Abstract:

To evaluate the reliability of intramyocardial electrocardiogram (IMEG) monitoring during episodes of acute rejection after heart transplantation. MethodsThere were 30 SpragueDawley(SD) to Wistar rat heterotopic neck heart transplantations. After the transplantations,  IMEG QRS amplitudes were collected daily. 3 or 4 rats were killed at postoperative day 3,5,8 and 10. The myocardial tissues were evaluated by hematoxylineosin(HE) staining and immunofluorescence evaluation based on the criteria of the International Society for Heart and Lung Transplantation classification by a pathologist who was blinded to study protocol. ResultsThere was a severe decrease of IMEG QRS amplitude and an increase of myocardial impedance on the  6th or 7th postoperative day, which highly indicated an acute rejection. 22 rats had distinguished changes on the IMEG QRS amplitudes. Among them, acute rejecting episodes were certified in 21 rats after myocardial tissues were evaluated by HE staining and immunofluorescence evaluation. Sensitivity of the IMEG QRS amplitude was 95%, and specificity was 78%. ConclusionsIMEG can detect an acute rejection early and reliably, especially for monitoring the effect of rejection therapy.

Key words: Intramyocardial electrocardiogram; Heart transplantation; Models, aninal; Acute rejection; Rats, inbred strains