IntroductionElectroconvulsive therapy (ECT) is a cornerstone of treatment for severe depression, suicidality, and catatonia. Anesthetic choice directly influences seizure threshold, seizure quality, hemodynamic stability, and ultimately therapeutic efficacy. Cardiovascular comorbidity amplifies these challenges. For psychiatrists, acquiring fluency in anesthetic principles contributes to safety, tolerability, and quality outcomes.
MethodsNarrative educational review of psychiatric, anesthetic, pharmacologic literature (2010–2025), focus on four mainstay agents showcasing the effect on hemodynamics, cardiac function, and therapeutic seizure characteristics.
ResultsECT anesthetics differ substantially in both neuropsychiatric and cardiovascular profiles (Table 1):
Methohexital is the gold standard: it lowers seizure threshold, sustains adequate seizure duration, and provides remarkable hemodynamic stability in the majority of patients. However, its dose-dependent negative inotropy can become significant in patients with advanced heart failure.
Etomidate preserves cardiac output and reliably produces long seizure durations, often yielding higher efficacy in treatment-resistant depression. Downsides include temporary adrenal suppression, especially in the context of frequent treatments and limited availability outside North America.
Propofol blunts hypertensive surges and provides rapid emergence, though slower than methohexital. It raises seizure threshold and shortens seizure duration. Hemodynamic effects include vasodilation leading to lower systemic vascular resistance and some negative inotropy, making it less suitable in patients with heart failure.
Ketamine prolongs seizure duration and augments sympathetic tone, occasionally improving mood acutely. Yet its indirect sympathetic activation may be destabilizing in patients with arrhythmias or advanced coronary disease.Table 1.
| Onset time (s) (IV) | Seizure Threshold | Context-sensitive half time 1 hour infusion (min) | Half-life (hours) | Effect on LVEF |
|---|
| Methohexital | ~30 | ← → “Gold Standard” | Less than propofol | 2-6 | ↓↓ |
| Propofol | 40-60 | ↑ | 10 | 4-7 | ↓ |
| Ketamine | 10-30 | ↑ | ~10 | 2.5-2.8 | ←→/↑ |
| Etomidate | 40-60 | ↓ | 8 (bolus dose) | 2.9-5.3 | ←→/↑ |
A comparison table of four anesthetic drugs and their pharmacological properties including onset time, seizure threshold, and effect on L V E F. See long description.
ConclusionsPsychiatrists who understand anesthetic pharmacology can better anticipate treatment trajectories and maintain treatment efficacy and safety, especially in patients with cardiovascular comorbidities. Education in anesthetic-psychiatric intersections within the psychiatric curriculum would benefit safe ECT therapy in cardiac patients.