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Objective. Wide-bandwidth electronic stethoscopy is reliable and accurate for pediatric telecardiology. We tested a much less expensive and more convenient system for the same purpose, a narrow-bandwidth telephonic stethoscope (TS). Methods. Seventy-six consecutive patients (mean age: 10.0; standard deviation: 6.5 years) in a pediatric cardiology outpatient clinic were studied. One pediatric cardiologist examined the patients with his acoustic stethoscope (AS); a second examined them within a few minutes using a remote TS. A nurse placed the TS chest piece as directed by the remote examiner via intercom, but neither video examination nor conversation with the parent/patient were permitted. Examiners independently recorded the stethoscope findings for all heart sounds, all murmurs, and heart disease (present/absent). TS accuracy was indexed using the κ statistic for TS/AS agreement and for TS agreement with auscultatory findings predicted from echocardiographic (echo) studies (N = 49). Results. TS/AS agreement was satisfactory for presence/absence of heart disease (κ = 0.63) and for organic, functional, vibratory, diastolic aortic, and diastolic pulmonic murmurs (κ range: 0.65–0.75). For other specific murmurs and all heart sounds, TS/AS agreement was either unsatisfactory (κ ≤ 0.60) or indeterminate because prevalence was 0. TS-AS agreement improved when the TS was used by the more-experienced TS examiner and with patients at least 5 years of age. When the older children were examined by the more TS-experienced examiner, the TS-echo comparison yielded κ = 0.90, raw agreement = 0.96, sensitivity = 0.94, and specificity = 1.00. Conclusions. In pediatric patients, a narrow-bandwidth telephonic stethoscope can accurately distinguish between functional and organic murmurs and thus can detect heart disease. Accuracy is greatest when the instrument is used by an experienced examiner with patients at least 5 years of age.

Cardiopulmonary function was studied at rest and during exercise in 17 patients with Fallot's tetralogy who had systemic-pulmonary anastomoses to determine the factors which limit their work capacity (Wmax) and produce their limiting symptoms. The patients stopped exercise at a mean work rate of 355 kg-M·min-1 because of dyspnea or leg pain. The average pattern observed in room air was: a fall in arterial pO2 from 64 mm Hg at rest to 47 mm Hg during exercise due to increased right-to-left shunting; alveolar hyperventilation at rest (arterial pCO2 = 31.6 mm Hg) and during exercise (arterial pCO2 = 35.2 mm Hg); a progressive fall in arterial pH during exercise to pH = 7.369; and increased levels of wasted ventilation (VD:VT = 50.6) during exercise. Wmax was directly related to pulmonary blood flow, anaerobic threshold, and O2 pulse, and inversely related to the size of right-to-left shunt during exercise. Exercise response during O2 breathing in 16 patients studied showed decreased hypoxemia, decreased acidosis, and decreased minute ventilation. These results suggest that the excessive ventilation observed in these patients when they breathed room air was partly due to a chemoreceptor drive. Exercise response in the supine posture in seven patients studied was improved with decreased dyspnea, decreased minute ventilation, and decreased wasted ventilation without changes in the right-to-left shunt. These results suggest that the excessive ventilation observed was partly due to an increased wasted ventilation. Dyspnea appeared to be related to the inappropriateness of the level of ventilation relative to the metabolic needs of exercise.

Renal artery stenosis accounts for 12% of secondary causes of hypertension1 and must be considered in the evaluation of a child with sustained hypertension. The surgical treatment for renal artery stenosis is preferably renovascular reconstruction or partial or complete nephrectomy if the former procedure is not possible.2 In recent years, percutaneous angioplasty has been performed in adult patients with renal artery stenosis with encouraging results.3,4 However, there has been little experience with this procedure in pediatric patients. This report describes the successful use of this technique in a 4½-year-old boy with recurrent hypertension following renal artery reconstruction for unilateral stenosis.