. The goal of the study was to examine the frequency with which echocardiography was used in the evaluation of patients admitted to one medical center because of syncope and to examine the diagnostic information, over and above that provided by the initial history, physical examination, and electrocardiography, contributed by the echocardiogram.

DESIGN

A retrospective review was performed of all patients admitted to the study institution because of syncope over a seven-month period.

SETTING

University teaching hospital in an urban setting of 2.5 million population.

PATIENTS/PARTICIPANTS

One hundred twenty-eight patients were identified: 47 men and 81 women (average age 67 +/- 17 years). Patients for whom syncope was of a known cause, those with near-syncope or vertigo, those with clinically obvious seizure, or those referred for electrophysiologic testing were excluded, leaving 128 patients for analysis. Details from the admission history, physical examination, and electrocardiography for each patient were recorded. The results of all other diagnostic tests ordered to evaluate syncope were recorded along with any consultations obtained. The cause of syncope was assigned by examining all physicians' notes and test results and with the use of previously published diagnostic criteria as guidelines.

MEASUREMENTS AND MAIN RESULTS

Ninety percent of the patients underwent cardiac testing other than routine electrocardiography and continuous telemetry monitoring while in the hospital. An echocardiogram was obtained for 64% of the patients and did not reveal an unsuspected cause for syncope in any case. The echocardiogram was normal for 52% of the patients undergoing the test. Echocardiograms of patients with syncope and no clinical evidence of heart disease by history, physical examination, or electrocardiography either were normal (63%) or provided no useful additional information for arriving at a diagnosis (37%). Nearly half (46%) of the patients undergoing echocardiography fit this clinical profile. Among the patients for whom cardiac disease was suspected after history, physical examination, or electrocardiography, the echocardiogram confirmed the suspected diagnosis for 48% and served to rule out a suspected diagnosis for the remaining 52%. In no instance did echocardiography provide an unsuspected cause for syncope. The history, physical examination, and initial electrocardiography provided sufficient information to permit a diagnosis to be made for 37 of the 48 patients (77%) for whom a cause of syncope was ultimately determined.

CONCLUSION

Echocardiography was frequently used in the evaluation of patients admitted to the hospital because of syncope of unclear cause. For patients without suspected cardiac disease after history, physical examination, and electrocardiography, the echocardiogram did not appear to provide additional useful information, suggesting that syncope alone may not be an indication for echocardiography. For patients with suspected heart disease, echocardiography served to confirm or refute the suspicious in equal proportions. These data provide an objective basis to prospectively define the optimal role of echocardiography in the evaluation of patients with syncope.

Is cardiac catheterization necessary in the era of echocardiography? Cost-effective approach combining echocardiography and cardiac catheterization

Definitive evaluation of cardiovascular disease is traditionally accomplished by cardiac catheterization. Advances in transthoracic and transesophageal Doppler echocardiography provides an accurate and cost-effective approach when compared to cardiac catheterization. Recent data suggests that for most adult patients with aortic or mitral valve disease, Doppler echocardiographic data enables the clinician to make the same decision reached with catheterization data. Echo and Doppler studies are useful in guiding certain therapeutic interventional procedures, and in the diagnosis of aortic dissection, mechanical complications of myocardial infarction, and in identifying aortic atheromas as a potential source of embolism. Future research will need to demonstrate that not only is echocardiography cost-effective, but that it will change the outcome of the patient.