ECG changes after electroconvulsive therapy, cause or consequence?

Electroconvulsive therapy (ECT) is a commonly used treatment in psychiatric disease for severe depression. It is considered to be a relatively safe procedure, although several case reports have described cardiac complications. Significant ECG changes may occur after this treatment [1–3] and echocardiographic abnormalities have been described [4–6]. Noninvasive evaluation of several cases after ECT failed to demonstrate underlying cardiac abnormalities [1, 7]. Despite the lack of invasive studies, a generally accepted viewpoint is that ECG changes after ECT are the result of increased sympathetic activity due to massive release from the hypothalamus [2]. However, in the following two cases, we demonstrate by using invasive evaluation that the relation between ECT and subsequent ECG changes may not always be explained by this theory.