**15. Atherosclerosis**

As atherosclerotic coronary artery disease seen in adults originates in childhood, it is necessary to start taking preventative measures against atherosclerosis in that period. However, as there are few cases related to atherosclerosis within the PMI cases reported in literature it is thought that MI cases developing on an atherosclerotic basis are rare in children [3, 7, 54].

In an autopsy study of 760 murder or accident cases aged 15–34 years, atheroma was determined in males at 2% and was not determined in females [54]. Other risk factors increasing atherosclerotic changes are known to be familial hypercholesterolemia in particular, and elevated LDL level, substance abuse, smoking, hypertension, obesity and cardiovascular events experienced by a family member at an early age [54].

The use of a vasoconstrictor substance, especially by those who smoke, increases the risk of ischaemic cardiac complications, even in a healthy heart. [62]. Marijuana stimulates the sympathetic nervous system by expressing epinephrine and the effect is seen with an increase in vasoconstriction, tachycardia, hypertension and cardiac output [63]. Furthermore, by increasing the carboxyhaemoglobin level, the oxygen carrying capacity is reduced [62]. The coronary ischaemia and MI which occur as a result of increased heart rate, vasoconstriction and the increased need for oxygen can be life-threatening for the patient [63–65]. As most substances causing Paediatric MI are illegal, the users may deny having used them. In cases suspected of substance abuse, a toxicology examination must be made. Cardiac ischaemia can also be seen

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Cocaine with sympathomimetic effect on coronary arteries can cause MI by vasoconstriction. As a result of increasing blood pressure and heart rate, the myocardium has an increased need for oxygen and with the tendency for thrombosis resulting from endothelial dysfunc-

In an autopsy examination of 477 cases of sudden cardiac death aged 1–49 years, Bjune et al. determined positive results in the toxicology scan of 57% of the cases [61]. The toxicological substances determined in the blood in that study were benzodiazepines, opioids, antidepressants, anticonvulsants, antipsychotics, ethanol, cannabis, cocaine, amphetamines and gamma hydroxybutyrate. In 39% of the cases with substances determined in the blood, multiple substances were present. Despite the subpharmacological basis of the substances determined and the pharmacological dose, that death occurred was concluded to be due to the interaction of

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

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%

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].

related to the use of bonzai, which is a synthetic cannabinoid [63].

tion, MI can develop in patients [4].

multiple drugs and/or substances.

**19. Myocardial bridge**

is the LAD [38, 67, 69].

of the coronary is in diastole.
