Clinical characteristics of myocardial stunning in acute stroke

Clinical characteristics of aneurysmal subarachnoid haemorrhage complicated by Takotsubo cardiomyopathy resulting in good neurological outcome

BACKGROUND

Takotsubo cardiomyopathy (TC) is a well-known complication of subarachnoid haemorrhage (SAH), often accompanied by neurogenic myocardial dysfunction. Although TC has been reported to be associated with higher morbidity and mortality among patients with aneurysmal SAH (aSAH), some patients have been reported to recover, the profiles and follow-up outcomes of these survivors remain unclear.

MATERIALS AND METHODS

To characterize the profiles of patients with aSAH complicated by TC who experienced favourable outcomes using long-term follow-up data, a consecutive series of patients with aSAH were enrolled and TC diagnosis was based on the revised version of the Mayo Clinic criteria. Clinical outcomes were assessed at 6 months according to modified Rankin Scale scores.

RESULTS

Among 165 consecutive patients with aSAH, 15 cases were complicated by TC, corresponding to an occurrence rate of 9.0%. Five patients with aSAH complicated by TC (33.3%) experienced a favourable outcome, and the mean value of systolic blood pressure on arrival was significantly lower than in those who experienced an unfavourable outcome (p = 0.032).

CONCLUSION

According to analysis, it is possible cardiac dysfunction with decreased cerebral perfusion pressure and catecholamine toxicity transiently worsens conscious disturbance in aSAH complicated by TC. Therefore, it is important to carefully screen patients with aSAH to identify those complicated by TC, and for close collaboration of the multidisciplinary team to design appropriate treatment strategies.

Cardiac patterns for differentiation of neurogenic stunned myocardium in aneurysmal subarachnoid hemorrhage versus acute ischemic stroke

AIMS

Neurogenic stunned myocardium (NSM) has heterogeneous presentations for acute ischemic stroke (AIS) and aneurysmal subarachnoid hemorrhage (SAH). We sought to better define NSM and differences between AIS and SAH by evaluating individual left ventricular (LV) functional patterns by speckle tracking echocardiography (STE).

METHODS

We evaluated consecutive patients with SAH and AIS. Via STE, LV longitudinal strain (LS) values of basal, mid, and apical segments were averaged and compared. Different multivariable logistic regression models were created by defining stroke subtype (SAH or AIS) and functional outcome as dependent variables.

RESULTS

One hundred thirty-four patients with SAH and AIS were identified. Univariable analyses using the chi-squared test and independent samples t-test identified demographic variables and global and regional LS segments with significant differences. In multivariable logistic regression analysis, when comparing AIS to SAH, AIS was associated with older age (OR 1.07, 95% CI 1.02-1.13, p = 0.01), poor clinical condition on admission (OR 7.74, 95% CI 2.33-25.71, p < 0.001), decreased likelihood of elevated admission serum troponin (OR .09, 95% CI .02-.35, p < 0.001), and worse LS basal segments (OR 1.18, 95% CI 1.02-1.37, p = 0.03).

CONCLUSION

In patients with neurogenic stunned myocardium, significantly impaired LV contraction by LS basal segments was found in patients with AIS but not with SAH. Individual LV segments in our combined SAH and AIS population were also not associated with clinical outcomes. Our findings suggest that strain echocardiography may identify subtle forms of NSM and help differentiate the NSM pathophysiology in SAH and AIS.

Sex Hormone-Specific Neuroanatomy of Takotsubo Syndrome: Is the Insular Cortex a Moderator?

Takotsubo syndrome (TTS), a transient form of dysfunction in the heart’s left ventricle, occurs predominantly in postmenopausal women who have emotional stress. Earlier studies support the concept that the human circulatory system is modulated by a cortical network (consisting of the anterior cingulate gyrus, amygdala, and insular cortex (Ic)) that plays a pivotal role in the central autonomic nervous system in relation to emotional stressors. The Ic plays a crucial role in the sympathovagal balance, and decreased levels of female sex hormones have been speculated to change functional cerebral asymmetry, with a possible link to autonomic instability. In this review, we focus on the Ic as an important moderator of the human brain–heart axis in association with sex hormones. We also summarize the current knowledge regarding the sex-specific neuroanatomy in TTS.

Cerebral-Cardiac Syndrome and Diabetes: Cardiac Damage After Ischemic Stroke in Diabetic State

Cerebral-cardiac syndrome (CCS) refers to cardiac dysfunction following varying brain injuries. Ischemic stroke is strongly evidenced to induce CCS characterizing as arrhythmia, myocardial damage, and heart failure. CCS is attributed to be the second leading cause of death in the post-stroke stage; however, the responsible mechanisms are obscure. Studies indicated the possible mechanisms including insular cortex injury, autonomic imbalance, catecholamine surge, immune response, and systemic inflammation. Of note, the characteristics of the stroke population reveal a common comorbidity with diabetes. The close and causative correlation of diabetes and stroke directs the involvement of diabetes in CCS. Nevertheless, the role of diabetes and its corresponding molecular mechanisms in CCS have not been clarified. Here we conclude the features of CCS and the potential role of diabetes in CCS. Diabetes drives establish a “primed” inflammatory microenvironment and further induces severe systemic inflammation after stroke. The boosted inflammation is suspected to provoke cardiac pathological changes and hence exacerbate CCS. Importantly, as the key element of inflammation, NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome is indicated to play an important role in diabetes, stroke, and the sequential CCS. Overall, we characterize the corresponding role of diabetes in CCS and speculate a link of NLRP3 inflammasome between them.

Cardiovascular autonomic dysfunction after stroke

Strokes are the paradigmatic example of the sudden impairment of the cerebral regulation of cardiac autonomic regulation. Although several aspects of dysautonomic cardiovascular regulation post stroke remain unanswered, there has been a wealth of research in this area in the last decade. In this article, we present a state-of-the-art review on the anatomical and functional organization of cardiovascular autonomic regulation, and the pathophysiology, incidence, time course, diagnosis, clinical aspects, prognosis, and management of post-stroke cardiovascular autonomic dysfunction.

Circulatory dipeptidyl peptidase 3 (cDPP3) is a potential biomarker for early detection of secondary brain injury after aneurysmal subarachnoid hemorrhage

INTRODUCTION

Delayed cerebral ischemia (DCI) is a common complication after aneurysmal subarachnoid hemorrhage (aSAH) that can culminate in secondary brain damage. Although it remains one of the main preventable causes of aSAH-related morbidity, there is still a lack of prognostic criteria for identification of patients at risk of developing DCI. Because elevated circulatory levels of the enzyme dipeptidyl peptidase 3 (cDPP3) were recently identified as a potential biomarker for outcome prediction in critically ill patients, we evaluated the time-course of changes in cDPP3 levels after aSAH.

MATERIALS AND METHODS

cDPP3 levels were quantified in serum obtained from 96 confirmed aSAH patients during the early (EP: d_1-4), critical (CP: d_5-8, d_9-12, d_13-15) and late (LP: d_16-21) phase after aSAH onset. Associations between cDPP3 levels and demographic or clinical parameters were evaluated. The relations between cDPP3 levels and DCI, DCI-related infarctions and long-term clinical outcomes were examined by receiver operating characteristics (ROC) curve analysis and multivariate logistic regression.

RESULTS

Significantly higher cDPP3 levels during CP (d_5-8, d_9-12, d_13-15) were observed in patients with poor clinical (p < 0.001 to p = 0.033) or radiological (p = 0.012 to p = 0.039) status on admission, DCI (p < 0.001 to p = 0.001), DCI-related infarctions (p = 0.002 to p = 0.007), and poorer long-term outcome (p = 0.007 to p = 0.019). ROC curve analysis indicated that higher cDPP3 levels on d_5-8 are predictive for a poor clinical outcome (area under the curve = 0.677, p = 0.007). In multivariate analysis, there was an independent association between cDPP3 levels on d_5-8 and development of DCI-related infarctions (p = 0.038).

CONCLUSION

Our results provide first evidence that cDPP3 could serve as a promising biomarker for early diagnosis of DCI-related infarctions in poor grade aSAH patients.

Cardiac Dysfunction in Neurocritical Care: An Autonomic Perspective

A number of neurologic disorders can cause cardiac dysfunction by involving the conductive system and contractile apparatus of the heart. This is especially prominent in the neurocritical care setting where the spectrum of cardiac dysfunction due to acute neurologic injury ranges from trivial and isolated electrocardiographic changes to malignant arrhythmias and sudden death (Table 1). The mechanism of these cardiac complications is complex and not fully understood. An understanding of the neuroanatomical structures and pathways is of immense importance to comprehend the underlying pathophysiology that culminates as cardiac damage and dysregulation. Once the process is initiated, it can complicate and adversely affect the outcome of primary neurologic conditions commonly seen in the neurocritical care setting. Not only are these cardiac disorders under-recognized, there is a paucity of data to formulate evidence-based guidelines regarding early detection, acute management, and preventive strategies. However, certain details of clinical features and their course combined with location of primary neurologic lesion on neuroimaging and data obtained from laboratory investigations can be of great value to develop a strategy to appropriately manage these patients and to prevent adverse outcome from these cardiac complications. In this review, we highlight the mechanisms of cardiac dysfunction due to catastrophic neurologic conditions or due to stress of critical illness. We also address various clinical syndromes of cardiac dysfunction that occur as a result of the neurologic illness and in turn may complicate the course of the primary neurologic condition.

Myocardial ischemic changes of electrocardiogram in intracerebral hemorrhage: A case report and review of literature

BACKGROUND

Cardiac injury may occur after acute pathology of central nervous system (CNS) without any evidence of primary cardiac diseases. The resulting structural and/or functional changes are called cerebrocardiac syndrome (CCS). The great majority of studies have been performed in patients with subarachnoid hemorrhage (SAH), while CCS data after intracerebral hemorrhage (ICH) are rare. It may cause diagnostic and therapeutic pitfalls for the clinician due to a lack of specific clinical manifestations and diagnostic methods. Understanding the underlying pathophysiological and molecular mechanism(s) following cerebrovascular incidents will help to implement prevention and treatment strategies to improve the prognosis.

CASE SUMMARY

A 37-year-old man with a history of hypertension presented to our department on an emergency basis because of a sudden dizziness and left limb weakness. Cerebral computed tomography (CT) suggested ICH in the occipital and parietal lobes, and the chosen emergency treatment was hematoma evacuation. Left ventricular (LV) dysfunction occurred after the next 48 h and the electrocardiogram (ECG) showed non-ST elevation myocardial infarction. CCS was suspected first in the context of ICH due to the negative result of the coronary CT angiogram.

CONCLUSION

Misinterpretation of ischemic-like ECGs may lead to unnecessary or hazardous interventions and cause undue delay of rehabilitation after stroke. Our objective is to highlight the clinical implications of CCS and we hope the differential diagnoses will be considered in patients with acute CNS diseases.

Central action of rapamycin on early ischemic injury and related cardiac depression following experimental subarachnoid hemorrhage

Early brain injury and related cardiac consequences play a key role in the devastating outcomes after subarachnoid hemorrhage (SAH). We reported that rapamycin exerts neuroprotection against cortical hypoxia early after SAH, but its mechanism is poorly understood. This in vivo study aimed to determine the potential role of the transcription factor STAT3 in the rapamycin-mediated neuroprotection in a mouse model of SAH. Forty C57BL/6 N mice were treated with an intracerebroventricular injection of rapamycin or vehicle (control) given after SAH induction by a filament perforation method, with or without STAT3 (Stattic) or ERK (PD98059) inhibitor pretreatment. Cerebral blood flow signals (%vascularity), brain tissue oxygen saturation (SbtO₂), and cardiac output (CO) were analyzed using an ultrasound/photoacoustic imaging system. Clinically relevant neurocardiac depression was notable in severe SAH mice. Rapamycin improved %vascularity, SbtO₂, and CO on day 1 after SAH onset. The beneficial effects of rapamycin on cerebral blood flow and oxygenation persisted until day 3, resulting in a significant reduction in post-SAH new cerebral infarctions and survival, as well as improved neurological functions, compared to the control group. All of the effects were attenuated by pretreatment with Stattic or PD98059. These data suggest that ERK and JAK/STAT3 pathways play an important role in the neurocardiac protection by rapamycin after SAH. We propose that rapamycin is a novel pharmacological strategy to target STAT3 activation, with a possible crosstalk through the ERK pathway, for the treatment of post-SAH early brain injury.

Takotsubo Syndrome: Clinical Features, Pathogenesis, Treatment, and Relationship with Cerebrovascular Diseases

PURPOSE OF REVIEW

This review paper aims to provide a complete and updated overview on the clinical and pathophysiological aspects of Takotsubo syndrome (TTS), including prognosis, therapy, and the association with cerebrovascular conditions.

RECENT FINDINGS

TTS is an increasingly recognized non-ischemic cardiomyopathy characterized by sudden, temporary weakening of the myocardium, of which the pathogenesis is unknown. Although pathogenesis of TTS remains unclear, a complex interaction between catecholamine-mediated stimulation, myocardial stunning, and subsequent stress-related myocardial dysfunction seems to be the main pathophysiological mechanism. Stroke is linked to TTS by a dual relationship since it may induce TTS by catecholamine release even if TTS itself also may be complicated by left ventricular thrombi leading to stroke. Given its possible complications, including the association with neurological diseases, both cardiologist and neurologists should be aware about TTS in order to diagnose it promptly and to initiate appropriate therapeutic measures.

Current interpretation of myocardial stunning

Myocardial stunning is a temporary post-ischemic cardiac mechanical dysfunction. As such, it is a heterogeneous entity and different conditions can promote its occurrence. Transient coronary occlusion, increased production of catecholamines and endothelin, and myocardial inflammation are all possible causes of myocardial stunning. Possible underlying mechanisms include an oxyradical hypothesis, calcium overload, decreased responsiveness of myofilaments to calcium, and excitation-contraction uncoupling due to sarcoplasmic reticulum dysfunction. The aim of this review is to summarize the clinical conditions that may be responsible for stunned myocardium.

Association Between Troponin Levels and Embolic Stroke of Undetermined Source

Background

Our aim was to determine whether patients with embolic strokes of undetermined source (ESUS) have higher rates of elevated troponin than patients with noncardioembolic strokes.

Methods and Results

CAESAR (The Cornell Acute Stroke Academic Registry) prospectively enrolled all adults with acute stroke from 2011 to 2014. Two neurologists used standard definitions to retrospectively ascertain the etiology of stroke, with a third resolving disagreements. In this analysis we included patients with ESUS and, as controls, patients with small‐ and large‐artery strokes; only patients with a troponin measured within 24 hours of stroke onset were included. A troponin elevation was defined as a value exceeding our laboratory's upper limit (0.04 ng/mL) without a clinically recognized acute ST‐segment elevation myocardial infarction. Multiple logistic regression was used to evaluate the association between troponin elevation and ESUS after adjustment for demographics, stroke severity, insular infarction, and vascular risk factors. In a sensitivity analysis we excluded patients diagnosed with atrial fibrillation after discharge. Among 512 patients, 243 (47.5%) had ESUS, and 269 (52.5%) had small‐ or large‐artery stroke. In multivariable analysis an elevated troponin was independently associated with ESUS (odds ratio 3.3; 95% confidence interval 1.2, 8.8). This result was unchanged after excluding patients diagnosed with atrial fibrillation after discharge (odds ratio 3.4; 95% confidence interval 1.3, 9.1), and the association remained significant when troponin was considered a continuous variable (odds ratio for log[troponin], 1.4; 95% confidence interval 1.1, 1.7).

Conclusions

Elevations in cardiac troponin are more common in patients with ESUS than in those with noncardioembolic strokes.

Acute cardiac support with intravenous milrinone promotes recovery from early brain injury in a murine model of severe subarachnoid haemorrhage

Early brain injury/ischaemia (EBI) is a serious complication early after subarachnoid haemorrhage (SAH) that contributes to development of delayed cerebral ischaemia (DCI). This study aimed to determine the role of inotropic cardiac support using milrinone (MIL) on restoring acute cerebral hypoperfusion attributable to EBI and improving outcomes after experimental SAH. Forty-three male C57BL/6 mice were assigned to either sham surgery (SAH-sham), SAH induced by endovascular perforation plus postconditioning with 2% isoflurane (Control), or SAH plus isoflurane combined with MIL with and without hypoxia-inducible factor inhibitor (HIF-I) pretreatment. Cardiac output (CO) during intravenous MIL infusion (0.25-0.75 μg/kg/min) between 1.5 and 2.5 hours after SAH induction was monitored with Doppler echocardiography. Magnetic resonance imaging (MRI)-continuous arterial spin labelling was used for quantitative cerebral blood flow (CBF) measurements. Neurobehavioral function was assessed daily by neurological score and open field test. DCI was analyzed 3 days later by determining infarction on MRI. Mild reduction of cardiac output (CO) and global cerebral blood flow (CBF) depression were notable early after SAH. MIL increased CO in a dose-dependent manner (P<.001), which was accompanied by improved hypoperfusion, incidence of DCI and functional recovery than Control (P<.05). The neuroprotective effects afforded by MIL or Control were attenuated by hypoxia-inducible factor (HIF) inhibition (P<.05). These results suggest that MIL improves acute hypoperfusion by its inotropic effect, leading to neurobehavioral improvement in mice after severe SAH, in which HIF may be acting as a critical mediator.

Neurocardiac protection with milrinone for restoring acute cerebral hypoperfusion and delayed ischemic injury after experimental subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Acute cerebral hypoperfusion following subarachnoid hemorrhage (SAH) is highly related to the pathogenesis of delayed cerebral ischemia (DCI), but the therapeutic option is poorly available. This study aimed to clarify the effect of milrinone (MIL) on cerebral blood flow (CBF) and related outcomes after experimental SAH.

METHODS

Twenty-seven male C57BL/6 mice were assigned to either sham surgery (SAH-sham; n=6), SAH induced by endovascular perforation (control; n=10), or SAH followed by cardiac support with intravenous MIL (n=11) performed 1.5-h after SAH induction. CBF, neurobehavioral function, occurrence of DCI were assessed by MR-continuous arterial spin labeling, daily neurological score testing, and diffusion- and T2-weighted MR images on days 1 and 3, respectively.

RESULTS

Initial global CBF depression was notable in mice of control and MIL groups as compared to the SAH-sham group (P<0.05). MIL raised CBF in a dose-dependent manner (P<0.001), resulted in lower incidence of DCI (P=0.008) and better recovery from neurobehavioral decline than control (P<0.001). The CBF values on day 1 predicted DCI with a cut-off of 42.5ml/100g/min (82% specificity and 83% sensitivity), which was greater in mice treated with MIL than those of control (51.7 versus 37.6ml/100g/min; P<0.001).

CONCLUSION

MIL improves post-SAH acute hypoperfusion that can lead to the prevention of DCI and functional worsening, acting as a neurocardiac protective agent against EBI.

Inotropic support against early brain injury improves cerebral hypoperfusion and outcomes in a murine model of subarachnoid hemorrhage

Early brain injury/ischemia is a recent therapeutic target that contributes to triggering delayed cerebral ischemia (DCI) in the setting of subarachnoid hemorrhage (SAH). This study aimed to determine the role of dobutamine for inotropic cardiac support in improving cerebral blood flow (CBF) and outcomes after experimental SAH, mediated by hypoxia-inducible factor (HIF). Thirty-one mice were subjected to SAH by endovascular perforation, and assigned to either 2% isoflurane postconditioning performed between 1 and 2.5h after SAH induction or concomitant intravenous dobutamine infusion (15μg/kg/min) with or without HIF inhibitor 2-methoxyestradiol (2ME2) (10mg/kg) administered intraperitoneally. Neurobehavioral function was assessed daily by neurological scores and open field testing. DCI was defined 3days later by detecting a new infarction on MRI. Global CBF depression was notable early after SAH, but dobutamine showed significant improvement in CBF, lower incidence of DCI, and better recovery of neuroscores and open field test variables compared with isoflurane postconditioning (P<0.05). CBF over the entire brain on day 1 predicted DCI with a cut-off of 36.5ml/100g/min (80% specificity and 67% sensitivity), with a better area under the curve (0.83 versus 0.75) than the hemispheric CBF measured on the perforated side. The dobutamine-mediated outcomes were attenuated (P<0.05) by 2ME2 pretreatment. The data suggest that cardiac support with dobutamine improves global CBF depression induced by early brain injury, leading to reduced prevalence of DCI and better functional outcomes after experimental SAH, in which HIF may be acting as a critical mediator.

Clinical and Echocardiographic Characteristics of Acute Cardiac Dysfunction Associated With Acute Brain Hemorrhage - Difference From Takotsubo Cardiomyopathy

BACKGROUND

Cardiac dysfunction (CD) associated with brain hemorrhage is similar to that with takotsubo cardiomyopathy but still not well understood. We aimed to investigate the clinical and echocardiographic findings of acute CD (ACD) related to brain hemorrhage.

METHODS AND RESULTS

Between 2013 and 2014, consecutive patients diagnosed with spontaneous and traumatic brain hemorrhage were prospectively enrolled. Electrocardiography, cardiac enzymes, and echocardiography were performed. Left ventricular (LV) systolic dysfunction on echocardiography was defined as ACD related to brain hemorrhage when all the following conditions were satisfied: abnormal ECG and cardiac troponin level, LV wall motion abnormality or decreased LV systolic function on echocardiography, and no previous history of cardiac disease. Otherwise, LV dysfunction was considered to be other CD unrelated to brain hemorrhage. In a total of 208 patients, 15 (7.2%) showed ACD. Of them, 8 patients were men and 8 showed apex-sparing LV hypokinesia and 9 died in hospital. Other cardiac abnormalities observed in the study patients were NT-proBNP elevation (n=123), QT interval prolongation (n=95), LV hypertrophy (n=89), and troponin I elevation (n=47). There were 36 in-hospital deaths (17.3%). Glasgow coma score and ACD were independently associated with in-hospital death.

CONCLUSIONS

ACD was observed in patients with various brain hemorrhages. Unlike takotsubo cardiomyopathy, high proportions of male sex, apex-sparing LV dysfunction, and in-hospital death were observed for ACD associated with brain hemorrhage. (Circ J 2016; 80: 2026-2032).

The evaluation of myocardial function of patients in the early stage of acute ischemic stroke by two-dimensional speckle tracking echocardiography

PURPOSE

To evaluate the myocardial dysfunction in the early stage of nonhemorrhagic stroke and its association with the National Institutes of Health Stroke Scale (NIHSS) score, by two-dimensional speckle tracking echocardiography.

METHODS

We included 29 patients with acute ischemic stroke, in whom NIHSS scores were calculated and stroke infarct volumes recorded. Within 48 hours of admission, cardiac evaluation with speckle tracking echocardiography was performed and left ventricular global longitudinal strain (GLS) and global longitudinal systolic strain rate were obtained. These measurements were repeated on the 10th day.

RESULTS

NIHSS score improved, but infarct volume increased (p = 0.011 and 0.065, respectively) from admission to day 10. Ejection fraction was 53.2% and 55.8%, respectively, at admission and day 10 (p = 0.482), while GLS improved from -16.41% to -18.76% (p = 0.003).

CONCLUSIONS

GLS and global longitudinal systolic strain rate showed significant improvement together with NIHSS score. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:305-311, 2016.

Isoflurane postconditioning with cardiac support promotes recovery from early brain injury in mice after severe subarachnoid hemorrhage

AIMS

Neurocardiac dysfunction is a life-threatening systemic consequence of subarachnoid hemorrhage (SAH) that contributes to triggering delayed cerebral ischemia (DCI). This study aimed to determine the impact of dobutamine cardiac support during isoflurane postconditioning on post-SAH DCI.

MAIN METHODS

Male C57BL/6 mice were subjected to SAH, SAH plus isoflurane postconditioning, or SAH plus isoflurane postconditioning with dobutamine. Severity of SAH was graded from 1 to 4 (mild, 1-2; severe, 3-4) based on T2*-weighted magnetic resonance imaging (MRI). Cardiac output (CO) measured by transthoracic pulsed wave Doppler-echocardiography was titrated at a supra-normal level with intravenous dobutamine infusion. Neurological function was examined daily by neurological score and Rotarod tests. DCI was analyzed 3days later by determining new infarction on diffusion-weighted MRI. In a separate experiment, mice were pretreated with hypoxia-inducible factor (HIF) inhibitor 2-methoxyestradiol (2ME2).

KEY FINDINGS

Clinically relevant CO depression was notable in severe SAH grade mice, in which dobutamine CO management combined with isoflurane postconditioning showed earlier and improved functional recovery than postconditioning with single isoflurane inhalation. Incidence of infarction and volumes on day 3 reduced significantly in this subgroup. All of the effects during preconditioning were attenuated by 2ME2 pretreatment.

SIGNIFICANCE

Isoflurane postconditioning under dobutamine cardiac support improves recovery from SAH-induced early brain injury, leading to reduced DCI resultant from severe experimental SAH. These results indicate the importance of neuro-cardiac protection, in which HIF may be acting as a critical mediator, as a promising therapeutic approach to SAH.

Routine Troponin Measurements Are Unnecessary to Exclude Asymptomatic Coronary Events in Acute Ischemic Stroke Patients

BACKGROUND

Obtaining serum troponin levels in every patient with acute stroke is recommended in recent stroke guidelines, but there is no evidence that these contribute positively to clinical care. We sought to determine the clinical significance of measuring troponin levels in acute ischemic stroke patients.

METHODS

We reviewed 398 consecutive patients with acute ischemic stroke at a large academic institution from 2010 to 2012. Troponin levels were measured as a result of protocol in place during part of the study period. The mean age was 70 years (standard deviation ±16 years) and 197 (49.5%) were men.

RESULTS

Chronic kidney disease was present in 78 (19.6%), coronary artery disease in 107 (26.9%), and atrial fibrillation in 107 (26.9%). Serum troponin T was measured in 246 of 398 patients (61.8%). Troponin was elevated (>.01 ng/mL) at any point in 38 of 246 patients (15.5%) and was elevated in 28 patients at all 3 measurements (11.3% of those with troponin measured). Only 4 of 246 patients (1.6%) had a significant uptrend. Two were iatrogenic in the setting of hemodynamic augmentation using vasopressors to maintain cerebral perfusion. One case was attributed to stroke and chronic kidney disease and another case to heart failure from inflammatory fibrocalcific mitral valvular heart disease.

CONCLUSIONS

Serum troponin elevation in patients with ischemic stroke is not usually caused by clinically significant acute myocardial ischemia unless iatrogenic in the setting of vasopressor administration. Serum troponin levels should be measured judicially, based on clinical context, rather than routinely in all stroke patients.

GABAB Encephalitis: A Fifty-Two-Year-Old Man with Seizures, Dysautonomia, and Acute Heart Failure

Autoantibodies to the γ-aminobutyric acid receptor, subtype B (GABAB), are a known cause of limbic encephalitis. The spectrum of clinical manifestations attributable to this antibody is not well defined at the present time. Here we present a case of GABAB encephalitis presenting with encephalopathy, status epilepticus, dysautonomia, and acute heart failure. To our knowledge, heart failure and dysautonomia have not yet been reported with this syndrome.

Subarachnoid hemorrhage mimicking myocardial infarction

We discuss a patient with an aneurysmal subarachnoid hemorrhage (SAH) presenting with chest pain, electrocardiogram changes compatible with myocardial infarction, and headache. SAH is a medical emergency but an initial misdiagnosis is common, and diagnosis can be delayed due to atypical presentations. The delay of diagnosis of SAH may endanger the life of the patient. Electrocardiogram abnormalities have been described previously in aneurysmal SAH, and can obscure the correct diagnosis.

In-hospital outcomes of aneurysmal subarachnoid hemorrhage associated with cocaine use in the USA

Cocaine use is associated with higher mortality in small retrospective studies of brain-injured patients. We aimed to explore in-hospital outcomes in a large population based study of aneurysmal subarachnoid hemorrhage (aSAH) with cocaine use. aSAH patients were identified from the 2007-2010 USA Nationwide Inpatient Sample using International Classification of Disease, Ninth Revision codes. Demographics, comorbidities and surgical procedures were compared between cocaine users and non-users. The primary outcomes were in-hospital mortality and home discharge/self-care. Secondary outcomes were vasospasm treated with angioplasty, hydrocephalus, gastrostomy and tracheostomy. There were 103,876 patients with aSAH. The cocaine group were younger (45.8 ± 9.8 versus 58.4 ± 15.8, p<0.001), predominantly male (53.3% versus 38.5%, p<0.001) and had a higher proportion of black patients (36.9% versus 11.5%, p<0.001). The incidence of seizures was higher among cocaine users (16.2% versus 11.1%, p<0.001). Endovascular coiling of intracranial aneurysms (24% versus 18.5%, p<0.001) was more frequent in cocaine users. The univariate analysis showed higher rates of in-hospital mortality and vasospasm treated with angioplasty, but lower home discharge in the cocaine group. In the multivariate analysis, the cocaine cohort had higher in-hospital mortality (odds ratio [OR] 1.43, 95% confidence interval [CI] 1.27-1.61, p<0.001) and lower home discharge rates (OR 0.79, 95% CI 0.69-0.87, p<0.001) after adjusting for confounders. Rates of vasospasm treated with angioplasty however were similar between the two groups. Cocaine use was found to be independently associated with poor outcomes, particularly higher mortality and lower home discharge rates. Cocaine use however, was not associated with vasospasm that required treatment with angioplasty. Prospective confirmation is warranted.