Echocardiography in the management of mitral valve prolapse

Effect of left ventricular remodeling after cardiac resynchronization therapy on frequency of ventricular arrhythmias

We evaluated whether cardiac resynchronization therapy affects the prevalence of ventricular tachycardia in relation to reverse remodeling in patients with end-stage heart failure. Clinical, echocardiographic, and implantable cardioverter-defibrillator (ICD) data of 17 patients with ICDs were obtained before and after they had received an upgrade to an ICD-cardiac resynchronization therapy device.

Accuracy and cost- and time-effectiveness of digital clip versus videotape interpretation of echocardiograms in patients with valvular disease

BACKGROUND

Although digital and videotaped images are known to be comparable for the evaluation of left ventricular function, their relative accuracy for assessment of more complex anatomy is unclear. We sought to compare reading time, storage costs, and concordance of video and digital interpretations across multiple observers and sites.

METHODS

One hundred one patients with valvular (90 mitral, 48 aortic, 80 tricuspid) disease were selected prospectively, and studies were stored according to video and standardized digital protocols. The same reviewer interpreted video and digital images independently and at different times with the use of a standard report form to evaluate 40 items (e.g., severity of stenosis or regurgitation, leaflet thickening, and calcification) as normal or mildly, moderately, or severely abnormal. Concordance between modalities was expressed at kappa. Major discordance (difference of >1 level of severity) was ascribed to the modality that gave the lesser severity. CD-ROM was used to store digital data (20:1 lossy compression), and super-VHS videotape was used to store video data. The reading time and storage costs for each modality were compared.

RESULTS

Measured parameters were highly concordant (ejection fraction was 52% +/- 13% by both). Major discordance was rare, and lesser values were reported with digital rather than video interpretation in the categories of aortic and mitral valve thickening (1% to 2%) and severity of mitral regurgitation (2%). Digital reading time was 6.8 +/- 2.4 minutes, 38% shorter than with video (11.0 +/- 3.0, range 8 to 22 minutes, P <.001). Compressed digital studies had an average size of 60 +/- 14 megabytes (range 26 to 96 megabytes). Storage cost for video was A$0.62 per patient (18 studies per tape, total cost A$11.20), compared with A$0.31 per patient for digital storage (8 studies per CD-ROM, total cost A$2.50).

CONCLUSION

Digital and video interpretation were highly concordant; in the few cases of major discordance, the digital scores were lower, perhaps reflecting undersampling. Use of additional views and longer clips may be indicated to minimize discordance with video in patients with complex problems. Digital interpretation offers a significant reduction in reading times and the cost of archiving.

Echocardiographic evaluation of patients with acute rheumatic fever and rheumatic carditis

BACKGROUND

Cardiac involvement is the most important component of acute rheumatic fever. The role of echocardiography in the evaluation of rheumatic carditis has not been adequately defined. We used echocardiography in a large sample of patients with acute rheumatic fever to describe morphological abnormalities associated with rheumatic carditis and to assess its role in the diagnosis of rheumatic carditis.

METHODS AND RESULTS

Cross-sectional and color Doppler echocardiographic examination was performed in 108 consecutive patients with acute rheumatic fever within 24 to 48 hours of diagnosis. Twenty-eight patients had acute rheumatic fever without clinical evidence of carditis (group 1). Thirty-five patients had a presumed first episode of rheumatic carditis (group 2), and 45 patients had a recurrence of carditis (group 3). Patients in group 1 did not demonstrate any evidence of valvular regurgitation. Mitral regurgitation was the most common Doppler echocardiographic feature in groups 2 (94%) and 3 (84%). Valvular thickening with or without restriction of leaflet mobility was frequently seen in rheumatic carditis. One of every 4 patients with rheumatic carditis demonstrated echocardiographic presence of focal valvular nodules. These nodules were found on the body and the tips of the mitral valve leaflets and disappeared on follow-up. Ventricular dilatation (group 2, 54%; group 3, 74%) and restriction of leaflet mobility (group 3, 37%) were common mechanisms of mitral regurgitation in rheumatic carditis; valve prolapse (group 2, 9%; group 3, 16%) and annular dilatation (group 2, 12%; group 3, 21%) were infrequent. The majority of patients with rheumatic carditis had normal left ventricular systolic function. Congestive heart failure (group 2, 17%; group 3, 40%) was invariably associated with the presence of hemodynamically significant valve lesions. On follow-up, no patient in group 1 developed valvular regurgitation. In group 2 patients, a progressive decrease in left ventricular dimensions was observed without any change in ventricular fractional shortening. Valvular regurgitation remained unchanged in 69% of patients, decreased in 22%, and disappeared in 9%.

CONCLUSIONS

In patients with rheumatic carditis, the mitral valve is most often involved and mitral regurgitation is the most common finding on color flow imaging. Mitral regurgitation in rheumatic carditis is related to ventricular dilatation and/or restriction of leaflet mobility. Rheumatic carditis does not result in congestive heart failure in the absence of hemodynamically significant valve lesions. In a quarter of patients with rheumatic carditis, we observed valve nodules that may represent echocardiographic equivalents of rheumatic verrucae. Our study failed to reveal any incremental diagnostic utility of echocardiography and Doppler color flow imaging in rheumatic fever without clinical evidence of carditis.

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.