Etiology and Diagnosis of Systolic Murmurs in Adults

Abstract

Background It is unknown whether echocardiography can provide insights into the origin of systolic murmurs and the modern value of bedside cardiovascular diagnosis. Methods The author examined 376 inpatients and compared their physical findings to transthoracic echocardiography, exploring the associations between echocardiography and systolic murmurs and investigating the diagnostic accuracy of physical examination for pathologic murmurs. Results Four echocardiographic variables predict the presence of systolic murmurs: peak aortic velocity ( P <.001); mitral regurgitation severity ( P <.001); mitral valve E-point velocity ( P = .09); and absence of pericardial effusion ( P = .09). When diagnosing murmurs, the most helpful finding is its distribution on the chest wall with respect to the 3 rd left parasternal space, a landmark that distinguishes murmurs into 6 patterns. The “apical-base” pattern indicates increased aortic velocity (likelihood ratio [LR] 9.7; 95% confidence interval [CI]; 6.7-14): a delayed carotid upstroke (LR 6.8; 95% CI; 4.0-11.5); absent S2 (LR 12.7; 95% CI; 5.3-30.4); and humming quality to the murmur (LR 8.5; 95% CI; 4.3-16.5) further increase the probability of aortic valve disease. The “broad apical” murmur pattern suggests significant mitral regurgitation (LR 6.8; 95% CI; 3.9-11.9); and the “left lower sternal” murmur pattern indicates significant tricuspid regurgitation (LR 8.4; 95% CI; 3.5-20.3): additional bedside observations refine these diagnoses. Nonetheless, this study shows that some classic physical findings are no longer accurate, that physical examination cannot reliably distinguish severe aortic stenosis from less severe stenosis, and that classic physical findings, despite having proven value, are absent in many patients with significant cardiac lesions. Conclusions In the diagnosis of systolic murmurs, physical examination has limitations but also unappreciated value. A simple system using onomatopoeia and classifying systolic murmurs into 1 of 6 patterns is diagnostically helpful.