The purpose of this study is to improve secondary prevention of ischemic stroke patients by

1. Estimating prevalence and the prognostic significance of frequent premature atrial complexes in ischemic stroke patients in relation to death, recurrent stroke and atrial fibrillation.

2. Characterize ischemic stroke patients by

   1. Echocardiographic characteristics

   2. Biochemical markers

   3. Plaque composition in the carotid arteries

      • in order to improve risk stratification.

Patients with atrial fibrillation (AF) have a five-fold increased risk of ischemic stroke compared to the general population. Identifying AF can be challenging, but prolonged rhythm monitoring of ischemic stroke patients have shown to enhance detection rates of AF. Therefore it is important to identify predictors of AF to allow targeted screening of patients after ischemic stroke and thereby reduce the recurrent stroke rate. Few former studies have shown an association between excessive numbers of premature atrial complexes (PACs) and AF.

The study population of ischemic stroke patients will at admission undergo following examinations:

1. ECG
2. 48 hours inpatient cardiac telemetry (If not known AF)
3. 24 hours holter monitoring (if not known AF)
4. echocardiogram
5. blood sample
6. CT scan of carotid arteries with contrast made on Dual Energy CT scan.

In the follow-up period, patients will have two visits with 48 hour holter monitoring (after 6 and 12 months, respectively) It will be noticed if patients have any recurrent events, die og developing AF.

The study population will be divided into four groups as follows:

1. patients with new AF at admission
2. patients with known AF
3. patients with frequent PACs
4. patients without frequent PACs. These groups will be compared on baseline characteristics and on outcome as mentioned.

The overall perspective is to make better strategies for detecting occult AF after ischemic stroke to improve secondary stroke prevention care.

Inclusion Criteria:

• admitted with ischemic stroke at a single center
• time from diagnose to inclusion maximum 7 days.
• written informed consent or surrogate informed consent eligible
• age > 18 years.

Exclusion Criteria:

• hemorrhagic stroke
• terminal illness and expected lifespan of less than 6 months.
• any physical or mental condition which make the patients unsuitable for participation in the study.
• known with a pacemaker
• anticoagulation treatment of other reasons than atrial fibrillation.

Ischemic stroke patients admitted to the hospital