Intramyocardial electrograms for non-invasive rejection monitoring: initial experience with an infection-specific parameter.
Non-invasive rejection monitoring based on the analysis of paced intramyocardial electrograms enables repeated or even daily graft surveillance. The rejection-sensitive parameter is calculated from the maximum slope of the descending part of the t wave. Biopsy-proven rejection grade 2 or higher (ISHLT classification) can safely be detected. Nevertheless, infection influences the rejection-sensitive parameter in the same manner as does rejection (99% negative predictive value for rejection grade 2 or higher, 17% positive predictive value). We defined the infection-specific parameter as the time on the O line between the pacemaker stimulus and the crossover with the maximum slope of the descending part of the t wave. Patients were classified prospectively according to infection status: patients without infection and those with clinically apparent infection. Patients with clinically apparent infections had a significantly longer infection-specific parameter. A simultaneous decrease of the rejection-sensitive parameter and an increase in the infection-specific parameter was observed during clinical infection: a decrease in the rejection-sensitive parameter and no changes in the infection-specific parameter were observed during rejection. This preliminary analysis revealed that discrimination of rejection and infection might be possible by the analysis of intramyocardial electrograms.
Grasser
B
B
Karl-Franzens-University of Graz, Department of Transplantation, Austria.
Iberer
F
F
Schreier
G
G
Allmayer
A
A
Schaffellner
S
S
Prenner
G
G
Wasler
A
A
Petutschnigg
B
B
Müller
H
H
Tscheliessnigg
K
K
D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000379:methods; D006084:Graft Rejection / Q000175:diagnosis* / Q000503:physiopathology*; D016027:Heart Transplantation / Q000502:physiology*; D006801:Humans; D007239:Infections / Q000175:diagnosis*; D008991:Monitoring, Physiologic; D011237:Predictive Value of Tests; D011446:Prospective Studies