**19. Myocardial bridge**

atherosclerotic changes are known to be familial hypercholesterolemia in particular, and elevated LDL level, substance abuse, smoking, hypertension, obesity and cardiovascular events

Racemic adrenaline is a sympathomimetic drug used in Paediatric bronchiolitis and severe upper respiratory tract obstructions. Although this treatment has been used safely for many years, there is a need for heart rate and ECG monitorisation in cases administered epinephrine consecutively [55]. It has been reported that MI has developed associated with epinephrine not only in cases with racemic epinephrine but also in cases where epinephrine has been used when applying cardiopulmonary resuscitation [56]. The coronary vasospasm of epinephrine is made over alpha 1 and alpha 2 receptors. While low-dose adrenaline shows a beta mimetic effect, at high doses the effect is seen by vasoconstriction, primarily over the alpha 1 and alpha 2 receptors. As there is a relationship between epinephrine used intravenously and a higher complication rate, the selection of intramuscular or subcutaneous routes could contribute greatly to reducing the cardiovascular risks [56] Vasodilators such as nitrate and calcium

In sickle cell anaemia (SCA), because of the sickle cells that develop during the disease, infarcts affect the lungs, heart, spleen, central nervous system, retina, bones and kidneys [59]. SCA is known to create a widening in the left ventricle, hypertrophy, pulmonary hypertension and heart failure. The reason for MI seen in children with SCA is not fully known. However, it has been reported that vasospasm caused by thromboxane expressed from sequestered thrombocytes could play an important role in coronary ischaemia and necrosis [60]. Varying membrane flexibility and varying viscosity in SCA patients have also been reported to be possible

More detailed examinations should be made of SCA patients especially in conditions of acidosis, deep anaemia, kidney failure and infection. During a vaso-occlusive crisis in SCA children, when there are non-specific ST-T changes on ECG together with chest pain, cardiac enzymes should be examined and the patient should be closely monitored. In patients with suspected myocardial ischaemia, hydration and oxygenation must be provided. It is thought that nitrates could be useful [59]. Although the role of anti-thrombotic treatment is not known,

The use of marijuana and cocaine should be investigated in adolescents seen with MI. Tramadol, amphetamines, benzodiazepines and opiates are also substances that can cause PMI [61].

channel blockers are selected in MI cases related to epinephrine [57, 58].

experienced by a family member at an early age [54].

**16. Epinephrine use**

116 Myocardial Infarction

**17. Sickle cell anaemia**

causes of ischaemia and infarction.

it should be considered in treatment.

**18. Substance abuse**

In normal individuals, the coronary arteries have a course over the myocardium. Myocardial bridge [MB] is a clinical event characterised by the course of a section of the coronary arteries within the myocardium [4, 66, 67]. On angiography, the loss in diastole of the narrowing in the vessel lumen that is observed during systole [milking effect] is valuable for diagnosis. The degree of coronary obstruction created by the MB depends on the localisation of the MB, the thickness, length and degree of cardiac contractility [68]. It has been reported to be seen more often in patients with left ventricle hypertrophy such as HCM and aortic stenosis in particular [38]. Other coronary arteries can be affected, but the most commonly affected is the LAD [38, 67, 69].

It has been shown that there is a relationship between the clinical results of MB and ischaemic heart disease, MI, arrhythmia and sudden death and that MB can cause MI even in Paediatric cases [66]. It has not yet been understood how important the haemodynamic effects are of the coronary artery in the intramural region remaining under pressure during systole when >75% of the coronary is in diastole.

Despite the use of beta-blockers at appropriate doses, it has been reported that in symptomatic patients with >75% systolic narrowing, good results can be obtained with supra-arterial myotomy and the risk of MI and sudden death can be prevented [70].
