Pavlos Lelovas

Cardiac implications of Lyme disease, diagnosis and therapeutic approach

Lyme is a tick-borne disease. The genetic diversity of Borreliae its distribution worldwide and its epidemiology have been related to different clinical manifestations. Carditis is a rare manifestation of Lyme disease. The commonest abnormality is atrioventricular block of various degrees, though other rhythm abnormalities have been reported. Pericarditis, myocarditis, cardiomyopathy and degenerative valvular disease have been associated with B. burgdorferi. Temporary pacing might be required in unstable patients. The majority of the conduction disturbances have a benign prognosis, if the infectious agent is identified and treated appropriately.

Impact of Nesiritide on Renal Function and Mortality in Patients Suffering from Heart Failure

IntroductionAcutely decompensated congestive heart failure is a major public health problem, with constantly rising prevalence, morbidity, mortality and need for hospitalization in both America and Europe. In 2001, the FDA approved the use of the drug nesiritide, which is a recombinant form of human brain or B-type natriuretic peptide (BNP) for the treatment of acutely decompensated congestive heart failure. In 2005, suspicions arose that nesiritide may worsen renal function and increase the risk of short term mortality when given to patients with acutely decompensated heart failure.MethodsThe present study reviews the recent literature with respect to the risk of deterioration in renal function and survival after the use of nesiritide in these patients.ResultsAdministration of nesiritide may be considered for the treatment of heart failure and especially in patients with dyspnea at rest or with minimal activity.ConclusionExtreme caution is required when using nesiritide in patients with both heart failure and concurrent morbidities such as renal dysfunction.

Chondroprotective effect of high‐dose zoledronic acid: An experimental study in a rabbit model of osteoarthritis

To address the need to impact the subchondral bone‐articular cartilage interaction for the treatment of degenerative osteoarthritis (OA), bisphosphonates may be used as a means to inhibit the subchondral bone resorption. The purpose of the present study is to evaluate the chondroprotective effect of zoledronic acid (ZOL) in a model of OA. Eighteen adult male rabbits underwent an anterior cruciate ligament transection and were separated into two groups: ZOL group (n = 10) received 0.6 mg/kg intravenous injection of ZOL on day 1, 15, and 29 and placebo group (n = 8) received saline. The animals were euthanized at 8 weeks. Macroscopically, the ZOL group had significantly milder ulcerations, cartilage softening and fibrillation compared to the placebo group. Microscopically, morphology of the articular cartilage was better in the ZOL treated group compared with the placebo group, without complete disorganization in any section of the ZOL group. Furthermore, the chondrocytes in the ZOL treated group were mainly cloning, indicating cartilage repairing and regeneration process, while in the placebo group hypocellularity predominated. Additionally, subchondral necrosis was evident in some specimens of the placebo group. Zoledronic acid, in a high‐dose regimen, proved to be chondroprotective in a well‐established animal model of OA.

A comparison of autopsy detected injuries in a porcine model of cardiac arrest treated with either manual or mechanical chest compressions.

The objective of this study was to evaluate and compare the complications of cardiopulmonary resuscitation after manual or mechanical chest compressions in a swine model of ventricular fibrillation. In this retrospective study, 106 swine were treated with either manual (n=53) or mechanical chest compressions with the LUCAS device (n=53). All swine cadavers underwent necropsy. The animals with no autopsy findings were significantly fewer in the LUCAS group (P=0.004). Sternal fractures were identified in 18 animals in the manual and only two in the LUCAS group (P=0.003). Rib fractures were present in 16 animals in the manual and only four in the LUCAS group (P=0.001). Nine animals in the manual, and two in the LUCAS group had liver hematomas (P=0.026%). In the manual group, eight animals were detected with spleen hematomas whereas no such injury was identified in the LUCAS group (P=0.003). LUCAS devise minimized the resuscitation-related trauma compared with manual chest compressions in a swine model of cardiac arrest.

Abdominal compressions do not achieve similar survival rates compared with chest compressions: an experimental study

AIM The aim of this study is to investigate whether abdominal compression cardiopulmonary resuscitation (CPR) would result in similar survival rates and neurologic outcome than chest compression CPR in a swine model of cardiac arrest. MATERIALS AND METHODS Forty Landrace/Large White piglets were randomized into 2 groups: group A (n = 20) was resuscitated using chest compression CPR, and group B (n = 20) was resuscitated with abdominal compression CPR. Ventricular fibrillation was induced with a pacemaker catheter, and animals were left untreated for 8 minutes. Abdominal and chest compressions were applied with a mechanical compressor. Defibrillation was then attempted. RESULTS Neuron-specific enolase and S-100 levels were significantly higher in group B. Ten animals survived for 24 hours in group A in contrast to only 3 animals in group B (P < .05). Neurologic alertness score was worse in group B compared with group A. CONCLUSION Abdominal compression CPR does not improve survival and neurologic outcome in this swine model of cardiac arrest and CPR.

The use of mice and rats as animal models for cardiopulmonary resuscitation research

Cardiopulmonary resuscitation (CPR) after the induction of cardiac arrest (CA) has been studied in mice and rats. The anatomical and physiological parameters of the cardiopulmonary system of these two species have been defined during experimental studies and are comparable with those of humans. Moreover, these animal models are more ethical to establish and are easier to manipulate, when compared with larger experimental animals. Accordingly, the effects of successful CPR on the function of vital organs, such as the brain, have been investigated because damage to these vital organs is of concern in CA survivors. Furthermore, the efficacy of several drugs, such as adrenaline (epinephrine), vasopressin and nitroglycerin, has been evaluated for use in CA in these small animal models. The purpose of these studies is not only to increase the rate of survival of CA victims, but also to improve their quality of life by reducing damage to their vital organs after CA and during CPR.

Enhancement of bone regeneration with the combination of platelet-rich fibrin and synthetic graft.

Introduction Platelet-rich fibrin (PRF) is a relatively new developed platelet concentrate with several benefits over platelet-rich plasma. The aim of this study was to compare healing properties of PRF and its combination with a ceramic synthetic material (graft) composed of hydroxyapatite and b-tricalcium phosphate in an animal model. Methods A bone deficit was surgically created in each femoral condyle of 15 New Zealand white rabbits. In each animal, 1 limb had (a) PRF only and the other (b) PRF plus synthetic graft material randomly implanted. Experimental animals were killed 3 months postoperatively. Histological and radiological examinations were made by means of computed tomography and peripheral quantitative computed tomography. Results Mean density of the healed bone was statistically significantly greater when synthetic material was used (P < 0.0005). Moreover, combination of PRF with the synthetic material resulted in more cortical and subcortical bone formation (P = 0.038 and P = 0.037, respectively). Conclusions The addition of the ceramic material significantly increased the formation of new bone, providing a better substrate for bone regeneration.

Effects of early amiodarone administration during and immediately after cardiopulmonary resuscitation in a swine model

Aim of this experimental study was to compare haemodynamic effects and outcome with early administration of amiodarone and adrenaline vs. adrenaline alone in pigs with prolonged ventricular fibrillation (VF).

Levosimendan Improves Neurological Outcome in a Swine Model of Asphyxial Cardiac Arrest

BACKGROUND In asphyxial cardiac arrest, the severe hypoxic stress complicates the resuscitation efforts and results in poor neurological outcomes. Our aim was to assess the effects of levosimendan on a swine model of asphyxial cardiac arrest. METHODS Asphyxial cardiac arrest was induced in 20 Landrace/Large White piglets, which were subsequently left untreated for four minutes. The animals were randomised to receive adrenaline alone (n=10, Group A) and adrenaline plus levosimendan (n=10, Group B). All animals were resuscitated according to the 2010 European Resuscitation Council guidelines. Haemodynamic variables were measured before arrest, during arrest and resuscitation, and during the first 30 minutes after return of spontaneous circulation (ROSC), while survival and neurologic alertness score were measured 24 hours later. RESULTS Return of spontaneous circulation was achieved in six animals (60%) from Group A and nine animals (90%) from Group B (p=0.303). During the first minute of cardiopulmonary resuscitation, coronary perfusion pressure was significantly higher in Group B (p=0.046), but there was no significant difference at subsequent time points until ROSC. Although six animals (60%) from each group survived after 24 hours (p=1.000), neurologic examination was significantly better in the animals of Group B (p<0.01). CONCLUSIONS The addition of levosimendan to adrenaline improved coronary perfusion pressure immediately after the onset of cardiopulmonary resuscitation and resulted in better 24-hour neurological outcome.

Inflammation and oxidative stress biomarkers in neonatal brain hypoxia and prediction of adverse neurological outcome: a review

Despite advances in perinatal care, the outcome of newborns with hypoxic-ischemic encephalopathy is poor and the issue still remains challenging in neonatology. The use of an easily approachable and practical biomarker not only could identify neonates with severe brain damage and subsequent adverse outcome, but could also target the group of infants that would benefit from a neuroprotective intervention. Recent studies have suggested interleukin-1b, interleukin-6, tumour necrosis alpha (TNF-a) and neuron specific enolase (NSE) to be potential biomarkers of brain damage in asphyxiated newborns. S100B, lactate dehydrogenase, nitrated albumin-nitrotyrosine, adrenomedullin, activin-A, non protein bound iron, isoprostanes, vascular endothelial growth factor and metalloproteinases have also been proposed by single-centre studies to play a similar role in the field. With this review we aim to provide an overview of existing data in the literature regarding biomarkers for neonatal brain damage.