Utility of echocardiography in patients with suspected mitral valve prolapse

Past and Present of Point-of-Care Ultrasound (PoCUS): A Narrative Review

This article aims to conduct a literature review to gain insight into point-of-care ultrasound (PoCUS). PoCUS is a rapid, accurate, non-invasive, and radiation-free imaging modality that can be used in stable and unstable patients. PoCUS can be performed parallel to physical examination, resuscitation, and stabilization; repeated exams in critical patients are essential for improving sensitivity. The review highlights how PoCUS, which was initially used to detect free intraperitoneal fluid in trauma patients, has developed into a life-saving diagnostic tool that could be utilized by treating physicians during various stages of diagnosis, resuscitation, operation, and postoperative critical care when managing sick patients. The review also notes the barriers to the widespread uptake of PoCUS in general internal medicine and the recent commercial availability of "pocket" or handheld probes that have made PoCUS more readily available. This review concludes that adopting a focused binary decision-making approach can maximize PoCUS's value in many clinical settings, including emergency departments, intensive care units, and operation theatres. Overall, the review emphasizes the importance of awareness of common indications, limitations, and strengths of this evolving and promising technology to determine its future trajectory: Providing comprehensive PoCUS training within internal medicine curriculums and supporting trainers to do so.

Utilisation and clinical efficacy of echocardiography in a regional hospital

OBJECTIVE

To determine utilisation and clinical efficacy of echocardiography in a regional setting.

DESIGN

Consecutive patients referred for echocardiography studied prospectively using a pro-forma to be completed before and after echocardiography.

SETTING

Regional hospital in New South Wales.

PARTICIPANTS

A total of 103 consecutive patients.

MAIN OUTCOME MEASURES

Utilisation and clinical efficacy of echocardiography.

RESULTS

No significant abnormalities were detected in 41.7% of patients, but unexpected abnormalities were found in 31.1%. For 60% of pretest diagnoses there was a clinically important change in diagnostic certainty following the test and changes to treatment occurred in 30.1% of patients. A total of 19 patients with neurological events underwent echocardiography but none had cardiac thrombus demonstrated although thrombus was demonstrated in additional seven.

CONCLUSIONS

Echocardiography appears to be used appropriately in our regional setting, resulting in major changes to diagnostic certainty and leading to alterations to treatments in almost one-third of patients. Education in relation to the use of echocardiography in patients with neurological events is warranted.

The clinical impact of echocardiography on antibiotic prophylaxis use in patients with suspected mitral valve prolapse

PURPOSE

To determine the impact of echocardiography on the use of antibiotic prophylaxis in patients with suspected mitral valve prolapse (MVP).

PATIENTS AND METHODS

We evaluated 147 consecutive patients who were referred for "rule out mitral valve prolapse" to a university hospital echocardiography laboratory. Chart review and phone contact were used to determine the demographic characteristics of the patients; past diagnosis of MVP, symptoms, and exam at referral; practice specialty of referring MD; echocardiographic findings; and change in prophylaxis usage as a result of the echocardiogram (ECHO). Prophylaxis was considered to be indicated if the echocardiogram demonstrated MVP with at least mild regurgitation or abnormal thickening of at least one mitral leaflet.

RESULTS

Based on the ECHO a change in antibiotic prophylaxis was indicated in 20 of 147 (14%) patients including initiation of prophylaxis in 6, and discontinuation of prophylaxis in 14. However, only 4 of 20 patients (20%) actually changed their prophylaxis habits leading to an actual yield of 4 management changes per 131 ECHOs ordered (3%). This corresponded to 1 change in management per $36,250 in hospital and physician costs. Younger age, female gender, and presence of symptoms were associated with a benign ECHO. Indications for a change in management were not significantly different between physician specialities: 18% for generalists (internal medicine and family practice), 12% for cardiologists, and 7% for other specialists, P = 0.3.

CONCLUSIONS

In patients referred for evaluation of MVP, echocardiography infrequently resulted in changes in antibiotic prophylaxis management and was associated with significant expense.

Cost-effectiveness of echocardiography for evaluation of children with murmurs

Echocardiography is widely accepted as an accurate diagnostic test to evaluate heart murmurs in children, however its costs, and the ubiquity of murmurs in children, discourage its universal application. The purpose of this article is to identify some clinical circumstances in which the cost of echocardiography is justified for the evaluation of heart murmurs in infants and children. Eight common clinical problems were selected in which a heart murmur is present and a diagnosis is called for. Effectiveness of echocardiography and less costly clinical diagnostic methods in these settings were compared. In some circumstances, echocardiography is worth the cost, because clinical evaluation is unacceptably insensitive to important disease (the premature infant with a murmur which might represent a patent ductus arteriosus, the infant with a dysmorphic syndrome and a murmur). In others, the expert clinical examination is highly accurate (the asymptomatic child with a heart murmur) and is preferred over the echocardiogram as the initial diagnostic approach on the grounds of cost. When the expert clinical examination suggests minor structural heart disease, a continuum of echocardiographic cost-effectiveness relative to the expert clinical examination exists between these extremes depending on the working diagnosis. A threshold has not yet been defined at any point on this continuum above which the public will demand the greater diagnostic detail available echocardiographically, and below which the public will refuse to accept its greater cost. Quantitative formal cost-effectiveness analysis of echocardiography for evaluation of heart murmur in infants and children is not yet feasible because the benefits of echocardiography are indirect, dependent upon the as yet unmeasured benefits of correct management of congenital heart defects. To go beyond simple comparison of efficacy of echocardiography with less costly methods, further work is required in outcomes research in congenital heart disease.

Risk of stroke with mitral valve prolapse in population-based cohort study

BACKGROUND AND PURPOSE

The purpose of this study was to clarify whether mitral valve prolapse increases the subsequent risk of stroke.

METHODS

A historical cohort study was conducted on 1079 residents of Olmsted County, Minnesota, who had an initial echocardiographic diagnosis of mitral valve prolapse between 1975 and 1989 without prior stroke or transient ischemic attack and who were followed up for first stroke occurrence.

RESULTS

There was an overall twofold increase in the incidence of stroke among individuals with mitral valve prolapse relative to the reference population (standardized morbidity ratio, 2.1; 95% confidence interval, 1.3 to 3.2). Sex, duration of follow-up from the diagnosis of mitral valve prolapse, or calendar year of initial diagnosis did not modify the association. Within the cohort of patients who were at least 35 years old at diagnosis of mitral valve prolapse, a time-dependent proportional-hazards multivariate model and a person-years analysis revealed that age, ischemic heart disease, congestive heart failure, and diabetes mellitus were important determinants for stroke when person-years of observation after mitral valve replacement were excluded. Among seven persons with mitral valve replacement, three strokes occurred in 24 person-years of follow-up. For those with an auscultatory diagnosis of mitral valve prolapse only as the indication for echocardiography (44%), the risk of stroke relative to the population was 1.0 (95% confidence interval, 0.2 to 2.9); for those with another cardiac diagnosis, the standardized morbidity ratio was 2.5 (95% confidence interval, 1.5 to 4.0).

CONCLUSIONS

Individuals with uncomplicated mitral valve prolapse did not have an increased risk of stroke, although a small increase in the risk may not have been detected.

A decision aid for referring patients with systolic murmurs for echocardiography

OBJECTIVE

To describe the practice pattern of a group of primary care providers in ordering echocardiography for healthy patients and to derive a decision aid to identify patients with systolic murmurs who have significant cardiac lesions.

DESIGN

Retrospective case review of clinical variables, including the demographic, historical, and physical examination features obtained from chart review of the physician evaluation prior to referral for echocardiography and the echocardiographic results, with both univariate and multivariate regression analyses used to identify variables predictive of positive echocardiographic outcomes and to derive a regression model.

SETTING

General internal medicine clinic in an urban major teaching hospital.

PATIENTS/PARTICIPANTS

169 patients between the ages of 18 and 55 years selected retrospectively from medical records.

MEASUREMENTS AND MAIN RESULTS

Symptoms and auscultatory findings were not predictive of positive echocardiographic outcomes among the patients referred for the test. For the patients who had systolic murmurs, a logistic regression model had three significant predictors of positive echocardiographic results: additional year of age (odds ratio: 1.08, 95% CI: 1.02-1.13; p = 0.007); male gender (odds ratio: 5.87, 95% CI: 1.99-17.3; p = 0.002); and murmur grade > or = 3 (odds ratio: 4.99, 95% CI: 1.27-19.6; p = 0.02). The receiver-operating characteristic (ROC) curve area for this model was 0.741. If women aged 35 years and less with murmur grades < or = 2 had not been referred, 47% of the echocardiographies could have been avoided while retaining a sensitivity of 90%.

CONCLUSIONS

The study suggested that healthy patients with systolic murmurs are least likely to have positive echocardiographic results when they are young and female and have murmur grades < or = 2. More careful screening of this group might make unnecessary almost half of the echocardiographies yielding negative results ordered for healthy patients with systolic murmurs.

The clinical utility of transcranial Doppler ultrasound in suspected vertebrobasilar ischemia

The impact of transcranial Doppler ultrasound (TCD) on the management of 107 consecutively referred patients with suspected vertebrobasilar ischemia was studied. Physicians who referred patients for TCD of the posterior circulation were interviewed before and after being given the results of the TCD examination. Management plans devised prior to knowledge of the TCD results were compared to those devised after TCD results were given. Management changed in 42% of the patients after TCD results were given, and there was a 58% reduction in the use of angiography (p = 0.04) and a 128% increase in the use of aspirin (p = 0.005). Changes in the use of anticoagulants and other diagnostic or therapeutic approaches were not significant. TCD appears to have a significant impact on the management of patients with suspected vertebrobasilar ischemia.