Sevoflurane Effect on Left Atrial Performance: A Transoesophageal Echocardiographic Study

Study Overview
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Brief Summary
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The left atrial performance is affected by the preload as well as the afterload. The LA active pumping is increased by stretching of the LA but within limits, after which the active pumping declines. The LV stiffness acts as the LA afterload. Whenever the LV stiffness increases, the overall emptying fraction becomes more pumpdependent

Detailed Description
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The echocardiographic assessment of the LA was frequently overlooked. While left atrial performance reflects both systolic and diastolic functions of the LV, it looks like more studies are being conducted to detect the effect of different interventions on the left atrial size and function. Other studies focus on the prognostic value and the ability to risk stratify different cohorts of patients, based on the early recognition of deranged LA performance. Many studies were conducted on the effect of inhalational anesthetics on the left atrial function. Yet the results are inconclusive and sometimes contradictory. In a study on dogs, Gare Meir and his colleagues proved that desflurane, sevoflurane, and isoflurane depress left atrial contractility, delay relaxation, reduce chamber stiffness, preserve reservoir and conduit function, and impair left atrial-left ventricular coupling in vivo. Volatile anesthetics may cause impairment of both left atrial (LA) and left ventricular (LV) contractility. The mechanisms suggested were a decrease in the influx of calcium via voltage gated calcium channels as well as a decrease in calcium availability from sarcoplasmic reticulum.Echocardiographic assessment of the LA volumetric measures is comparable to that of Cardiovascular Magnetic Resonance (CMR) with clinically irrelevant difference. This makes echocardiographic assessment of LA volumes reliable, cheaperand easier to obtain.

Official Title
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Sevoflurane Effect on Left Atrial Performance: A Transoesophageal Echocardiographic Study on Patients Undergoing Coronary Artery Bypasses Grafting

Conditions
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Ischemic Heart Disease

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinical diagnosis of ischemic heart disease Elective coronary artery bypass grafting. Exclusion Criteria: Atrial or ventricular dysrhythmias, Associated mitral valve disease, Ejection Fraction <40%, Emergency coronary artery bypass grafting, Pericardial disease Contraindication to perform a TEE, e.g. Esophageal tumor

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| intraoperative transoesophageal echocardiography to test the effect of Sevoflurane on left atrial performance | Mitral inflow early diastolic velocity (meter/second)(m/s) | 30 Minutes (Start point: After induction of anesthesia and before starting sevoflurane (first set of data). End point: After achieving one MAC sevoflurane anesthesia and before skin incision (second set of data)). |