ECG abnormalities in predicting secondary cerebral ischemia after subarachnoid haemorrhage

Electrocardiogram alterations in non-traumatic brain injury: a systematic review

The presence of abnormal electrocardiograms in individuals without known organic heart disease is one of the most common manifestations of cardiac dysfunction occurring during acute non traumatic brain injury. The primary goal of the present review is to provide an overview of the available data and literature regarding the presence of new-onset electrocardiographic (ECG) alterations in acute non traumatic brain injury. The secondary aim is to identify the incidence of ECG alterations and consider the prognostic significance of new-onset ECG changes in this setting. To do so, English language articles from January 2000 to January 2022 were included from PubMed using the following keywords: "electrocardiogram and subarachnoid hemorrhage", "electrocardiogram and intracranial hemorrhage", "Q-T interval and subarachnoid hemorrhage ", "Q-T interval and intracranial bleeding ", "Q-T interval and intracranial hemorrhage", and "brain and heart- interaction in stroke". Of 3162 papers, 27 original trials looking at electrocardiogram alterations in acute brain injury were included following the PRISMA guideline. ECG abnormalities associated with acute brain injury could potentially predict poor patient outcomes. They could even herald the future development of neurogenic pulmonary edema (NPE), delayed cerebral ischemia (DCI), and even in-hospital death. In particular, patients with SAH are at increased risk of having severe ventricular dysrhythmias. These may contribute to a high mortality rate and to poor functional outcome at 3 months. The current data on ECG QT dispersion and mortality appear less clearly associated. While some patients demonstrated poor outcomes, others showed no relationship with poor outcomes or increased in-hospital mortality. Observing ECG alterations carefully after cerebral damage is important in the critical care of these patients as it can expose preexisting myocardial disease and change prognosis.

Role of electrocardiogram findings in predicting 48-h mortality in patients with traumatic brain injury

OBJECTIVE

Electrocardiogram (ECG) patterns can change, especially in patients with central nervous system disorders such as spontaneous subarachnoid hemorrhage. However, the association between the prognosis of traumatic brain injury (TBI) and ECG findings is unknown. Therefore, this study aimed to compare and to analyze ECG findings to predict early mortality in patients with TBI.

METHODS

This retrospective observational study included patients with severe trauma and TBI who were admitted to the emergency department (ED) between January 2018 and December 2020. TBI was defined as an abbreviated injury scale score of the head of ≥3. We examined ECG findings, including PR prolongation (≥ 200 ms), QRS complex widening (≥ 120 ms), corrected QT interval prolongation (QTP, ≥ 480 ms), ST-segment elevation, and ST-segment depression (STD) at ED arrival. The primary outcome was 48-h mortality.

RESULTS

Of the total patients with TBI, 1024 patients were included in this study and 48-h mortality occurred in 89 patients (8.7%). In multivariate analysis, QTP (odds ratio [OR], 2.017; confidence interval [CI], 1.203-3.382) and STD (OR, 8.428; 95% CI, 5.019-14.152) were independently associated with 48-h mortality in patients with TBI. The areas under the curve (AUCs) of the revised trauma score (RTS), injury severity score (ISS), QTP, STD, and the combination of QTP and STD were 0.790 (95% CI, 0.764-0.815), 0.632 (95% CI, 0.602-0.662), 0.605 (95% CI, 0.574-0.635), 0.723 (95% CI, 0.695-0.750), and 0.786 (95% CI, 0.759-0.811), respectively. The AUC of the combination of QTP and STD significantly differed from that of ISS, QTP, and STD, but not RTS.

CONCLUSION

Based on the ECG findings, QTP and STD were associated with 48-h mortality in patients with TBI.

Myocardial Injury after Stroke

The cardiovascular system is markedly affected by stress after stroke. There is a complex interaction between the brain and heart, and the understanding of the mutual effects has increased in recent decades. Stroke is accompanied by pathological disturbances leading to autonomic dysfunction and systemic inflammation, which leads to changes in cardiomyocyte metabolism. Cardiac injury after stroke may lead to serious complications and long-term cardiac problems. Evidence suggests that blood biomarkers and electrocardiogram analyses can be valuable for estimating the severity, prognosis, and therapy strategy in patients after stroke. It is necessary to distinguish whether these abnormalities presenting in stroke patients are caused by coexisting ischemic heart disease or are caused by brain injury directly. Distinguishing the origin can have a great impact on the treatment of patients after acute stroke. In this article, we focus on epidemiology, pathophysiological mechanisms, and the presentation of cardiac changes in patients after stroke.

Investigation of the Value of T peak to T end and QTc Intervals as Electrocardiographic Arrhythmia Susceptibility Markers in Acute Ischemic Stroke

INTRODUCTION

Arrhythmias are one of the most common causes of mortality in patients with acute ischemic stroke (AIS). This study aimed to investigate the relationships of arrhythmia susceptibility markers (QT, QTc, Tpe, Tpe-D, Tpe/QT, and Tpe/QTc) with the localization and volume of the ischemic area, the National Institutes of Health Stroke Scale (NIHSS) scores, and troponin levels in AIS.

METHODS

Patients diagnosed with AIS in the emergency department in the period from 01 November 2016 to 31 March 2019 were retrospectively reviewed. Patients admitted to the emergency department with no pathological ECG findings were included. The measurements of QT, QTc, Tpe, Tpe-D, Tpe/QTc, and Tpe/QT were performed under a digital microscope. The NIHSS scores, troponin values, and the ischemic area volume based on the diffusion-weighted magnetic resonance imaging findings at the time of admission were found.

RESULTS

A total of 135 patients, comprising 70 AIS patients and 65 individuals as controls, were included in the study. The male/female ratio was 73/62 and the mean age was 68.51±10.80 years. All of the ECG parameters in the AIS group and the control group were statistically significantly different between the groups except Tpe-D (p=0.454) (For QT, QTc, Tpe, Tpe/QTc, and Tpe/QT; p=0.003, 0.022, <0.001, 0.001, 0.001; respectively). QT, QTc, Tpe, Tpe/QTc, and Tpe/QT values were not significantly different between the groups with a NIHSS score of ≤5 and >5 (p=0.480, 0.688, 0.663, 0.512, 0.333, respectively).

CONCLUSIONS

Arrhythmia susceptibility markers including QT, QTc, Tpe, the values of Tpe-D, Tpe/QT, and Tpe/QTc are different in AIS patients compared to the individuals in the control group; therefore, these parameters can be included among the other parameters of close cardiac monitoring.

Crosstalk between brain, lung and heart in critical care

Extracerebral complications, especially pulmonary and cardiovascular, are frequent in brain-injured patients and are major outcome determinants. Two major pathways have been described: brain-lung and brain-heart interactions. Lung injuries after acute brain damages include ventilator-associated pneumonia (VAP), acute respiratory distress syndrome (ARDS) and neurogenic pulmonary œdema (NPE), whereas heart injuries can range from cardiac enzymes release, ECG abnormalities to left ventricle dysfunction or cardiogenic shock. The pathophysiologies of these brain-lung and brain-heart crosstalk are complex and sometimes interconnected. This review aims to describe the epidemiology and pathophysiology of lung and heart injuries in brain-injured patients with the different pathways implicated and the clinical implications for critical care physicians.

Development and external validation of new nomograms by adding ECG changes (ST depression or tall T wave) and age to conventional scoring systems to improve the predictive capacity in patients with subarachnoid haemorrhage: a retrospective, observational study in Korea

OBJECTIVES

To develop new nomograms by adding ECG changes (ST depression or tall T wave) and age to three conventional scoring systems, namely, World Federation of Neurosurgical Societies (WFNS) scale, Hunt and Hess (HH) system and Fisher scale, that can predict prognosis in patients with subarachnoid haemorrhage (SAH) using our preliminary research results and to perform external validation of the three new nomograms.

DESIGN

Retrospective, observational study SETTING: Emergency departments (ED) of two university-affiliated tertiary hospital between January 2009 and March 2015.

PARTICIPANTS

Adult patients with SAH were enrolled. Exclusion criteria were age <19 years, no baseline ECG, cardiac arrest on arrival, traumatic SAH, referral from other hospital and referral to other hospitals from the ED.

PRIMARY OUTCOME MEASURES

The 6 month prognosis was assessed using the Glasgow Outcome Scale (GOS). We defined a poor outcome as a GOS score of 1, 2 or 3.

RESULTS

A total of 202 patients were included for analysis. From the preliminary study, age, ECG changes (ST depression or tall T wave), and three conventional scoring systems were selected to predict prognosis in patients with SAH using multi-variable logistic regression. We developed simplified nomograms using these variables. Discrimination of the developed nomograms including WFNS scale, HH system and Fisher scale was superior to those of WFNS scale, HH system and Fisher scale (0.912 vs 0.813; p<0.001, 0.913 vs 0.826; p<0.001, and 0.885 vs 0.746; p<0.001, respectively). The calibration plots showed excellent agreement. In the external validation, the discrimination of the newly developed nomograms incorporating the three scoring systems was also good, with an area under the receiver-operating characteristic curve value of 0.809, 0.812 and 0.772, respectively.

CONCLUSIONS

We developed and externally validated new nomograms using only three independent variables. Our new nomograms were superior to the WFNS scale, HH systems, and Fisher scale in predicting prognosis and are readily available.

Acute Cardiac Complications in Critical Brain Disease

Acute cardiac complications in critical brain disease should be understood as a clinical condition representing an intense brain-heart crosstalk and might mimic ischemic heart disease. Two main entities (neurogenic stunned myocardium [NSM] and stress cardiomyopathy) have been better characterized in the neurocritically ill patients and they portend worse clinical outcomes in these cases. The pathophysiology of NSM remains elusive. However, significant progress has been made on the early identification of neurocardiac compromise following acute critical brain disease. Effective prevention and treatment interventions are yet to be determined.

Acute Cardiac Complications in Critical Brain Disease

Acute cardiac complications in critical brain disease should be understood as a clinical condition representing an intense brain-heart crosstalk and might mimic ischemic heart disease. Two main entities (neurogenic stunned myocardium [NSM] and stress cardiomyopathy) have been better characterized in the neurocritically ill patients and they portend worse clinical outcomes in these cases. The pathophysiology of NSM remains elusive. However, significant progress has been made on the early identification of neurocardiac compromise following acute critical brain disease. Effective prevention and treatment interventions are yet to be determined.

Electrocardiographic Abnormalities Predict Adverse Clinical Outcomes in Patients with Subarachnoid Hemorrhage

BACKGROUND

We conducted a retrospective cohort study of a large sample to assess whether electrocardiographic (ECG) abnormalities are independently associated with the occurrence of neurogenic pulmonary edema (NPE), delayed cerebral ischemia (DCI), and in-hospital death after nontraumatic subarachnoid hemorrhage (SAH).

METHODS

In this retrospective observational study, patients who were admitted within 72 hours of SAH symptom onset between 2013 and 2015 were enrolled. Twelve-lead ECG findings obtained within 72 hours after SAH and the presence of NPE, DCI, and in-hospital death were collected based on the results reported in the medical records.

RESULTS

We included 834 patients. NPE occurred in 192 patients (23%). The median delay from SAH onset to NPE was 3 days (interquartile range [IQR]: 5 days). DCI occurred in 223 patients (27%; median delay to DCI, 4 days; IQR: 5 days). In total, 141 patients (17%) died in the hospital (median time to death, 12 days; IQR: 18 days). The frequency of ECG abnormalities for all enrolled patients was 65%. Corrected QT prolongation had an adjusted risk ratio (RR) of 1.5 (1.1-2.2) for NPE and 1.8 (1.3-2.4) for DCI. ST depression had an adjusted RR of 3.0 (1.2-7.5) for in-hospital death. NSSTTCs (nonspecific ST- or T-wave changes) had an adjusted RR of 2.7 (1.8-4.2) for NPE, 2.8 (1.9-4.3) for DCI, and 2.2 (1.3-3.5) for in-hospital death. All RRs were adjusted for age and Hunt-Hess scores.

CONCLUSIONS

ECG abnormalities assessed within 72 hours after SAH using a standard 12-lead ECG are independently associated with an increased risk of adverse clinical outcomes in patients with nontraumatic SAH.

Risk Factors for Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage: A Review of the Literature

OBJECTIVE

To examine the literature on risk factors for cerebral vasospasm (CV), one of the most serious complications following aneurysmal subarachnoid hemorrhage (SAH), with special reference to the definition of CV.

METHODS

Using standard search engines, including PubMed, the medical literature on risk factors for CV after SAH was reviewed, and the best definition representative of CV was searched.

RESULTS

Severe SAH evident on computed tomography scan was the only consistent risk factor for CV after SAH. Effects of risk factors on CV, including age, clinical grade, rebleeding, intraventricular or intracerebral hemorrhage on computed tomography scan, acute hydrocephalus, aneurysm site and size, leukocytosis, interleukin-6 level, and cardiac abnormalities, appeared to be associated with the severity of SAH rather than each having a direct effect. Cigarette smoking, hypertension, and left ventricular hypertrophy on electrocardiogram were associated with CV without any relationship to SAH severity. With regard to parameters representative of CV, the grade of angiographic vasospasm (i.e., the degree of arterial narrowing evident on angiography) was the most adequate. Nevertheless, few reports on the risk factors associated with angiographic vasospasm grade have been reported to date.

CONCLUSIONS

Severe SAH evident on computed tomography scan appears to be a definite risk factor for CV after SAH, followed by cigarette smoking, hypertension, and left ventricular hypertrophy on electrocardiogram. To understand the pathogenesis of CV, further studies on the relationships between risk factors, especially factors not related to the severity of SAH, and angiographic vasospasm grade are necessary.

Cardiac Troponin Elevation and Outcome after Subarachnoid Hemorrhage: A Systematic Review and Meta-analysis

BACKGROUND

Cardiac abnormalities frequently occur after subarachnoid hemorrhage (SAH). Cardiac troponin (cTn) is a preferred biomarker for the diagnosis of cardiac damage, and the clinical significance of cTn elevation after SAH remains controversial. This meta-analysis was performed to assess the association between cTn elevation and patient outcomes, including delayed cerebral ischemia (DCI), poor outcome (death or dependency), and death in SAH patients.

METHODS

PubMed, Embase, and the Cochrane Library were searched for observational studies reporting an association between cTn elevation and outcome after SAH that were published before December 31, 2014. We extracted data regarding patient characteristics, cTn elevation, and outcome measurements (DCI, poor outcome, or death). Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using a random-effects model.

RESULTS

Twelve studies involving 2214 patients were included in data analysis. Elevation of cTn was observed in 30% of the patients. The cTn elevation was associated with an increased risk of DCI (RR, 1.48; 95% CI, 1.23-1.79), poor outcome (RR, 1.91; 95% CI, 1.51-2.40), and death (RR, 2.53; 95% CI, 2.04-3.12). At the 3- and 12- month follow-ups, cTn elevation was associated with higher rates of DCI (RR, 1.51; 95% CI, 1.11-2.07), poor outcome (RR, 1.91; 95% CI, 1.51-2.40), and death (RR, 2.78; 95% CI, 1.80-4.29). At in-hospital follow-ups, cTn elevation was also associated with the higher rate of death (RR, 2.33; 95% CI, 1.76-3.07).

CONCLUSIONS

cTn elevation in SAH patients is associated with an increased risk of DCI, poor outcome, and death after SAH.

Inter-observer agreement on the diagnosis of neurocardiogenic injury following aneurysmal subarachnoid hemorrhage

BACKGROUND

Neurocardiogenic injury results from increased sympathetic nervous system activation following acute brain injury. No diagnostic criteria for neurocardiogenic injury exist, and agreement has not been tested. We investigated the agreement by neurointensivists for the presence of neurocardiogenic injury on routine cardiac studies.

METHODS

Six neurointensivists rated 100 consecutive cases of aneurysmal subarachnoid hemorrhage (aSAH) for the presence of neurocardiogenic injury. A fixed-panel design was employed for the agreement among the whole cohort, as well as stratified by modified Fisher Scale (mFs), Hunt and Hess grade, gender, and the presence of elevated cardiac enzymes. Overall percent agreement, paired agreement, and agreement above change (Fleiss' Kappa) were calculated. Overall percent agreement between groups was compared using Chi square tests.

RESULTS

Six raters completed the survey for a total 600 responses. Overall percent agreement was 79.3 %, and agreement among cases at least one rater thought had neurocardiogenic injury was 66.5 % (paired agreement). Fleiss' Kappa was 0.66 (95 % CI, 0.1-0.71; p < 0.0001), indicating substantial agreement above chance. Similarly, on subgroup analysis, significant agreement beyond chance was seen in all groups (p < 0.001). Overall percent agreement was significantly better among mFs 3-4 compared to mFs ≤ 2 (81.3 vs. 63.6 %; p = 0.018) and among cases with positive cTI (96.9 vs. 70.1 %; p ≤ 0.001).

CONCLUSIONS

Overall, we demonstrated substantial agreement for the presence of neurocardiogenic injury on early cardiac studies following aSAH. However, inter-observer variability increased when evaluating patients without the objective finding of elevated cTI and among those with lower clinical and radiographic grades.

Risk factors associated with cerebral vasospasm following aneurysmal subarachnoid hemorrhage

We studied the risk factors associated with cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH). The subjects were 370 patients with ruptured aneurysms who fulfilled all of the following criteria: admission by day 2 after onset, operation performed by day 3 by the same surgeon (T.I.), Hunt-Hess grade I–IV, availability of bilateral carotid angiograms acquired by day 2 and repeated between days 7 and 9. The demographic, clinical, radiographic, surgical, laboratory, and electrocardiographic data were analyzed for angiographic vasospasm (AV), symptomatic vasospasm (SV), and cerebral infarction on computed tomography (CT) scan. Both CT-evident SAH and AV were graded as 0–IV. Among the 370 patients, AV grade III–IV, SV, and cerebral infarction occurred in 26%, 24%, and 20%, respectively. Univariate analysis showed that Hunt-Hess grade III–IV, SAH grade III–IV, intracerebral or/and intraventricular hemorrhage, rebleeding, cigarette smoking, hypertension, alcohol intake, leukocytosis, hyperglycemia, and electrocardiographic QTc prolongation, left ventricular hypertrophy (LVH), and ST depression were significantly related to at least one of AV grade III–IV, SV, or cerebral infarction. Multivariate analysis showed that SAH grade III–IV was the most important risk factor for vasospasm followed by LVH on electrocardiogram, cigarette smoking, and hypertension. AV grade III– IV, SV, and cerebral infarction occurred in 57%, 54%, and 39% of the 46 smokers with LVH, and in 43%, 49%, and 35% of the 68 patients who had both LVH and hypertension, respectively. CT-evident SAH, LVH, cigarette smoking, and hypertension are associated with vasospasm. In smokers or hypertensive patients, premorbid LVH appears to predict much more severe vasospasm.

Neurogenic Stunned Myocardium Following Acute Subarachnoid Hemorrhage

Neurogenic stunned myocardium (NSM) is a triad of transient left ventricular dysfunction, electrocardiogram changes, and elevation in cardiac enzymes, often mimicking a myocardial infarction. It has been described following acute brain injury. The purported mechanism is catecholamine excess resulting in cardiac dysfunction. From the clinical standpoint, the most frequently encountered electrocardiographic changes are QTc prolongation and ST-T changes, with modest elevations in troponin levels. Basal and mid-ventricular segments of the left ventricle are most commonly involved. NSM poses therapeutic challenges when it occurs secondary to aneurysmal subarachnoid hemorrhage, particularly in the setting of coexisting vasospasm. Overall, NSM carries good prognosis if recognized early, with appropriate management of hemodynamic and cardiopulmonary parameters.

Delayed Cerebral Ischemia After Subarachnoid Hemorrhage

Background and Purpose—

Established predictors of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage are large amounts of extravasated blood and poor clinical condition on admission. The predictive value of other factors is uncertain.

Methods—

We searched MEDLINE (1960–2012) for clinical, laboratory, and radiological predictors routinely available within 72 hours after subarachnoid hemorrhage. The studies were categorized according to methodological quality. Crude data and effect estimates (odds ratio [OR], hazard ratios, and risk ratio) with 95% CI were extracted, (re-)calculated and pooled if possible. For every potential predictor we assessed all effect estimates on consistency (point estimates in equal direction) and clinical relevance (size and 95% CI).

Results—

Fifty-two studies on 33 potential predictors were included. There was strong evidence (≥3 high-quality studies) for a higher risk of delayed cerebral ischemia in smokers (pooled OR, 1.2; 95% CI, 1.1–1.4), and moderate evidence (2 high-quality studies) for an increased risk in patients with hyperglycemia (OR, 3.2; 1.8–5.8 and hazard ratios, 1.7; 1.1–2.5), hydrocephalus (OR, 1.3; 1.1–1.5 and OR, 2.6; 1.2–5.5), history of diabetes mellitus (pooled OR, 6.7; 1.7–26), and early systemic inflammatory response syndrome (pooled OR, 2.1; 1.4–3.3). Evidence was limited for increased risk in women (pooled OR, 1.3; 1.1–1.6) and in patients with history of hypertension (pooled OR, 1.5; 1.3–1.7). The evidence on initial loss of consciousness, history of migraine, previous use of selective serotonin reuptake inhibitors, hypomagnesemia, low hemoglobin, or high blood flow on early transcranial Doppler was also limited.

Conclusions—

There is strong evidence that smoking is a predictor of delayed cerebral ischemia. For several other potential predictions the evidence is moderate, limited, or inconsistent.

Predictors of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage: a cardiac focus

BACKGROUND

Myocardial injury after aneurysmal subarachnoid hemorrhage (aSAH) is associated with poor outcomes. Delayed cerebral ischemia (DCI) is also a complication of aSAH. We sought to determine whether (1) DCI could be predicted by demographics, aSAH severity/aneurysm location, or aSAH-associated myocardial injury (SAHMI), and (2) DCI is associated with increased mortality after aSAH.

METHODS

Prospective longitudinal study of 149 aSAH subjects with definitive DCI evaluation, age 18-75 years, Hunt and Hess (HH) ≥ 3, and/or Fisher ≥ 2, and admitted to the Neurovascular ICU. DCI was defined by the presence of neurological deterioration accompanied by evidence of abnormal cerebral blood flow.

RESULTS

Subjects were 48% DCI(+) and 52% DCI(-). DCI(+) subjects had more severe aSAH [HH (P = 0.002), Fisher (P = 0.004), admission Glasgow Coma Scale (P = 0.018)]. More DCI(+) subjects had pulmonary congestion than DCI(-) subjects (63 vs. 39%, P = 0.003). On echocardiogram, cardiac output (CO, liters per minute [LPM]) was significantly higher in DCI(+) than in DCI(-) subjects (6 ± 2 vs. 5 ± 1 LPM; P = 0.015). Multivariate analysis identified CO and Fisher grade as independent predictors of DCI (P = 0.02, 0.019). For each 1 LPM increase in CO, the odds of DCI increased by 1.5 (95% CI: 1.1-2.1). Fisher grade 4 increased the odds of DCI by 6.5 compared to Fisher grade 2 (95% CI: 1.6-25.8). After controlling for Fisher grade, CO remained an independent predictor of DCI (P = 0.02). Three-month mortality rate was not significantly different between DCI groups, P = 0.786.

CONCLUSION

Elevated CO and Fisher grade are predictors of DCI after aSAH. However, prevention of DCI may not decrease mortality.

Cardiac damage after subarachnoid hemorrhage

Patients who had no heart disease had T-wave inversion and prolongation of the QT interval in electrocardiogram after Subarachnoid hemorrhage (SAH), which was reported 70years before. Cardiac complications, including focal myocytolysis, electrocardiographic changes, arrhythmias and left ventricular wall motion abnormalities and pulmonary edema. The autonomic and cardiovascular effects of SAH, however, are modulated by concomitant factors such as pre-existent cardiac diseases, electrolyte disorders and, probably, by genetic alterations in the ionic control of myocyte repolarization. Although beta-blockers have been reported to prevent myocardial damage following SAH, adequate clinical trials are lacking, and the widespread use of these drugs in acute cerebrovascular disease is not supported by evidence. Cardiac injury occurs frequently after SAH, and the most widely investigated form of neurocardiogenic injury.

Medical complications after subarachnoid hemorrhage

The prevention and management of medical complications are important for improving outcomes after subarachnoid hemorrhage (SAH). Fever, anemia requiring transfusion, hyperglycemia, hyponatremia, pneumonia, hypertension, and neurogenic cardiopulmonary dysfunction occur frequently after SAH. There is increasing evidence that acute hypoxia and extremes of blood pressure can exacerbate brain injury during the acute phase of bleeding. There are promising strategies to minimize these complications. Randomized controlled trials are needed to evaluate the risks and benefits of these and other medical management strategies after SAH.

Evaluation of P Wave and Corrected QT Dispersion in Subarachnoid Haemorrhage

The aim of our study was to investigate P wave dispersion (Pwd), QT, corrected QT (QTc), QT dispersion (QTd) and corrected QT dispersion (QTcd) intervals in subarachnoid haemorrhage.

Thirty-five subarachnoid haemorrhage patients (Group S) and 35 neurologically normal patients (Group C) were included in this retrospective study. The standard 12 derivations of the electrocardiograms of all patients were analysed and Pwd, QT and QTd intervals were measured. QTc and QTcd intervals were determined with the Bazett formula.

There was no significant difference between the study groups according to demographic characteristics, hypertension and diabetes mellutus incidences (P >0.05). The Pwd, QT, QTc, QTd and QTcd durations of Group S were significantly longer than those of Group C (P <0.001).

Subarachnoid haemorrhage patients may have a higher likelihood of arrhythmia during anaesthesia and in intensive care due to extended QTcd and Pwd durations.

Elevated cardiac troponin I and relationship to persistence of electrocardiographic and echocardiographic abnormalities after aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Cardiac injury persistence after aneurysmal subarachnoid hemorrhage (aSAH) is not well described. We hypothesized that post-aSAH cardiac injury, detected by elevated cardiac troponin I (cTnI), is related to aSAH severity and associated with electrocardiographic and structural echocardiographic abnormalities that are persistent.

METHODS

Prospective longitudinal study was conducted of patients with aSAH with Fisher grade >or=2 and/or Hunt/Hess grade >or=3. Serum cTnI was collected on Days 1 to 5; cohort dichotomized into peak cTnI >or=0.3 ng/mL (elevated) or cTnI <0.3 ng/mL. Relationships among cTnI and aSAH severity, 12-lead electrocardiography early (<or=4 days) and late (>or=7 days), Holter monitoring on Days 1 to 5, and transthoracic echocardiogram (left ventricular ejection fraction and regional wall motion abnormalities) early (Days 0 to 5) and late (Days 5 to 12) were evaluated.

RESULTS

Of 204 subjects, 31% had cTnI >or=0.3 ng/mL. cTnI >or=0.3 ng/mL was incrementally related to aSAH severity by admission symptoms (Hunt/Hess P=0.001) and blood load (Fisher P=0.028). More patients with cTnI >or=0.3 ng/mL had prolonged QTc on early (63% versus 30%, P<0.0001) and late electrocardiography (24% versus 7%, P=0.024). On Holter monitoring, more patients with cTnI >or=0.3 ng/mL had ventricular tachycardia/fibrillation (22% versus 9%, P=0.018) but not atrial fibrillation/flutter (P=0.241). Cardiac troponin I >or=0.3 ng/mL was associated with both early ejection fraction <50% (44% versus 5%, P<0.0001) and regional wall motion abnormalities (44% versus 4%, P<0.0001). Regional wall motion abnormalities predominated in basal and midventricular segments and persisted to some degree in 73% of patients affected, whereas ejection fraction <50% persisted in 59% of patients affected.

CONCLUSIONS

Cardiac injury is incrementally worse with increasing aSAH severity and associated with persistent QTc prolongation and ventricular arrhythmias. Regional wall motion abnormalities and depressed ejection fraction persist to some degree in the majority of those affected.

Independent associations between electrocardiographic abnormalities and outcomes in patients with aneurysmal subarachnoid hemorrhage: findings from the intraoperative hypothermia aneurysm surgery trial

BACKGROUND AND PURPOSE

Electrocardiographic abnormalities are common after subarachnoid hemorrhage, but their significance remains uncertain. The aim of this study was to determine whether any specific electrocardiographic abnormalities are independently associated with adverse neurological outcomes.

METHODS

This was a substudy of the Intraoperative Hypothermia Aneurysm Surgery Trial, which was designed to determine whether intraoperative hypothermia would improve neurological outcome in patients with subarachnoid hemorrhage undergoing aneurysm surgery. The outcome was the 3-month Glasgow Outcome Score treated as both a categorical measure (Glasgow Outcome Score 1 [good outcome] to 5 [death]) and dichotomously (mortality/Glasgow Outcome Score 5 versus Glasgow Outcome Score 1 to 4). The predictor variables were preoperative electrocardiographic characteristics, including heart rate, corrected QT interval, and ST- and T-wave abnormalities. Univariate logistic regression was performed to screen for significant electrocardiographic variables, which were then tested for associations with the outcome by multivariate logistic regression adjusting for clinical covariates.

RESULTS

The study included 588 patients, of whom 31 (5%) died. There was a significant, nonlinear association between heart rate and mortality such that lowest quartile (<or=60 beats/min; OR, 6.5; P=0.027) and highest quartile (>80 beats/min; OR, 8.8; P=0.006) were associated with higher risk. There was also a significant association between nonspecific ST- and T-wave abnormalities and mortality (OR, 3.1; P=0.031).

CONCLUSIONS

Bradycardia, relative tachycardia, and nonspecific ST- and T-wave abnormalities are strongly and independently associated with 3-month mortality after subarachnoid hemorrhage. Further research should be performed to determine whether there is a causal relationship between cardiac dysfunction and neurological outcome after subarachnoid hemorrhage.

Cardiac arrhythmias after subarachnoid hemorrhage: risk factors and impact on outcome

OBJECTIVE

Serious cardiac arrhythmias have been described in approximately 5% of patients after subarachnoid hemorrhage (SAH). The aim of this study was to identify the frequency, risk factors and clinical impact of cardiac arrhythmia after SAH.

METHODS

We prospectively studied 580 spontaneous SAH patients and identified risk factors and complications associated with the development of clinically significant arrhythmia. Multiple logistic regression analysis was used to calculate adjusted odds ratios for the effect of arrhythmia on hospital complications and 3-month outcome, as measured by the modified Rankin Scale, after controlling for age, neurological grade, APACHE-2 physiologic subscore, brain herniation and aneurysm size.

RESULTS

Arrhythmia occurred in 4.3% (n = 25) of patients. Atrial fibrillation and flutter were the most common arrhythmias, occurring in 76% (n = 19) of these patients. Admission predictors of cardiac arrhythmia included older age, history of arrhythmia and abnormal admission electrocardiogram (all p < 0.05). After adjusting for length of stay, hospital complications associated with arrhythmia included myocardial ischemia, hyperglycemia, and herniation (all p < 0.05). Arrhythmia was associated with an excess ICU stay of 5 days (p = 0.002). After adjusting for other predictors of outcome, arrhythmia was associated with an increased risk of death (adjusted OR 8.0, 95% confidence interval 1.9-34.0, p = 0.005), and death or severe disability (adjusted OR 6.9, 95% confidence interval 1.5-32.0, p = 0.014).

CONCLUSIONS

Clinically important arrhythmias, most often atrial fibrillation or flutter, occurred in 4% of SAH patients. Arrhythmias are associated with an increased risk of cardiovascular comorbidity, prolonged hospital stay and poor outcome or death after SAH, after adjusting for other predictors of poor outcome.

[Aneurysmal subarachnoid hemorrhage. Significance and complications]

Despite substantial improvement in the management of patients with aneurysmal subarachnoid hemorrhage (SAH), including early aneurysm occlusion by endovascular techniques and surgical procedures, a significant percentage of patients with SAH still experience serious sequelae of neurological or cognitive deficits as a result of primary hemorrhage and/or secondary brain damage. Available neuromonitoring methods for early recognition of ischemia include, among others, measurement of brain tissue O(2) partial pressure, brain metabolism with microdialysis and monitoring of regional blood flow. The triple-H therapy (arterial hypertension, hypervolemia and hemodilution) is the treatment of choice of a symptomatic vasospasm and leads to an enduring recession of ischemic symptoms, if initiated early after the onset of a vasospasm-linked ischemic neurological deficit. Further promising therapy approaches are the administration of highly selective ET(A) receptor antagonists and intracisternal administration of vasodilators in depot form. This review summarizes the major neurological and non-neurological complications following aneurysm occlusion. Possible neuromonitoring techniques to improve diagnosis and therapy for treatment of symptomatic vasospasm as well as extracranial complications are discussed.

Prognostic implications of left ventricular wall motion abnormalities associated with subarachnoid hemorrhage

Left ventricular (LV) dysfunction generally occurs early in the course of subarachnoid hemorrhage (SAH). We evaluated the prognostic value of electrocardiographic (ECG) abnormalities and echocardiographic LV dysfunction evaluated shortly after SAH. We prospectively enrolled 47 SAH patients (62 +/- 14 years, mean +/- SD) who were admitted to the neurosurgical care unit of our institute. Neurological status was rated on the day of admission. Twelve-lead ECG and 2-dimensional echocardiography were recorded 2 +/- 1 day after onset of SAH. ECG abnormalities (pathological Q-wave, ST-segment deviation, T-wave inversion, and QT prolongation) were evaluated and the incidences of global (LV ejection fraction < 50%) and segmental (regional wall motion abnormality [RWMA]) LV dysfunction were measured. During a follow-up period of 44 +/- 23 days, 17 (36%) patients died. ECG abnormalities, LV ejection fraction < 50%, and RWMA were observed in 62%, 11%, and 28% of patients, respectively. Univariate Cox proportional hazards regression analysis revealed that neurological status, rate-corrected QT interval, LV ejection fraction, and RWMA were significant predictors of death. After adjustment for these significant clinical variables, and age and sex, independent predictors of mortality were neurological status and RWMA. RWMA may provide significant prognostic information in patients with SAH.