Atrial Fibrillation (AFib) is the most common cardiac arrhythmia (irregular heart beat). Although AFib may cause no symptoms, it is often associated with symptoms such as palpitations, fainting, chest pain, or congestive heart failure. In some people, however, Afib is caused by otherwise idiopathic or benign conditions. AFib also increases the risk of stroke.
If you have AFib, what are the odds of you having a stroke?
The CHADS2 score is one way to measure this risk. The CHADS2 score is calculated by giving points to various comorbidities in the following way:
| Condition | Points | |
| C | Congestive heart failure | 1 |
| H | Hypertension: blood pressure consistently above 140/90 mmHg (or treated hypertension on medication) | 1 |
| A | Age ≥75 years | 1 |
| D | Diabetes mellitus | 1 |
| S2 | Prior Stroke or TIA or Thromboembolism | 2 |
Based on you score, you can calculate your annual stroke risk as follows:
| CHADS2 Score | Stroke Risk % | 95% CI |
|---|---|---|
An alternative to the is the CHADS2 score is the CHA2DS2-VASc score. this approach includes the following additional risk factors: age 65-74, female gender and vascular disease. In the CHA2DS2-VASc score score, ‘age 75 and above’ also has extra weight, with 2 points.
| Condition | Points | |
| C | Congestive heart failure (or Left ventricular systolic dysfunction) | 1 |
| H | Hypertension: blood pressure consistently above 140/90 mmHg (or treated hypertension on medication) | 1 |
| A2 | Age ≥75 years | 2 |
| D | Diabetes Mellitus | 1 |
| S2 | Prior Stroke or TIA or thromboembolism | 2 |
| V | Vascular disease (e.g. peripheral artery disease, myocardial infarction, aortic plaque) | 1 |
| A | Age 65–74 years | 1 |
| Sc | Sex category (i.e. female gender) | 1 |
The CHA2DS2-VASc score indicates an annual stroke risk of:
| CHA2DS2-VASc Score | Stroke Risk % | 95% CI |
|---|---|---|