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F Iberer

Publications and source records attributed to F Iberer.

At least 37 records · Page 2Linked to original sources
PubMed1996

Evoked epimyocardial electrogram for rejection diagnosis after heart transplantation.

An endomyocardial electrogram (ECG) was reported to be a sensitive and practicable method for rejection monitoring after heart transplantation. Long-term follow up was limited, however, by variations of signals. The repolarization part of ECG signals vary with changes of heart rate. Both can be avoided by using pacemaker-induced signals. For stimulation and sensing of the ventricular-evoked response, a new type of electrode with fractal surface structure was used. Twenty patients undergoing heart transplantation were evaluated. Amplitudes of the depolarization and repolarization part of the ventricular-evoked response signals were analyzed and related to the degree of acute rejection according to histological findings from endomyocardial biopsy. Signals were transferred by Internet and analyzed automatically. In the case of focal moderate rejection (grade 2, International Society for Heart Transplantation grading) and higher degrees of rejection, a significant amplitude decrease was found. This sensitive non-invasive method for rejection monitoring with a high level of reliability provides the possibility of reducing the number of endomyocardial biopsies.

Adult↗
PubMed1996

Donor heart quality control. Analysis of echocardiographic (EC) findings and patient outcome.

In a retrospective analysis, 149 echocardiographic (EC) evaluations were compared with conventional clinical parameters for donor heart selection. Of these cases, 12% were found with severe impairment of ventricular wall motion or with morphological abnormalities. Nearly half of the echocardiographically diagnosed pathological findings in donor hearts were not detected by conventional standards for heart screening. Analysis of EC-screened donor heart outcome showed a primary graft nonfunction rate of 3.1%. We suggest EC as an additional screening instrument for further dynamic and morphological information about donor heart condition. Potential donors can be saved for transplantation and severe complications can be avoided by detecting occult cardiac dysfunction. Early detection of cardiac dysfunction may have an impact on donor therapy and can avoid unnecessary and expensive transportation of the surgical team to the harvest site.

Adolescent↗
PubMed1996

Definitions of cytomegalovirus disease after heart transplantation: antigenemia as a marker for antiviral therapy.

In this prospective study, cytomegalovirus (CMV) antigenemia was defined as the marker for initiation and episodes of antigenemia as the indicator for the duration of antiviral therapy (CMV hyperimmune globulin and ganciclovir). The CMV antigenemia assay and CMV-specific IgM and IgG antibody tests were used to monitor CMV infection in 22 heart transplant recipients who, between October 1992 and July 1994, were followed up for 6 months. A total of 178 out of 627 antigenemia assays tested positive. The highest number of positive cells was greater after primary infection than after either reactivation (43.3 vs 0.3; P < 0.01) or reinfection (43.3 vs 9.3; P = NS). Sixty episodes of antigenemia were observed. More episodes of antigenemia were seen after primary infection than after either reactivation (4.6 vs 0.2; P < 0.01) or reinfection (4.6 vs 2.2; P = NS). The detection of antigenemia indicated the initiation of antiviral therapy within 24 h after the blood sample was harvested. Therapy was stopped immediately after a subsequent negative result became available. Our experience indicates that antigenemia directed antiviral therapy prevents CMV disease after primary and secondary infection in heart transplant recipients.

Adolescent↗
PubMed1996

[Cardiac pacemaker as bridge to cardiac telemonitoring].

Modern pacemakers and electrodes are equipped with supplementary features that can be utilized for many problems related to cardiac diagnosis and therapy management. Especially the recording and computer-assisted analysis of intramyocardial electrograms (IEGM), particularly of ventricular evoked responses (VER), supplies important information. The IEGMs are transmitted with large bandwidth from the implanted pacemaker to an extracorporeal receiver and from there via Internet to a central data processing station, where a specially designed software for IEGM processing is available. An individual password secured account is installed for each user. After signal processing is completed, a comprehensive patient report including trend courses and relevant clinical data is provided and can be utilized by the user for further decisions. Using this basic structure, CHARM (Computerized Heart Acute Rejection Monitoring), a system for non-invasive rejection monitoring after heart transplantation, has been developed and successfully evaluated in a clinical environment.

Computer Systems↗
PubMed1996

Troponin T as a marker for posttransplantation adaptational problems of the donor heart.

BACKGROUND: Troponin T is used as a marker for myocardial cell damage (e.g., in aiding diagnosis and follow-up of myocardial infarction). Elevated troponin T levels are also observed after heart transplantation, although until now no explanation could be found for this phenomenon. METHODS AND RESULTS: Serum samples of 15 patients who underwent orthotopic heart transplantation were tested for troponin T with a one-step enzyme immunoassay. The highest concentrations of troponin T were seen between day 3 and 14 after transplantation (3.05 +/- 1.30 micrograms/L) and remained elevated up to 3 months. A correlation (r = 0.61, p < 0.02) was found between pretransplantation systolic pulmonary artery pressure and the cumulative troponin T release after transplantation. No association was found with rejection, and no correlation was found with ischemic time of the donor heart. CONDITIONS: These findings support the hypothesis that the acute exposure of the donor heart to the preexisting elevated right ventricular afterload in the recipient represents a strong mechanical stress for the transplanted heart. Measurement of troponin T may therefore be helpful in the posttransplantation monitoring and management of ventricular function after orthotopic heart transplantation.

Adaptation, Physiological↗
PubMed1996

Paced epimyocardial electrograms for noninvasive rejection monitoring after heart transplantation.

BACKGROUND: Diagnosis of acute heart rejection after transplantation with the help of epimyocardial electrograms has been reported as a sensitive and practicable method. Long-term follow-up has been limited, however, by variations o signal, which can be avoided by using pacemaker-induced signals. METHODS: For stimulation and detection of the ventricular evoked response, a new type of electrode with fractal surface structure was used. Seventeen patients undergoing heart transplantation were included in the study. Amplitudes of the depolarization and repolarization parts of ventricular evoked response signals were analyzed and related to the degree of acute rejection according to histologic findings from endomyocardial biopsy. RESULTS: In cases of focal moderate rejection (grade 2, International Society for Heart and Lung Transplantation grading) and higher degrees of rejection, significant amplitude decreases were found. CONCLUSION: This sensitive noninvasive method for rejection monitoring with a high level of reliability provides the possibility of reducing the number of endomyocardial biopsies.

Biopsy↗
PubMed1995

CMV antigenemia (the lower matrix protein PP65), a marker for the guidance of antiviral therapy in cytomegalovirus disease after orthotopic heart transplantation.

During CMV viremia, the CMV specific lower matrix protein CMV pp65 can be detected in the nucleus of polymorphonuclear cells. A relationship has been found between the number of CMV pp65 positive cells, the clinical course and the effect of antiviral treatment on CMV disease. From 1990, heart recipients (triple drug therapy) were screened for CMV pp65 (antigenemia, according to the method described by The et al.), anti-CMV-IgM and -IgG. Tests were repeated at least every 4 weeks. Group 1 consisted of 23 patients who had been transplanted at least one year before the introduction of CMV testing as described. Between 1990 and 1992 26 patients were followed up during the first year after transplantation and represent group 2. In group 1, 1184 antigenemia assays were performed and 13 tested positive. In group 2 (1195 tests, 261 positive results), 20 out of the 26 recipients tested positive for CMV pp65. Without preceding evidence of a positive CMV pp65, no rise of IgM or IgG antibodies was observed. The time until the first antigenemia (time from detection until a subsequent test remains negative); 13 were found in group 1, 84 in group 2. In group 2, 46 episodes of antigenemia (mean duration 24.5 +/- 27.1 days) consisted of more than 1 consecutive positive result of the antigenemia assay (4.8 +/- 4.1). During these episodes the white blood cell count was 3460 +/- 1790/mm3. After the episodes, the mean leucocyte count was 6320 +/- 1870/mm3. The detection of CMV antigenemia indicated the initiation of antiviral treatment (hyperimmune globulin and ganciclovir). Therapy was stopped again when the antigenemia assay tested negative again. Antigenemia disappeared in all patients after initiation of antiviral treatment, CMV disease was not observed. CMV antigenemia mainly cumulates within the first year after heart transplantation. Antigenemia directed antiviral therapy does not prevent infection or repeated antigenemia but prevents CMV disease after heart transplantation.

Adult↗
PubMed1995

Cytomegalovirus after heart transplantation: definitions for the guidance of antiviral therapy.

Besides the current classification of cytomegalovirus (CMV) infection and disease we defined "CMV antigenaemia" as the marker for initiation of antiviral therapy (CMV hyperimmune globulin 2 ml/kg/d and ganciclovir 1000 mg/d), and "episodes of CMV antigenaemia"(the time from detection of antigenaemia until a subsequent antigenaemia assay tested negative again) indicated the time period of antiviral treatment. Patients were at highest risk for antigenaemia at day 38.2 +/- 20.9 after heart transplantation. We observed 50 episodes of antigenaemia in 18 patients. The mean duration was 7.3 +/- 6.4 days. No antigenaemia associated symptoms and no anti-CMV IgM was observed without preceding evidence of antigenaemia. Antigenaemia-associated symptoms and antigenaemia disappeared after antiviral therapy was initiated. Our therapy did not prevent CMV infection, but despite the repeated evidence of active CMV infection, no patient suffered CMV disease.

Antigens, Viral↗
PubMed1993

Twenty-four years' implant duration of the aortic Starr-Edwards Silastic ball prosthesis: a valve of the past?

Six years after the first aortic valve replacement with the Starr-Edwards Silastic ball prosthesis at Oregon Health Sciences University, the model 1260 was implanted in a 44-year-old patient at our department. During 24 years no signs of dysfunction, thromboembolism, thrombosis, periprosthetic leaks or hemolysis were observed. Material test showed no signs of fatigue. The dimension of the Silastic poppet was found to be one millimeter less than the original specifications of these poppets and there were some lipid infiltrations. Functionally the poppet was found to be nonvariant. Histologic findings detected focal hyalinization and giant cells without signs of acute inflammation or ulceration. With regard to its reliability and durability, the Starr-Edwards valve prosthesis should not be viewed with disfavor.

Adult↗