[Total artificial heart]. / Das komplett künstliche Herz.

BACKGROUND: To date the CardioWest™ total artificial heart is the only clinically available implantable biventricular mechanical replacement for irreversible cardiac failure. OBJECTIVES: This article presents the indications, contraindications, implantation procedere and postoperative treatment. MATERIAL AND METHODS: In addition to a overview of the applications of the total artificial heart this article gives a brief presentation of the two patients treated in our department with the CardioWest™. RESULTS: The clinical course, postoperative rehabilitation, device-related complications and control mechanisms are presented. CONCLUSION: The total artificial heart is a reliable implant for treating critically ill patients with irreversible cardiogenic shock. A bridge to transplantation is feasible with excellent results.

Electromechanical synchronization of the heterotopic and native heart by dual atrial stimulation following heart transplantation.

After heterotopic heart transplantation, a 59-year-old woman presented with remarkable symptoms of breathlessness and fatigue, despite excellent donor heart function. Asynchrony of donor and native heart provoked haemodynamic instability. Dual atrial pacemaker implantation lead to linkage and synchronization of atrial and ventricular contraction in both the donor and native heart with the faster organ executing the synchronization. Remarkable relief of symptoms has been evident during the long-term follow-up.

Successful management of recurrent Epstein-Barr virus-associated multilocular leiomyosarcoma after cardiac transplantation.

BACKGROUND: In contrast to Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disorders (PTLD), EBV-associated leiomyomatous tumors have thus far only rarely been described. CASE REPORT: Two years after heart transplantation with ATG induction, cyclosporine (CsA; trough levels of 250 ng/mL)-based triple drug immunosuppression), a 23-year-old patient developed a small round lesion within the left lateral liver segment. The patient underwent ultrasound-guided biopsy followed by liver resection. Histological and immunohistological examination showed a leiomyosarcoma. In situ hybridization using EBV-specific EB endoplasmic reticulum-RNA showed an intensive signal in almost all tumor cells. The tumor stained for EB nuclear antigen (EBNA)-2-protein. Immunosuppression was drastically reduced, namely, CsA levels <100 ng/dL, prednisolone 5 mg, azathioprine withdrawn, and antiviral chemotherapy initiated with 10 days of IV gancyclovir and acyclovir followed by oral famcyclovir. During the follow-up, anti-EBV-IgM, anti-early antigen antibodies, and anti-EBNA antibodies were continuously monitored excluding significant EBV replication. Eighteen months post-liver resection, and high-resolution computed tomography scan demonstrated two paravertebral tumors. These lesions and a small nodule at the left ankle were resected revealing identical leiomyosarcomata. Immunosuppression was further reduced (CsA levels 75 ng/dL) and famcyclovir maintenance therapy started. Nevertheless, 2 years later the patient again developed tumor recurrence (perirectal, liver, and right adrenal gland); the tumors were surgically removed. The therapy was switched to Rapamycin and famcyclovir was continued. Three years after the last surgical intervention, the patient is well and recurrence-free. CONCLUSION: Long-term survival in patients with posttransplant EBV-associated leiomyosarcoma can be achieved by combined surgical intervention, reduction of immunosuppression, switch to Sirolimus, and antiviral chemotherapy.

Kaposi sarcoma in solid organ transplant recipients: a single center report.

BACKGROUND: Human herpes virus (HHV8) is associated with Castleman's disease, primary effusion lymphoma, and the Kaposi's sarcoma (KS). PATIENTS AND METHODS: Among 3815 solid organ transplants performed at our center between 1977 and 2003, five patients (0.1%) were identified with KS. RESULTS: There were one cardiac, one liver, and three renal allograft recipients of median age of 52 (range 38 to 60) years, three of whom were females. Three patients were of Italian and one of Turkish descent; only one patient was a native Austrian. The onset of the disease was 2.0, 7.5, 7.8, 9.4 months, and 22 years posttransplant. Diagnosis of KS was based in all cases on histology. The heart recipient developed a tumor on the planta pedis; one renal recipient, on both legs. The liver and the two remaining renal recipients presented with disseminated disease. Treatment in all cases consisted of reduction in immunosuppression, together with surgery (n = 1), chemotherapy (n = 1), or irradiation (n = 2). Furthermore, immunosuppression was switched in two cases from Tacrolimus to Sirolimus. In the liver recipient a complete response was achieved; he died, however, due to noncompliance followed by graft failure. One renal recipient died without evidence of recurrent disease from myocardial infarction. The cardiac and two renal recipients are alive between 4 months and 17 years with well-functioning grafts and no evidence of recurrent disease. DISCUSSION: HHV8-associated lesions seem to be extremely rare in the Central European transplant population. Nevertheless, awareness of KS is important for early diagnosis and optimal treatment.

Left atrial thrombus mistaken as a tumor after heart transplantation.

The occurrence of neoplastic malignancy due to chronic immunosuppression in heart transplant recipients is a well-known threat. Continuous check-ups are therefore mandatory in this patient group. We describe the case of a 58-year-old man transplanted for dilated cardiomyopathy. During regular diagnostic check-up, a solid mass in the left atrium was discovered on the transesophageal echocardiogram. Since the mass became progressively larger over three years and showed features of neither myxoma nor thrombus, a cardiac sarcoma was suspected. A secondary diagnostic magnetic resonance tomography (MRT) investigation was contraindicated due to an implanted pacemaker. Intraoperatively, the mass proved to be an organized thrombus. Surgery had to be performed without an established accurate diagnosis due to a suspected malignancy in chronically immunosuppressed patients.

Analysing ventricular fibrillation ECG-signals and predicting defibrillation success during cardiopulmonary resuscitation employing N(alpha)-histograms.

Mean fibrillation frequency may predict defibrillation success during cardiopulmonary resuscitation (CPR). N(alpha)-histogram analysis should be investigated as an alternative. After 4 min of cardiac arrest, and 3 versus 8 min of CPR, 25 pigs received either vasopressin or epinephrine (0.4, 0.4, and 0.8 U/kg vasopressin versus 45, 45, and 200 microg/kg epinephrine) every 5 min with defibrillation at 22 min. Before defibrillation, the N(alpha)-parameter histogramstart/histogramwidth and the mean fibrillation frequency in resuscitated versus non-resuscitated pigs were 2.9+/-0.4 versus 1.7+/-0.5 (P=0.0000005); and 9.5+/-1.7 versus 6.9+/-0.7 (P=0.0003). During the last minute prior to defibrillation, histogramstart/histogramwidth of > or =2.3 versus mean fibrillation frequency > or =8 Hz predicted successful defibrillation with subsequent return of a spontaneous circulation for more than 60 min with sensitivity, specificity, positive predictive value and negative predictive value of 94 versus 82%, 96 versus 89%, 98 versus 93% and 90 versus 74%, respectively. We conclude, that N(alpha)-analysis was superior to mean fibrillation frequency analysis during CPR in predicting defibrillation success, and distinction between vasopressin versus epinephrine effects.

Coronary endothelial injury after local occlusion on the human beating heart.

BACKGROUND: Occlusion of coronary arteries during beating heart surgery bears the potential for mechanical trauma to the arterial wall with consequent endothelial injury. The aim of this study was to elucidate the effects of local occlusion on the beating heart in human coronary arteries. METHODS: Coronary arteries of patients with dilated cardiomyopathy (n = 7) or ischemic heart disease (n = 10) undergoing heart transplantation were locally occluded after starting cardiopulmonary bypass. Immediately after excision of the diseased heart, the vessels were fixed. Unoccluded segments served as controls. Integrity of endothelial lining was observed with scanning electron microscopy. RESULTS: Scanning electron microscopy revealed significantly more severe endothelial injury in the area of occlusion than in the adjacent, not manipulated control segments. In the region of local occlusion, plaque rupture was noted in three of 34 atherosclerotic vessel specimens, injury to side branches was evident in two of 44, and local microthrombus formation was evident in six of 44 samples. CONCLUSIONS: Local occlusion of human coronary arteries during beating heart coronary surgery may cause focal endothelial denudation, local microthrombosis, atherosclerotic plaque rupture, and injury to target vessel side branches.

Inferior vena caval loop of an endocardial pacing lead did not solve the growth problem in a child.

This report describes a transvenous pacemaker lead insertion into a child's right ventricle with a loop formed within the inferior vena cava to allow growth. Five years later emergency revision was necessary because of loss of capture. The expected lead release had not taken place.

Monitoring of immune activation using biochemical changes in a porcine model of cardiac arrest.

In animal models, immune activation is often difficult to assess because of the limited availability of specific assays to detect cytokine activities. In human monocytes/macrophages, interferon-gamma induces increased production of neopterin and an enhanced activity of indoleamine 2,3-dioxygenase, which degrades tryptophan via the kynurenine pathway. Therefore, monitoring of neopterin concentrations and of tryptophan degradation can serve to detect the extent of T helper cell 1-type immune activation during cellular immune response in humans. In a porcine model of cardiac arrest, we examined the potential use of neopterin measurements and determination of the tryptophan degradation rate as a means of estimating the extent of immune activation. Urinary neopterin concentrations were measured with high-performance liquid chromatography (HPLC) and radioimmunoassay (RIA) (BRAHMS Diagnostica, Berlin, Germany). Serum and plasma tryptophan and kynurenine concentrations were also determined using HPLC. Serum and urine neopterin concentrations were not detectable with HPLC in these specimens, whereas RIA gave weakly (presumably false) positive results. The mean serum tryptophan concentration was 39.0 +/- 6.2 micromol/l, and the mean kynurenine concentration was 0.85 +/- 0.33 micromol/l. The average kynurenine-per-tryptophan quotient in serum was 21.7 +/- 8.4 nmol/micromol, and that in plasma was 20.7 +/- 9.5 nmol/micromol (n = 7), which corresponds well to normal values in humans. This study provides preliminary data to support the monitoring of tryptophan degradation but not neopterin concentrations as a potential means of detecting immune activation in a porcine model. The kynurenine-per-tryptophan quotient may serve as a short-term measurement of immune activation and hence permit an estimate of the extent of immune activation.

[Cytomegalovirus infection after heart transplantation. Retrospective analysis of an antiviral CMV prevention]. / Cytomegalievirus-Infektion nach Herztransplantation. Retrospektive Analyse einer antiviralen CMV-Prophylaxe.

OBJECTIVE: Cytomegalovirus (CMV) infection is the most common viral infection in the early period after heart transplantation (HTX) and causes a significant morbidity and mortality. Although controversial, CMV is related to acute and chronic allograft rejection and to the development of graft vascular disease. It therefore plays an important role in the long-time outcome after solid organ transplantation. PATIENTS AND METHODS: 45 patients received a new heart between 1.1.97 and 31.12.1998. All of them were enrolled postoperatively in three-month antiviral prophylaxis (Cymevene). Only those patients were excluded from prophylaxis who were seronegative for CMV and received hearts from seronegative donors (n = 6). The pp65 antigenaemia assay and the murex hybrid capture CMV DNA assay on peripheral blood as well as the early antigen detection in the urine were used for CMV detection and also for monitoring. RESULTS: A total number of 580 assays were analysed (12.9 assays/patient). 561 tests (96.7%) were negative, 19 (3.3%) were positive. For CMV testing the pp65 antigenemia assay was used in 64.1%, the murex hybrid capture CMV DNA assay in 18.4% and the urine early antigen detection in 17.4%. Three patients (6.7%) developed viraemia during the first 3 postoperative months. Two patients (4.4%) suffered from CMV infection 8 and 9 months after heart transplantation and had to be treated with antiviral agents. Three patients (6.7%) died early after transplantation, but none had a CMV infection. CONCLUSION: Prevention of CMV disease was successful with three months of antiviral CMV prophylaxis after HTX. Asymptomatic viraemia during the prophylaxis period did not lead to tissue invasive disease. It is possible to carry out rapid CMV detection and CMV monitoring with the commercially available antigenaemia assays.

Pacemaker therapy in a pediatric patient with hypertrophic obstructive cardiomyopathy and rapid intrinsic atrioventricular conduction.

A 13-year-old boy with hypertrophic obstructive cardiomyopathy was treated with dual-chamber pacing after severe progression of left ventricular outflow tract obstruction and of clinical symptoms despite drug therapy. Rapid intrinsic atrioventricular conduction was overcome and complete preexcitation of the septum achieved by omitting atrial sensing and programming constant atrial pacing with a short atrioventricular delay of 70 msec. After 8 weeks of therapy, a reduction of the left ventricular outflow tract gradient from 125 to 16 mmHg and remodeling of the left ventricle were demonstrated.

Isolated right ventricular assist for postcardiotomy myocardial infarction.

Due to myocardial infarction, profound postcardiotomy right heart failure developed in a 57-year-old man after implantation of an aortic homograft for infective aortic valve endocarditis. Despite maximum medical therapy and intraaortic balloon counterpulsation, signs of endorgan injury developed, and therefore a Thoratec (Pleasanton, CA) right ventricular assist device was implanted. After 17 days of support, myocardial and endorgan function had recovered and the fully mobilized patient was successfully weaned from support and discharged from the hospital.

Single coronary artery bypass grafting--a comparison between minimally invasive 'off pump' techniques and conventional procedures.

OBJECTIVE: At present, few studies directly comparing minimally invasive and conventional coronary artery bypass grafting are available. The aim of the present study was to evaluate the clinical outcome of the two techniques. METHODS: We retrospectively compared our first consecutive 20 patients undergoing minimally invasive coronary artery single bypass grafting on the beating heart (group I) with 23 consecutive patients receiving single coronary artery bypass via sternotomy using cardiopulmonary bypass and cardioplegia (group II). The procedures were performed during the period from Jan 1, 1994 to Feb 20, 1997. There were no significant differences in demographic data. RESULTS: Statistically significant differences were found concerning total operative time (172.6 min in group I and 149.6 min in group II P = 0.0009) and myocardial ischemic time (23.7 min local coronary occlusion time in group I and 17.6 min aortic cross-clamp time in group II P = 0.03. Patients treated minimally invasive received significantly fewer blood transfusions (25.0% vs. 69.6% P = 0.0035) and were discharged significantly earlier from the hospital (admission rate on the fifth postoperative day 68.4% in group I vs. 100.0% in group II P = 0.0004). CONCLUSION: We conclude that minimally invasive coronary artery bypass grafting on the beating heart in comparison to conventional single coronary artery bypass grafting during the learning curve requires longer operative times but can reduce blood transfusion requirements and hospital stay.

Atrial natriuretic peptide-induced release of cyclic guanosine monophosphate by coronary bypass grafts.

BACKGROUND: Superior long-term patency rates of the internal mammary artery (IMA) versus saphenous vein (SV) after coronary artery bypass grafting are well documented. Higher production rates of vasodilating and platelet-inhibiting mediators (prostacyclin and nitric oxide) by the IMA seem to have a major impact on its long-term durability and resistance to coronary artery graft disease. For the right gastroepiploic artery (RGEA) marked release of protective mediators is reported as well. The vasodilating effect of cyclic guanosine monophosphate (cGMP) released after stimulation by atrial natriuretic peptide might serve as another graft protective system. The aim of the present study was to determine cGMP release by IMA, RGEA, and SV after atrial natriuretic peptide challenge. METHODS: Samples of human IMA (n = 19), RGEA (n = 7), and SV (n = 18) discarded during coronary artery bypass grafting were stimulated with 10(-6) mol/L atrial natriuretic peptide after a resting phase in nutrient medium. Release of cGMP was determined by 125-iodide radioimmunoassay. RESULTS: Basal cGMP production rates of the IMA (759.9 +/- 277.0 fmol/cm2) and RGEA (739.9 +/- 186.0 fmol/cm2) were higher than production rates of SV (281.2 +/- 64.0 fmol/cm2). Application of atrial natriuretic peptide led to a statistically significant increase of cGMP release in IMA grafts (1,939.3 +/- 778.0 fmol/cm2), whereas RGEA (618.4 +/- 141.3 fmol/cm2) and SV (221.7 +/- 64.5 fmol/cm2) remained at basal levels (p < 0.05). CONCLUSIONS: From these data we conclude that the IMA in comparison with the RGEA and SV produces more extracellular cGMP when stimulated by atrial natriuretic peptide. This effect might support the cGMP-mediated protective properties of nitric oxide and could underline the extraordinary suitability of the IMA as a bypass conduit.

Stimulated prostacyclin release by conduits used for coronary artery bypass grafting.

A direct comparison of the three coronary artery bypass conduits internal mammary artery (IMA), right gastroepiploic artery (RGEA), and saphenous vein (SV) concerning arachidonic acid (AA) stimulated release of the vasodilating and platelet inhibiting mediator prostacyclin was the aim of the present study. Pieces of saphenous vein (n = 16), right gastroepiploic artery (n = 8), and internal mammary artery (n = 19) were obtained from patients undergoing coronary artery bypass grafting. After a resting phase of 30 min in HEPES medium arachidonic acid (AA) was added in order to stimulate prostacyclin release. Time-dependent production of the stable prostacyclin metabolite 6-keto-prostaglandin F1 alpha was determined following stimulation. Under basal conditions the IMA (12.4 ng/cm2) and RGEA (12.0 ng/cm2) released more prostacyclin than saphenous vein (4.0 ng/cm2). After AA stimulation 6-keto-prostaglandin F1 alpha release at 30 min was as follows: IMA 806.0 ng/cm2, RGEA 35.9 ng/cm2, SV 82.3 ng/cm2 (p < 0.0001 within grafts, p < 0.0001 between grafts, ANOVA for repeated measures). The internal mammary artery in comparison with the right gastroepiploic artery and saphenous vein seems to be better protected against local thrombotic events and development of coronary artery graft disease with the aid of the vasodilating and platelet inhibiting mediator prostacyclin.

Temporary extracorporeal membrane oxygenation in the treatment of acute traumatic lung injury.

PURPOSE: To report two cases of acute life-threatening traumatic lung injury, who required temporary extracorporeal veno-venous membrane oxygenation (ECMO), and airlifting to a level I trauma centre. CLINICAL FEATURES: The first patient suffered a severe motor vehicle accident with prolonged entrapment in the wreckage. After extrication, tracheal intubation, and fluid resuscitation, respiratory therapy failed to result in sufficient ventilation and oxygenation within the first hours after trauma due to severe lung contusion and intraparenychmal bleeding. The second patient was hit by a falling tree and suffered isolated blunt chest trauma. Due to pulmonary contusions and tracheal rupture, subsequent ventilation management was limited by extensive mediastinal emphysema. Both patients were airlifted to a University Hospital and placed on ECMO for four and six days without complications, respectively. After emergency surgery and 21 and 26 days intensive care treatment, both patients were transferred to a general ward, and discharged from the hospital with full recovery. CONCLUSION: These cases demonstrate the role of ECMO in the treatment of traumatic respiratory failure. If ventilatory support strategies fail due to severe lung or airway injury, ECMO may be an option for the temporary management of gas exchange in trauma patients.