The aim of the study is to test whether stimulation of acupuncture points CV24 and P6 is better than placebo acupuncture in treatment of gagging in patients undergoing elective transesophageal echocardiography (TEE)

Patients undergoing elective transesophageal echocardiography (TEE) often report discomfort because of active gagging reflex, which sometimes preclude the performance of TEE and requires additional medication. According to existing literature, needling of acupoint CV24 effectively prevents gagging during dental procedures. We are going to use this phenomenon in patients scheduled to TEE in order to reduce discomfort during insertion of TEE probe and reduce the need for additional sedative medication. Within this investigation the patients will be randomly assigned to receive either verum acupuncture of CV24 and P6 acupoints or placebo procedure immediately before TEE examination. As outcome the incidence and intensity of gagging, total dose of additional sedative medication and hemodynamic parameters will be recorded.

Inclusion Criteria:

1. Patients with an American Society of Anesthesiologists physical status of I to III scheduled for elective ambulatory transesophageal echocardiography (TEE) without sedation
2. TEE time does not exceed 30 minutes
3. Patients without previous opioid and psychotropic medication
4. Patients aged between 30 and 65 years, able to use visual analogue scale 100 mm
5. Patients who have given written informed consent

Exclusion Criteria:

1. Current psychiatric disease
2. Local skin infection at the sites of acupuncture
3. Aged < 30 or > 65 years
4. TEE time more than 30 min
5. Patients who consumed opioid medication at least 6 months before surgery
6. Patients with the history of: i) psychiatric disease; ii) insulin-dependent diabetes mellitus; iii) radio- or chemotherapy; iv) peripheral polyneuropathy.
7. Patients who are unable to understand the consent form or to use visual analogue scale 100 mm