Normal Variants

Right axis deviation Tall R waves in lead Vi 

R wave in Vi + S wave in Ve 10 mm in height Accompanied right atrial abnormality 

In severe cases associated ST segment depression and T wave inversion due to strain . 

It is possible to have enlargement of both ventricles, termed biventricular hypertrophy. This can be difficult to spot as the two may cancel each other out to some degree, and the ECG may appear normal. Biventricular hypertrophy may be present if the voltage criteria for LVH is present in limb leads, with tall R waves in lead Vi (Fig. 5.14). 

When the voltage criterion for LVH exists in adults under the age of 40, this may be a normal variant and not a pathological change. Tall R waves may be found as a normal variant in  

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Ibanez L, Dimartino-Nardi J, Potau N, Saenger P (2000) Premature adrenarche — normal variant or forerunner of adult disease Endocr Rev, 21 671-696. 

Unless specifically contraindicated the pupils of both eyes should be dilated rather than dilating only one eye for initial examinations. Failure to dilate the pupil of the contralateral eye can cause diagnostic errors because lesions considered to be normal variants frequently occur bilaterally. In addition, the contralateral eye can serve as a control, or normal eye, for that individual. Once a lesion has been documented, on subsequent visits the affected eye can be dilated alone, with the unaffected eye being dilated on a routine periodic basis. However, dilating one eye only could be determined by patient preference due to the Pulfrich effect. 

Normal variants Children, pertaining to black race... 

Figure 4.13 More characteristic ST-segment elevation morphologies observed in patients with ischaemic heart disease (A) and other processes (B). Type A(1) to A(6) morphologies are suggestive of acute coronary syndrome type B ST-segment elevation in other processes B(1) early repolarisation B(2) normal variant in V1 B(3) pericarditis B(4) and B(5) Brugada s syndrome (B(4) is similar to A(6)...

There are normal variants and many others clinical situations without ischaemia that present ST-segment elevation even evident (see ST-segment elevation in other clinical settings ) (p. 107). The differential diagnosis is usually easy when the elevation is evident but may be difficult when it is small (see ST-segment elevation in other clinical settings ), (p. 107)... 

The ST may be mildly elevated in VI -V2 as a normal variant presenting ascending slope of the T wave, a little convex with respect to isoelectric... 

Persistent (chronic) Q wave. Recording artefacts, normal variants (Figure 5.42) and different types of heart diseases (among them, hypertrophic cardiomyopathy (Figure 5.41) and congenital heart diseases) are included in this group. It is important to emphasise that often the duration of the Q wave is normal but its amplitude is... 

Normal variants. Q wave may be seen in VL in the vertical heart and in III in the dextrorotated and horizontalised... 

Normal variants. The R is prominent but of low voltage. These include (Bayes de Luna 1977). 

Uchida A, Moffa P, Perez-Riera A et al., 2006). On the other hand in patients without heart disease the presence of prominent R wave inVl, especially if the voltage of R is low, is much probably due to a normal variant (see Table 5.5). 

Guizton LE, Lacks MM. The differential diagnosis of acute pericarditis from normal variant new ECG criteria. Circulation 1982 65 1004. 

R17. Rudman, D., Kutner, M. H., Blackston, R. D., Cushman, R. A., Bain, R. P., and Patterson, J. H., Children with normal-variant short stature Treatment with human growth hormone for six months. N. Engjt. J. Med. 305, 123-131 (1981). 

Polymorphism One of several normal variants across the human population at a particular position in a gene or protein. 

When taking into account the frequency of categories in a dataset, a normalized variant of the above measure is defined as follows ... 

Caceres J., Mata J.M., Andreu J. (1998) The azygos lobe normal variants that may simulate disease. Eur J Radiol 27 15-20. 

Formerly this MDA was classified as the mildest form of either a bicornuate or septate uterus. In 1988, the American Fertility Society issued a separate classification of arcuate uterus. Arcuate uterus should be considered a normal variant and it has no effect on fertility. 

Accessory ossicle - Small supernumerary bone found at characteristic sites as normal variants. They occur most commonly in the carpus, foot and ankle and vary in size. Typically a round, well corticated separate nodule of ossification adjacent to bone formed by the primary or secondary ossification centre. These may he mistaken for avulsion or chip fractures. Occasionally an accessory ossicle may fuse with the adjacent hone. These ossicles are usually of no clinical significance although they can occasionally cause pain. Some may be the result of previous trauma. 

The ossification centres for the proximal femur consist of the capital femoral epiphysis, and ossification centres in the greater and lesser trochanters. The capital femoral epiphysis may be cleft or bifid as a normal variant. During development the ossification centres for the greater and lesser trochanters are irregular and often appear separated from the neck and proximal femoral shaft (Fig. 7.30). The distal femoral epiphysis increases rapidly in width between the second and sixth years of life. Irregularity of the lateral and medial margins of the epiphysis is... 

Fig. 19.24. Pseudoepiphysis at the distal thumb metacarpal (arrow), a common normal variant...

In this chapter, the anatomy, normal variants and injuries to the paediatric spine are discussed with emphasis on the role of imaging and the concept of stability. 

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