Pulsewidth, Cardiovascular Response, ECT

Out on PubMed, from researchers in India and Australia, is this LTE :

Comparable effects of 0.5 ms and 1.5 ms pulse-widths on cardiovascular response in schizophrenia patients receiving electroconvulsive therapy.

Ithal D, Mitra S, Nallur SV, Arumugham SS, Kumar CN, Ramesh VJ, Thirthalli J, Gangadhar BN.J Psychiatr Res. 2020 Oct 16;132:195-197. doi: 10.1016/j.jpsychires.2020.10.013. Online ahead of print.PMID: 33126013

The pdf is here.

And from the text:

...For the mean charge of 110 mC observed in the 0.5 ms PW (Table- 1) group, the stimulus train would last for about double the duration (2.2s) as compared to 163 mC at 1.5 ms PW (1.04s) - the stimulus frequency and stimulus amplitude were kept constant. Thus, despite the lower charge of stimulus in the 0.5 ms group, the group received longer train of stimulus. However, no differences were observed in cardiovascular response. Although the 0.5 ms group had a lower seizure threshold, both groups received similar electrical dosage in relation to threshold and had similar seizure duration – which may partially explain the similar RPP observed in both groups. There was also no significant difference in clinical outcome (viz. PANSS score, number of ECT sessions and cognitive effects (Ithal et al., 2020)). These findings imply that alterations in PW in this range might not be clinically relevant.

This is a dataset from a previously published study

(Ithal, D., Arumugham, S.S., Kumar, C.N., Venkatapura, R.J., Thirthalli, J., Gangadhar, B. N., 2020. Comparison of cognitive adverse effects and efficacy of 2 pulse widths (0.5 ms and 1.5 ms) of brief pulse bilateral electroconvulsive therapy in patients with schizophrenia - a randomized single blind controlled trial. Schizophr. Res. 216, 520–522). The authors compared pulse rate, systolic blood pressure and rate-pressure-product.

Cardiovascular response to ECT is a fascinating subject, both as a marker of seizure intensity and because of clinical management issues. These negative data add incrementally to our knowledge base. Since the stimulus train durations here are both quite short, it would be useful to know if much longer stimulus train durations (now commonly in the 5-8 second range) have a different effect on these cardiovascular parameters.