FAQs Understanding A-Fib: Enlarged Left Atrium
“How do I know if I have an enlarged left atrium and what does it mean, if it is? What is the size of a normal left atrium?
When in A-Fib, your left atrium has to work harder than normal and tends to stretch and dilate over time. Obstructive sleep apnea (OSA) and high blood pressure can also contribute to an enlarged left atrium.
Consequences of an Enlarged Left Atrium: One study showed that Persistent A-Fib was associated with left atrium size (but not the number of years that a patient had A-Fib).
Left atrium size has been found to be a predictor of mortality due to both cardiovascular issues as well as all-cause mortality (although other factors may contribute).
As a result, some medical centers won’t do a Pulmonary Vein Ablation (Isolation) procedure if the left atrium is enlarged (over 5.5 cm). However, with the newer ablation techniques, other centers will. Surgeons also are reluctant to operate on someone with an enlarged heart.
Why You Need to Know Your Measurement: If you’ve had A-Fib for a while with significant symptoms, we often advise you to ask your doctor for this measurement to see if your left atrium is enlarged. This will be your benchmark for future comparison. It will be described in either centimeters (e.g. 2.0 cm) or millimeters (e.g. 20 mm).
Store this info with your other A-Fib test results and other papers in your A-Fib Binder or folder. Use the table below to rank the size of your atrium. (Reference note: 1 cm = 10 mm) Indexing the Left Atrial Size:
Women | ||||
Left Atrium | Normal | Enlarged | ||
mild | moderate | severe | ||
Diameter (mm) | 27–38 | 39–42 | 43–46 | ≥ 47 |
Volume (ml) | 22–52 | 53–62 | 63–72 | ≥73 |
Volume/BSA* | 16–28 | 29–33 | 34–39 | ≥ 40 |
Men | ||||
Left Atrium | Normal | Enlarged | ||
mild | moderate | severe | ||
Diameter (mm) | 30–40 | 41–46 | 47–52 | ≥52 |
Volume (ml) | 18–58 | 59–68 | 69–78 | ≥79 |
Volume/BSA* | 16–28 | 29–33 | 34–39 | ≥40 |
Note: Indexing the left atrial volume to body surface area* (BSA) is recommended by the American Society of Echocardiography and the European Association of Echocardiography. * BSA=body surface area.
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Last updated: August 26, 2020