TEE may be the most useful diagnostic modality in sudden, life-threatening hypotension. Hypotension is ALWAYS caused by either decreased cardiac function, decreased afterload, or a combination of both. TEE is capable of helping differentiate the two – hypotension predominantly due to decreased afterload will manifest as a hypercontractile ventricle. Hypotension predominantly due to decreased cardiac function will manifest as a hypocontractile ventricle with/without wall motion abnormalities. LVEDA may also be increased. Note that most TEE assessments of ventricular function are load-dependent, but preload can easily be assessed by looking at cross sectional area. TEE is the best modality for identifying anatomical causes of hypotension (ex. flail mitral valve).
Etiologies of Hypotension Easily Identifiable by TEE
- Poor LV function
- Decreased LV afterload
- Decreased LV preload
- Pericardial tamponade
- Acute valvular dysfunction
Multiple studies in ICU patient populations have shown that TEE is highly effective at quickly (average time to diagnosis of 11 minutes) and cost-effectively (because unlike TTE, it has a high sensitivity) determining the causes of life-threatening hypotension.