ASA: Holter Needed Following tPA

Stroke patients treated with tPA should be considered for 24-hour heart monitoring to rule out new onset atrial fibrillation.

A review of medical records of 97 stroke patients identified three previously undiagnosed arrhythmias, said Paul Blackburn, MD, a resident in psychiatry at the University of British Columbia, Vancouver.

Blackburn reported the results at the American Stroke Association’s International Stroke Conference.

“The current pilot study has demonstrated that 24-hour cardiac monitoring has a role in diagnosing new cardiac arrhythmia and hypertensive urgency in stroke patients post-tissue plasminogen activator (tPA),” Blackburn told MedPage Today.

“We found three new cases of atrial fibrillation among those patients who underwent monitoring,” Blackburn said during his poster presentation. “That represents about 3% of the patients monitored. The most common arrhythmia detected in the setting of stroke is atrial fibrillation, which either may be related to the cause of the stroke or may be a complication.”

“No clinical trials have tested the utility of mobile electrocardiography in regards to blood pressure, electrocardiogram changes and cardiac events post stroke,” Blackburn said.

In addition to identifying the three cases of atrial fibrillation, the researchers also discovered that several patients required intravenous treatment of high blood pressure.

Blackburn said that 40% of the patients on the monitor had a systolic blood pressure between 180 mm Hg and 209 mm Hg and 8.4% of the group had systolic blood pressure greater than 210 mm Hg.

These patients were treated with intravenous labetalol and/or hydralazine.

Overall, 27 patients demonstrated arrhythmias while on the cardiac monitors, Blackburn said. They included 24 patients with atrial fibrillation or atrial flutter, including the three previously undiagnosed cases. There was one case of supraventricular tachycardia, one brief episode of ventricular fibrillation — both of which resolved without therapy — and one fatal case of pulseless electrical activity.

In commenting on the study, Daniel Lackland, DrPH, a spokesperson for the American Stroke Association and a professor of neurosciences at the Medical College of South Carolina Charleston, told MedPage Today, “The finding of three new cases of atrial fibrillation out of less than 100 patients is huge. However, the question that is unanswered is whether this arrhythmia would have been discovered without use of the 24-hour heart monitoring.

“We need to know that answer because the expense of putting post-stroke patients on these monitors would be enormous. I would like to see other institutions perform similar retrospective studies to see if their data is similar to the group in Canada,” Lackland said.

“If there are similar findings, then I think there would be enough evidence to undertake a controlled clinical trial,” he said.

Blackburn said that the findings on the cardiac monitors did help guide acute therapy for the patients. However, he and his colleagues did not observe an impact on myocardial infarction.

The mean age of the patients was 67 and 55% were men. About 38% had diabetes, 86.7% were dyslipidemic, and 90.6% had high blood pressure — including 60.1% who were receiving antihypertensive therapy. About 43% had a previous history of stroke and 42% of the patients were smokers.

“Future analysis comparing nonmonitored groups for arrhythmia diagnosis and outcome measures and further prospective studies are required for more complete validation of 24-hour cardiac monitoring,”Blackburn said.

-Ed Susman, Contributing Writer, MedPage Today

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