Should functional cardiac murmurs be diagnosed by auscultation or by Doppler echocardiography?

Background: For many years, cardiac auscultation has been the only availabl e method for distinguishing between functional and organic murmurs; however , a more reliable differential diagnosis can now be achieved with Doppler e chocardiography. The question remains as to whether a Doppler echocardiogra m needs to be routinely recorded in the presence of a heart murmur or wheth er the auscultatory diagnosis of a functional murmur is sufficient. Hypothesis: This prospective study attempts to answer this important questi on at a time when medical costs have to be curbed. Methods: The three cardiologists involved in this study saw 516 new patient s in their private practice over a 10-month period; of these, 321 (63.6%) u nderwent Doppler echocardiography. All patients underwent careful auscultat ion prior to echocardiography. At the end of their examinations, the cardio logists noted whether they considered the murmur to be of functional or org anic origin. Minimal mitral or aortic regurgitations of short duration and low velocity occurring on non-thickened valves were considered functional. Results: The results for cardiac auscultation and Doppler echocardiography were considered to be concordant, that is, both techniques diagnosed either a functional or organic murmur in 250 of 321 patients (77.9%). The results for cardiac auscultation and Doppler echocardiography showed a major disco rdance in just six cases (1.9%). All were mitral regurgitations of moderate severity. Conclusion: The prevalence of cardiac murmurs in the general population is very high. As echocardiography currently represents a significant proportio n of cardiac medical expenditure, it would be wise to limit the use of this technique to essential indications. This study confirms that both cardiac auscultation and Doppler echocardiography possess important limitations. Ne vertheless, it also shows that well-trained cardiologists can identify the vast majority of functional murmurs on auscultation. Better training of non specialist physicians in cardiac auscultation may help in containing medica l expenses.