This letter addresses potential cardiovascular changes following spinal anesthesia. High spinal anesthesia with a T4 sensory blockade can lead to decreased venous return, reduced right atrial pressure, and bradycardia. These effects result from diminished sympathetic activity, increased parasympathetic activity, and inhibition of cardiac accelerator fibers. In some cases, bradycardia following spinal anesthesia may progress to cardiac arrest. Therefore, patients receiving high spinal anesthesia should be monitored closely.
Keywords: cardiac arrest; lipid emulsion; spinal anesthesia; toxicity.