Figure 4

CN. Paradiscal lesion. Always associated with the pancellular lesion, is already visible in experimental intravenous infusion of catecholamines within 5 minutes (pancellular within 10 minutes). It is formed by a unique band of hypercontraction involving 10–15 sarcomeres adjacent to an intercalated disc. The major part of the myocell is normal and this lesion shows ultrastructurally (A) a clear aspect without rhexis, thin myofibrils and Z lines (rebuilding of normal sarcomeres?) or as a band with different grade of density (B-D), often involving two myocells (C). The dense band can be see histologically (E). An hypercontracted "center" (F) induces wavyness of normal adjacent myocells seen by EM.