Cerebral arterial gas embolism and neurogenic stunned myocardium in a previously healthy freediver

Cardiomyopathy is a known but rare sequelae of diving-related cerebral arterial gas embolism (CAGE). In previously reported cases, patient findings have been consistent with takotsubo cardiomyopathy (TCM) per the revised Mayo Clinic's diagnostic criteria. A lesser-known variant of stress-related cardiomyopathy is neurogenic stunned myocardium (NSM), which occurs after a neurological event such as subarachnoid hemorrhage and typically presents in younger patients. Presentation tends to differ slightly to TCM with non-specific left ventricular dysfunction and T wave inversions. This case adds to the rare numbers of reported cardiomyopathy from diving and is the first reported case of suspected NSM associated with CAGE.

Lethal event in diving with self-contained underwater breathing apparatus: A forensic study

Introduction

In fatal accidents during scuba diving, it is necessary to differentiate a death from primary drowning from a secondary drowning death that is primarily due to other etiopathogenetic factors. The inhalation of water can only be the end point of a series of events capable of causing the diver's exitus. This study aims to demonstrate that even low-risk heart disease in daily life become potentially fatal during scuba diving.

Methods

In this case series, we describe all cases of deaths in the course of diving that came to the observation of the Forensic Institute of the University Bari over 20 years (2000-2020). A judicial autopsy was performed on all subjects, with ancillary execution of histological and toxicological investigations.

Results

The results of the medicolegal investigations carried out in the complex identified heart failure with acute myocardial infarction as the cause of death in four cases characterized by severe myocardiocoronarosclerosis, a primary drowning in a subject without previous pathological substrate in one case, and a terminal atrial fibrillation induced by acute dynamic heart failure due to functional overload of the right ventricle in one case.

Conclusion

Our study demonstrates that lethal events during diving are often related to the presence of unrecognized or subclinical cardiovascular diseases. Such deaths could be prevented and avoided if a greater regulatory sensitivity to preventing and controlling diving was encouraged, considering both the inherent risks of this activity and the possible unrecognized or underestimated pathologies.

Carbon monoxide poisoning can act as a stress test to reveal underlying coronary artery disease: case report

Carbon monoxide (CO) poisoning presents with many different cardiac effects, but one important presentation is its effect as a CO stress test to reveal underlying coronary artery disease (CAD). There are a limited number of publications detailing this phenomenon, but after CO intoxication it is important to suspect CAD in association with mild troponin leak or non-ST segment elevation myocardial infarction (NSTEMI) shown on electrocardiogram (EKG). We recently treated three patients with CO poisoning who had underlying CAD. In the first case a man presented to the emergency department with CO toxicity and an ST segment elevation myocardial infarction (STEMI), resulting in emergent angioplasty and the discovery of severe CAD. The second case involved an individual who presented with CO poisoning with rising troponin levels. An angioplasty discovered a stable 90% occlusion. The third case was a patient with CO poisoning and transient inferior T wave inversion EKG with borderline troponin elevation. Angioplasty showed only 30% occlusion, so the patient's presentation was likely due to direct CO cardiac toxicity. These cases demonstrate the varied presentations that CO poisoning can have on patients with underlying heart disease.

Successful use of hyperbaric oxygen therapy for limb salvage of acute limb ischemia as a complication of acute carbon monoxide poisoning

Acute limb ischemia (ALI) as a complication of acute carbon monoxide (CO) poisoning is rare. Several reports have utilized hyperbaric oxygen therapy (HBO2) as an adjunctive therapy for peripheral arterial diseases. However, no study has yet described the use of HBO2 for ALI precipitated by CO poisoning. Herein we report successful limb salvage achieved with adjunctive HBO2 and conventional therapies in a patient with CO-induced ALI. A 69-year-old man was admitted with acute CO poisoning; ALI of both lower extremities occurred on hospitalization day 3. Pre-existing risk factors for ALI other than CO were not definite. After conventional treatments including catheter-directed thrombolysis and endovascular thrombectomy, the right-side lesion remained and a left-side lesion was newly developed. In addition to prior therapies, 47 sessions of serial HBO2 were administered as adjunctive therapy, resulting in limb salvage. Acute CO poisoning can cause ALI as a rare complication. HBO2 may be utilized as an adjunctive treatment in ALI.

Carbon monoxide-induced atrial fibrillation resolved with hyperbaric oxygen

Carbon monoxide (CO) exposure is a prevalent cause of poisoning worldwide. The cardiac effects of CO poisoning are well described and can manifest as angina, myocardial ischemia or infarction, cardiogenic shock, and/or life-threatening arrhythmias. Atrial fibrillation has been associated with severe CO poisoning; however, few cases have described atrial fibrillation in acute CO poisoning with regard to hyperbaric oxygen (HBO2) therapy. Herein, we describe a case of severe CO poisoning that caused atrial fibrillation with successful conversion to sinus rhythm following HBO2 therapy and discuss implications for further research.

Immersion pulmonary edema: case reports from Oceania

INTRODUCTION

We aimed to document identified cases of immersion pulmonary edema (IPE) in divers from Oceania (the Indo-Pacific region) from January 2002 to May 2018, inclusive.

METHOD

Cases were identified using various sources, including searches of the Divers Alert Network Asia-Pacific (DAN AP) Fatality Database, published case reports, and interviews with survivors who had reported their incident to DAN AP. Where available, investigations, pathology and autopsy results were obtained. Only incidents diagnosed as IPE by diving physicians or pathologists with experience in the investigation of diving accidents were included. Individual case histories and outcomes, together with brief individual summaries of the associations and possible contributing factors were recorded.

RESULTS

Thirty-one IPE incidents in divers from Oceania were documented. There were two surface snorkelers, 22 scuba air divers and seven nitrox divers which included three closed-circuit rebreathers (CCR). The mean (SD) age was 53 (12) years, 58% of victims were females, and the average dive profile was to a maximum depth of 19 meters of seawater for 25 minutes. Six victims (19%) had previous episodes of IPE. There were nine recorded fatalities. Cardiac anomalies dominated the associated or possible contributing factors. These included valvular disease in 29%, transient cardiomyopathies in 26% and dysrhythmias in 16%.

CONCLUSIONS

Previously reported associations of IPE such as exertion, stress, cold exposure, negative inspiratory pressure, hypertension, overhydration, ascent or surfacing, tight wetsuit, aspiration and certain medications were identified. Cardiac conditions were frequent and included chronic disorders (valvular pathology, coronary artery disease) and transient disorders (dysrhythmias, transient myocardial dysfunction, takotsubo or stress cardiomyopathy). It is likely that the chronic cardiac disorders may have contributed to the IPE, whereas the transient cases could be either sequelae, contributors or coincidental to the IPE.

Immersion pulmonary edema: an analysis of 31 cases from Oceania

AIM

To review incidents of immersion pulmonary edema (IPE) from Oceania, to determine the demographics, diving parameters, and comorbidities that may be related to this disorder.

METHOD

Incidents of IPE, most of which were documented by Divers Alert Network Asia-Pacific (DAN AP) or reported in our medical literature, were analyzed. They included interviews with the survivors and a review of available medical records. Only incidents diagnosed as IPE by specialist diving physicians or pathologists with experience in the investigation of diving accidents were included.

RESULTS

Thirty-one IPE incidents in divers from Oceania were documented. There were two surface snorkelers, 22 scuba air divers and seven nitrox divers, which included three closed-circuit rebreathers (CCR). The mean (SD) age was 53 (12) years, 58% of victims were females, and the average dive profile was to a maximum depth of 19 msw for 25 minutes. Six victims (19%) had previous episodes of IPE. There were nine recorded fatalities in this cohort. Medical comorbidities were recorded in 68%, with 42% being cardiac. The latter included valvular disease in 29%, transient cardiomyopathies in 26% and dysrhythmias in 16%.

CONCLUSION

IPE was more likely in middle-aged females, in experienced divers, and during ascent or after surfacing. Commonly reported associations such as exertion, stress, cold exposure, negative inspiratory pressure, hypertension, overhydration, tight wetsuit, aspiration and certain medications were identified. This series supports the hypothesis that the elderly IPE subjects are likely to have comorbidities and be susceptible to IPE recurrences and fatalities unless the contributing factors can be identified and addressed.