Evaluation of asymptomatic heart murmurs
| Citation | Study group | Study type (level of evidence) | Outcome | Key result | Comments |
|---|---|---|---|---|---|
| Smythe et al (1990) | 161 children aged 1 month to 17 years with asymptomatic heart murmur referred to paediatric cardiologist | Prospective cohort (level 2b) Reference standard was echocardiography | Correct identification of a pathologic heart murmur after clinical evaluation & then ECG | ECG led to no change in diagnosis Clinical evaluation: Sensitivity = 96% Specificity = 95 % PPV = 88% NPV = 98% LR+ =19.2 LR− =0.04 | Prevalence of heart murmur: up to 50% of paediatric population Paediatric cardiologist evaluating patients & ECG Independent reference standard ECHO applied to all but not blinded |
| Birkebaek et al (1995) | 100 children aged 1 month to 15 years with asymptomatic heart murmur referred to general paediatrician | Prospective cohort (level 2b) Reference standard was echocardiography | Correct diagnosis of heart murmur after clinical evaluation then ECG & CXR | 3 abnormal ECGs all evaluated to have heart disease after clinical evaluation CXR: Sensitivity = 43% Specificity = 82% PPV=42% NPV= 83% LR+ = 2.36 LR− = 0.70 | Independent reference standard ECHO applied blindly to all patients No prevalence for heart murmurs given |
| Birkebaek et al (1999) | 100 children aged 1 month to 15 years with asymptomatic heart murmur referred to general paediatrician | Prospective cohort (level 2b) | Accuracy of chest x ray evaluation by paediatric radiologists | Mean intra-observer k value: All films = 0.452 Normal films = 0.320 Abnormal films = 0.595 Mean inter-observer k value: All films = 0.282 Normal films = 0.106 Abnormal films = 0.531 | Same cohort of patients as in above paper Interpretation of chest x ray by a paediatric radiologist is only poorly to moderately reproducible |
| Temmerman et al (1991) | 284 children referred to paediatric cardiologist for cardiology evaluation aged 0.5–17 years (nearly all heart murmurs) | Prospective cohort (level 3b) Reference standard was echocardiography | Correct diagnosis of a heart murmur after clinical evaluation & then CXR | CXR led to diagnosis of heart disease in 2.8% of patients diagnosed with normal heart after primary evaluation In 2.8% of patients with a diagnosis of heart disease after 1st evaluation CXR led to a change in diagnosis to no heart disease | No prevalence given for heart murmurs Not specified asymptomatic heart murmurs CXR not performed in all referred patients Reference standard ECHO not applied to all patients |
| Swenson et al (1997) | 106 children aged 1 month to 14 years with heart murmur or chest pain, referred to paediatric cardiologist | Prospective cohort (level 4) Reference standard was echocardiography | Correct diagnosis of heart murmur after clinical evaluation then ECG & CXR | 4 patients evaluated normal heart, diagnosed heart disease on basis of ECG & CXR 3 patients ECG & CXR misled diagnosis | ECHO only applied to 45/106 patients Patients included with chest pain ?skewed results as higher proportion of abnormal ECGs than previous studies |
| Rajakumar et al (1999) | 128 children aged 1 month to 18 years referred to paediatric cardiologist with a heart murmur | Prospective cohort study (level 4) Reference standard was echocardiography | Correct diagnosis of heart murmur by general paediatrician compared to paediatric cardiologist after clinical evaluation then ECG & CXR | General paediatricians clinical evaluation alone/after ECG & CXR Sensitivity = 79%/82% Specificity = 55%/54% PPV = 39%/39% NPV = 88%/89% LR+ = 1.76/1.78 LR− = 0.38/ 0.33 Paediatric cardiologist clinical evaluation alone/after ECG & CXR Sensitivity = 85%/88% Specificity = 77%/70% PPV = 57%/51% NPV = 93%/94% LR+ = 3.7/2.9 LR− = 0.19/ 0.17 General paediatrician: ECG & CXR helpful in 2 cases & misleading in 3 cases Paediatric cardiologists: ECG & CXR misleading in 9 cases & helpful in 5 cases | Reference standard was applied blindly to all 128 patients but 28 patients were excluded from the study (as no ECHO was performed as deemed no heart disease by paed. cardiologists) |