Suspicion of aortic coarctation in an outpatient clinic: How should blood pressure measurements be performed?

We conducted a study on blood pressure (BP) measurements in 40 healthy children (aged 11.0 +/- 0.4 years), in 20 healthy students (18.8 +/- 0.9 years), and in 19 children with a history of coarctation (9.3 +/- 4.0 years). Both a standard sphygmomanometer and an oscillometric device (Dinamap, Critikon Inc, Tampa, FL, USA) were used. BP measurements in the arms, thighs and ankles were performed according to a fixed protocol. Although the site of measuring was switched each time successive measurements in the same limb resulted in lower systolic values than the first measurement. In patients with coarctation all gradient estimates correlated well with each other and with the gradient estimates obtained by Doppler-echocardiography. In healthy children, the systolic BP measured by Dinamap was 2 mmHg lower in the right arm than in the thighs, and 12 mmHg lower than in the ankles. In young adults, the differences were 12 and 16 mmHg, respectively. The BP difference between the right arm and the thighs by sphygmomanometer was +4 mmHg in children and -4 mmHg in adults. The cut point value to warrant further examinations was similar with both methods: 5-10 mmHg higher readings in the arm than in the leg. The first BP measurement should be ignored. After that, repetitive measurements in the arm with the higher systolic BP and the legs should be performed.