ACCURACY OF PRECORDIAL PERCUSSION IN DETECTING CARDIOMEGALY

STUDY OBJECTIVE: To assess the value of precordial percussion in detecting cardiomegaly, and to compare it with palpation of the apical impulse. DESIGN: Descriptive study. SETTING: Hospitals and clinics of a university medical center. PATIENTS: Light indirect percussion of the precordium was performed on 72 inpatients and 28 outpatients. All patients had a posteroanterior radiograph of the chest. Percussors were unaware of the clinical history and of chest roentgenogram results. MEASUREMENTS AND MAIN RESULTS: Thirty-six patients (36%) had Cardiomegaly, defined as a cardiothoracic ratio of greater than 0.5 on chest roentgenogram. The cardiothoracic ratio was significantly correlated with percussion distance from the midsternal line in the left fourth (r = 0.35, p < 0.0006), fifth (r = 0.65, p < 0.00001), and sixth (r = 0.40, p < 0.0001) intercostal spaces. After adjustment for clinical symptoms and systolic and diastolic blood pressures, percussion distance in the left fifth intercostal space remained a significant independent predictor of the cardiothoracic ratio. Percussion distance in the left fifth interspace discriminated cardiomegaly with a receiver-operating characteristic (ROC) area of 0.95. Percussion dullness more than 10.5 cm from the midsternal line in the left fifth interspace had a sensitivity of 94.4% (95% confidence interval [CI], 79.9% to 99.0%) and a specificity of 67.2% (CI, 54.2% to 78.1%). Distance of the apical impulse from the midsternal line discriminated with an ROC area of 0.95, but an impulse was palpated in only 40% of cases. CONCLUSIONS: Percussion in the left fifth intercostal space accurately discriminates patients with and without cardiomegaly, and adds information beyond that obtainable from the history and other parts of the physical examination.