Assessment of ventricular function after total cavo-pulmonary derivation in adult patients: Interest of global longitudinal strain

Ventricular dysfunction is the most frequent complication in adult patients post-Fontan completion. Through this work, we aim to evaluate ventricular systolic function by conventional echographic parameters and by global longitudinal strain (GLS) to determine the prediction of early ventricular systolic dysfunction. This is a prospective monocentric study enrolling 15 clinically stable adult Fontan patients with preserved ejection fraction (EF). Myocardial deformation study by GLS with speckle tracking technique in addition to a standard Doppler transthoracic echocardiography (TTE) was performed. Cardiac magnetic resonance imaging (CMR) was also performed. A comparison of echocardiographic and CMR parameters was made. In comparison to CMR-derived EF, we found a significant correlation with GLS and TTE-derived EF (P=0.003 and 0.014). We divided our population into two groups based on the cut-off value of 50% of CMR derived EF. Comparison of GLS in both groups showed a significant correlation (P=0.003). A cut-off value of -13.3% showed sensitivity of 67% and specificity of 100%. GLS has a moderate diagnostic value for systolic myocardial dysfunction in the population of adult patients with Fontan circulation.

The yield of 24-hour ambulatory electrocardiography in the assessment of symptomatic school-age children

INTRODUCTION

Lightheadedness, syncope, dyspnea, chest pain, palpitation, loss of consciousness (LOC) or malaise are a frequent reason for consultation in school-age children (SAC). The yield of holter monitoring (HM) in the investigation of these symptoms in SAC is still controversial given the scarce studies.

AIM

To determine the prevalence of baseline ECG abnormalities and those detected in HM in SAC, and to assess the predictive factors of abnormal HM test.

METHODS

We conducted a retrospective descriptive study in which we had included all the consecutive SAC (6 to 12 years) presenting: syncope or lightheadedness or palpitation, dyspnea, or chest pain, malaise, LOC and referred to our department for HM.

RESULTS

We included 366 children. Mean age was 9.7 ± 1.88 years. The major symptoms experienced by the patients were: palpitation (50.7%), chest pain (16.9%), lightheadedness (11.9%), syncope (6.9%), LOC (5.3%), ECG was abnormal in 8.7%. The two most common baseline ECG abnormalities were premature ventricular contractions (PVCs) (1.8%) and right bundle branch block (1.6%). HM was positive in 101 (26.6%) patients. The most common abnormalities in HM were vagal hypertonia in 61 patients (16.1%), PVCs in 29 patients (7.7%), Malignant abnormalities were encountered in 16 patients (13.9%) whereas benign abnormalities in 99 patients (86.1%). In the multivariate analysis: Age≥10 years, mean heart rate <94 beats per minute, the presence of syncope, LOC, malaise and the presence of PVCs in baseline ECG were identified as independent risk factors of abnormal holter.

CONCLUSION

HM has an important diagnostic value in symptomatic SAC. It allows the identification of benign as well as malignant arrhythmias, which require urgent management.

P1004Diagnosis and management of fetal cardiac arrhythmias: about 100 cases

Background

Fetal cardiac arrhythmia complicates 1–2% of pregnancies and presents a major risk of morbidity and mortality in 10% of the cases. Different questions raised by this pathology must be asked: Is it necessary to treat the rhythm disorder? What are the risks of an anti-arrhythmic treatment for the fetus and its mother? In case of failure, should the fetus be extracted at the cost of prematurity, or must the therapeutic escalation be attempted?

Purpose

To emphasize the primordial role of fetal echocardiography in the diagnosis and management of fetal cardiac arrhythmias through our own experience and a review of the literature.

Methods

We present a series of 100 cases of fetal rhythm disorders diagnosed and treated in our department of pediatric cardiology during the last 12 years.

Results

The diagnosis was made at an average gestational age of 30 weeks of amenorrhoea. Extra-systoles were by far the most frequent (50 cases), followed by hetero-topic tachycardia (28 cases) and complete atrio-ventricular blocks (22 cases). We have excluded bradycardia and sinus tachycardia from our study. Our attitude regarding extra-systoles was mostly a simple surveillance and the total post natal disappearance was the rule. The tachycardias were distributed as follows: 9 flutters, 16 junctional tachycardias and 3 chaotic atrial tachycardias. 10 patients were in feto-placental anasarca. The medical treatment resulted in a reduction of the in utero tachycardia in 14 cases, 9 were only post natally reduced and 6 died. Mono-therapy was the rule and dual therapy was indicated in case of resistance to medical treatment or in front of a table of foeto-placental anasarch. With a mean follow-up of 2 years, there was no recurrence. A complete atrio-ventricular block was diagnosed in 22 fetuses at an average gestational age of 26 amenorrhea weeks. 4 patients had associated heart disease. The ventricular rate varied from 35 to 70 beats per minute. 7 fetuses were in heart failure. An immunoassay was positive in 10 mothers. At birth, the presence of antibodies against SSA and/or SSB was detected in 8 newborns.15 patients were stimulated epicardially, including the neonatal period. Six patients died.

Conclusion

We conclude that if the prognosis of fetal tachycardia is generally satisfactory, the atrio-ventricular blocks are more reserved because the conduction disorder is irreversible, and even in the absence of associated congenital cardiopathy, complications related to Stimulation in the newborn doesn't remain risk-free.

Particularities of neonatal isthmic aortic coarctation (A Tunisian study)

METHODS

This is a retrospective study including 47 patients with isthmic coarctation (CoA) diagnosed in ante et postnatal périod, hospitalized in pediatric cardiology departement of la Rabta Hospital-Tunisia during the period from 2000 to 2017.

RESULTS

They were 36 girls and 11 boys with an average age of 14 days. The diagnosis of CoA was suspected during the anténatalperiod in eight cases. In postnatal period heart failure was observed in (38.5%), abolition of femoral pulse (74%), a tension asymetry was found in all patients. Antenatal echocardiography suspected indicators of fetal coarctation especially ventriculo-arterial asymmetryechocardiography confirmed the diagnosis of CoA ,The ejection fraction was impaired in 31% of the cases.The abnormalities associated with coarctation were dominated by the patent ductus arteriosus (68%), atrial septal defect (55.5%), aortic hypoplasia, bicuspidia in respectively in 34% and 31% coarctation syndrome in (23.4%). Prostaglandin wasneccessary in (89.3%). forty two patients were operated with good immédiaterésults. the early postoperative mortality was 12.5%. In the long term, we deplored two late deaths, six cases of recoarctation with a follow-up of 14 months treated by percutaneous angioplasty with a result considered good in all cases.

CONCLUSION

Coarctation of the aorta in neonates is a special form of aorticcoarctaion that differs from the child and adult forms in clinical, echocardiographic, and therapeutic characteristics . His clinical diagnosis must be early, if possible in antenatal , to asssure optimal management.

[Heart and combined heart-lung transplantation. Indications, chances and risks]

Orthotopic heart transplantation (HTX) is nowadays the worldwide accepted gold standard for the treatment of terminal heart failure. The main indications for HTX are non-ischemic dilatative (54%) and ischemic (37%) heart failure. In the acute phase after HTX the survival rate is approximately 90%. Good short and long-term results with survival rates ranging from 81% after 1 year to more than 50% after 11 years demonstrate that there is currently no real treatment alternative to HTX for treatment of end-stage heart failure. In the case of irreversible pulmonary hypertension in combination with end-stage heart failure or complex congenital heart syndromes, a combined heart and lung transplantation (HLTX) is necessary. Compared with HTX the short-term survival of HLTX is reduced, mostly for technical reasons. Improved long-term results after HTX and HLTX are a result of highly specialized transplantation units and effective immunosuppression. However, a major problem is the shortage of organ donors in Germany and the resulting long waiting times for patients with frequently occurring blood groups of up to 10 months for transplantation. The consequence of the latter is the ever increasing number of implanted cardiac assist devices in patients not only as a bridge to transplant but also as destination therapy.

[Striatopallidodentate calcinosis, hypoparathyroidism and neurological features: a case series study]

INTRODUCTION

The respective roles of hypocalcemia and intracerebral calcifications in the occurrence of various neurological manifestations in hypoparathyroidism is not entirely clear. Nevertheless, therapeutic and prognostic implications are important.

OBJECTIVES

We analyze the neurological clinical aspects observed in hypoparathyroidism and correlate them to the biological calcium abnormality and radiological CT scan findings. We also compare these results with data reported in the idiopathic form of striatopallidodentate calcinosis.

PATIENTS

The neurological clinical, CT scan findings and outcome have been retrospectively studied in patients recruited during 13 years (2000-2012) for neurological features associated with hypoparathyroidism or pseudohypoparathyroidism.

RESULTS

Twelve patients with primary hypoparathyroidism (n=5), secondary to thyroidectomy (n=4) and pseudohypoparathyroidism (n=3) were studied. The sex-ratio was 1 and mean age was 39 years. All patients had a tetany, 60% had epilepsy, associated in one patient with "benign" intracranial hypertension; 50% had behavioral changes. Response to calcium therapy was excellent for all these events. Moderate cognitive deficit was noted in three patients (25%), parkinsonism in two patients and hyperkinetic movement disorders in one other. These events were not responsive to calcium therapy and were more common in cases of extensive brain calcifications and in patients who had pseudohypoparathroidism.

COMMENTS

This study suggests that, in patients with hypoparathyroidism, epilepsy and psychiatric disorders are induced by hypocalcemia and reversible after its correction. Cognitive and extrapyramidal impairment seem to be related to the progressive extension of intracerebral calcification, particularly in patients with a late diagnosis. In patients with pseudohypoparathyroidism, this finding is different because of the contribution of other factors, specific to this disease.

[Late reinterventions after repair of common arterial trunk]

BACKGROUND

The common arterial trunk is a heart disease in witch a unique arterial trunk, with a unique ventriculo-arterial valve, exits from the ventricular mass and supply directly the coronary, the aortic and also the pulmonary arterial circulations. Its anatomic repair is now possible but necessitates the use of conduit in pulmonary position.

AIM

To evaluate the incidence and the causes of late reinterventions after repair of common arterial trunk.

METHODS

We retrospectively study the outcome of 17 patients who underwent repair of common arterial trunk between January 1983 and December 2006. The 15 early survivors were followed during a median period of 7 years (range 10 months and 13 years).

RESULTS

Nine reinterventions were necessary in 8 patients. Only one conduit reintervention was necessary in the 8 patients. Freedom from conduit reintervention was 73% at 5 years and 33% at 10 years. Three reinterventions were performed in 2 patients for severe truncal valve incompetence, including repair in 2 cases and replacement in one case. Freedom from truncal valve reintervention was 67% at 10 years.

CONCLUSION

Late reinterventions are inevitable after repair of common arterial trunk. The most common reasons are conduit stenosis and truncal valve incompetence.

[Subacute myelopathy revealing systemic sarcoidosis]

INTRODUCTION

The spinal localization is rare for neurosarcoidosis (0.43 percent of cases) but can be the inaugural manifestation of the disease. We report two cases of spinal neurosarcoidosis in a 57-year-old man and a 43-year*old woman with uneventful past medical histories. Both presented progressive myelopathic features.

METHODS

Magnetic resonance imaging (MRI) of the spine demonstrated intramedullary lesions, dorsal in the first case, and cervical in the second case. Serum angiotensin converting enzyme was elevated. Radiographs of the chest revealed bilateral symmetric hilar mediastinal lymphadenopathy in the first patient, and bronchial biopsy demonstrated non caseating granulomas. In the second patient the diagnosis was made on pathological examination of a minor salivary gland biopsy.

RESULTS

The patients received corticosteroid therapy with good response in the second patient.

CONCLUSION

The diagnosis of intramedullary sarcoidosis is difficult without a previous diagnosis of systemic sarcoidosis or other apparent symptom(s). Extraneurologic biopsies may be suggestive. We reviewed the literature on the diagnosis and treatment of intramedullary sarcoidosis.

Neuropathie périphérique au cours du lupus érythémateux disséminé avec vascularite épineurale et anticorps antiphospholipides

Neurological manifestations of systemic lupus erythematosus are frequent and polymorphic. Their frequency varies according to authors (24-75p.cent). Central nervous system complications predominate; peripheral features are rare, classically symmetrical polyneuropathy, multiple mononeuropathies or cranial nerve involvement. We report a case of a 48-year-old woman presenting a histologically documented sensitivo-motor polyneuropathy with severe motor involvement complicating lupus associated with antiphospholipides antibodies. Outcome was good after cyclophosphamid pulse. We discuss the frequency of peripheral involvement in systemic lupus erythematosus, pathogenic mechanisms, therapeutic possibilities and outcome of this complication.

Accidents vasculaires cérébraux révélant un syndrome catastrophique des anti-phospholipides associé à une hépatite virale C

INTRODUCTION

Very little cases of antiphospholipid syndrome (APLS) have been described among patients having chronic hepatitis C virus infection (HCV).

CASE REPORT

We report the observation of a 43-year-old woman who presented APLS diagnosed following recurrent strokes. Etiological investigations concluded on an association of APLS with HCV infection.

DISCUSSION

Besides being exceptional, this association raises certain etiopathogenic problems. Indeed while antiphospholipid antibodies (aPL) are frequently noted during chronic hepatitis C, they rarely generate thromboembolic complications.

Increased cardiac endothelial nitric oxide synthase expression in patients taking angiotensin-converting enzyme inhibitor therapy

BACKGROUND

The efficacy of angiotensin-converting enzyme (ACE) inhibitors has been demonstrated in large clinical trials, but knowledge of the underlying mechanisms remains incomplete. Therefore, this study investigated the impact of ACE inhibitor therapy on cardiac nitric oxide (NO) synthases in patients with coronary artery disease (CAD) or heart failure.

PATIENTS AND METHODS

The mRNA expression was quantified by standard calibrated competitive RT-PCR, protein expression by Western blotting and NOS activity by monitoring the conversion of [3H]arginine to [3H]citrulline during enzymatic formation of NO in tissue homogenates of myocardium of patients with, or without, ACE inhibitor treatment before elective coronary artery bypass grafting or heart transplantation.

RESULTS

The mRNA expression (amol microg(-1) RNA) of endothelial NO synthase (eNOS) was higher (22.5 +/- 4.8, n = 23) in the atrial myocardium of patients taking ACE inhibitor treatment, before elective coronary artery bypass grafting, compared with patients not taking this therapy (8.9 +/- 0.7, n = 33, P < 0.0001). The ACE inhibitor therapy increased eNOS protein expression from [(9 +/- 0.7) relative units (RUs) to (12 +/- 0.9) RUs, P < 0.05, respectively] and cardiac NOS activity from 17.6 +/- 1.3 to 23.7 +/- 1.1 pmol mg protein(-1) min(-1) (P < 0.001, respectively). Inducible and neuronal NO synthase expression was not changed by the ACE inhibition. A similar up-regulation of eNOS by ACE inhibition was found in the left ventricles of patients with heart failure. The augmented endothelial NOS expression and activity was not the result of differences in clinical characteristics and concomitant therapy between the patient groups.

CONCLUSION

Increased eNOS expression and activity might contribute to the beneficial effects of ACE inhibitor therapy in the treatment of CAD and heart failure.

Neuropathies périphériques sans cryoglobulinémie révélatrices de l’hépatite virale C

INTRODUCTION

Peripheral neuropathies are the most common neurological complication of viral hepatitis C infection with mixed cryoglobulinemia.

CASES REPORT

We report five cases (three men, two women) of peripheral neuropathies revealing viral hepatitis C infection without cryoglobulinemia; the patients' mean age was 56 years. Paresthesias were the most frequent symptom. Electroneuromyographic examination found one case of polyneuropathy and four cases of multiplex mononeuropathies; the complement level was normal in all patients and the rheumatoid factor positive in two cases. Etiological investigations for peripheral neuropathy remained negative. Treatment and outcome were variable.

DISCUSSION

Negative cryoglobulinemia in cases of VHC infection with neurological features has been described in the last few years, suggesting the possibility of other mechanisms such as direct action of the virus on the nervous system. There is no consensus on the treatment and outcome is variable.

CONCLUSION

Peripheral neuropathy may reveal VHC infection, underscoring the need for VHC serology testing in etiological investigations for peripheral neuropathies.

Syndrome choréo-athétosique révélant une maladie lupique associée à des anticorps antiphospholipides

INTRODUCTION

Chorea is a rare manifestation of systemic lupus erythematosus (1-4 percent), commonly affecting young woman. Chorea is revealing lupic disease in 50 percent, in the other cases it occurs early in the course of the disease.

OBSERVATION

A 33-year-old woman was hospitalized for choreo-athetosic movements prevailing on the left leg and arm accompanied by behavioral and general state deterioration. The biological assessment consolidated the diagnosis of lupic disease associated antiphospholipides antibody (aPL). Cerebral magnetic resonance imaging (MRI) was normal except for cortical and subcortical atrophy. The patient was treated by corticosteroids (1mg/kg/day) and then was lost to follow-up.

CONCLUSION

We review data in the literature on the pathophysiological mechanisms of lupic chorea focusing particularly on role of aPL.

[Atrial flutter in neonates and infants: diagnosis and treatment]

Between 1995 and 2002, 5 patients with a mean age of 32 years have been treated for atrial flutter in the Department of Paediatric Cardiology at Hospital La Rabta. In all cases, diagnosis was established on surface electrocardiogram (12 leads. All patients had a normal heart. The 3 infants were in heart failure and In the 2 neonates, the arrhythmia was well tolerated despite a very fast ventricular rate. Reduction of the first episode of atrial flutter was possible by cardioversion in 3 patients, 2 of them had a good impregnation with Amiodarone. The two neonates died at 8th and 10th day of life. In the long term follow-up, on infant presented two recurrent episodes at 4 months x 2 years. Atrial flutter, when diagnosed in neonatal period is a rare but serious rhythm disturbance. The mechanism of activation of this rhythm disturbance remains unknown in the foetus, neonate and infant.

Angiotensin-converting enzyme inhibitor therapy prevents upregulation of endothelin-converting enzyme-1 in failing human myocardium

In this study, we investigated the role of the renin-angiotensin system in expression of the endothelin system in atrial myocardium of patients with congestive heart failure. Atrial myocardium of control patients without angiotensin-converting enzyme (ACE) inhibitor therapy and heart failure patients without or with ACE inhibitor therapy undergoing aorto-coronary bypass surgery was studied. Endothelin-converting enzyme-1 (ECE-1) expression and endothelin-1 peptide level was upregulated in myocardium of heart failure patients without ACE inhibition. ACE inhibitor therapy prevented upregulation of ECE-1 and endothelin-1 in failing myocardium. Prepro-endothelin-1 and endothelin receptor A expression were not affected by heart failure. Endothelin receptor B was downregulated in heart failure patients. Our data demonstrate an upregulation of ECE-1 mRNA expression in failing human myocardium. Inhibition of the renin-angiotensin system by ACE inhibitor treatment prevents upregulation of ECE-1, suggesting that angiotensin II regulates ECE-1 expression in vivo.

FK506 does not affect cardiac contractility and adrenergic response in vitro

FK506 (tacrolimus) is a new immunosuppressant being used in cardiac allograft transplantation. While cyclosporine A has been shown to exert an acute negative inotropic effect on isolated heart muscle preparations, little is known of the inotropic influence of FK506. The Ca(2+) release channel of human skeletal muscle and cardiac muscle is associated with FK506 binding proteins (FKBP), FKBP12 and FKBP12.6, respectively. FKBPs can be dissociated by treatment with FK506. As a consequence of FK506 exposure, isolated skeletal muscle and cardiac muscle ryanodine receptors show altered gating characteristics. Therefore, we analyzed the direct inotropic effect of FK506 exposure to isolated, intact heart muscle preparations from the human and rabbits. Experiments were performed on isolated, electrically stimulated right atrial auricular muscle strips obtained from human myocardium during elective open heart surgery and on intact right ventricular trabeculae from rabbit hearts. The human preparations were exposed to concentrations of 8 x 10(-9), 8 x 10(-8) and 8 x 10(-6) M FK506 followed by a cumulative dose-response curve with isoprenaline as a non-selective beta-adrenoceptor agonist. Our data suggest that FK506 does not exert any positive or negative inotropic effect in either human or rabbit myocardium.

Angiotensin II induces LOX-1, the human endothelial receptor for oxidized low-density lipoprotein

BACKGROUND

Oxidatively modified LDL (oxLDL) plays an important role in the development of atherosclerosis. OxLDL effects, eg, foam cell formation, are mediated in part by the classic scavenger receptor, whereas other effects may involve the recently cloned endothelial oxLDL receptor, LOX-1 (lectinlike oxLDL receptor-1), which is distinct from macrophage scavenger receptors. Because the regulation of LOX-1 must still be defined, we investigated whether LOX-1 is regulated by the potentially proatherosclerotic stimulant angiotensin II (Ang II).

METHODS AND RESULTS

Using competitive reverse transcription-polymerase chain reaction (RT-PCR), we quantified mRNA expression of LOX-1 in primary cultures of human umbilical vein endothelial cells (HUVECs). After treatment with Ang II for 3 hours (1 nmol/L to 1 micromol/L), LOX-1 mRNA was concentration-dependently induced (from 6.9+/-1.4 to 23.1+/-5.5 relative units [RU] by 1 micromol/L Ang II; P<0.05). The angiotensin II type 1 (AT(1)) receptor antagonist losartan prevented this induction. Incubation of HUVECs with Ang II (100 nmol/L, 3 hours) induced LOX-1 protein expression (212+/-21% of control level; P<0. 01) and uptake of 1,1'-dioctadecyl-3,3,3', 3'-tetramethylindocarbocyanine perchlorate (DiI)-labeled oxLDL (209+/-17% of control level; P<0.05) by an AT(1)-dependent pathway, reaching its maximum after 24 hours (680+/-89%; P<0.05). In internal mammary artery biopsy samples from patients with or without ACE inhibitor treatment before coronary artery bypass surgery, LOX-1 mRNA was downregulated by ACE inhibition (6.4+/-2.0 versus 19.3+/-5. 9 RU; n=12 each; P<0.05).

CONCLUSIONS

We conclude that LOX-1 is regulated by Ang II in vitro and in vivo, that induction of LOX-1 is mediated by the AT(1) receptor, and that repression of LOX-1 by long-term ACE inhibitor treatment may contribute to the antiatherosclerotic potential of this therapy.

Diminished responsiveness of Gs-coupled receptors in severely failing human hearts: no difference in dilated versus ischemic cardiomyopathy

In end-stage heart failure, cardiac beta-adrenoceptors are decreased and cardiac Gi protein is increased. We assessed beta-adrenoceptors, G proteins, and effects of several beta-adrenoceptor agonists, histamine, and 5-HT on adenylyl cyclase activity in right and left atria and left ventricles and on left ventricular contractility in six potential heart transplant donors (nonfailing hearts; NFHs) and in nine patients with end-stage dilated cardiomyopathy (DCM) and 11 patients with end-stage ischemic cardiomyopathy (ICM) to establish whether the functional responsiveness of all cardiac Gs-coupled receptors is reduced. Beta-adrenoceptors were reduced in all three tissues; in DCM, beta1-adrenoceptors were more markedly downregulated; in ICM, both beta1- and beta2-adrenoceptors were diminished. In all three tissues, isoprenaline-, terbutaline-, histamine- and 5-HT-induced adenylyl cyclase activation was reduced similarly in DCM and ICM. Moreover, in DCM and ICM, guanosine triphosphate (GTP)- (involving Gs and Gi) activated adenylyl cyclase was significantly diminished, whereas NaF-activated (involving only Gs) and Mn2+-activated (acting at the catalytic unit of the enzyme) adenylyl cyclase was unaltered. Left ventricular positive inotropic responses to beta1- (noradrenaline, dopamine, and dobutamine), beta2- (terbutaline), and beta1- and beta2-adrenoceptors (isoprenaline, adrenaline, and epinine), as well as H2-receptor (histamine) stimulation were significantly reduced. The extent of reduction was not different for each agonist in ICM and DCM. We conclude that in DCM and ICM, functional responsiveness of all cardiac Gs-coupled receptors is similarly reduced.

Functional role of beta2-adrenoceptors in the transplanted human heart

In the transplanted human heart, beta-adrenoceptor subtypes change with time after transplantation: beta1-adrenoceptors tend to decline, whereas beta2-adrenoceptors are upregulated. The aim of this study was to determine whether, in the transplanted human heart, stimulation of beta2-adrenoceptors can induce heart-rate increases. For this purpose, we assessed in eight heart-transplant recipients (mean posttransplant time: 932 days) the effects of infusion of graded doses of isoprenaline (3.5-35 ng/kg/min) 120 min after pretreatment with the beta1-adrenoceptor antagonist bisoprolol (10 mg p.o.; beta1-adrenoceptor occupancy approximately 80%; beta2-adrenoceptor occupancy <5%) on heart rate in the recipient's native (innervated) and transplanted (denervated) sinus nodes. Isoprenaline, acting under these conditions predominantly at beta2-adrenoceptors, increased heart rate both in the recipient's transplanted and native sinus nodes in a dose-dependent manner; at each dose, increases were significantly higher in the transplanted than in the native sinus node. ED20 values (dose to increase heart rate by 20 beats/min) in the transplanted sinus node were 22.2 +/- 1.8 ng/kg/min, and in the native, >35 ng/kg/min (p < 0.01). We conclude that in the transplanted human heart, beta2-adrenoceptor stimulation does evoke increases in heart rate. The enhanced response to isoprenaline in the transplanted sinus node could be caused by the upregulated beta2-adrenoceptors or by the fact that during isoprenaline infusion, vagal activity increases, thus blunting the response in the native (innervated) but not in the transplanted (denervated) sinus node.

Alternative splicing of the primary Fas transcript generating soluble Fas antagonists is suppressed in the failing human ventricular myocardium

Apoptosis of cardiomyocytes has been proposed as a factor contributing to severe heart failure. Since the trigger for apoptotic cellular suicide in nonischemic myocardium is unknown, we analyzed in human myocardial tissue the expression of the apoptosis-inducing membrane receptor Fas/APO-1 and of its alternatively spliced soluble isoforms which antagonize Fas by binding of the Fas ligand. Using reverse transcription polymerase chain reaction (RT-PCR) we found mRNA for Fas and 5 isoforms in nonfailing left ventricles, whereas Fas and only one isoform (FasExo6Del) were detectable in failing left ventricles. Standard calibrated, competitive RT-PCR revealed no significant increase of Fas mRNA in failing compared to nonfailing ventricles. However, the mRNA for FasExo6Del, expressed nearly on the same level as Fas in nonfailing ventricles, was decreased about 3-fold in failing ventricles. We propose that this altered expression of the Fas system renders the myocardium more susceptible for Fas-mediated apoptosis in end-stage heart failure.

Endothelial damage of the venous graft in CABG. Influence of solutions used for storage and rinsing on endothelial function

A significant proportion of early graft occlusions after aortocoronary revascularization using autologous saphenous vein grafts (SVG) are due to mechanical and/or metabolic or biochemical endothelial lesions. The morphological examination of the endothelium, usually carried out using light microscopy or by various types of scanning electron microscopy (SEM), does not give any indication of the functioning of the endothelium (E). Functionally intact E is capable of producing endothelium-derived relaxing factor (EDRF); a practicable in vitro test is the relaxation of pre-contracted vein segments (VS) in response to acetylcholine (ACh) application. To study the effect of the solution used to rinse and store the SVG between removal and implantation on the functional characteristics of the E, we performed in vitro tests on macroscopically intact VS removed from the saphenous vein of 30 male patients who underwent elective CABG surgery. Isolated VS rings were incubated for 60 min in heparinized whole blood (HWB), Bretschneider's cardioplegic solution (HTK), human albumin solution (HAS), or Ringer's solution (RS) and compared with the results obtained immediately after the removal of untreated control samples (C) taken from the same patients. After equilibration in carbogen aerated Krebs-Henseleit solution and precontraction by 3 x 10(-7) M noradrenaline (NE), relaxation induced by 10(-6) M ACh was measured. Only the samples stored in HWB (13.4 +/- 0.4 mN) showed similar maximal contractions with NE to those in the control group (14.4 +/- 0.5 mN), i.e. all those segments which showed both contractions with NE and relaxation with ACh.(ABSTRACT TRUNCATED AT 250 WORDS)