Conduction system abnormalities in alcoholics with asymptomatic valvular disease who suffer sudden death

An autopsy case of sudden unexpected death with Barlow's disease

A 45-year-old man was clinically diagnosed with mitral valve regurgitation 2 years before death. The autopsy showed left ventricular hypertrophy and mitral valve prolapse of the bileaflet with billowing valve and excessively thickened leaflet, the findings of which were consistent with Barlow's disease. Microscopically, destruction of the three-layer structure of the mitral valve and advanced interstitial fibrosis of the left ventricular wall were evident. Additionally, a marked but limited reduction in conduction fibers was found in the branching point of the left and right branches, as seen in cases of idiopathic complete atrioventricular block. Genetic investigation using whole-exome sequencing showed some genetic variants with uncertain significance. In patients with Barlow's disease, a marked reduction of conduction fibers might be a subtype of sudden cardiac death. The overlap of some arrhythmogenic substrate in the heart may increase the risk of sudden cardiac death with asymptomatic Barlow's disease.

High-degree atrioventricular block in acute ethanol poisoning: a case report

Introduction

Acute ethanol ingestion can prolong the PR interval, but searching Medline, we have found only one report of Wenckebach-type atrioventricular block in ethanol poisoning. We present a high-degree atrioventricular block in an ethanol-poisoned patient.

Case presentation

A 17-year-old woman with a non-contributory medical history ingested 3dcl of vodka and was found comatose. On arrival she was somnolent with nausea, tympanic temperature 36.0°C, pulse 70 counts/min, blood pressure 90/60 mmHg, respiratory rate 12 counts/min and SpO₂ 96% on room air. Her blood ethanol level was 130 mg/dL; other blood laboratory test results were normal. ECG revealed sinus rhythm, first-degree atrioventricular block with a PR interval of 0.32 seconds and intermittent second- and third-degree atrioventricular blocks with up to 4-second-long pauses that appeared 15-30 seconds after each vomiting. She was given thiethylperazine and vomiting resolved within an hour. ECG 12 hours after admission revealed a first-degree atrioventricular block with a PR interval of 0.24 seconds. One month later Holter monitor showed a sinus rhythm and first-degree atrioventricular block with a PR interval of 0.21 seconds. Vagal maneuvers did not provoke high-degree atrioventricular block. The echocardiogram was normal.

Conclusion

Acute ethanol poisoning has the potential to prolong the PR interval in adults with first-degree atrioventricular block and provoke intermittent second- and third-degree atrioventricular blocks, possibly by its direct inhibitory action on the conduction system and increasing parasympathetic tone due to nausea and vomiting.

Mitral valve prolapse syndrome as cause of sudden death in young adults

Mitral valve prolapse syndrome (MVPS) is a relatively common disorder of the mitral valve and most cases take a benign clinical course. Only a subset of patients develop severe clinical symptoms such as arrhythmia, insufficiency of the mitral valve or infective endocarditis. As a consequence, sudden death might occur in these patients, thought to be caused by an arrhythmogenic event. By presenting six cases of sudden unexpected death in young female adults, we point at clinical and pathological data from the literature, which are of interest from the viewpoint of legal medicine. The incidence of MVPS in autopsy series has been reported to be about 4-5%, while clinical data hint at an incidence of about 2.5%. The presented cases suggest that even clinically benign cases of MVPS in young adults might result in sudden unexpected death. Such cases are not included in hospital based studies on the topic. This might lead to an underestimation of the fatal risk associated with the disease, even if sudden death might be a rare event in MVPS.

The sudden and unexpected death of a female-to-male transsexual patient

A 32-year-old woman, who was intramuscularly injected with testosterone enanthate (125 mg) once or twice a month over a two-year period for female-to-male transsexualism, died suddenly. A forensic autopsy was performed to investigate the cause of death. Concentric cardiac hypertrophy was macroscopically observed. In the left and right coronary arteries, atherosclerosis was generally observed within the endothelium. In particular, there was severe stenosis (>90%) at the start of the left descending branch. In the myocardium, both coagulation necrosis and contraction band necrosis were microscopically observed. Moreover, myocardial fibrosis and myocardial calcification were diffusely detected, respectively. The cause of death was diagnosed as ischemic heart disease due to coronary stenosis. There is some debate as to whether cross-hormone replacement is related to the occurrence of coronary artery disease or not, however, it is possible that the development of ischemic heart disease was aggravated by the administration of testosterone enanthate in the current case.

Postmortem cardiac troponin T levels in the blood and pericardial fluid. Part 2: Analysis for application in the diagnosis of sudden cardiac death with regard to pathology

Although previous forensic pathological studies have suggested the possible application of cardiac troponins in the diagnosis of myocardial infarction, there appears to be insufficient data with regard to its cardiac pathology. The present study analyzed the heart blood, peripheral blood and pericardial fluid levels of cardiac troponin T (cTnT) in sudden cardiac deaths (n = 96) within 48h postmortem in relation to pathological findings of acute myocardial infarction (AMI, n = 34), recurrent myocardial infarction (RMI, n = 23), ischemic heart disease without any pathological evidence of infarction (IHD, n = 24) and other heart diseases (OHD, n = 15). Control groups (n = 75, survival time <24 h) within 48 h postmortem consisted of asphyxiation (n = 35), drowning (n = 27) and cerebrovascular diseases (n = 13). There was a marked correlation in the cTnT levels between right and left heart blood samples. The pericardial level was usually higher than either heart blood level, and the external iliac venous blood level was the lowest. Although postmortem time-dependent increases in heart and pericardial blood cTnT levels were observed in most groups, they were most evident for AMI and asphyxiation. In the early postmortem period (<12 h) there was no significant difference between AMI or RMI and the other groups except for drowning. After 12 h postmortem, significantly elevated heart blood and pericardial cTnT levels were observed for AMI and RMI showing multiple interstitial hemorrhages and necrosis compared to those with localized eosinophilic changes or patchy interstitial hemorrhages, IHD and OHD. These differences were the smallest for peripheral blood. For sudden cardiac death cases, the difference in cTnT level at each site among the causes of death was independent of gender, age, heart or lung weight and pathologies of affected coronary artery and severity of coronary stenosis. These observations suggest that the elevation in postmortem blood and pericardial cTnT levels in sudden cardiac death may depend on the severity of ischemic myocardial damage including the size and intensity of myocardial lesions involving multiple interstitial hemorrhages and necrosis, and also the postmortem period for heart and pericardial levels.

Relationship between cardiopulmonary resuscitation and injuries of the cardiac conduction system: Pathological features and pathogenesis of such injuries*

OBJECTIVE

The purpose of this study was to assess the incidence, features, and pathogenesis of microscopic injuries to the cardiac conduction system caused by cardiopulmonary resuscitation.

DESIGN

: Prospective study.

SETTING

Autopsy unit of the university.

PATIENTS

Victims who had been transferred to the emergency room due to cardiac arrest arising from nontraumatic cause plus age-matched control patients.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

The cardiac conduction system of 80 hearts without gross injury from patients who had received cardiopulmonary resuscitation due to nontraumatic causes was examined. Of these 80 patients, seven (9%) showed fresh injuries, including a lesion that had gone unreported in the previous literature. Localized hemorrhage without inflammatory reaction was evident in six of these patients. Three of the six patients showed hemorrhage in the sinoatrial node, whereas the other three patients showed hemorrhage in the atrioventricular conduction system. The remaining one patient showed localized dissection of the atrioventricular node artery with the appearance of red blood cells in the false lumen. There was no significant difference with regard to age, gender, cause of cardiopulmonary arrest, whether victim had received electrical shock treatment, whether victim had received anticoagulants, and the duration of cardiopulmonary resuscitation between the seven patients with fresh injuries and the other 73 patients. Fracture of the sternum or rib was found in only one of the seven patients but in 14 of the 73 patients. No pathologic lesions were found in the 30 control patients who did not receive cardiopulmonary resuscitation.

CONCLUSIONS

It can be presumed that injuries to the conduction system do occur in limited regions during cardiopulmonary resuscitation. Minute differences in the location of the cardiac silhouette or cardiac conduction system also need to be considered, rather than just the severity of force to the anterior chest, when determining the pathogenesis of these injuries.

Sudden unexpected death of a 17-year-old male infected with the influenza virus

We report a case of sudden unexpected death in a 17-year-old male student showing similar clinical background and pathological findings to Reye's syndrome. He was found following cardio-pulmonary arrest in his bed, and was immediately transferred to a hospital. However, resuscitation was not successful. He had a history of high fever of 38.3 degrees C, general malaise, myalgia, and gastrointestinal discomfort for the 2 days prior to his death, and an injection of pylazolon and medication comprising anti-emetics had been administered the day before he died. His biochemical findings showed almost normal levels of transaminase, electrolytes and protein fractions at the emergency room, but blood from the heart at autopsy revealed a high titer of the influenza A virus. Macroscopically, in addition to considerable fatty metamorphosis of the liver, concentric hypertrophy of the left ventricle, muscular bridge of left anterior descending artery, moderate coronary atherosclerosis, and mild downward displacement of the septal leaflet of the tricuspid valve were noted in the heart. Although panlobular microvesicular fatty infiltration of the liver was seen, deposition of lipid droplets was detected only in hepatocytes by frozen section of several organs. Serial sectioning of the epicardial coronary arteries showed about 50% stenosis at the distal site of the left circumflex artery, and diffuse interstitial fibrosis was evident in the bilateral ventricle and this was relatively severe for his age. In addition, the atrioventricular (AV) node artery showed severe narrowing just before entering the AV node, and downward displacement of the AV node with longitudinal elongation was also remarkable. We consider that the cause of death was sudden cardiac death rather than Reye's syndrome (RS), and that an arrhythmogenic event due to some preceding unusual cardiac lesions may have become overt due to the influenza infection and/or some related disorders. The present case would seem to suggest that a postmortem diagnosis of RS should be determined very carefully in cases of sudden death, even if the general circumstances would seem to be consistent with RS.