**6. Echocardiographic evaluation of Paediatric acute myocardial infarction**

**Table 3.** Non-coronary events which increase troponin.

The increasing experience with echocardiography [echo] in recent decades has greatly facilitated the diagnosis of acute myocardial infarction [AMI], as echo is an inexpensive, readily available, ambulatory, non-invasive method [24]. **Echo is useful, not only in the diagnosis of AMI but also in prognosis, the monitoring of complications and in follow-up.** In Paediatric AMI patients, echo provides very valuable information in the determination of segmentary wall movement abnormalities and in the diagnosis of CHD, pericarditis, myocarditis, Kawasaki disease, cardiomyopathy, aortic stenosis and ALCAPA which often accompanies chest pain. In adult studies, abnormal wall movement findings have been determined in 91% of patients applied with echo in the early stage in the emergency departments [25]. It has also been shown in studies of adults that a decrease in left ventricular ejection fraction [LVEF] and left ventricle volume loading are significant risk factors for morbidity and mortality [24].

Neonatal Causes

Lung pathologies

 Metabolic causes Myocarditis Cardiomyopathy

Endocardial fibroelastosis

Renal artery thrombosis

Left ventricular aneurisms

 Kawasaki disease Congenital heart disease Coronary artery abnormalities Hypertrophic cardiomyopathy Dilated cardiomyopathy

 Myocarditis Viral Idiopathic Rheumatic

 Substance Use Cocaine Marijuana

 Mediocalsinosis of the coronary arteries Disseminated intravascular coagulation

Causes of MI in childhood and adolescence

Collagen vascular diseases' induced

Previous surgery to the Truncus Arteriosus

Bonzai (synthetic cannabis)

Tumours

 Idiopathic Coagulopathies

Sepsis

 Coronary artery abnormalities Congenital heart disease Severe neonatal asphyxia

Admission to Intensive Care Unit

Pulmonary atresia with intact ventricular septum

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Segmentary wall movement abnormalities are seen in the necrotic region in AMI. If left ventricle function is looked at globally, this finding can be overlooked [24]. The American Society of Cardiology recommends examination of the heart in 16 segments and scoring from 1 to 5 as follows:


A higher score indicates a greater wall abnormality [26]. The score increases in cases with more widespread MI. It has been shown in studies of adults that in addition to segmentary wall movement abnormalities, complications which are rarely seen in children including post-infarct ventricular septal defect, left ventricle free wall rupture, right ventricle failure, and papillary muscle rupture have both value in diagnosis and follow-up of MI [24].

#### **6.1. Aetiology**

Paediatric myocardial infarction may be associated with many different diseases (**Table 4**) [2, 3, 5–9, 15]. It has been proposed that the reasons that coronary ischaemia and MI are frequently seen in CHD are multifactorial [27]. Abnormalities in the coronary artery anatomy have been reported to increase the risk of MI. It has been suggested that the stenosis risk after cutting and transfer of coronary arteries could have a potential role in early atherosclerosis and premature coronary artery disease [9]. In addition, congenital heart diseases with right to left shunts may cause paradoxal embolism. A sedentary lifestyle, diabetes mellitus and hypertension are other risk factors for ischaemic heart disease.

In autopsies performed between 1996 and 2010, Bamber et al. determined myocardial necrosis in 1637 patients, and in a group of 187 infant patients with perinatal asphyxia, sepsis, pulmonary disease, cardiomyopathy, tumour, coagulopathy and left ventricle aneurism. The myocardial necrosis was reported to be focal in patients with coronary artery abnormality, while it was diffuse among patients; who died in intensive care unit, with metabolic disease, or myocarditis, the idiopathic group, with mechanical asphyxia and who died during a surgical intervention [6]. In that study, the necrosis in 50% of the cases was determined at the subendocardial region, the papillary muscle and trabeculae. In the same study, CHD, asphyxia and coronary artery abnormalities were reported to be the most common causes of MI seen in this period. It was also strange that there was most frequently ASD, VSD and


the emergency departments [25]. It has also been shown in studies of adults that a decrease in left ventricular ejection fraction [LVEF] and left ventricle volume loading are significant

Segmentary wall movement abnormalities are seen in the necrotic region in AMI. If left ventricle function is looked at globally, this finding can be overlooked [24]. The American Society of Cardiology recommends examination of the heart in 16 segments and scoring from 1 to 5

A higher score indicates a greater wall abnormality [26]. The score increases in cases with more widespread MI. It has been shown in studies of adults that in addition to segmentary wall movement abnormalities, complications which are rarely seen in children including post-infarct ventricular septal defect, left ventricle free wall rupture, right ventricle failure, and papillary muscle rupture have both value in diagnosis and follow-up

Paediatric myocardial infarction may be associated with many different diseases (**Table 4**) [2, 3, 5–9, 15]. It has been proposed that the reasons that coronary ischaemia and MI are frequently seen in CHD are multifactorial [27]. Abnormalities in the coronary artery anatomy have been reported to increase the risk of MI. It has been suggested that the stenosis risk after cutting and transfer of coronary arteries could have a potential role in early atherosclerosis and premature coronary artery disease [9]. In addition, congenital heart diseases with right to left shunts may cause paradoxal embolism. A sedentary lifestyle, diabetes mellitus and

In autopsies performed between 1996 and 2010, Bamber et al. determined myocardial necrosis in 1637 patients, and in a group of 187 infant patients with perinatal asphyxia, sepsis, pulmonary disease, cardiomyopathy, tumour, coagulopathy and left ventricle aneurism. The myocardial necrosis was reported to be focal in patients with coronary artery abnormality, while it was diffuse among patients; who died in intensive care unit, with metabolic disease, or myocarditis, the idiopathic group, with mechanical asphyxia and who died during a surgical intervention [6]. In that study, the necrosis in 50% of the cases was determined at the subendocardial region, the papillary muscle and trabeculae. In the same study, CHD, asphyxia and coronary artery abnormalities were reported to be the most common causes of MI seen in this period. It was also strange that there was most frequently ASD, VSD and

hypertension are other risk factors for ischaemic heart disease.

risk factors for morbidity and mortality [24].

as follows:

108 Myocardial Infarction

**1.** Normal.

**3.** Akinesis. **4.** Dyskinesis. **5.** Aneurismal.

of MI [24].

**6.1. Aetiology**

**2.** Hypokinesis.

 Arterial switch operation Post-transplantation Post-coronary surgery Drugs Epinephrine Amphetamine Benzodiazepines Hyperlipidemia Blunt Chest trauma Nephrotic syndrome Vasculitis Polyarteritis nodosa Systemic lupus erythematosus Behcet's disease Takayasu arteritis Atherosclerotic coronary artery disease Disseminated intravascular coagulation Genetic diseases ALKaptonuria Fabry's disease Familial hypercholesterolemia (homozygotes or heterozygotes)] Homocysteinuria Hurler's syndrome Hyperbetalipoproteinemia, familial combined hyperlipidaemia, and hypoalphalipoproteinemia Mucopolysaccharidoses Pompe's Disease Progeria Pseudoxanthoma elasticum Sepsis Occult Malignancy Myocardial bridging Pulmonary atresia with intact ventricular septum

PDA accompanying the CHD. Of 105 cases with acquired or inherited CHD, 63 [60%] were

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In another study conducted in Sweden between 1970 and 1993, the presence of CHD was seen to be a reason for hospitalisation because of ischaemic heart disease (IHD). The risk was reported 16.5 fold increased compared to the control group [27]. These data support that the presence of CHD as an additional risk factor for MI in children. Fedchenko et al. reported the possible mechanisms as; a] a physiological response to a previous surgical procedure could contribute to the development of IHD, b] a predisposition to IHD because of an increased need for oxygen with reduced maximal oxygen re-uptake due to volume and pressure loading in CHD patients, and c] exposure of CHD patients at an early age to radiological proce-

Coronary artery abnormalities generally do not cause clinical findings or the findings are subclinical. However, some coronary artery abnormalities cause serious haemodynamic outcomes [16]. The left coronary artery emerging from the right coronary sinus and the right coronary artery emerging from the left coronary sinus can cause coronary artery circulation problems. The section of the coronary artery that passes between the aorta and the pulmonary

Congenital cardiac abnormalities are a significant cause of MI-related sudden death, most often in the neonatal period (**Table 5**) [28]. Sudden death is often related to exercise especially in patients where the coronary arteries originate from the pulmonary artery and pass between the aorta and the pulmonary artery [28]. Although some cases may show clinical findings with MI in the neonatal period, some cases can remain asymptomatic [29]. In infancy, there may be noticeable findings of heart failure, such as rapid fatigue, sweating, tachypnea and

Exercise-related death is most often encountered when the left coronary artery emerges from the right coronary sinus, in ALCAPA, and when the right coronary artery emerges from the left coronary sinus [28]. In patients with coronary artery abnormality, the symptoms include chest pain, syncope and findings of heart failure. In infants with ALCAPA, Q-wave seen at DI,

In a Paediatric autopsy study, cardiomegaly was seen in all the cases of children with coronary artery abnormality [30]. The cause of MI seen during exercise in children with coronary artery abnormality has been suggested to originate from an increase in acute angulation of the

Sudden death in the asymptomatic period is a frightening complication of the disease in a

determined to be severe, multiple and complex [6].

dures and radiation could accelerate atherosclerosis [27].

**7. Congenital coronary artery abnormalities**

retarded growth and development [2].

coronary artery during exercise [29].

AVL or V5–6 on ECG is a good marker for diagnosis [7].

significant proportion of cases with coronary artery abnormality [28].

artery exposed to pressure at a critical level causes clinical findings [28].

**Table 4.** Causes of Paediatric myocardial infarction.

PDA accompanying the CHD. Of 105 cases with acquired or inherited CHD, 63 [60%] were determined to be severe, multiple and complex [6].

In another study conducted in Sweden between 1970 and 1993, the presence of CHD was seen to be a reason for hospitalisation because of ischaemic heart disease (IHD). The risk was reported 16.5 fold increased compared to the control group [27]. These data support that the presence of CHD as an additional risk factor for MI in children. Fedchenko et al. reported the possible mechanisms as; a] a physiological response to a previous surgical procedure could contribute to the development of IHD, b] a predisposition to IHD because of an increased need for oxygen with reduced maximal oxygen re-uptake due to volume and pressure loading in CHD patients, and c] exposure of CHD patients at an early age to radiological procedures and radiation could accelerate atherosclerosis [27].
