Morbidly obese patients are at risk for diastolic cardiac dysfunction, which can lead to adverse event, such as, diastolic heart failure postoperatively. Preoperative screening by transthoracic echocardiogram is difficult due to anatomical challenge, therefore the prevalence of this problem may be underestimated. The investigator would like to perform transesophageal echocardiogram in this group of patients after anesthesia induction to demonstrate the true prevalence of this syndrome.

Morbidly obese patients are at risk for both respiratory and cardiovascular abnormalities. Many cardiac problems were previously reported including left ventricular hypertrophy, right and left ventricular systolic dysfunction etc. Diastolic cardiac dysfunction can be found in normal left ventricular systolic function and can lead to diastolic heart failure postoperatively.

Preoperative screening by transthoracic echocardiogram is difficult due to anatomical challenge (thick chest wall, narrowing of inter-rib space), therefore the prevalence of this problem may be underestimated. Transesophageal echocardiogram provides better cardiac view, but requires sedation during procedure. So, it is not practical for out-patient setting. The investigator would like to perform transesophageal echocardiogram in this group of patients after anesthesia induction to demonstrate the true prevalence of this syndrome.

Inclusion Criteria:

• Every patient scheduled for bariatric surgery in Siriraj hospital

Exclusion Criteria:

• Patient refusal
• patient with contraindication for transesophageal echocardiogram such as preexisting esophageal disease, recent upper gastrointestinal bleeding, coagulopathy, etc. (according to American society of Echocardiography guideline)

Criteria for patient enrolled to bariatric surgery in Siriraj hospital

• BMI more than 40 kg/m2
• BMI more than 35 kg/m2 with hypertension, type 2 diabetes, hyperlipidemia, obstructive sleep apnea, chronic arthritis
• age between 18 - 70 years old