Myocardial Infarction and Cardiac Arrest During Acquisition of 18 F-FDG PET/CT.

ABSTRACT: An 83-year-old man with multiple myeloma and history of coronary artery disease and ischemic cardiomyopathy experienced cardiac arrest during the 18 F-FDG PET/CT examination. The patient had not yet been treated for multiple myeloma. The PET/CT demonstrated focal FDG uptake about the left anterior descending coronary artery. Diffuse intense FDG uptake in the liver and less than normal uptake in other organs of usual FDG distribution were also present, likely due to altered hemodynamics and heart failure in the setting of an acute coronary syndrome.

Quantitative magnetic resonance imaging assessment of brain injury after successful cardiopulmonary resuscitation in a rat model of asphyxia cardiac arrest.

The aim of this study was to use dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted magnetic resonance imaging (DWI) to measure changes in blood-brain barrier (BBB) permeability and cerebral edema over time in a rat model of asphyxial cardiac arrest (ACA). ACA was established by endotracheal tube clamping. Male rats were randomized into a sham group (n = 5) and three ACA groups (n = 18). After return of spontaneous circulation (ROSC), the rats were randomized to perform DWI and DCE-MRI exam in the 6 h, 24 h and 72 h timepoint (ROSC + 6 h, ROSC + 24 h, and ROSC + 72 h). Results shows that fifteen of 18 animals achieved successful resuscitation in the ACA groups. The average apparent diffusion coefficient(ADC) value of the whole brain in ROSC + 6 h was markedly lower than those of the sham, ROSC + 24 h, and ROSC + 72 h. The aquaporin-4(AQP4) score in ROSC + 6 h was significantly higher than those in the other groups, which were negatively correlated with the ADC values. The ratio of whole brain to masseter muscle of volume transfer constant (rKtrans), tissue interstitium-to-plasma rate constant(rKep), and fractional extra-cellular space volume(rVe) in ROSC + 6 h were all significantly higher than those in the sham, ROSC + 24 h, and ROSC + 72 h. The transforming growth factor ß1(TGF-ß1) and vascular endothelial growth factor A(VEGF-a) scores in ROSC + 6 h were significantly higher than those in the other groups, which were all positively correlated with rKtrans and rKep. In conclusions, brain injury is a frequent complication after CA and resuscitation. DWI and DCE-MRI can quantitatively evaluate brain injury in term of cerebral edema and BBB permeability after successful CPR.

Inhaled nitric oxide preserves ventricular function during resuscitation using a percutaneous mechanical circulatory support device in a porcine cardiac arrest model: an echocardiographic myocardial work analysis.

BACKGROUND: Resuscitation using a percutaneous mechanical circulatory support device (iCPR) improves survival after cardiac arrest (CA). We hypothesized that the addition of inhaled nitric oxide (iNO) during iCPR might prove synergistic, leading to improved myocardial performance due to lowering of right ventricular (RV) afterload, left ventricular (LV) preload, and myocardial energetics. This study aimed to characterize the changes in LV and RV function and global myocardial work indices (GWI) following iCPR, both with and without iNO, using 2-D transesophageal echocardiography (TEE) and GWI evaluation as a novel non-invasive measurement. METHODS: In 10 pigs, iCPR was initiated following electrically-induced CA and 10 min of untreated ventricular fibrillation (VF). Pigs were randomized to either 20 ppm (20 ppm, n = 5) or 0 ppm (0 ppm, n = 5) of iNO in addition to therapeutic hypothermia for 5 h following ROSC. All animals received TEE at five pre-specified time-points and invasive hemodynamic monitoring. RESULTS: LV end-diastolic volume (LVEDV) increased significantly in both groups following CA. iCPR alone led to significant LV unloading at 5 h post-ROSC with LVEDV values reaching baseline values in both groups (20 ppm: 68.2 ± 2.7 vs. 70.8 ± 6.1 mL, p = 0.486; 0 ppm: 70.8 ± 1.3 vs. 72.3 ± 4.2 mL, p = 0.813, respectively). LV global longitudinal strain (GLS) increased in both groups following CA. LV-GLS recovered significantly better in the 20 ppm group at 5 h post-ROSC (20 ppm: - 18 ± 3% vs. 0 ppm: - 13 ± 2%, p = 0.025). LV-GWI decreased in both groups after CA with no difference between the groups. Within 0 ppm group, LV-GWI decreased significantly at 5 h post-ROSC compared to baseline (1,125 ± 214 vs. 1,835 ± 305 mmHg%, p = 0.011). RV-GWI was higher in the 20 ppm group at 3 h and 5 h post-ROSC (20 ppm: 189 ± 43 vs. 0 ppm: 108 ± 22 mmHg%, p = 0.049 and 20 ppm: 261 ± 54 vs. 0 ppm: 152 ± 42 mmHg%, p = 0.041). The blood flow calculated by the Impella controller following iCPR initiation correlated well with the pulsed-wave Doppler (PWD) derived pulmonary flow (PWD vs. controller: 1.8 ± 0.2 vs. 1.9 ± 0.2L/min, r = 0.85, p = 0.012). CONCLUSIONS: iCPR after CA provided sufficient unloading and preservation of the LV systolic function by improving LV-GWI recovery. The addition of iNO to iCPR enabled better preservation of the RV-function as determined by better RV-GWI. Additionally, Impella-derived flow provided an accurate measure of total flow during iCPR.

Mortality in patients with hepatic gas on point-of-care ultrasound in cardiac arrest: Does location matter?

PURPOSE: Prior research has suggested an association of hepatic venous gas with mortality in cardiac arrest. As point of care ultrasound (POCUS) is frequently used in the context of resuscitation, we sought to evaluate if the presence of hepatic gas on POCUS had a similar mortality association. METHODS: A retrospective review was conducted of patients who experienced nontraumatic cardiac arrest. Archived ultrasound images were independently reviewed to determine the presence of gas in the hepatic parenchyma and vasculature. Electronic medical records were then reviewed to collect remaining clinical data. RESULTS: From 1 January 2017 through 16 June 2019, 87 patients met inclusion criteria. Among them, 68 (78.2%) patients died. Among those who died, 40 (58.8%) had hepatic gas, while 28 (41.2%) had none. Only a single survivor demonstrated hepatic venous gas (11%). While the difference in mortality with respect to presence of undifferentiated hepatic gas was not significant (P = .37), there was a significant difference with respect to the presence of venous gas (P = .004). CONCLUSION: Our study demonstrated that the incidence of postarrest hepatic gas on POCUS was common, and that the presence of hepatic venous gas during cardiac resuscitation was associated with increased mortality, while hepatic parenchymal gas alone was not.

Hypoxic-Ischemic Encephalopathy Evaluated by Brain Autopsy and Neuroprognostication After Cardiac Arrest.

Importance: Neuroprognostication studies are potentially susceptible to a self-fulfilling prophecy as investigated prognostic parameters may affect withdrawal of life-sustaining therapy. Objective: To compare the results of prognostic parameters after cardiac arrest (CA) with the histopathologically determined severity of hypoxic-ischemic encephalopathy (HIE) obtained from autopsy results. Design, Setting, and Participants: In a retrospective, 3-center cohort study of all patients who died following cardiac arrest during their intensive care unit stay and underwent autopsy between 2003 and 2015, postmortem brain histopathologic findings were compared with post-CA brain computed tomographic imaging, electroencephalographic (EEG) findings, somatosensory-evoked potentials, and serum neuron-specific enolase levels obtained during the intensive care unit stay. Data analysis was conducted from 2015 to 2020. Main Outcomes and Measures: The severity of HIE was evaluated according to the selective eosinophilic neuronal death (SEND) classification and patients were dichotomized into categories of histopathologically severe and no/mild HIE. Results: Of 187 included patients, 117 were men (63%) and median age was 65 (interquartile range, 58-74) years. Severe HIE was found in 114 patients (61%) and no/mild HIE was identified in 73 patients (39%). Severe HIE was found in all 21 patients with bilaterally absent somatosensory-evoked potentials, all 15 patients with gray-white matter ratio less than 1.10 on brain computed tomographic imaging, all 9 patients with suppressed EEG, 15 of 16 patients with burst-suppression EEG, and all 29 patients with neuron-specific enolase levels greater than 67 µg/L more than 48 hours after CA without confounders. Three of 7 patients with generalized periodic discharges on suppressed background and 1 patient with burst-suppression EEG had a SEND 1 score (<30% dead neurons) in the cerebral cortex, but higher SEND scores (>30% dead neurons) in other oxygen-sensitive brain regions. Conclusions and Relevance: In this study, histopathologic findings suggested severe HIE after cardiac arrest in patients with bilaterally absent cortical somatosensory-evoked potentials, gray-white matter ratio less than 1.10, highly malignant EEG, and serum neuron-specific enolase concentration greater than 67 µg/L.

Interventionist videothermometry: a new model of cardiac ischemia evaluation.

BACKGROUND: The purpose of the present study was to evaluate, through videothermometry, the temperature variation in the hearts of rabbits, that underwent induced myocardial ischemia and reperfusion. RESULTS: A total of 20 female rabbits were divided into two groups: a treated group and a sham group, the treatment group underwent 5 min of cardiac arrest and reperfusion, using the inflow occlusion technique. Throughout the experiment, the animals were monitored by videothermometry, observing the thermal variations of the myocardial tissue. During the experiment, at different times, blood gas tests and tests to evaluate the lactate concentrations were performed. At the end of the experiment, each heart was submitted to histopathological evaluation. In the treated group, there was a reduction in temperature of the myocardial tissue during the circulatory arrest compared to the sham group. Additionally, a colder area next to the caudal vena cava ostium and the right atrium was observed. Notably, despite the 5 min of cardiac arrest in the treated group, both the lactate and bicarbonate levels were maintained without significant variation. However, there was an increase in PaCO2 and pH reduction, featuring respiratory acidosis. In relation to the histopathological study, the presence of hydropic degeneration in the myocardium of animals in the treated group was observed. CONCLUSIONS: Based on these results, the videothermometry was efficient in identifying the range of myocardial tissue temperature, suggesting that the first areas to suffer due to cardiac arrest were the caudal vena cava ostium and the right atrium. However, in regard to the angiographic coronary thermography, the study was not feasible due to the small size of the coronary. There was no variation between the groups regarding the presence of myocardial infarction, myocardial congestion, myocardial edema and myocardial hemorrhage.

Ultrasound improves the outcomes of cardiopulmonary resuscitation in rats by stimulating the cholinergic anti­inflammatory pathway.

The present study investigated the effects of the ultrasound (US), a noninvasive technique, on ischemia­reperfusion injury (IRI) following cardiopulmonary resuscitation (CPR). The animals used in the present study were randomized into five groups (n=8 per group) as follows: i) The CPR group, where the rats underwent 6 min of untreated ventricular fibrillation (VF) followed by CPR and defibrillation; ii) the US group, in which the treatment was identical to the CPR group with the exception that rats were exposed to US treatment 24 h prior to CPR; iii) the MLA group, in which the treatment was identical to the US group with the exception that the α7 nicotinic acetylcholine receptor (α7nAChR) antagonist MLA (4 mg/kg) was administered 30 min prior to US and VF respectively; iv) the GTS group, in which the treatment was identical to the CPR group with the exception that the α7nAChR agonist GTS­21 (4 mg/kg) was injected 30 min prior to VF; and v) the SHAM group, in which the rats were exposed to surgical preparation without CPR and US application. At 1 day prior to CPR, the US treatment was administered to the left kidney by US pulses (contrast general mode with 9 MHz) with a bursting mechanical index of 0.72 for 2 min. Following treatment of the left kidney, the right kidney was exposed to identical US treatment for an additional 2 min. The results demonstrated that US preconditioning decreased the number of defibrillations required and shortened the duration of CPR. US also suppressed tumor necrosis factor­α and interleukin­6 levels following resuscitation (P<0.05), and a significantly longer overall survival time was observed in the US­treated animals (P<0.01). In addition, US attenuated neuronal injury and promoted the expression of α7nAChR in hippocampal neurons (P<0.05). However, the protective effects of US were abolished by MLA and imitated by GTS­21. The results of the present study demonstrated that prior exposure to US may improve animal outcomes following CPR, and the protective effects of US may be dependent on the cholinergic anti­inflammatory pathway (CAP) via α7nAChR.

Congenital absence of coronary ostia in a single/common coronary system.

Coronary ostial atresia seen with pulmonary atresia and coronary-cameral fistulae or, more rarely, in isolation manifested as left main coronary artery atresia, is well described. We describe the clinical course and post-mortem findings in a neonate who suffered a fatal cardiac arrest and was found to have congenital absence of both coronary ostia in a single/common coronary system.

Cardiac arrest due to acute massive aortic root thrombosis after pericardial bioprosthetic aortic valve replacement.

Acute aortic root thrombosis extended to coronary ostia is a rare but potentially life-threatening complication of aortic valve replacement with bioprosthetic substitutes. We aimed to present the case of a 72-year-old woman with symptomatic rheumatic valve disease and associated atrial fibrillation who underwent conventional mitroaortic valve replacement with two stented bioprostheses (pericardial and porcine, respectively). Eight days after surgery, she had cardiac arrest due to ventricular fibrillation, requiring immediate cardiopulmonary resuscitation. Left ventricle akinesia by echocardiography and troponin levels up to 35,000 ng/L pointed to coronary ischemia. Emergent coronary angiography showed a subocclusion of the left main trunk, with the suspicion of aortic root thrombosis. The patient was immediately reoperated, fresh thrombi were removed from the aortic root, and the aortic Magna Ease 21-mm bioprosthesis was replaced with a stentless Solo Smart 21-mm bioprosthesis. The patient died of septic complications.

A Case Report Describing the Use of Point of Care Ultrasound to Guide Successful Cardiopulmonary Resuscitation After Unanticipated Arrest in Ambulatory Surgery.

We present a case of a 41-year-old man who suffered cardiac arrest after induction of general anesthesia for an ambulatory ophthalmologic procedure. In this report, we highlight the use of focused transthoracic echocardiography by the anesthesia team to guide a prolonged resuscitation. Emergency room and critical care physicians have described the use of focused echocardiography to aid in diagnosing correctible causes of cardiac arrest, predicting outcomes, and in decision making regarding termination of resuscitation. We discuss benefits and barriers to anesthesiologists incorporating focused cardiac ultrasound into the perioperative arena.

Optimizing Patient Access During an Emergency While Using Intraoperative Computed Tomography.

BACKGROUND: As minimally invasive spine surgery evolves, spine surgeons increasingly rely on advanced intraoperative computed tomography (iCT). iCT provides rapid acquisition of high-resolution images, reduces radiation exposure, improves surgical accuracy, and decreases operative time. However, all iCT systems currently available pose a patient safety risk as their physical space requirements limit patient access in the event of an emergency, particularly when patients are in the prone position. After a near-cardiac arrest at our institution during posterior cervical spine surgery, it was apparent that the presence of the iCT complicated the ability to rapidly reposition the patient in order to provide appropriate resuscitation. METHODS: To ensure our ability to provide timely care during an emergency, we determined that a process which included all members of the operating room (OR) team was required. We held an initial planning meeting where a detailed plan-of-action was created, reviewed, and revised in response to feedback from all stakeholders. We then simulated a cardiac arrest to test our resuscitation plan with all members of the neurosurgery team. A mannequin was positioned prone on an OR table within the iCT, and a resuscitation plan was created. RESULTS: The team orchestrated the mock resuscitation, and the time of cardiac arrest in the prone position to supine repositioning required 110 seconds. The simulation was recorded for post-"code" performance review. Application of the protocol during an actual cardiac arrest was associated with successful restoration of spontaneous circulation and full recovery. CONCLUSIONS: The development and rehearsal of an emergency plan of action greatly facilitated the timely responsiveness of the neurosurgical OR team during a simulated cardiac arrest and was an effective way to identify and address key logistical issues regarding the use of an iCT system.

Point-of-care ultrasound (POCUS): unnecessary gadgetry or evidence-based medicine?

Over the last decade there has been increasing interest and enthusiasm in point-of-care ultrasound (POCUS) as an aide to traditional examination techniques in assessing acutely unwell adult patients. However, it currently remains the domain of a relatively small handful of physicians within the UK. There are numerous reasons for this, notably a lack of training pathways and supervisors but also a lack of understanding of the evidence base behind this imaging modality. This review article aims to explore some of the evidence base behind POCUS for a number of medical pathologies, and where possible compare it to evidenced traditional examination techniques. We discuss the issues around training in bedside ultrasound and recommend a push to integrate POCUS training into internal medicine curricula and support trainers to comprehensively deliver this.

Cardiac Arrest During Spine Surgery in the Prone Position: Case Report and Review of the Literature.

OBJECTIVE: Intraoperative cardiac arrest (CA) is usually attributable to pre-existing disease or intraoperative complications. In rare cases, intraoperative stress can demask certain genetic diseases, such as catecholaminergic polymorphic ventricular tachycardia (CPVT). It is essential that neurosurgeons be aware of the etiologies, risk factors, and initial management of CA during surgery with the patient in the prone position. METHODS: We present a case of CA directly after spinal fusion for lumbar spondylolisthesis and review the literature on cardiac arrests during spinal neurosurgery in the prone position. We focus on etiologies of CA in patients with structurally normal hearts. RESULTS: After resuscitation, a 53-years-old female patient achieved return of spontaneous circulation after 17 minutes, without any neurologic deficits and with substantial improvement of functional disability and pain scores. Extensive imaging, stress testing, and genetic screening ruled out common etiologies of CA. In this patient with a structurally normal heart, CPVT was established as the most likely cause. We identified 18 additional cases of CA associated with spinal neurosurgery in the prone position. Most cases occurred during deformity or fusion procedures. Commonly reported etiologies of CA were air embolism, hypovolemia, and dural traction leading to vasovagal response. In patients with structurally normal hearts, inherited arrhythmia syndromes including CPVT, Brugada syndrome, and long QT syndrome should be included in the differential diagnosis and specifically included in testing. CONCLUSIONS: Although intraoperative CA is rare during spine surgery, neurosurgeons should be aware of the etiologies and the specific difficulties in the management associated with the prone position.