Post-mortem genetic testing in sudden cardiac death and genetic screening of relatives at risk: lessons learned from a Czech pilot multidisciplinary study.

Sudden cardiac death (SCD) might have an inherited cardiac condition background. Genetic testing supports post-mortem diagnosis and screening of relatives at risk. Our aim is to determine the feasibility of a Czech national collaboration group and to establish the clinical importance of molecular autopsy and family screening. From 2016 to 2021, we have evaluated 100 unrelated SCD cases (71.0% males, age: 33.3 (12.8) years). Genetic testing was performed by next-generation sequencing utilizing a panel of 100 genes related to inherited cardiac/aortic conditions and/or whole exome sequencing. According to autopsy, cases were divided into cardiomyopathies, sudden arrhythmic death syndrome, sudden unexplained death syndrome, and sudden aortic death. We identified pathogenic/likely pathogenic variants following ACMG/AMP recommendations in 22/100 (22.0%) of cases. Since poor DNA quality, we have performed indirect DNA testing in affected relatives or in healthy parents reaching a diagnostic genetic yield of 11/24 (45.8%) and 1/10 (10.0%), respectively. Cardiological and genetic screening disclose 83/301 (27.6%) relatives at risk of SCD. Genetic testing in affected relatives as starting material leads to a high diagnostic yield offering a valuable alternative when suitable material is not available. This is the first multidisciplinary/multicenter molecular autopsy study in the Czech Republic which supports the establishment of this type of diagnostic tests. A central coordinator and proper communication among centers are crucial for the success of a collaboration at a national level.

Issues of electric shock in forensic medical practice.

The authors summarize the current state of knowledge of electric shock as a minority group of injuries in forensic practice. Initially, they deal with electric current as a physical quantity and its effect on the human body, how it enters and moves in the body, which tissues due to their electrical activity and properties are the best conductors and which, on the contrary, due to their high resistance, practically do not conduct current. Subsequently, different pathways of current passage through the body are mentioned, leading to different types of damage, the most serious of which appears to be damage to the cardiovascular system, which can lead to immediate death due to disturbed heart rhythm with subsequent arrest, but is also likely to leave permanent effects leading to late health complications. The effect of electric current at the cellular level is demonstrated in experimental animal models exposed to both low- and high-voltage electric current, with damage described not only at the site of entry but also by microscopic examination in organs distant from the site of direct electric current. Since the effect of electric current on the organism is not fully understood and experimental studies have produced results indicating damage mainly to the cardiovascular system, this opens up certain possibilities for improving not only the diagnosis of deaths due to electric shock but also the follow-up care of patients who survive these injuries.

Burden of sudden cardiac death in persons aged 1-40 years in the Czech Republic.

OBJECTIVES: The aim of the study was to ascertain the incidence, circumstances and causes of sudden cardiac death in persons aged 1-40 years in the Czech Republic. METHODS: De-identified autopsy reports of all individuals who died suddenly between the ages of 1-40 years during the period 2014-2019 inclusive in a selected area of the Czech Republic were analysed retrospectively. Persons with substantial cardiovascular pathology defined by histopathological criteria and those with a negative autopsy were included in the study. The latter were designated as sudden arrhythmic death syndrome. RESULTS: In total, 245 sudden cardiac death cases were identified resulting in an incidence rate of 2.4/100,000 person-years. Among the deceased, we found an enormous gender gap with men representing 81% of cases. More than 80% of deaths occurred during everyday activities or sleep, whereas only 7% were sports-related. The most common cause of death was coronary artery disease detected in 38%, which was followed by cardiomyopathies in 15%, sudden arrhythmic death syndrome in 12%, left ventricular hypertrophy in 10%, and congenital heart defects in 7%. CONCLUSIONS: Coronary artery disease is the predominant cause of sudden cardiac death in the young population of the Czech Republic. Hence, effective preventive measures targeted at the reduction of risk factors associated with early coronary artery disease should be reinforced. The second most prevalent cause in our population are potentially heritable heart conditions such as cardiomyopathies and sudden arrhythmic death syndrome. This fact has already prompted the introduction of molecular autopsy and cardiogenetic care for relatives in the Czech Republic.

Cement augmentation of odontoid peg fractures: the effect of cement volume and distribution on construct stiffness.

PURPOSE: The cement augmentation of a conventional anterior screw fixation in type II odontoid process fractures for elderly patients significantly increased stiffness and load to failure under anterior-posterior load in comparison with non-augmented fixation. The amount and quality of bone cement are usually taken ad hoc in clinical practise. In this study, we wanted to clarify the role of bone cement amount and its quality to the stiffness of odontoid and vertebrae body junction. METHODS: Finite-element method was used to achieve different scenarios of cement augmentation. For all models, an initial stiffness was calculated. Model (1) the intact vertebrae were virtually potted into a polymethylmethacrylate base via the posterior vertebral arches. A V-shaped punch was used for loading the odontoid in an anterior-posterior direction. (2) The odontoid fracture type IIa (Anderson-D'Alonzo classification) was achieved by virtual transverse osteotomy. Anterior screw fixation was virtually performed by putting self-drilling titanium alloy 3.5 mm diameter anterior cannulated lag screw with a 12 mm thread into the inspected vertebrae. A V-shaped punch was used for loading the odontoid in an anterior-posterior direction. The vertebrae body was assumed to be non-cemented and cemented with different volume. RESULTS: The mean cement volume was lowest for body base filling with 0.47 ± 0.03 ml. The standard body filling corresponds to 0.95 ± 0.15 ml. The largest volume corresponds to 1.62 ± 0.12 ml in the presence of cement leakage. The initial stiffness of the intact C2 vertebrae was taken as the reference value. The mean initial stiffness for non-porous cement (E = 3000 MPa) increased linearly (R2 = 0.98). The lowest stiffness (123.3 ± 5.8 N/mm) was measured in the intact C2 vertebrae. However, the highest stiffness (165.2 ± 5.2 N/mm) was measured when cement leakage out of the odontoid peg occurred. The mean initial stiffness of the base-only cemented group was 147.2 ± 8.4 N/mm compared with 157.9 ± 6.6 N/mm for the base and body cemented group. This difference was statistically significant (p < 0.0061). The mean initial stiffness for porous cement (E = 500 MPa) remains constant. Therefore, there is no difference between cemented and non-cemented junction. This difference was not statistically significant (p < 0.18). CONCLUSION: The present study showed that the low porous cement was able to significantly influence the stiffness of the augmented odontoid screw fixation in vitro, although further in vivo clinical studies should be undertaken. Our results suggest that only a small amount of non-porous cement is needed to restore stiffness at least to its pre-fracture level and this can be achieved with the injection of 0.7-1.2 ml of cement. These slides can be retrieved under Electronic Supplementary Material.

[Double homicide with a damning bite mark on the offender´s body - case report]. / Dvojnásobná vrazda s usvedcujícím kousnutím na tele pachatele - kazuistika.

The authors deal with a case of a double homicide, the parental murder made by their older son, which was committed by a combination of stabbing and cutting wounds. The perpetra-tor tried to hide the bodies, so he doused them with gasoline and set fire to them on a lonely forest road. Then he ran over the remains by his car. The cause of death was in both cases open wound of the neck - autopsy findings of the woman´s body testified for a blood aspi-ration, on the man´s body it was not clear for a partial charring, so the possibilities were blood aspiration, air embolism or external bleeding with haemorrhagic shock. There were also many other injuries on the bodies, especially of the post-mortem origin. During the combat, one of the victims - the mother - bit the assailant´s left forearm. So a few days after creation the injury on murderer´s left upper extremity, the police technicians took photos and during the forensic autopsies of both bodies, authors created the impressions of the teeth. The utilities were loaned from Department of Stomatology of University Hospital Královské Vinohrady in Prague and they were designed for the general adult population. The work was more difficult for the state of mortal remains, which were damaged by combination of fire and blunt violence. However finally the impressions of each arch were made, and they were given to the experts from Institute of Criminalistic Prague, who compared them with pictures of the bite mark. The results of this analysis were used in a court as evidence against the perpetrator.

Anterior transposition of the radial nerve to achieve primary suture for its reconstruction: Anatomical feasibility study.

INTRODUCTION: Radial nerve palsy after humeral shaft fractures is often associated with formation of a neuroma in continuity. The current standard of treatment is neuroma resection and nerve grafting with contentious results. Anterior transposition of the radial nerve may reduce the length of its path, allowing reconstruction by primary suture. The aim of this study was to determine the maximum length of radial nerve defect that can be treated by the anterior transposition to allow primary suture to be performed. METHODS: We use 10 arms from five fresh cadavers. The radial nerve was dissected in the lateral inter-muscular septum and along the anterior aspect of the forearm. The radial nerve was transected at the level of the spiral groove and both stumps were than transposed anterior to the medial inter-muscular septum. The length of tension-free overlap that could be achieved was measured. RESULTS: The average length of the overlap at zero degrees of elbow flexion was 10.00 ± 1.84 mm. Theoretically, this will allow a defect of 20 ± 3.69 mm SD to be treated by primary suture. CONCLUSION: Our results suggest that anterior transposition can be used for radial nerve defects up to 2 cm; however, dissection of both stumps proved to be challenging.

Biomechanical comparison of cemented versus non-cemented anterior screw fixation in type II odontoid fractures in the elderly: a cadaveric study.

BACKGROUND CONTEXT: Odontoid process fractures are the most common injuries of the cervical spine in the elderly. Anterior screw stabilization of type II odontoid process fractures improves survival and function in these patients but may be complicated by failure of fixation. PURPOSE: The present study aimed to determine whether cement augmentation of a standard anterior screw provides biomechanically superior fixation of type II odontoid fractures in comparison with a non-cemented standard screw. STUDY DESIGN: Twenty human cadaveric C2 vertebrae from elderly donors (mean age 83 years) were obtained. METHODS: Anderson and D'Alonzo type IIa odontoid fracture was created by transverse osteotomy, and fluoroscopy-guided anterior screw fixation was performed. The specimens were divided into two matched groups. The cemented group (n=10) had radiopaque high viscosity polymethylmethacrylate cement injected via Jamshidi needle into the base of the odontoid process. The other group was not augmented. A V-shaped punch was used for loading the odontoid in an anteroposterior direction until failure. The failure state was defined as screw cutout or 5% force decrease. Mean failure load and bending stiffness were calculated. RESULTS: The mean failure load for the cemented group was 352±12 N compared with 168±23 N for the non-cemented group (p<.001). The mean initial stiffness of the non-cemented group was 153±19 N/mm compared with 195±29 N/mm for the cemented group (p<.001) CONCLUSIONS: Cement augmentation of an anterior standard screw fixation of type II odontoid process fractures in elderly patients significantly increased load to failure under anteroposterior load in comparison with non-augmented fixation. This may be a valuable technique to reduce failure of fixation.

A comparison of age-related changes in axial prestretch in human carotid arteries and in human abdominal aorta.

It is known that large arteries in situ are subjected to significant axial prestretch. This prestretch plays an important physiological role in optimizing the biomechanical response of an artery. It is also known that the prestretch declines with age. However, a detailed description of age-related changes in prestretch is available only for the abdominal aorta and for the femoropliteal artery. Our study presents results of measurements of axial prestretch in 229 left common carotid arteries excised in autopsies. It was found that the prestretch of the carotid artery correlates significantly with age ([Formula: see text], p value < 0.001). A linear regression model was used to fit the observations. Simultaneously with the measurement of the prestretch in the carotid artery, the axial prestretch was also measured in abdominal aorta. By comparing data obtained from these locations, it was concluded that the axial prestretch in the carotid artery is greater than in the abdominal aorta, and that atherosclerosis develops more rapidly in the abdominal aorta than in the carotid artery. Histological sections obtained from 8 carotid arteries and aortas suggest that the medial layer of the left common carotid artery is significantly thinner than aortic media (median/IQR: 0.343/0.086 vs. 0.482/0.172 mm, [Formula: see text] in Wilcoxon signed-rank test) and simultaneously that carotid media contains a lower number of elastic membranes (median/IQR: 26.5/11.8 vs. 31.5/11.8, [Formula: see text] in the Wilcoxon signed-rank test). This could be a reason for the different extent of the prestretch observed in aorta and in carotid artery. Our data sample also contains 5 measurements of the axial prestretch in abdominal aortas suffering from an aneurysm. It was found that aneurysmatic aortas also exhibit axial retraction when excised from in situ position. To the best of our knowledge, this is the first time that detailed data characterizing axial prestretch of the human left common carotid artery have been presented.

Analysis of axial prestretch in the abdominal aorta with reference to post mortem interval and degree of atherosclerosis.

It is a well-known fact that the length of an artery in situ and the length of an excised artery differs. Retraction of blood vessels is usually observed. This prestretch plays an important role in arterial physiology. We have recently determined that the decrease of axial prestretch in the human abdominal aorta is so closely correlated with age that it is suitable for forensic applications (estimation of the age at time of death for cadavers of unknown identity). Since post mortem autolysis may affect the reliability of an estimate based on axial prestretch, the present study aims to detail analysis of the effect of post mortem time. The abdominal aorta is a prominent site of atherosclerotic changes (ATH), which may potentially affect longitudinal prestretch. Thus ATH was also involved in the analysis. Axial prestretch in the human abdominal aorta, post mortem interval (PMI), and the degree of ATH were documented in 365 regular autopsies. The data was first age adjusted to remove any supposed correlation with age. After the age adjustment of the sample, the correlation analysis showed no significant PMI effects on the prestretch in non-putrefied bodies. Analysis of the prestretch variance with respect to ATH suggested that ATH is not a suitable factor to explain the prestretch variability remaining after the age adjustment. It was concluded that, although atherosclerotic plaques may certainly change the biomechanics of arteries, they do not significantly affect the longitudinal prestretch in the human abdominal aorta.