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Vol. 4, No. 1, March 2012 Journal of South India Medicolegal Association 4 (2012) 32-35
Case Report
Sudden death due to arrhythmogenic right ventricular disease M. V. Pradeep Kumar,a* Sharanagouda M. Arikerib Department of Forensic Medicine Rajarajeshwari Medical College and Hospital, Bangalore, Karnataka, India b Malabar Medical College Hospital and Research Centre, Modakkalur, Kerala, India a
Abstract Sudden death in young people due to involvement of the cardiovascular system is not uncommon. Sudden death due to acute myocardial infarction may occur in relatively young persons and without evidence of coronary artery obstruction. In such a situation, histopathological examination of the organs helps to demonstrate the lesion that led to the death of an individual. Arrhythmogenic right ventricular disease (ARVD) is an important cause of ventricular arrhythmias in children and adolescents. It is a type of nonischaemic cardiomyopathy that involves primarily the right ventricle. Sudden death without any gross pathological feature will pose a problem in opining the cause of death. Herein, we report a case of sudden death due to ARVD in a young female. © 2012 South India Medico-Legal Association. All rights reserved.
Keywords: Sudden death; Arrhythmia; Hypertrophic cardiomyopathy; Arrhythmogenic right ventricular disease. Article received 5 Nov 2011; Accepted 5 Jan 2012
1. Introduction
2. Case report
Majority of sudden deaths in children and adolescents are related to the cardiovascular system followed by infection, epilepsy, intracranial 1 haemorrhage and asthma. Cardiovascular system is involved in 80-85% of the cases and death may be caused due to cardiac arrhythmia, in particular ventricular fibrillation. The diseases associated with sudden cardiac death (SCD) in adolescents and young adults are hypertrophic cardiomyopathy, long QT syndrome, acute myocardial infarction, bridging of coronaries, congenital coronary artery anomalies, aortic stenosis etc., which may be recognised or suspected based on symptoms prior to death, family history of premature sudden death or incidental clinical data.2,3 Herein, we report a case of SCD of a young female due to arrhythmogenic right ventricular dysplasia.
An 18-year-old nursing student suddenly collapsed while partying with her friends after completion of the examinations. She was taken immediately to a nearby hospital where she was declared brought dead. An autopsy was conducted on the next day.
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Postmortem examination revealed a moderately built and moderately nourished adult female with froth at the nostrils. The other external appearances were unremarkable. On dissection, all the internal organs were congested. Cut section of the lungs displayed blood and froth. The heart weighed 350 gm and measured 14 x 8 x 6 cm. The circumference of tricuspid and mitral valves measured 10 cm and 6 cm respectively. The thickness of right and left ventricular walls measured 0.5 cm and 1.5 cm respectively. The right coronary artery was branched immediately after its origin, and was thinned out with narrow lumen but was patent. The aorta and left coronary artery were unremarkable.
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The viscera and blood routinely sent to the forensic science laboratory for chemical analysis revealed absence of any common poisonous substances and drugs. The histopathological examination of the right ventricle showed partial involvement of the apical myocardium with fatty tissue infiltration and without any thinning of the wall (Fig. 1). The left ventricle and ventricular septum were normal. No inflammatory infiltrates were seen in the fatty infiltration. There was partial obstruction of the right coronary artery by organising thrombi with immediate branching and abrupt ending (Figs. 2 and 3). Histopathological examination of the remaining organs was unremarkable.
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to right ventricular failure such as lower extremity oedema, liver congestion with elevated hepatic enzymes etc.6 In the present case, the deceased had no characteristic features on screening when she had a syncopal attack. Sudden death was the first manifestation except for few occasional syncopal attacks.
Fig. 2: Narrowed lumen of the right coronary artery.
Fig. 1: Fatty infiltration in the myocardium of the right ventricle (Haematoxylin and Eosin 400x).
The cause of death was opined as “heart block as a result of partial occlusion of the right coronary artery and right ventricular dysplasia”. 3. Discussion Arrhythmogenic right ventricular dysplasia (ARVD), also known as arrhythmogenic right ventricular cardiomyopathy (ARVC) is a type of nonischaemic cardiomyopathy, which is characterised Fig. 3: Partial obstruction of the right coronary artery with organising by hypokinetic areas involving the free wall of the right thrombi (Haematoxylin and Eosin 100x). ventricle. It is seen predominantly in males, and 30-50% of the cases have a familial distribution.4 The pathogenesis of ARVD is largely unknown. Symptoms are usually exercise-related and mainly The disease process starts in the subepicardial region present as syncope or SCD.4,5 Other manifestations and spreads towards the endocardial surface, leading to include palpitations, light-headedness, and signs related transmural involvement.7 There are two pathological [33]
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patterns seen in ARVD, fatty infiltration and fibrofatty infiltration.8 Residual myocardium is confined to the subendocardial region and trabeculae of the right ventricle. These trabeculae may become hypertrophied. Aneurysmal dilatation may be seen in 50% of the cases, which usually occurs in the diaphragmatic, apical, and infundibular regions. However, it is reported that the left ventricle is involved in 50-67% of the individuals.7 In the present case, the left ventricle was not involved and no such dilatation was seen. In the present case, friends of the deceased gave history of 2 to 3 syncopal attacks, each attack lasting for 2-3 minutes at an interval of 3-4 months apart. The ECG and echocardiography were normal. Syncope is due to obstruction to cardiac output and cardiac arrhythmia in individuals with abnormalities of ventricular repolarisation. Those with the inherited form of this syndrome often have a family history of sudden death in young individuals.9 As there was no obvious family history of sudden death in young individuals, in the present case, these causes were ruled out.
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thinning of the wall. The left ventricle and ventricular septum were normal. It is well known that a large majority of patients with ARVC have histological evidence suggestive of inflammation. Although it is not clear whether inflammation in ARVC is a primary event or a reaction to spontaneous necrosis, inflammatory infiltrates are a histopathologic marker of ongoing myocardial damage.5,10 However, in the present case, no inflammatory infiltrates were seen in the fatty infiltration. These findings are suggestive of an early stage of arrhythmogenic right ventricular disease. Ventricular arrhythmias due to ARVD typically arise from the diseased right ventricle. It ranges from frequent premature ventricular complexes to ventricular tachycardia to ventricular fibrillation. While the initiating factor of the ventricular arrhythmias is unclear, it may be due to triggered activity or re-entry. In the present case, the victim was singing and dancing by which she might have been exhausted triggering ventricular arrhythmia. 4. Conclusion
In the present case, histopathology suggested that there was a partial obstruction of the right coronary artery by organising thrombi with immediate branching and abrupt ending. Immediate branching with abrupt ending of the right coronary artery is one of the rare congenital coronary artery anomalies. As the deceased had no other significant history except for the syncopal attacks and heart dissection did not reveal any defects, the congenital anomalies as the cause of death were ruled out. Other pathological lesions such as aortic stenosis, tumours, mitral valve regurgitation, hypertrophic cardiomyopathy were ruled out by autopsy and histopathological examination. Sudden death associated with stressful condition was also ruled out as the deceased had completed her examination and was enjoying at a party.
Sudden death of young adults raises many questions of forensic importance. Even though many cases of SCD are due to myocardial ischaemia, other heart diseases like the conduction system disturbances described here should not be overlooked. Detailed medical history, meticulous dissection during autopsy, histopathological examination and toxicological analysis were helpful in concluding the diagnosis of the cause of death. References
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