Zdravniški Vestnik (Jun 2001)
INTRAMYOCARDIAL ELECTROGRAMS FOR NONINVASIVE MONITORING OF REJECTION IN CARDIAC TRANSPLANT RECIPIENTS. INITIAL EXPERIENCE WITH SEVEN CASES
Abstract
Background. Despite the use of increasingly specific immunosuppressive therapy, rejection remains the leading cause of death in cardiac transplant patients. Clinical manifestations tend to occur at an advanced stage of the disease when its course is difficult to reverse. Endomyocardial biopsy is the gold standard for early detection and monitoring of cardiac transplant rejection. However, this approach is invasive and not suitable for routine use. A new, noninvasive alternative for monitoring cardiac transplant patients uses analysis of the ventricular evoked response (EPP) obtained by programmed electrical stimulation. Rejection-sensitive parameters (RSP) and infection-specific parameters (ISP) are extracted from changes in the slope of the T-wave and from the duration of repolarization, respectively. Rejection grade 2 or higher is diagnosed without exposing the patient to undue risk. The results obtained accord with biopsy findings.Methods. During the heart transplant procedure, two epimyocardial electrode leads are placed on the right ventricular outflow tract and the left ventricular lateral wall, and connected to the Physios CTM 01 pacemaker (Biotronik, Germany) implanted in the subcutaneous tissue of the abdominal wall. For the analysis of intramyocardial electrograms separate left ventricular and right ventricular pacing at a rate of 100 beats/ min and lasting 60 seconds is required, following the same protocol. The electrogram data are then transferred via the Internet to the central data processing site in Graz (Austria). The processed data in the form of prognostic curves are sent back within a few minutes.Results. In the year 2000, the Physios CTM 01 diagnostic pacemaker was implanted in all 7 patients undergoing heart transplantation at this institution. A total of 18 endomyocardial biopsies and 105 ventricular evoked response measurements were carried out. A strong correlation was established between the results of biopsy and the ventricular evoked response parameters, both as concerns the diagnosis of reaction and infection, and the monitoring of treatment.
