Electroanatomic mapping system guided his bundle pacemaker implantation: experience of the his bundle registry graz

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with bradyarrhythmia in need for ventricular pacing may suffer from pacing-induced heart failure due to unphysiological right ventricular pacing. His bundle pacing (HBP) allows to overcome this common issue with a more physiologic approach but real-life procedural data using this technology is scarce.

Methods

We report a single centre experience of the first 44 consecutive patients being implanted with a His-bundle-based pacemaker 09/2020-11/2021 per 3D-mapping guided implantation due to different types of bradyarrhythmia, or for cardiac resynchronisation therapy in heart failure combined with a left-ventricular lead (HOT-CRT) ± a right ventricular defibrillator lead. The positioning of the His-bundle-lead was done by identifying the His-bundle-location with a 3D electroanatomic mapping system via an introducing sheath that is provided with electrodes at its tip.

Results

Mean age was 70 [16;86] years, 12/44 (27%) patients were female, mean baseline LVEF was 44±18%. Baseline ECG was captured: QRS width was 123±33ms, with typical LBBB in 14/44 (32%), typical RBBB in 4/44 (9%), alternating BBB in one patient (2%) and either no BBB or ventricular escape rhythm in 25/44 (57%). Indications for implantation were AV-block grade II-III in 19/44 (43%), primary prophylactic ICD indication in HFrEF in 13/44 (30%), atrial fibrillation with bradycardic conduction in 7/44 patients (16%), sick-sinus-syndrome in 4/44 (9%) and secondary prophylactic ICD indication in one patient (2%). In 41/44 (93%) a primary device was implanted, in 3/44 (7%) a pre-existent device was upgraded with a HB lead.

Therefore, 14 dual-chamber-pacemaker, 5 single-chamber-pacemaker, 8 single-chamber CRT-P, 11 dual-chamber CRT-P, 4 single-chamber CRT-D, 2 dual-chamber CRT-D were implanted. In 50 patients HBP was attempted, while in 6/50 (12%) patients outside of this analysis the attempt was not successful, these patients were consecutively implanted with a non-HBP-device and therefor excluded from the further analysis.

In the 44 patients included in this analysis with primary successful HBP, 4/44 (9%) his-bundle-leads dislocated within the first 48 hours, leading to a secondary success rate of 91%. There were two post-procedural pneumothorax that needed drainage, no major procedure-related complications occurred. Median skin-to skin procedure time was 109±50 minutes. The paced QRS width at the post-implantation follow up was 115±32ms with a change in QRS width of -10ms (+72;-92ms). When excluding the secondary lead dislocations and including only the successful HB paced QRS complexes, the paced QRS width was 105±30ms and the change in QRS width was -12±42ms. The mean his-bundle threshold was 1,2±1V over 0,5ms (0,5;1,5ms). The proportion of ventricular pacing was 69±38%.

Conclusion

Electroanatomic-guided His bundle pacing is feasible, with high implantation success rate and electric impact, both regarding QRS width and pacing threshold.

Ventral incisional hernia (VIH) repair after liver transplantation (OLT) with a biological mesh: experience in 3 cases

BACKGROUND

Hernias after orthotopic liver transplant (OLT) occur in about 30 % of cases. Predisposing factors in liver cirrhotic patients of cases are ascites, low abdominal muscle mass and cachexia before and immunosuppression after OLT. Standard operative transplant-technique even in small hernias is to implant a mesh. For patients after liver transplantation a porcine non-cross linked biological patch being less immunogenic than synthetic and cross-linked meshes is chosen for ventral incisional hernia repair.

METHODS

3 patients (1 female, 2 male), OLT indications Hepatitis C, exogenous- toxic cirrhosis, median-age 53 (51 - 56) and median time to hernia occurrence after OLT were 10 month (6 - 18 m) are documented. 2 patients suffered from diabetes, 2 from chronic-obstructive lung disease. Maintenance immunosuppressions were Everolimus in 1 patient, Everolimus + MMF in the second and Everolimus +Tacrolimus in the third patient. The biological was chosen for hernia repair due to the preexisting risk- factors. Meshes, 10 × 16 cm were placed, in IPOM (Intra-Peritonel-Onlay-Mesh) -position by relaparatomy. Insolvable, monofile, interrupted sutures were used.

RESULTS

All patients recovered primarily, and were dismissed within 10 d post OP. No wound healing disorders or signs of postoperative infections occurred. All are free of hernia recurrence in a mean observation time of 22 month (10 - 36).

CONCLUSION

The usage of porcine non-cross-linked biological patches seems feasible for incisional hernia repair after OLT. Wound infections in these patients have been observed with other meshes. Further investigation is needed to prove potential superiority of this biological to the other meshes.

Immunohistochemical and radiological characterization of wound healing in porcine liver after radiofrequency ablation

BACKGROUND

Radiofrequency ablation (RFA) is a minimal invasive therapeutic option for patients with hepatocellular carcinoma or liver metastases. We investigated RFA-induced cellular changes in the liver of pigs.

MATERIAL AND METHODS

Healthy pigs (n=18) were sacrificed between day 0 and 3 months after RFA. The wound healing process was evaluated by computed tomography (CT), chromotrope anilinblue (CAB) staining of large-scale and standard tissue sections. Immunohistochemistry (IHC) for heat shock protein 70, Caspase-3, Ki67, Reelin, Vinculin, Vimentin and α-SMA was perfomed.

RESULTS

One day after RFA, CAB staining showed cell damage and massive hyperaemia. All IHC markers were predominantly expressed at the outer borders of the lesion, except Reelin, which was mainly detected in untreated liver regions. By staining for Hsp70, the heat stress during RFA was monitored, which was most distinct 1-2 days after RFA. CT revealed decreased lesion size after one week. Development of a Vimentin and α-SMA positive fibrotic capsule was observed.

CONCLUSION

In the early phase signs of cell damage, apoptosis and proliferation are dominant. Reduced expression of Reelin suggests a minor role of hepatic stellate cells in the RFA zone. After one week myofibroblasts become prominent and contribute to the development of the fibrotic capsule. This elucidates the pathophysiology of RFA and could contribute to the future optimization of RFA procedures.

[Successful preclinical thoracotomy in a 17-year-old man]

We report the case of a 17-year-old man who sustained multiple stab wounds after a knife attack. After arrival of the emergency medical team the patient suffered a cardiac arrest caused by cardiac tamponade. After emergency thoracotomy and open heart massage the patient developed ROSC and could be discharged 13 days later without neurological deficits. Prehospital thoracotomy is rarely performed in Austria but is the only realistic chance for survival in cases of hematopericardium and tamponade. Better training of emergency physicians in Austria concerning surgical resuscitation could increase survival rates especially after penetrating thoracic trauma.

Early remodeling of perinuclear Ca2+ stores and nucleoplasmic Ca2+ signaling during the development of hypertrophy and heart failure

BACKGROUND

A hallmark of heart failure is impaired cytoplasmic Ca(2+) handling of cardiomyocytes. It remains unknown whether specific alterations in nuclear Ca(2+) handling via altered excitation-transcription coupling contribute to the development and progression of heart failure.

METHODS AND RESULTS

Using tissue and isolated cardiomyocytes from nonfailing and failing human hearts, as well as mouse and rabbit models of hypertrophy and heart failure, we provide compelling evidence for structural and functional changes of the nuclear envelope and nuclear Ca(2+) handling in cardiomyocytes as remodeling progresses. Increased nuclear size and less frequent intrusions of the nuclear envelope into the nuclear lumen indicated altered nuclear structure that could have functional consequences. In the (peri)nuclear compartment, there was also reduced expression of Ca(2+) pumps and ryanodine receptors, increased expression of inositol-1,4,5-trisphosphate receptors, and differential orientation among these Ca(2+) transporters. These changes were associated with altered nucleoplasmic Ca(2+) handling in cardiomyocytes from hypertrophied and failing hearts, reflected as increased diastolic Ca(2+) levels with diminished and prolonged nuclear Ca(2+) transients and slowed intranuclear Ca(2+) diffusion. Altered nucleoplasmic Ca(2+) levels were translated to higher activation of nuclear Ca(2+)/calmodulin-dependent protein kinase II and nuclear export of histone deacetylases. Importantly, the nuclear Ca(2+) alterations occurred early during hypertrophy and preceded the cytoplasmic Ca(2+) changes that are typical of heart failure.

CONCLUSIONS

During cardiac remodeling, early changes of cardiomyocyte nuclei cause altered nuclear Ca(2+) signaling implicated in hypertrophic gene program activation. Normalization of nuclear Ca(2+) regulation may therefore be a novel therapeutic approach to prevent adverse cardiac remodeling.

Oxidative stress and apoptosis in a pig model of brain death (BD) and living donation (LD)

Background

As organ shortage is increasing, the acceptance of marginal donors increases, which might result in poor organ function and patient survival. Mostly, organ damage is caused during brain death (BD), cold ischemic time (CIT) or after reperfusion due to oxidative stress or the induction of apoptosis. The aim of this study was to study a panel of genes involved in oxidative stress and apoptosis and compare these findings with immunohistochemistry from a BD and living donation (LD) pig model and after cold ischemia time (CIT).

Methods

BD was induced in pigs; after 12 h organ retrieval was performed; heart, liver and kidney tissue specimens were collected in the BD (n = 6) and in a LD model (n = 6). PCR analysis for NFKB1, GSS, SOD2, PPAR-alpha, OXSR1, BAX, BCL2L1, and HSP 70.2 was performed and immunohistochemistry used to show apoptosis and nitrosative stress induced cell damage.

Results

In heart tissue of BD BAX, BCL2L1 and HSP 70.2 increased significantly after CIT. Only SOD2 was over-expressed after CIT in BD liver tissue. In kidney tissue, BCL2L1, NFKB, OXSR1, SOD2 and HSP 70.2 expression was significantly elevated in LD. Immunohistochemistry showed a significant increase in activated Caspase 3 and nitrotyrosine positive cells after CIT in BD in liver and in kidney tissue but not in heart tissue.

Conclusion

The up-regulation of protective and apoptotic genes seems to be divergent in the different organs in the BD and LD setting; however, immunohistochemistry revealed more apoptotic and nitrotyrosine positive cells in the BD setting in liver and kidney tissue whereas in heart tissue both BD and LD showed an increase.

Knowledge and attitude of ICU nurses, students and patients towards the Austrian organ donation law

Background

A survey on the knowledge and attitudes towards the Austrian organ donation legislation (an opt-out solution) of selected groups of the Austrian population taking into account factors such as age, gender, level of education, affiliation to healthcare professions and health related studies was conducted.

Methods

An online survey among 3 target groups (ICU nurses, health science students and non health science students) was performed and results were compared to the answers from transplantation patients to a paper questionnaire. A total of 8415 persons were asked to participate in the survey and 2025 (24%) persons correctly completed the questionnaire. 1945 online responses (ICU nurses n = 185; students of health sciences n = 1277; students of non-health science related courses n = 483) were analysed and data were compared to 80 manually filled-in responses from patients from a previous study.

Results

84% of participants state that they know the Austrian organ donation legislation; this percentage varies significantly (p < 0.05) within the target groups and is influenced by demographic variables of the participants. 74% think that the law is good and 79% do not favour a change. Opinions and attitudes towards the legal situation are positively influenced by the affiliation to healthcare professions and health-related fields of study. Interviewed persons who were aware of the legislation before the survey had a more positive attitude towards the existing legislation (77% versus 74%, p < 0.05).

Conclusions

The information level on Austrian organ donation legislation is high. ICU nurses and those who did not know the law before were most critical towards the existing legislation. Therefore education to increase knowledge in the general population and goal-oriented efforts to increase awareness in the target groups should be emphasized.

Docosahexaenoic acid (DHA)-induced heme oxygenase-1 attenuates cytotoxic effects of DHA in vascular smooth muscle cells

OBJECTIVE

Docosahexaenoic acid (DHA), a member of n-3 polyunsaturated fatty acids (n-3 PUFA) is a potent regulator of molecular events implicated in cardiovascular health. In a previous study we found that Ca(2+)-dependent oxidative stress is the central and initial event responsible for induction of unfolded protein response (UPR), cell cycle arrest and apoptosis in DHA treated primary human smooth muscle cells isolated from small pulmonary artery (hPASMC). In the present study we examined the impact of heme oxygenase (HO)-1, induced by DHA, on DHA-induced oxidative stress, UPR, cell proliferation and apoptosis in hPASMC.

METHODS & RESULTS

DHA led to a time- and concentration-dependent increase in HO-1 mRNA and protein levels in hPASMC. The DHA-induced HO-1 upregulation could be attenuated by preincubation of cells with a strong antioxidant Tempol or by siRNA-mediated depletion of nuclear factor erythroid 2-related factor-2 (Nrf2). In DHA-treated hPASMC, depletion of HO-1 by siRNA-mediated silencing resulted in increased levels of reactive oxygen species (ROS) and increased duration of UPR, the latter revealed by monitoring of spliced X-box binding protein 1 (XBP-1) variant. Moreover, HO-1 silencing augmented apoptosis in DHA-treated hPASMC as found by increased numbers of cleaved caspase-3-positive cells. HO-1 silencing did not affect proliferation of hPASMC exposed to DHA.

CONCLUSION

Our results indicate that DHA-induced, ROS-dependent upregulation of HO-1 attenuates oxidative stress, UPR and apoptosis in DHA-treated hPASMC.

Complication profile of the Berlin Heart EXCOR biventricular support in children

In chronic cardiomyopathy, mechanical circulatory support (MCS) plays an increasingly important role for children as the shortage of suitable donor hearts increases waiting time on the transplant list. We report our experience with the paracorporal Berlin Heart EXCOR System (Berlin Heart AG, Berlin, Germany) used as a biventricuclar assist device (BVAD). Nine patients with a BVAD EXCOR system were treated between 2006 and 2012; out of these patients, four were less than 18 years old (6, 14, 14, and 17 years old). Their diagnoses were postcardotomy failure (n = 1), dilatative cardiomyopathy (n = 2), and terminal heart failure (n = 1). Overall survival, waiting time for heart transplantation (HTx) and complication profile for the BVAD were analyzed retrospectively. Thirty days' mortality was 25% (n = 1). One child died after 84 days on support due to cerebral bleeding. Mean support time was 218.75 days (4, 84, 262, and 525 days). Pump chamber exchange was necessary three times due to pump chamber thrombosis (n = 2) and partial pump chamber membrane rupture (n = 1). Complications included: sepsis (n = 1), drive line infection requiring intravenous antibiotics (n = 2), and recurrent epistaxis (n = 3). Two children were successfully transplanted after 262/525 days on BVAD; they are currently at home (follow-up: 1.9 and 2.3 years). The EXCOR is a life-saving MCS system suitable for long-term paracorporeal biventricular assistance.

Establishing a brain-death donor model in pigs

INTRODUCTION

An animal model that imitates human conditions might be useful not only to monitor pathomechanisms of brain death and biochemical cascades but also to investigate novel strategies to ameliorate organ quality and functionality after multiorgan donation.

METHODS

Brain death was induced in 15 pigs by inserting a catheter into the intracranial space after trephination of the skull and augmenting intracranial pressure until brain stem herniation. Intracranial pressure was monitored continuously; after 60 minutes, brain death diagnostics were performed by a neurologist including electroencephalogram (EEG) and clinical examinations. Clinical examinations included testing of brain stem reflexes as well as apnoe testing; then intensive donor care was performed according to standard guidelines until 24 hours after confirmation of brain death. Intensive donor care was performed according to standard guidelines for 24 hours after brain death.

RESULTS

Sixty minutes after brain-death induction, neurological examination and EEG examination confirmed brain death. Intracranial pressure increased continuously, remaining stable after the occurrence of brain death. All 15 animals showed typical signs of brain death such as diabetes insipidus, hypertensive and hypotensive periods, as well as tachycardia. All symptoms were treated with standard medications. After 24 hours of brain death we performed successful multiorgan retrieval.

DISCUSSION

Brain death can be induced in a pig model by inserting a catheter after trephination of the skull. According to standard guidelines the brain-death diagnosis was established by a flat-line EEG, which occurred in all animals at 60 minutes after induction.

Establishing a brain-death donor model in pigs

INTRODUCTION

An animal model that imitates human conditions might be useful not only to monitor pathomechanisms of brain death and biochemical cascades but also to investigate novel strategies to ameliorate organ quality and functionality after multiorgan donation.

METHODS

Brain death was induced in 15 pigs by inserting a catheter into the intracranial space after trephination of the skull and augmenting intracranial pressure until brain stem herniation. Intracranial pressure was monitored continuously; after 60 minutes, brain death diagnostics were performed by a neurologist including electroencephalogram (EEG) and clinical examinations. Clinical examinations included testing of brain stem reflexes as well as apnoe testing; then intensive donor care was performed according to standard guidelines until 24 hours after confirmation of brain death. Intensive donor care was performed according to standard guidelines for 24 hours after brain death.

RESULTS

Sixty minutes after brain-death induction, neurological examination and EEG examination confirmed brain death. Intracranial pressure increased continuously, remaining stable after the occurrence of brain death. All 15 animals showed typical signs of brain death such as diabetes insipidus, hypertensive and hypotensive periods, as well as tachycardia. All symptoms were treated with standard medications. After 24 hours of brain death we performed successful multiorgan retrieval.

DISCUSSION

Brain death can be induced in a pig model by inserting a catheter after trephination of the skull. According to standard guidelines the brain-death diagnosis was established by a flat-line EEG, which occurred in all animals at 60 minutes after induction.

JTV519 (K201) reduces sarcoplasmic reticulum Ca²⁺ leak and improves diastolic function in vitro in murine and human non-failing myocardium

BACKGROUND AND PURPOSE

Ca²⁺ leak from the sarcoplasmic reticulum (SR) via ryanodine receptors (RyR2s) contributes to cardiomyocyte dysfunction. RyR2 Ca²⁺ leak has been related to RyR2 phosphorylation. In these conditions, JTV519 (K201), a 1,4-benzothiazepine derivative and multi-channel blocker, stabilizes RyR2s and decrease SR Ca²⁺ leak. We investigated whether JTV519 stabilizes RyR2s without increasing RyR2 phosphorylation in mice and in non-failing human myocardium and explored underlying mechanisms.

EXPERIMENTAL APPROACH

SR Ca²⁺ leak was induced by ouabain in murine cardiomyocytes. [Ca²⁺]-transients, SR Ca²⁺ load and RyR2-mediated Ca²⁺ leak (sparks/waves) were quantified, with or without JTV519 (1 µmol·L⁻¹). Contribution of Ca²⁺ -/calmodulin-dependent kinase II (CaMKII) was assessed by KN-93 and Western blot (RyR2-Ser(2814) phosphorylation). Effects of JTV519 on contractile force were investigated in non-failing human ventricular trabeculae.

KEY RESULTS

Ouabain increased systolic and diastolic cytosolic [Ca²⁺](i) , SR [Ca²⁺], and SR Ca²⁺ leak (Ca²⁺ spark (SparkF) and Ca²⁺ wave frequency), independently of CaMKII and RyR-Ser(2814) phosphorylation. JTV519 decreased SparkF but also SR Ca²⁺ load. At matched SR [Ca²⁺], Ca²⁺ leak was significantly reduced by JTV519, but it had no effect on fractional Ca²⁺ release or Ca²⁺ wave propagation velocity. In human muscle, JTV519 was negatively inotropic at baseline but significantly enhanced ouabain-induced force and reduced its deleterious effects on diastolic function.

CONCLUSIONS AND IMPLICATIONS

JTV519 was effective in reducing SR Ca²⁺ leak by specifically regulating RyR2 opening at diastolic [Ca²⁺](i) in the absence of increased RyR2 phosphorylation at Ser(2814) , extending the potential use of JTV519 to conditions of acute cellular Ca²⁺ overload.

Everolimus in different combinations as maintenance immunosuppressive therapy in heart transplant recipients

OBJECTIVES

We examined the experiences of heart transplant recipients receiving everolimus as maintenance therapy in different combinations over a long time.

MATERIALS AND METHODS

Between 2004 and 2009, forty patients (29 men, 11 women; mean age, 51.6 y) were switched from a routine immunosuppressive regimen to everolimus. Indications were other (2), renal insufficiency (17), cardiac allograft vasculopathy (14), and ongoing cellular rejection (7). Combinations were either along with cyclosporine (24), mycophenolate mofetil (14), or others (2). Indications for the introduction of everolimus including safety, efficacy, different combinations of everolimus, biopsy-proven acute rejections, renal function, and infections were evaluated retrospectively.

RESULTS

Five patients died, 4 of them were still on everolimus at the time of death; they died from intracerebral hemorrhage (1), embolism (1), cardiac arrest (2), and unknown (1). Everolimus was discontinued in 6 patients owing to severe adverse effects: Edema (2), gastrointestinal adverse effects (3), and dermal adverse effects (1). Mean everolimus trough levels were 5.8 μmol/L at 6 months and 4.9 at 60 months. Mean cyclosporine levels were 67.62 μmol/L at 6 months and 47.3 μmol/L at 60 months. Mean serum creatinine levels were stable (147.9 μmol/L after 60 months). Four life-threatening infections (all pneumonia) occurred but resulted in complete recovery.

CONCLUSIONS

Everolimus is safe with different immunosuppressive combinations after receiving a heart transplant.

Effect of oxidative stress and endotoxin on human serum albumin in brain-dead organ donors

Albumin, among other molecules, binds and detoxifies endotoxin in healthy people. Oxidative stress leads to protein oxidation and thus to the impaired binding properties of albumin. This property, in combination with increased gut permeability, leads to the appearance of endotoxin in the systemic circulation and to impaired organ function. We hypothesize that these processes occur in the serum of brain-dead organ donors. Endotoxin was determined with an adapted Limulus amoebocyte lysate assay. The albumin fractions and binding capacity were determined by high-performance liquid chromatography (HPLC). FlowCytomix (eBioscience, San Diego, Calif) was used to determine the cytokine levels. Carbonylated proteins (CPs) and myeloperoxidase (MPO) were measured by an enzyme-linked immunosorbent assay (ELISA). Eighty-four brain-dead organ donors were enrolled and categorized by the duration of intensive care unit (ICU) stay. The albumin-binding capacity for dansylsarcosine was reduced in brain-dead patients compared with controls. Endotoxin positivity in 16.7% of donors was associated with decreased binding capacity in donors and worse survival of recipients. The CP and MPO levels of organ donors were significantly higher than in healthy controls. The durations of ICU stay increased albumin oxidation. In addition, interleukin-6 (IL-6), IL-8, IL-10, and IL-1β levels were increased in patients, whereas the interferon-γ (IFN-γ) levels were within the normal range. We conclude that oxidative stress and systemic endotoxemia are present in brain-dead organ donors, which might affect recipient survival. High endotoxin levels might be caused by increased gut permeability and decreased binding capacity of albumin influenced not just by higher albumin oxidation.

Energy status of pig donor organs after ischemia is independent of donor type

BACKGROUND

Literature is controversial whether organs from living donors have a better graft function than brain dead (BD) and non-heart-beating donor organs. Success of transplantation has been correlated with high-energy phosphate (HEP) contents of the graft.

METHODS

HEP contents in heart, liver, kidney, and pancreas from living, BD, and donation after cardiac death in a pig model (n=6 per donor type) were evaluated systematically. BD was induced under general anesthesia by inflating a balloon in the epidural space. Ten hours after confirmation, organs were retrieved. Cardiac arrest was induced by 9V direct current. After 10min of ventricular fibrillation without cardiac output, mechanical and medical reanimation was performed for 30min before organ retrieval. In living donors, organs were explanted immediately. Freeze-clamped biopsies were taken before perfusion with Celsior solution (heart) or University of Wisconsin solution (abdominal organs) in BD and living donors or with Histidine-Tryptophan-Ketoglutaric solution (all organs) in non-heart-beating donors, after perfusion, and after cold ischemia (4h for heart, 6h for liver and pancreas, and 12h for kidney). HEPs (adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, and phosphocreatine), xanthine, and hypoxanthine were measured by high-performance liquid chromatography. Energy charge and adenosine triphosphate-to-adenosine diphosphate ratio were calculated.

RESULTS

After ischemia, organs from different donor types showed no difference in energy status. In all organs, a decrease of HEP and an increase in hypoxanthine contents were observed during perfusion and ischemia, irrespective of the donor type.

CONCLUSION

Organs from BD or non-heart-beating donors do not differ from living donor organs in their energy status after average tolerable ischemia.

A 10min "no-touch" time - is it enough in DCD? A DCD animal study

Donation after cardiac death (DCD) is under investigation because of the lack of human donor organs. Required times of cardiac arrest vary between 75s and 27min until the declaration of the patients' death worldwide. The aim of this study was to investigate brain death in pigs after different times of cardiac arrest with subsequent cardiopulmonary resuscitation (CPR) as a DCD paradigm. DCD was simulated in 20 pigs after direct electrical induction of ventricular fibrillation. The "no-touch" time varied from 2min up to 10min; then 30min of CPR were performed. Brain death was determined by established clinical and electrophysiological criteria. In all animals with cardiac arrest of at least 6min, a persistent loss of brainstem reflexes and no reappearance of bioelectric brain activity occurred. Reappearance of EEG activity was found until 4.5min of cardiac arrest and subsequent CPR. Brainstem reflexes were detectable until 5min of cardiac arrest and subsequent CPR. According to our experiments, the suggestion of 10min of cardiac arrest being equivalent to brain death exceeds the minimum time after which clinical and electrophysiological criteria of brain death are fulfilled. Therefore shorter "no-touch" times might be ethically acceptable to reduce warm ischemia time.

Case of Paracoccus yeei infection documented in a transplanted heart

After a successful cardiac transplantation, routine endomyocardial biopsies showed severe infiltrates comparable with myocarditis. Polymerase chain reaction analysis of native myocardial samples revealed infection with Paracoccus yeei, and the clinical condition of the patient deteriorated. After administration of ciprofloxacin, his clinical condition improved, and further biopsies showed no infiltrates in the cardiac specimens. To our knowledge this is the first documented case of P. yeei infection in a heart transplant patient.

Myeloperoxidase and carbonyl proteins: promising markers for non-invasive monitoring of graft rejection after heart transplantation

BACKGROUND

After heart transplantation (HTx), endomyocardial biopsy (EMB) is currently the standard method to diagnose acute graft rejection. A non-invasive marker of rejection would be desirable as an alternative or to permit more selective use of the costly and invasive EMB.

METHODS

In this retrospective study, outcomes of routinely taken EMBs were used to select 28 patients after HTx EMB Grade 0R (8 patients), 1R (9 patients) or 2R (11 patients). For these patients, myeloperoxidase (MPO) and carbonyl proteins (CP) in serum were measured using enzyme-linked immunoassay (ELISA).

RESULTS

MPO and CP levels in post-HTx patients with Grade 2R rejection were significantly (MPO: p < 0.01; CP: p < 0.001) elevated at the time of rejection compared with levels 1 month earlier. MPO and CP levels predicted Grade 2R rejection and the best cut-off point was 237.5 μg/l for MPO and 222.5 pmol/mg for CP, respectively. Clinically most important was the marked increase (doubling of basic values within 1 month) of MPO and CP levels in cases of Grade 2R rejection in post-HTx patients.

CONCLUSIONS

MPO and CP seem to be appropriate parameters to monitor rejection events non-invasively and to minimize the application of EMBs after HTx.