ANNOTATIONS

CARDIAC ARRHYTHMIA IN PREMATURE INFANTS CONGENITAL complete atrio-ventricular block excepted, there is no reason to suppose that the common cardiac arrhythmias of the early weeks of life originate in an underlying anatomical defect. Among these disorders of rhythm are premature systoles, paroxysmal supraventricular tachycardia and paroxysmal atrial flutter. Sinus arrhythmia, the physio- logical arrhythmia of childhood, does not as a rule, accompany the rapid heart rates of the earliest weeks of in fan~y.~ , However, when MORGAN and his colleagues4 made continuous electrocardiographic recordings on young infants with birth-weights under 1500 g. they found periods of sinus bradycardia, sinus arrhythmia and occasional AV nodal escape. CHURCH and others1 have now extended these observations by examining, between the ages of 16 hours and 14 weeks, thirty healthy prematures weighing 740-1,500 g. at birth. They obtained ECGS continuously recorded for periods of 6-12 hours at fortnightly intervals. These were scrutinized by a scanning device to detect disordered rhythm. Sinus bradycardia occurred in all these babies and intermittent bradycardia in 90 per cent, with heart-rates as low as 32 per minute. Two-thirds of the infants with bradycardia were found to have nodal escape, and a minority of these showed atrial and ventricular premature systoles, sinus arrest with nodal escape and varying AV block. 83 per cent of the episodes of arrhythmia took place while the infant was drowsy or asleep, while in over 25 per cent a ‘startle’ reaction war noted in the course of the arrhythmia, followed immediately by restoration of normal sinus rhythm. Among physical activities closely related to the autonomic nervous system, those involving gastro-intestinal stimulation seemed particularly likely to provoke arrhythmia. With increasing weight and age, the frequency and severity of the arrhythmias decreased, while in a group of normal newborn infants no arrhythmia was detected.

The authors argue that the probable cause of this apparently common, but until recently unsuspected, arrhythmia is immaturity of the autonomic regulation of cardiac activity and that with increasing maturity control exerted by higher cerebral centres modifies an earlier exaggerated vagal effect. The case for this feature as a reflection of immaturity of the autono- mic system in the premature is supported by comparing the very unstable fetal electro- cardiogram5 with the stable electrocardiogram of the newborn with normal birth-weight. If the authors’ theory of autonomic immaturity is correct, there may be an explanation here too for the pathological tachycardias of early infancy. They speculate on a possible connec- tion between sudden death in premature infants and cardiac arrhythmia with syncope arising from autonomic immaturity. It will take time to prove this point, but proof should be possible by using monitoring equipment of the type now described in a large population of premature infants. If the suspicion of CHURCH and his colleagues is correct, and a new hazard to the newborn premature has been discovered, the vitally important question would then be whether episodes of vagal arrhythmia might be prevented by means of atropine or sympathomimetic drugs. University Department of Child Health, Royal Hospital for Sick Children, Oakbank, Glasgow, C.4.

ERIC COLEMAN

REFERENCES 1. Church, S. C., Morgan, B. C., Oliver, T. K. Jr., Guntefoth, W. G. (1967) ‘Cardiac arrhythmias in

239 premature infants. An indication of autonomic immaturity? J. Pediat., 71,542.

DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY. 1968, 10

2. Coleman, E. N. (1961) ‘Time intervals in the electrocardiogram of healthy infants.’ Acra paediut.

3 . Lincoln, E. M., Nicholson, G . H. B. (1928) ‘The hearts of normal children. 111: Electrocardiographic (Uppsala), 50,377.

records.’ Amer. J . Dis. Child.. 35. 1001. 4. Morgan, B. C., Bloom, R. S.,’Gunteroth, W. G. (1965) ‘Cardiac arrhythmias in premature infants.’

5. Swartwout, J. R., Campbell, W. E. Jr., Williams, L. G . (1961) ‘Observations on the fetal heart rate.’ Pediatrics, 35, 658.

Amer. J . Obstet. Gynec., 82, 301.

THE BENDER FACE-HAND TEST IF two tactile stimuli are applied simultaneously to different parts of the body differences in their perception may be apparent in both normal and abnormal subjects. The use of simultaneous sensory stimuli to bring to light latent sensory deficit in patients with the parietal lobe syndrome3 and hemiplegias2 is well recognised and has been variously described as sensory extinction, sensory inattention or perceptual rivalry.

BENDER and other workers1* have studied the patterns of response to both symmetrical and asymmetrical simultaneous tactile stimuli, using a clinical test known as the Face-Hand Test. There are slight differences in the technique used by different examiners, but BENDER used the following technique. A preliminary explanation consistent with the subject’s age is given. The examiner then asks him to close his eyes and lightly touches his cheek and contralateral hand simultaneously. The subject is then asked what he felt and to point to the sites stimulated. Other paired stimuli, both symmetrical and asymmetrical, are used until at least 10 trials are recorded. In testing young children the test may be performed with the eyes open. Single stimuli may be interspersed in case there is a focal sensory disorder and to disrupt the response tendency of ‘twoness’; also as a check of the child’s ability and willingness to respond.

The results of this investigation fall into three main groups : (1) Both stimuli are felt and located accurately. (2) Only one of the stimuli is felt. Bender calls this the phenomenon of sensory extinc-

tion or extinction. Sometimes the second stimulus is felt but is ‘obscured’ or ‘dulled’. The part of the body where the stimulus is perceived is said to be dominant to that where it is not, or is only faintly, perceived.

(3) One of the stimuli is erroneously located. This is called ‘displacement’. On initial testing in previously untested subjects just under half of normal adults report

the expected perception, with slightly more than half showing face d0minance.l In normal young children aged 3 to 5 years, face dominance is the rule, even after

repeated testing and even with open eyes, but there is increasing perception of double stimuli with age and by about 8 years of age 80 per cent of normal children can identify and localise asymmetrical tactile s t i m ~ l i . ~ Symmetrical stimuli are more easily localised and the normal 3-year-old has this ability well developed. Whenever extinction occurs, face dominance is found at all ages.

Adults with diffuse disease of the brain may show similar difficulties to those of young children in the perception of asymmetrical. stimuli. FINK, GREEN and BENDER^ tested 57 mentally retarded adults with chronological ages of 13 to 41 years but with mental ages of 2 years 6 months to 9 years 8 months and found that 98 per cent made an initial error and that 50 per cent made persistent errors beyond 10 trials. There was a definite relation between the persistence of errors and the mental age of the subject as measured by the Stanford-Binet test.

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