Abnormal EKG can predict death in stroke patients

March 20, 2009

People who suffer an ischemic stroke and also have an abnormality in the heart's electrical cycle are at a higher risk of death within 90 days than people who do not have abnormal electrical activity at the time of emergency treatment, according to new research.

The study also provides a threshold at which the threat of death is highest: QTc intervals greater than 440 milliseconds in women and 438 milliseconds in men have the worst prognosis. The findings are published online March 20, 2009, in the Journal of Stroke and Cerebrovascular Diseases.

"From a clinical perspective, our study offers additional parameters to consider while treating stroke patients in the Emergency Department setting,' said corresponding author Latha G. Stead, M.D., professor and chair of the Department of Emergency Medicine at the University of Rochester Medical Center, who recently joined the URMC from the Mayo Clinic. "It appears that reviewing the medications a patient is taking and looking specifically for those that might prolong the QTc interval would be a useful practice."

The QTc interval is a measure of the electrical activity of the heart. An EKG records the waves of activity and its pattern, which is labeled with letters Q and T. Doctors look for the appropriate intervals between each letter, showing that the heart's electrical signals are steadily passing through the ventricles. A prolonged QTc interval means it takes too long for the electrical signal to pass.

Prolonged QTc intervals can be the result of a rare genetic disorder, medications, electrolyte imbalances, or congenital heart disease. Scientific data on the relationship between abnormal QTc intervals and death has been inconsistent, and few studies have looked at this relationship in the context of acute ischemic stroke, Stead said.

Researchers studied the medical records of 345 ischemic stroke patients at the Mayo Clinic, treated between 2001 and 2004, and followed for 90 days. Further analysis was done to see if the researchers could identify a QTc cutoff that would accurately predict death within 90 days.

About 35 percent of the patients had a prolonged QTc interval at the time of the emergency department visit. An estimated 81 percent of all patients were expected to survive the next three months. However, results showed that only 70.5 percent of the patients with a prolonged QTc interval survived compared with 87.1percent of the patients without a prolonged QTc interval.

In addition, researchers found that although the causes of death ranged from stroke to cardiac illnesses to cancer and respiratory failure, most patients died of stroke or cardiac causes. In those cases, about half of the patients had prolonged QTc intervals. Among the stroke survivors, patients with prolonged QT intervals had poorer functional outcomes.

About 795,000 Americans each year suffer a new or recurrent stroke. That means, on average, a stroke occurs every 40 seconds, according to the American Stroke Association. Ischemic strokes, obstructions of the blood vessels supplying blood to the brain, account for the majority of cases.

Stead is supported by the Mayo Foundation Emergency Medicine Career Research Career Development Award.

University of Rochester Medical Center

Hemorrhagic and Ischemic Stroke: Medical, Imaging, Surgical and Interventional Approaches
by Bernard R Bendok (Editor), Andrew Naidech (Editor), Matt Walker (Editor), H. Hunt Batjer (Editor)

Edited by renowned leaders in the field, Hemorrhagic and Ischemic Stroke: Medical, Imaging, Surgical, and Interventional Approaches provides comprehensive, practical, and cutting-edge information for neurosurgeons, neurologists, radiologists, neurointerventionalists, other health care professionals who care for stroke patients. This go-to reference covers the core of stroke care in a holistic and multidisciplinary approach and will prove essential for physicians and trainees alike.Key Features:
The four pillars of stroke care: medical management, imaging, open surgery and neurointerventional surgery, are brought together for the first time, providing a cohesive, strategic methodology for treating stroke patients Online access to chapter-specific videos that cover stroke procedures...

MANAGEMENT OF ACUTE ISCHEMIC STROKE (Postgraduate Medicine)
by JTE Multimedia

In the last 5 years, management of acute ischemic stroke has been revolutionized by the introduction of "clot busting" therapy with tissue plasminogen activator, or tPA. Unfortunately, many patients cannot benefit from this approach because they do not meet the treatment window of 3 hours, within which administration of the drug must be started or other options must be pursued. Knowing how to respond quickly and correctly to manifestations of suspected stroke is critical. In this article, Dr Meschia discusses current treatment approaches to ischemic stroke and appropriate management of complications, which can affect quality and length of life in patients who survive the initial event. Meschia JF. Management of acute ischmeic stroke: what is the role of tPA and antithrombotic agents?

Acute Ischemic Stroke: Imaging and Intervention
by R. Gilberto González (Editor), Joshua A. Hirsch (Editor), Michael H. Lev (Editor), Pamela W. Schaefer (Editor), Lee H. Schwamm (Editor)

This updated second edition of Acute Ischemic Stroke: Imaging and Intervention provides a comprehensive account of the state of the art in the diagnosis and treatment of acute ischemic stroke. The basic format of the first edition has been retained, with sections on fundamentals such as pathophysiology and causes, imaging techniques and interventions. However, each chapter has been revised to reflect the important recent progress in advanced neuroimaging and the use of interventional tools. In addition, a new chapter is included on the classification instruments for ischemic stroke and their use in predicting outcomes and therapeutic triage. All of the authors are internationally recognized experts and members of the interdisciplinary stroke team at the Massachusetts General...

Prevalence of Stroke/Transient Ischemic Attack Among Patients with Acute Coronary Syndromes in a Real-World Setting (Hospital Practice)
by JTE Multimedia

Background Atherothrombosis is a systemic disease that may manifest as acute ischemic events in multiple vascular beds. Patients who have experienced an atherothrombosis-related ischemic event in 1 vascular bed are at risk for developing ischemic events in other vascular beds. Antiplatelet therapy demands an understanding of the balance between arterial thrombosis benefit and adverse event risk. Clinical trials indicate that dual antiplatelet therapy with aspirin and the newer thienopyridines increases the risk of bleeding in patients with acute coronary syndromes (ACS) with prior cerebrovascular events. Informed clinical decision making requires a better understanding of the real-world prevalence of cerebrovascular events. Objective and Purpose To estimate the prevalence of stroke and/or...

Acute Ischemic Stroke and Thrmobolysis Location: Comparing Telemedicine and Stroke Center Treatment Outcomes (Hospital Practice)
by JTE Multimedia

Telemedicine has been increasingly used as an option for acute ischemic stroke treatment at hospitals where neurological expertise is not available. The aim of this study was to compare the outcome of stroke patients treated with systemic thrombolysis at our academic hub regional stroke centers (hub) versus our spoke hospital telemedicine locations (spoke) Methods Data were retrospectively reviewed for consecutive patients admitted for stroke treatment with intravenous tissue plasminogen activator at our hub (128 patients) and at the spoke centers (27 patients) over a 2-year period. Mortality was selected as a primary outcome measure, and post-thrombolysis intracranial hemorrhage (PT-ICH) rate, hospital length of stay (LOS), and discharge modified Rankin Scale (mRS) score were selected as...

Acute Ischemic Stroke: An Evidence-based Approach
by David M. Greer (Editor)

This focused book deals clearly and concisely with the principles of management of patients with acute ischemic stroke (AIS). It emphasizes the published and verifiable evidence in support of these principles, and highlights the areas of limited evidence. Best evidence is provided for the current standard treatment of acute ischemic stroke, including intravenous chemical thrombolysis, intra-arterial approaches, blood pressure management, and anti-thrombotic therapy. More modern techniques are also described, such as the use of mechanical devices to evacuate a thrombus, induced hypertension, hyper-oxygenation (hyperoxia), and neuroprotective or neuroregeneration agents. Hallmark features include:Focused on acute ischemic stroke, the most rapidly growing area of stroke managementEvidence...

Transient Ischemic Attack and Stroke: Diagnosis, Investigation and Management (Cambridge Medicine)
by Sarah T. Pendlebury (Author), Matthew F. Giles (Author), Peter M. Rothwell (Author)

Accurate diagnosis, appropriate investigation, reliable risk stratification, and urgent treatment are essential after TIA and minor stroke and can reduce the risk of stroke recurrence by up to 80%. This book reviews recent developments in each of these areas. To reflect the fact that TIAs and minor strokes are simply one end of the clinical spectrum of cerebrovascular disease, the book also covers the management of major stroke, and long-term outcomes - such as cognitive impairment - which can complicate all types of cerebrovascular events. The book is therefore a comprehensive primer in stroke medicine. Written by a leading team of researchers in the field, this book will be of interest to neurologists, stroke physicians, and all others with an interest in stroke.

Magnetic Resonance Imaging in Ischemic Stroke (Medical Radiology / Diagnostic Imaging)
by Rüdiger von Kummer (Editor), Tobias Back (Editor), K. Sartor (Editor)

Provides a comprehensive summary of the current role of MR imaging in patients with ischemic stroke. Specifically designed to meet the needs of both clinicians and radiologists. Documents the MR correlates of specific stroke syndromes. Contains many high-quality illustrations.

Antithrombotic Therapy in Prevention of Ischemic Stroke (Oxford American Pocket Notes)
by Richard C Becker M.D. (Author), Frederick A Spencer M.D. (Author)

Stroke is the most common cause of adult mortality in the United States. Antithrombotic agents form the mainstay of stroke prevention. Aspirin produces a modest reduction in the risk of second stroke and transient ischemic attack (TIA, mini-stroke) and is widely recommended for initial therapy. The thienopyridines (Ticlid) and clopodogrel (Plavix) are alternatives for secondary prevention in patients who do not respond to or cannot take aspirin. They are no more effective than aspirin and have been associated with thrombotic thrombocytopenic purpura. The combination of aspirin and extended-release dipyridamole (Aggrenox) has several mechanisms of action and an additive effect on reducing stroke risk compared with either agent alone. A 2-fold increase in risk reduction and favorable safety...

Ischemic Stroke (Advances in Neurology)
by H.J.M. Barnett (Author), Julien Bogousslavsky (Author), Heather Meldrum (Author)

Written by the world's foremost authorities, this volume reviews the latest basic science and clinical advances in the prevention, diagnosis, and treatment of ischemic stroke. The contributors examine recent breakthroughs in laboratory and clinical research and relate these research findings to clinical practice. Major sections focus on the epidemiology of ischemic stroke, the arterial lesions of stroke, the consequences of ischemia, risk factors for stroke, and strategies for prevention and treatment. Coverage includes detailed information on the new neuroprotective agents that have recently been developed and the new diagnostic procedures used to determine the best way to protect the brain during stroke.