After Stroke Onset, Prehospital ECG Helps Detect Atrial Fibrillation

Prehospital electrocardiogram (ECG) recordings in patients with stroke can help detect several relevant cardiac arrhythmias, including atrial fibrillation (AF), according to results published in Neurology.

Cardiac monitoring plays an important role in the care of patients with acute stroke. ECG abnormalities are common in patients with acute stroke, with AF accounting for 30% of all strokes. Extended cardiac monitoring has been associated with higher rates of AF detection, but there is little data on the benefits of prehospital cardiac monitoring in the setting of an acute stroke.

Tobias Bobinger, MD, of the department of neurology at Universitätsklinikum in Erlangen, Germany, and colleagues sought to examine the diagnostic yield of prehospital ECG monitoring of patients with suspected stroke evaluated by emergency medical services (EMS). They conducted a prospective 12-month study of patients presenting to a tertiary stroke center with prehospital ECGs.

The study included 259 patients (mean age, 76) with prehospital ECG. A full 12-lead ECG was available in 78% of cases; prehospital ECG was obtained a median of 189 minutes after the onset of stroke symptoms. Of the study participants, 90.3% were diagnosed with ischemic stroke (n=234) and 9.7% with hemorrhagic stroke (n=25). Compared with the 822 patients who presented without an ECG, patients with a prehospital ECG tended to be older (76 vs 72 years of age, P <.001), had a higher rate of heart disease (40.9% vs 25.2%,

P <.001), and presented with a worse National Institute of Health Stroke Scale (NIHSS) score (5 vs 4, P =.035).

A new diagnosis of AF was found in 16.7% (n=31) of the study population during their hospital stay. AF was detected with prehospital ECG in 9.7% of patients (n=18). In two of those patients, detection of AF was limited to prehospital ECG and did not reoccur during hospital stay.

The prehospital ECG was also able to detect significant ST-segment elevation in 5% of cases, second- or third-degree atrioventricular block in 5.4%, and pacemaker rhythm in 5.4%. In cases with 12-lead ECG, the prehospital ECG detected left bundle-branch block in 2% and right bundle-branch block in 8.9%. Overall, the prehospital ECG detected a relevant abnormality in 48.6% (n=126) of the study patients. Of those patients, 16.67% received antiarrhythmic medications in the prehospital phase, 6.35% were transferred to a cardiology unit with in the first 24 hours, and 1.6% required cardiac resuscitation within the first 24 hours.

“This study demonstrated that prehospital ECG recording detects a relevant rate of abnormalities… and can be a helpful tool in AF detection,” the investigators wrote. “Neglecting these ECG abnormalities may result in serious acute cardiac adverse events, and therefore, cardiac monitoring should start as early as possible.”

References

Bobinger T, Kallmünzer B, Kopp M, et al. Diagnostic value of prehospital ECG in acute stroke patients [published online April 21, 2017]. Neurology. doi:10.1212/WNL.0000000000003940