The effect of high thoracic epidural anesthesia on systolic and diastolic left ventricular function in patients with...

Area of Science:

• Cardiology
• Anesthesiology
• Cardiovascular Physiology

Background:

• Coronary artery disease involves sympathetic nervous system activation leading to vasoconstriction and myocardial ischemia.
• Alpha-adrenergic receptor activation contributes to epicardial and microvascular constriction.
• High thoracic epidural anesthesia (HTEA) can attenuate ischemia by inhibiting sympathetic activity, but its effect on left ventricular (LV) function is debated.

Purpose of the Study:

• To investigate the impact of HTEA on both systolic and diastolic left ventricular (LV) function.
• To clarify whether HTEA improves global LV function, specifically assessing its effects on diastolic and systolic parameters.

Main Methods:

• Thirty-seven patients undergoing coronary artery surgery received HTEA while awake.
• Echocardiographic and hemodynamic measurements, including myocardial performance index (MPI), fractional area change, and intraventricular flow propagation velocity (Vp), were recorded before and after HTEA.
• LV function was serially quantified using combined systolic/diastolic and specific systolic or diastolic variables.

Main Results:

• HTEA significantly improved diastolic LV function, evidenced by an increase in Vp (45.1 to 53.8 cm/s; P < 0.001).
• Indices of systolic function showed no significant change after HTEA.
• The overall myocardial performance index (MPI) improved significantly (0.51 to 0.35; P < 0.001), driven by enhanced diastolic characteristics.

Conclusions:

• HTEA administration leads to a significant improvement in diastolic left ventricular function.
• The observed improvement in global cardiac function with HTEA is primarily attributed to enhanced diastolic characteristics, not systolic performance.