BJSM Repolarisation findings in black/African athletes Growing attention has been paid to ethnic-related differences in morphological and ECG features of the athlete’s heart. Notably, there are specific repolarisation patterns in black/African athletes that are normal variants and should be distinguished from abnormal findings suggestive of a pathological cardiac disorder. Figure 16 (A) Normal variant repolarisation changes in a black/African athlete characterised by domed ST segment elevation and T wave inversion in V1–V4. (B) Pathological T wave inversion and ST depression in the lateral leads. T wave inversion in V5–V6 is always an abnormal finding and requires additional testing to rule out cardiomyopathy. This figure is only reproduced in colour in the online version. As aforementioned, early repolarisation is common in athletes and usually characterised by an elevated ST segment with upward concavity, ending in a positive (upright ‘peaked’) T wave (figure 11). There is also a normal variant early repolarisation pattern found in some black/African athletes, characterised by an elevated ST segment with upward convexity (‘dome’ shaped), followed by a negative Twave confined to leads V1–V4 (figure 15). The presence of either repolarisation pattern in an asymptomatic black/African athlete does not require additional testing. Figure 17 (A) Normal variant repolarisation changes in a black/African athlete characterised by domed ST segment elevation and T wave inversion in V1–V4. (B) Pathological T wave inversion in V1–V3. Note the isoelectric ST segment. The absence of ST segment elevation prior to T wave inversion makes this ECG abnormal. Additional testing is required to rule out arrhythmogenic right ventricular cardiomyopathy. This figure is only reproduced in colour in the online version. Differentiating normal repolarisation variants from pathological findings The presence of early repolarisation and Twave inversion in the anterior leads in black/African athletes probably represents a specific, ethnically dependent adaption to regular exercise. Figure 18 (A) Normal variant repolarisation changes in a black/African athlete characterised by domed ST segment elevation and T wave inversion in V1–V4. (B) A downsloping ST segment elevation followed by T wave inversion in V1–V2 suggestive of a Brugada-pattern ECG. Note the high-take off and absence of upward convexity (‘dome’ shape) of the ST segment distinguishing this from the repolarisation variant in black/African athletes. This figure is only reproduced in colour in the online version. 32 Sport & Geneeskunde | mei 2013 | nummer 2 More than two-thirds of black athletes exhibit ST segment elevation and up to 25% show T wave inversions.12 13 However, normal repolarisation changes in black/African athletes do not extend beyond V4. Thus, T wave inversion in the lateral leads (V5–V6) is always considered as an abnormal finding and requires additional testing to rule out HCM or other cardiomyopathies (figure 16). Repolarisation variants in black/African athletes also must be distinguished from pathological repolarisation changes in the anterior precordial leads found in ARVC and Brugadapattern ECGs. In ARVC, the ST segment is usually isoelectric prior to T wave inversion, in contrast to the ‘domed’ ST segment elevation which is the hallmark feature of the normal repolarisation variant in black/African athletes (figure 17). In Brugada-pattern ECGs, the high take-off and downsloping ST segment prior to Twave inversion distinguishes this from the ‘domed’ ST segment elevation preceding the negative Twave in black/African athletes (figure 18). Pathological repolarisation changes in the anterior precordial leads suggesting either ARVC or Brugada-pattern require additional testing. Pagina 31
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