Electrocardiographic abnormalities in cerebrovascular accidents

Autonomic Disturbances in Acute Cerebrovascular Disease

Autonomic disturbances often occur in patients with acute cerebrovascular disease due to damage of the central autonomic network. We summarize the structures of the central autonomic network and the clinical tests used to evaluate the functions of the autonomic nervous system. We review the clinical and experimental findings as well as management strategies of post-stroke autonomic disturbances including electrocardiographic changes, cardiac arrhythmias, myocardial damage, thermoregulatory dysfunction, gastrointestinal dysfunction, urinary incontinence, sexual disorders, and hyperglycemia. The occurrence of autonomic disturbances has been associated with poor outcomes in stroke patients. Autonomic nervous system modulation appears to be an emerging therapeutic strategy for stroke management in addition to treatments for sensorimotor dysfunction.

Relationship between QT interval dispersion in acute stroke and stroke prognosis: a systematic review

BACKGROUND

QT dispersion (QTd) has been proposed as an indirect electrocardiography (ECG) measure of heterogeneity of ventricular repolarization. The predictive value of QTd in acute stroke remains controversial. We aimed to clarify the relationship between QTd and acute stroke and stroke prognosis.

METHODS

A systematic review of the literature was performed using prespecified medical subjects heading terms, Boolean logic, and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Eligible studies included ischemic or hemorrhagic stroke and provided QTd measurements.

RESULTS

Two independent reviewers identified 553 publications. Sixteen articles were included in the final analysis. There were a total of 888 stroke patients: 59% ischemic and 41% hemorrhagic. There was considerable heterogeneity in study design, stroke subtypes, ECG assessment time, control groups, and comparison groups. Nine studies reported a significant association between acute stroke and baseline QTd. Two studies reported that QTd increases are specifically related to hemorrhagic strokes, involvement of the insular cortex, right-side lesions, larger strokes, and increases in 3,4-dihydroxyphenylethylene glycol in hemorrhagic stroke. Three studies reported QTd to be an independent predictor of stroke mortality. One study each reported increases in QTd in stroke patients who developed ventricular arrhythmias and cardiorespiratory compromise.

CONCLUSIONS

There are few well-designed studies and considerable variability in study design in addressing the significance of QTd in acute stroke. Available data suggest that stroke is likely to be associated with increased QTd. Although some evidence suggests a possible prognostic role of QTd in stroke, larger and well-designed studies need to confirm these findings.

Electrocardiographic abnormalities and elevated cTNT at admission for intracerebral hemorrhage: predictors for survival?

BACKGROUND

Cerebrovascular lesions are often associated with electrocardiographic (ECG) abnormalities. The main purpose of this work was to investigate the prognostic value of ECG abnormalities and/or elevated cardiac troponin (cTNT) on admission in patients with nontraumatic intracerebral hemorrhage (ICH).

METHODS

Ninety-seven consecutive patients with ICH were included. The predictive value of ECG abnormalities and increased TNT on survival were evaluated using Cox proportional hazard model.

RESULTS

The most frequently observed ECG abnormalities were the presence of a Q wave (39.6%), followed by prolonged QTc (>0.44 s; 35.4%), which was an independent predictor for long-term mortality (P = 0.019). No difference in QTc was observed between patients with right versus left ICH. Increased cTNT levels at admission had no prognostic value.

CONCLUSION

Various ECG changes were common in patients presenting with an ICH, but only prolonged QTc was found to be an independent predictor of poor survival during follow-up after ICH.

Electrocardiographic T-wave changes underlying acute cardiac and cerebral events

T-wave inversions produced by myocardial infarction (MI) are classically narrow and symmetric. Electrocardiography T-wave changes including low-amplitude and abnormally inverted T waves may be the result of noncardiac path physiology. We present a series of cases that presented with different electrocardiography T-wave changes. The first case involved a 64-year-old woman who presented to the emergency department with diffuse splayed T-wave inversions and was found to have an MI in the context of an acute cerebrovascular accident. We contrasted this case with that of a 76-year-old man with hypercholesterolemia who presented with T-wave widening and a prolonged QT interval and was found to have a subarachnoid hemorrhage secondary to a basilar aneurysm and no MI. Several mechanisms have been suggested to explain the cardiac and cerebral injury, including microvascular spasm and increased levels of circulating catecholamines. Accurate interpretation of T-wave changes can assist the clinician toward a timely therapeutic intervention and accurate diagnosis.

Insular Involvement Is Associated with QT Prolongation: ECG Abnormalities in Patients with Acute Stroke

PURPOSE

Aim was to assess the frequencies of electrocardiographic (ECG) abnormalities, including QT prolongation, in acute stroke patients and their association with stroke severity, stroke subtype and location, and cardiovascular risk factors.

METHODS

Prospectively, admission 12-lead ECG findings, stroke characteristics, cardiovascular risk factors, and potential QT-prolonging factors were collected in 122 consecutive patients with acute stroke.

RESULTS

Eighty-four patients (69%) had ECG abnormalities, most frequently ST changes in 34%, QT prolongation in 31%, and atrial fibrillation in 27% of them. Insular involvement and prior stroke independently predicted QT prolongation in small infarcts (insular involvement OR 0.12, 95% CI 0.02-0.74, p=0.022; prior stroke OR 0.20, 95% CI 0.06-0.70, p = 0.012).

CONCLUSION

Continuous ECG monitoring and assessment of the QT interval should be mandatory in patients with acute stroke.

Spontaneous subarachnoid hemorrhage and serious cardiopulmonary dysfunction--a systematic review

INTRODUCTION

: The association between the degree of neurological deficit and cardiopulmonary dysfunction in patients with spontaneous subarachnoid hemorrhage (SAH) is poorly understood.

METHOD

A systematic search (MEDLINE, bibliographies, to 9.2004) was performed for prospective studies (any architecture; > or = 10 patients with SAH), reporting on neurological deficit and cardiopulmonary dysfunction. Neurological deficit was graded according to the Hunt-Hess or Botterell scores as minimal (1 or 2 points), moderate (3), or severe (4 or 5), and tested for an association with cardiopulmonary dysfunction (Chi-square test).

RESULTS

Relevant data came from two randomized trials, four case control studies, and 31 uncontrolled series. In eight studies (386 patients), ECG abnormalities were found in 32% of patients with minimal, 55% with moderate, and 58% with severe neurological deficit (P < 0.0001). In six studies (135), echocardiographic abnormalities were found in 4% of patients with minimal, 30% with moderate, and 52% with severe neurological deficit (P = 0.0001). In two trials (63), creatinine phosphoskinase was increased in 18% of patients with minimal, 71% with moderate, and 100% with severe neurological deficit (P < 0.0001). In three trials (309), troponin-I was increased in 10% of patients with minimal, 20% of patients with moderate, and 46% with severe neurological deficit (P < 0.0001). In five trials (163), pulmonary edema was found in 4% of patients with minimal, 12% with moderate, and 35% with severe neurological deficit (P < 0.0001). Seventeen studies reported on mortality; 26% of the patients died, 80% of deaths were directly related to SAH.

CONCLUSIONS

In patients with spontaneous SAH, cardiopulmonary dysfunction is more likely to occur with increasing neurological deficit.

The relationship between electrocardiographic abnormalities and location of the intracranial aneurysm in subarachnoid hemorrhage

The purpose of this study was to determine the value of the ECG in subarachnoid hemorrhage (SAH) in predicting poor outcome, and to define if specific ECG changes are related to the location of the aneurysm in SAH. A retrospective cohort study was performed on 97 patients with symptoms of SAH. An ECG and an initial computer tomograph (CT) scan were the two major inclusion criteria. The primary endpoint was in hospital mortality. ECG changes were correlated with mortality and severity of hemorrhage expressed as the Hijdra score. A prolonged QTc interval occurred more frequently in patients who had experienced a severe hemorrhage (RR = 3.18; 95% CI = 1.07-10.22; P < 0.05). LV hypertrophy criteria were strongly related to an aneurysm in the anterior communicating artery. U wave presence showed a statistically significant relationship with the posterior communicating artery and the middle cerebral artery. A prolonged QTc interval is observed more frequently in patients with severe hemorrhage. Specific ECG abnormalities were seen to be associated with the location of the aneurysm in the circle of Willis in SAH.

Cardiac manifestations after subarachnoid hemorrhage: a systematic review of the literature

Cardiac alterations associated with subarachnoid hemorrhage (SAH) have been recognized and frequently reported. We systematically reviewed the literature on MEDLINE using the key words: SAH + (heart, cardiac, electrocardiogram, cardiac enzymes, troponin, myoglobin, echocardiography, scintigraphy, Holter, and regional wall motion abnormalities) and included all articles describing cardiac abnormalities in the course of SAH whether spontaneous or secondary. The diagnosis of SAH was established by computed tomography scan, lumbar puncture, or brain autopsy. Cardiac abnormalities were identified by electrocardiogram, enzymatic elevation, Holter monitoring, echocardiography, cardiac scintigraphy, coronary angiography, or autopsy. Despite the considerable literature describing cardiac alterations during the course of SAH, epidemiological, pathophysiological, and prognostic aspects are yet to be clarified. Further studies are needed to evaluate the magnitude of this problem.

[Myocardial stunning in the context of a subarachnoid hemorrhage]

Myocardial stunning has been poorly described in patients with cerebrovascular accidents. We present a patient in whom severe anteroapical wall motion abnormalities and extensive anterior ST-segment elevation developed after subarachnoid hemorrhage. Total recovery ensued within 2 days. Coronary vasospasm induced by stroke-related sympathetic surge might be the determinant factor of this cardiac event.

The brain-heart connection: cardiac effects of acute ischemic stroke

Cerebrovascular events are known to produce changes in the electrocardiogram (ECG). Whether or not these changes are actually reflective of myocardial damage has been the topic of much research. There are indications that these ECG changes result from an imbalance in the autonomic nervous system, resulting in a relative excess of sympathetic activity. This article provides an overview of the ECG and physiologic changes noted in patients with acute ischemic stroke and identifies subgroups that may be at high risk for developing these changes. Implications for nursing care are discussed.

Myocardial stunning after cerebral infarction

Myocardial stunning has not been described in patients with cerebrovascular accidents. We present a patient in whom inferior wall hypokinesis, ST-segment elevations and Q waves developed after acute right hemisphere ischemic stroke. Total recovery ensued within 5 days. Coronary vasospasm induced by stroke-related sympathetic surge might be the cause of this cardiac event.

Electrocardiographic changes associated with acute cerebrovascular disease: a clinical review

Patients with acute vascular disorders of the CNS demonstrate an abundance of both rhythm and morphologic changes in their ECG. Of these a few will demonstrate myocardial dysfunction and or damage. The value of the ECG in evaluating and predicting which patients will have myocardial dysfunction or damage is questionable. One would assume the echocardiogram would be of more help than the ECG in identifying patients with myocardial damage; however, little data are available. The reason for the poor correlation between ECG findings and clinical correlates has not been explained to date, but it is possible to postulate a theory. There are two mechanisms that might mediate ECG changes in these patients, ie, autonomic neural stimulation from the hypothalamus or elevated circulating catecholamines. Hypothalamic stimulation may cause ECG changes without associated myocardial damage whereas elevated catecholamines may result in myocardial damage. This might explain why so many patients have ECG changes and very few have demonstrable myocardial damage in general, or ischemic damage in particular. That cardiac antiischemic therapy does not change mortality may relate to the fact that treatment has been directed towards patients with ECG changes, which in turn do not correlate with myocardial damage. Better patient selection for such therapy might rest upon demonstration of wall motion abnormalities on echocardiogram. The weakness of this strategy is that many patients with stroke have preexisting coronary disease and wall motion abnormalities and thus echo findings may only document remote infarction rather than acute ischemia.

Electrocardiographic findings in acute cerebrovascular hemorrhage. A prospective study of 70 patients

Seventy patients with hemorrhagic stroke were prospectively evaluated regarding the electrocardiographic abnormalities observed within the first 48 hours of the ictus. Group I comprised 55 patients with spontaneous cerebral hemorrhage, and group II 15 patients with subarachnoid hemorrhage. Patients taking cardiac drugs (beta blockers, calcium-channel blockers, inotropic drugs) or with severe metabolic/electrolyte disturbances were excluded. The most common ECG abnormality was a prolonged Q-Tc interval: group I, 37 (67.2%); group II, 8 (53.3%). Only 4 (7.2% patients of group I and no patient of group II had a normal ECG. No relation was found between the site of the intracerebral hematoma and the occurrence of any particular ECG change. A prolonged Q-Tc may be related to the development of severe cardiac arrhythmias observed in some patients with acute cerebral hemorrhage.