Elsevier

Legal Medicine

Volume 53, November 2021, 101965
Legal Medicine

Unexpected death in a young child associated with anomalous aortic origin of the left main coronary artery without physical exertion: A case of an anomalous coronary artery with highly abundant elastic fibers

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Highlights

  • Anomalous aortic origin of a coronary artery can cause sudden death.

  • The fatal cases are usually associated with physical activity among young adults.

  • This report describes the sudden child death without exercise stress.

  • The anomalous coronary artery was composed almost exclusively of elastic fibers.

  • The vascular pathology and infection may contribute to the fatality in the anomaly.

Abstract

Sudden death due to anomalous aortic origin of a coronary artery is far less common among young children in the absence of exercise stress. This report describes the case of a 2-year-old boy with a lower respiratory tract infection who suffered sudden cardiac arrest in his bed at home. The autopsy revealed that the left coronary artery (LCA) originated from the right sinus of Valsalva with an acute angle takeoff and traveled between the aorta and the pulmonary trunk (an interarterial course). Upon histological examination, the LCA, before reaching its major branches, was located adjacent to the outside of the aortic wall without an intramural passage, and the arterial wall was composed almost exclusively of elastic fibers without media containing smooth muscle cells throughout the entire length of the abnormal running. Screening tests for respiratory virus infection detected enterovirus in the lung tissue. In association with an acute angle takeoff and interarterial course, the wall structure with highly abundant elastic fibers that are more flexible tissues among blood vessel components might suggest their vulnerability to compression during the great vessels’ systolic expansion in the sympathetic activation induced by the viral infection, leading to fatal myocardial ischemia without physical exertion.

Introduction

Sudden cardiac death is uncommonly caused by the anomalous origin of a coronary artery: a large-scale study of an autopsy registry revealed that this specific abnormality only accounts for 0.6% of sudden cardiac deaths [1]. Anomalous coronary artery origin is usually classified into 3 types: anomalous left coronary artery (LCA) arising from the pulmonary trunk (ALCA-P), anomalous right coronary artery (RCA) arising from the left coronary sinus of the aorta (ARCA-L), and anomalous LCA arising from the right coronary sinus of the aorta (ALCA-R) [2], [3]. In ALCA-P, a decrease of pulmonary artery pressure leads to myocardial ischemia of the area perfused by the coronary artery after the closure of the ductus arteriosus; therefore, most of these patients die during infancy, associated with congestive heart failure or dilated cardiomyopathy [4], [5].

In ARCA-L or ALCA-R, systolic compression of the coronary artery passing between the aorta and pulmonary trunk (traditionally called an “interarterial course”) is presumed to cause clinically significant outcomes, combined with taking a course within the aortic wall (an “intramural course”) or an anomalous coronary artery demonstrating an acute angle origin [6], [7], [8]. Sudden death due to ARCA-L or ALCA-R is usually associated with the interarterial course [9], [10], particularly among young adults or adolescents during physical activity that can cause a compression of the anomalous artery and subsequent myocardial ischemia through the systolic expansion of the great vessels [1], [4], [7], [11]. Among young children who are unlikely to experience exercise stress, sudden death due to ARCA-L or ALCA-R is far less common; therefore, there has been little discussion of the risk factors or mechanisms [1], [2], [7]. This report describes the case of a healthy young child with a lower respiratory tract infection who suffered sudden cardiac arrest due to ALCA-R and discusses the mechanisms of the fatal outcome considering the pathological findings in the vascular wall of the anomalous coronary artery with an ectopic origin.

Section snippets

Case history

A 2-year-old boy with no perinatal problems or significant medical history was found unresponsive in his bed by a family member. He was transferred to the emergency department in cardiac arrest. Spontaneous circulation was restored by cardiopulmonary resuscitation; however, he died in a coma the day after arrival. On the day of onset, he had presented with a fever (38 °C) and cold hands. A pediatrician had evaluated his condition and diagnosed it as a common cold. Based on the cause of death

Gross examination

External examination of the body (weight, 14 kg; height, 90 cm) did not produce any significant findings except for minor injuries associated with resuscitation procedures. Upon internal examination, heart weight was normal (63 g). There were no gross abnormalities in the large vessels or heart chambers. In the heart, the LCA originated from the right sinus of Valsalva with an acute angle takeoff from the separate orifice immediately to the left of the normal ostium of the RCA (Fig. 1a). The

Discussion

Since all the patients with ARCA-L or ALCA-R do not suffer from sudden cardiac death, several factors responsible for myocardial ischemia and fatal outcomes have been proposed [2], [6], [7], [8]. One of the factors is an obstruction in the ostium of the anomalous coronary artery. The abnormality includes a slit-like orifice, oblique takeoff, acute angle origin, valve-like ridge, and hypoplastic ostium and is frequently observed in cases of sudden death; therefore, it is presumed to cause

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

The authors thank a laboratory technician Norimasa Kageyama for the excellent technical assistance and a medical examiner Kumiko Asakura for the assistance of the manuscript preparation.

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