What does 'SVC' stand for in lung function tests?

'SVC' stands for Slow Vital Capacity, which is a measurement used in pulmonary function tests to assess how much air a person can exhale after taking a deep breath. In this test, the patient breathes in slowly to fill their lungs completely and then exhales slowly and steadily into a spirometer. This method contrasts with other measurements such as Forced Vital Capacity (FVC), where the exhalation is done forcefully and quickly.

Slow Vital Capacity is particularly useful for identifying lung conditions that may not be evident with rapid breathing tests. It can provide insight into restrictive lung disease, where lung expansion is compromised and the patient may not be able to exhale as much air. The SVC measurement can also help in assessing the overall lung volume and function, which is crucial for diagnosing and monitoring various respiratory conditions.