Cardiac function during halothane anf fluroxene anesthesia expressed by systolic time intervals

Area of Science:

• Cardiology
• Anesthesiology
• Physiology

Background:

• Systolic time intervals (STI) provide insights into cardiac function.
• Assessing cardiac function non-invasively during anesthesia is crucial.
• The pre-ejection period to left ventricular ejection time ratio (PEP/LVET-ratio) is a key indicator.

Purpose of the Study:

• To describe a non-invasive method for measuring STI during anesthesia.
• To evaluate the cardiac effects of different anesthetic agents using the PEP/LVET-ratio.
• To compare STI in patients undergoing anesthesia with healthy volunteers.

Main Methods:

• Developed and utilized a non-invasive method to measure STI.
• Calculated the PEP/LVET-ratio to assess cardiac function in 39 patients.
• Compared patient STI values with those from 27 healthy volunteers.

Main Results:

• Thiopental significantly increased PEP/LVET-ratio, indicating cardiac depression.
• Halothane aggravated this depression, while fluroxene improved the PEP/LVET-ratio.
• Changes were primarily due to alterations in the pre-ejection period (PEP).
• PEP/LVET-ratio correlated with 1/PEP-2.
• Patients exhibited shorter PEP and PEP/LVET-ratio compared to volunteers.

Conclusions:

• The non-invasive STI method effectively assesses cardiac function under anesthesia.
• Anesthetic agents have differential effects on cardiac function, with fluroxene showing a cardioprotective profile.
• PEP/LVET-ratio is a sensitive marker for anesthetic-induced cardiac changes.