Auscultatory perception of the fourth heart sound: effects of interval form fourth to first sound (S4-S1) and aging

The accuracy and interobserver agreement in detecting the 'gallop sounds' by cardiac auscultation

STUDY OBJECTIVES

To determine the observer accuracy and interobserver agreement in identifying S4 and S3 by cardiac auscultation and whether they improve with increasing observer experience.

DESIGN

Prospective, blinded study.

SETTING

Cardiology and general internal medicine wards in a university-affiliated teaching hospital.

PATIENTS

Forty patients with a cardiac diagnosis and 6 patients without were studied.

MEASUREMENTS AND RESULTS

Two cardiologists, one general internist, three senior and two junior postgraduate internal medicine trainees, blinded to the patients' characteristics, examined the patients and documented their findings on a questionnaire. Computerized phonocardiogram was obtained in all patients as a gold standard and was interpreted by a blinded, independent cardiologist. The mean positive predictive values for S4 and S3 were 51% (range, 24 to 100%) and 71% (range, 50 to 88%), respectively. The mean negative predictive values for S4 and S3 were 82% (range, 67 to 94%) and 64% (range, 56 to 85%), respectively. The overall interobserver agreements for detecting S4 was K = 0.05 (95% confidence interval [CI], 0.01 to 0.09) and S3 was K = 0.18 (95% CI, 0.13 to 0.24). There was no apparent trend in the accuracy or interobserver agreement with regard to the level of observer experience.

CONCLUSION

The agreement between observers and the phonocardiographic gold standard in the correct identification of S4 and S3 was poor and the lack of agreement did not appear to be a function of the experience of the observers. The overall interobserver agreement for the detection of either S4 or S3 was little better than chance alone.

Electrocardiographic responses to maximal exercise during acute pericarditis and early repolarization

Exercise testing is contraindicated during active pericarditis because of the possibility of myocarditis. In a patient suspected of having ischemic heart disease, a pericardial rub appeared for the first time following a maximal exercise test, during which the elevated J-points descended to baseline. In two normal volunteer subjects with early repolarization during a maximal exercise test, the elevated J-points behaved similarly. We conclude that, contrary to previous belief, electrocardiographic exercise responses cannot distinguish between pericarditis and early repolarization.