Boulos Asfour

Milrinone Modulates Endotoxemia, Systemic Inflammation, and Subsequent Acute Phase Response after Cardiopulmonary Bypass (CPB)

BACKGROUND Compromised splanchnic perfusion and the resulting intestinal mucosal injury leads to a decreased mucosal barrier function, which allows translocation of intestinal flora and endotoxemia. The authors evaluated the effects of milrinone on splanchnic oxygenation, systemic inflammation, and the subsequent acute-phase response in patients undergoing coronary artery bypass grafting. METHODS This open, placebo-controlled randomized clinical study enrolled 22 adult patients in two groups. Before induction of anesthesia, baseline values were obtained and patients were randomized to receive milrinone (30 microg/kg bolus administered progressively in 10 min, followed by a continuous infusion of 0.5 microg x kg(-1) x min(-1)) or saline. The following parameters were determined: hemodynamics; systemic oxygen delivery and uptake; arterial, mixed venous and hepatic venous oxygen saturation; intramucosal pH (pHi); and mixed and hepatic venous plasma concentrations of endotoxin, interleukin 6, serum amyloid A, and C-reactive protein. RESULTS Milrinone did not prevent gastrointestinal acidosis as measured by pHi, but its perioperative administration resulted in significantly higher pHi levels compared with control. Venous and hepatic venous endotoxin and the interleukin 6 concentration were reduced significantly in the milrinone group. Serum amyloid A values were attenuated in the milrinone group 24 h after surgery. No significant differences could be seen in routinely measured oxygen transport-derived variables. CONCLUSIONS Perioperative administration of low-dose milrinone may have antiinflammatory properties and may improve splanchnic perfusion in otherwise healthy patients undergoing routine coronary artery bypass grafting.

Fetoscopic Direct Fetal Cardiac Access in Sheep An Important Experimental Milestone Along the Route to Human Fetal Cardiac Intervention

BackgroundFetal cardiac interventions by direct ultrasound-guided approaches or open fetal cardiac surgery have been fraught with technical difficulties, as well as with significant maternal and fetal morbidity in humans. Therefore, the purpose of our study in sheep was to assess the feasibility and potential of fetoscopic direct fetal cardiac access. Methods and ResultsIn 15 anesthetized pregnant ewes (88 to 109 days of gestation; term, 145 days), 3 to 4 trocars were percutaneously placed in the uterus. Using videofetoscopic equipment, we assessed the feasibility of achieving direct fetal cardiac access. Minimally invasive direct fetal cardiac access by operative fetoscopy was achieved in 10 of the 15 fetal sheep. In 7 fetuses, the approach was successfully tested for fetal cardiac pacing (n=5) or antegrade fetal cardiac catheterization (n=2). Access was not achieved in 5 fetuses because of bleeding complications (n=2) or because the fetoscopic setup could not be established (n=3). All but 2 fetal sheep were alive at the end of the procedure. Acute fetal demise resulted from maternal hypotension or kinking of the fetal inferior caval vein by sternal suspension. Six ewes continued gestation; 3 of these went to term, with a normal fetal outcome. Two ewes died from septicemia 3 and 7 days after the procedure, and 1 ewe aborted 1 month after the procedure. ConclusionsMinimally invasive direct fetal cardiac access by operative fetoscopy is feasible in fetal sheep. The fetoscopic approach carries important potential for fetal cardiac pacing, antegrade fetal valvuloplasties, and resection of fetal intrapericardial teratomas in human fetuses.

Operative techniques and strategies for minimally invasive fetoscopic fetal cardiac interventions in sheep.

AbstractBackground: Recent efforts to develop procedures for fetoscopic fetal cardiac interventions have been prompted by the development of severe secondary damage to the fetal heart due to semilunar valvar obstructions and the poor outcome of therapy-refractory fetal arrhythmias. The purpose of our manuscript is to analyze and share our experience with the creation of an operative setup for these procedures in sheep. Methods: We studied a total of 48 fetal sheep between 81 and 106 days of gestation (term, 145 days). After entering the amniotic cavity by a percutaneous approach, we performed various fetoscopic fetal cardiac procedures. We analyzed the success of percutaneous fetal access, methods of trocar support, the incidence and management of trocar dislodgement or accidental insertion into the chorioamniotic space, problems related to amniotic insufflation and trocar placement, as well as techniques for fetal posturing and uterine closure. Results: Percutaneous fetal access was achieved in all sheep. The use of resterilizable trocars substantially decreased the costs of our procedures. Utilizing a percutaneous transuterine purse-string suture for trocar support helped to minimize the number of nonabsorbable T-fasteners remaining inside the uterus postoperatively. As complications such as trocar dislodgement, insertion of the trocar into the chorioamniotic space, and problems with intraamniotic insufflation and gas loss were mastered, conversion to an open operative approach was never required. A novel strategy that we devised for percutaneous fetal posturing permitted adequate fetal posturing with ease and minimal trauma to the fetal skin. Conclusion: As operative techniques have become more refined, the feasibility of performing fetoscopic fetal cardiac interventions in human fetuses now depends mainly on technical improvements in imaging and interventional catheters, as well as advances in pacemaker equipment.

A simple new model of physiologically working heterotopic rat heart transplantation provides hemodynamic performance equivalent to that of an orthotopic heart

BACKGROUND The widely used non-volume-loaded abdominal heterotopic heart transplant (NL) in rats undergoes atrophy after transplantation. Various techniques have been designed to load the transplanted heart because of its potential immunological impact. Our aim was to create a volume-loaded heterotopic heart transplantation model (VL) capable of ejection and practical for routine studies. Using this model, we tested the hypothesis that VL isografts would retain myocardial performance comparable to native hearts (NH). METHODS Heterotopic hearts were transplanted using and end-to-side anastomosis between the donors superior vena cava and the recipients abdominal inferior vena cava. The right ventricle loads the left ventricle (LV) via a direct anastomosis of the pulmonary artery to the left atrium. The LV ejects volume through an end-to-side anastomosis of the donors aorta to the recipients abdominal aorta. Hemodynamic data (systolic and diastolic LV pressures, dP/dt max and min, tau) were studied in-situ (at baseline and after adding volume) and in a Langendorff perfusion system (at baseline and after stimulation with isoproterenol) 2 weeks after transplantation. RESULTS In situ systolic pressure and diastolic function of VL was superior to NL, and beta-adrenergic stimulated performance in the Langendorff perfusion of VL showed hemodynamic performance equivalent to NH, unlike NL which had a diminished response. CONCLUSION This technique results in a volume-loaded ejecting heart transplant model that preserves anatomical structures. The VL can be evaluated in situ and after explantation in Langendorff perfusion system and may offer advantages if workload of the graft is of significance to the study performed.

Fetoscopic Transesophageal Electrocardiography and Stimulation in Fetal Sheep A Minimally Invasive Approach Aimed at Diagnosis and Termination of Therapy-Refractory Supraventricular Tachycardias in Human Fetuses

BACKGROUND Therapy-refractory supraventricular tachycardia commonly results in hydrops and death in human fetuses. The purpose of this study in fetal sheep was to assess the feasibility of a minimally invasive fetoscopic approach for fetal transesophageal electrocardiography and stimulation aimed at diagnosis and termination of these tachycardias. METHODS AND RESULTS We studied a total of 10 fetal sheep (87 to 103 days of gestation; term=145 days). We entered the amniotic cavity using a percutaneous fetoscopic approach and placed various electrophysiology catheters into the fetal esophagus. We recorded the number of animals in which fetoscopic transesophageal electrocardiography and stimulation were successful and assessed pacing success and thresholds for different catheters. In addition, we monitored for potential adverse effects from stimulation and for other complications of the operation. Recording of transesophageal electrocardiograms was successful in all fetal sheep. Capture during stimulation was successfully documented by additional fetal bipolar surface electrocardiograms in 7 fetuses. In fetuses in which fetal surface electrocardiograms were not recorded, pacing stimulus artifacts interfered with documentation of capture. Although stimulation thresholds were high, the maternal rhythm was not affected by fetal stimulation. CONCLUSIONS Fetoscopic fetal transesophageal electrocardiography and stimulation are feasible in fetal sheep. This minimally invasive approach might have the potential to improve diagnosis and management of therapy-refractory supraventricular tachycardias in human fetuses.

Surgical experience with defibrillator implantation using nonthoracotomy leads

Between October 10, 1989, and June 17, 1991, 109 patients with life-threatening ventricular arrhythmias received an implantable cardioverter-defibrillator at our institution. In 50 patients, nonthoracotomy lead systems consisting of a subcutaneous chest wall patch electrode near the cardiac apex and one (Cardiac Pacemakers, Inc: Endotak C) or two (Medtronic: Transvene) transvenous electrodes were tested. The mean ejection fraction was 0.44 +/- 0.15 with a range from 0.19 to 0.81. Twenty-four patients had a history of open heart operation. In 43 patients the nonthoracotomy lead system was implanted, whereas in 7 patients epicardial patch lead systems were required due to elevated defibrillation thresholds during nonthoracotomy lead testing. There was one perioperative death unrelated to the operative procedure (hydrocephalus internus). Hemorrhage from the subcutaneous patch pocket or the device pocket that required reintervention occurred in 4 patients. During a mean follow-up of 13 +/- 5 months (range, 4 to 26 months) no dislocation of an endocardial lead, insulation defect, or lead fracture has been observed. In 1 patient, the lead system had to be removed due to infection of the subcutaneous patch pocket. The cardiovascular survival rate was 98% at 12 and 18 months, and freedom from sudden cardiac death was 100% at 6 and 12 months. In conclusion, defibrillator implantation using nonthoracotomy lead systems is feasible with a success rate of 86%, and during short-term follow-up no problems related to the lead system such as dislocation, fracture, or insulation defect have occurred.

The influence of body temperature on transient evoked otoacoustic emissions.

Thirty patients undergoing open heart surgery under induced hypothermia had transient evoked otoacoustic emissions (TEOAE) recorded during cooling to 26.07 degrees C (standard deviation (SD) 4.25 degrees C) vesically measured temperature and 24.86 degrees C (SD 4.7 degrees C) nasopharyngeally measured temperature respectively. Subsequently tè patients were rewarmed until normal body temperature was reached again. There was a clear influence of body temperature on the amplitudes and reproducibilities of the TEOAE. The relationship of temperature and amplitude or reproducibility during the cooling phase was significantly different from that during rewarming. No TEOAE were measurable during cooling at a mean temperature lower than 33.41 degrees C (SD 2.04 degrees C) vesical temperature and 30.16 degrees C (SD 3.0 degrees C) nasopharyngeal temperature respectively. During rewarming the echoes became recognizable again at a mean temperature of 28.75 degrees C (SD 3.38 degrees C) vesical temperature and 27.49 degrees C (SD 2.99 degrees C) nasopharyngeal temperature. These results suggest a hysteresis in the relationship between the amplitude of TEOAE and temperature, similar to the well-established relationship between evoked potentials and temperature.

Left ventricular assist devices — reasons to be enthusiastic

Despite advances in medical treatment, the prognow x sis of advanced heart failure remains poor 1 . The clinical advent of cardiac transplantation in 1967, while being an extraordinary development in itself, intensified preexisting research into mechanical circulatory support devices that might serve either as a bridge or an alternative to biological heart transplanw x tation 12 . The first successful mechanical bridge to cardiac w x transplantation was reported in 1969 3 , but the first electrically driven implantable left ventricular assist w x device 22 marked the introduction of clinically relevant left ventricular assist support systems. Since then a full range of short-term, median-term and long-term left ventricular, right ventricular and biventricular implantable or paracorporeal systems have become w x available 11,13 . The Novacor and TCI HeartMate systems are currently the most widely used systems. It is the aim of this paper to briefly review reasons to be enthusiastic about the use of these long-term left ventricular assist devices. We will present evidence in support of the hypotheses that contemporary Ž . left ventricular assist systems LVAS .

Combining nonpharmacologic therapies for advanced heart failure: the münster experience with the assist device–defibrillator combination

Implantable cardioverter defibrillators (ICDs) and ventricular assist devices (VADs) have been used as a bridge to cardiac transplantation. In selected patients, the combined implantation may be required. This study was motivated by a case of a 33-year-old female patient with giant cell myocarditis who died of ventricular tachyarrhythmias after having been placed on a VAD with which she had been treated on an out-of-hospital basis for a prolonged period of time. A subsequent retrospective analysis of our data showed that, of 73 patients who had to be bridged mechanically (54 Novacor, 12 TCI Heartmate, 4 Thoratec, 3 Medos) in our institution between 1993 and 1998, 10 patients had undergone defibrillator implantation either before (n = 8) or after (n = 2) implantation of a VAD. The cases are presented, and the feasibility of the combination therapy discussed.

Are adults with congenital heart disease informed about their risk for infective endocarditis and treated in accordance to current guidelines

BACKGROUND Adults with congenital heart disease (ACHD) have an increased risk for infective endocarditis (IE). In the last decade, the recommendations for IE prophylaxis have changed substantially. The knowledge level of patients about IE and IE prophylaxis has not been studied. METHODS Patients recruited via the German National Register for Congenital Heart Defects were invited to an online survey about IE. Patients were divided into two groups based on ESC guidelines: high IE risk (antibiotic prophylaxis recommended) and low IE risk (prophylaxis not recommended). RESULTS Overall, 1458 patients participated and out of these 1211 (age 30.5±11.8years, female=54.2%) with detailed clinical information were further analyzed. 343 patients had a high IE risk, whereas 868 had a low risk. Overall, 74.5% (n=902) stated to know what IE is (low IE risk: 71.3%, high IE risk: 82.5%) Out of these who stated to know what IE is (n=902), 76.5% (n=690) chose the correct answer in a multiple choice question (low IE risk: 76.4%; high IE risk: 76.7%). Antibiotic prophylaxis was known to 66.2% (low IE risk: 59.9%; high IE risk: 82.2%). Out of these who stated to know what antibiotic prophylaxis is (n=802), 83.8% (n=672) chose the correct answer in a multiple choice question (low IE risk: 82.9%; high IE risk: 85.5%). CONCLUSIONS This study reveals important knowledge gaps regarding IE and antibiotic prophylaxis in ACHD patients. A discussion about IE and antibiotic prophylaxis should take place with every ACHD patient during regular clinical contacts to close this knowledge gap.