All volatile agents, including isoflurane and sevoflurane, cause a dose-dependent reduction in systemic vascular resistance (SVR). Both agents slightly reduce cardiac contractility and, as a result of this and the reduction in SVR, the blood pressure falls.

Isoflurane causes a greater reduction in SVR than sevoflurane. This drop in SVR is accompanied by reflex tachycardia. Isoflurane has also been associated with coronary steal.

Sevoflurane causes a less pronounced fall in SVR; blood pressure and heart rate are better preserved.

Nitrous oxide reduces cardiac contractility very slightly, but this is usually offset by an increase in sympathetic activity so that there is little overall effect.