Efthimios Livanis

Effects of growth hormone on circulating cytokine network, and left ventricular contractile performance and geometry in patients with idiopathic dilated cardiomyopathy

BACKGROUND Recent experimental and clinical data indicate that abnormal central and peripheral immune reactions contribute to the progression of chronic heart failure, and that immunomodulation may be an important therapeutic approach in this syndrome. Aims We sought to study the effects of growth hormone (GH) administration on circulating pro-inflammatory/anti-inflammatory cytokine balance, and to investigate whether these GH-induced immunomodulatory effects are associated with the improvement of left ventricular (LV) contractile performance in idiopathic dilated cardiomyopathy (DCM) patients. METHODS Plasma pro-inflammatory cytokines tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), granulocyte-macrophage colony-stimulating factor (GM-CSF) and its soluble receptor (sGM-CSFR), chemotactic cytokine macrophage chemoattractant protein-1 (MCP-1), soluble adhesion molecules intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1), and, finally, anti-inflammatory cytokines interleukin-10 (IL-10) and transforming growth factor-beta2 (TGF-beta2) were measured (ELISA method) in 12 patients with DCM (NYHA class III; LV ejection fraction: 23.6+/-1.7%) before and after a 3-month subcutaneous administration of GH 4IU every other day (randomized crossover design). Peak oxygen uptake (VO2 max), LV dimensions, LV mass index, end-systolic wall stress (ESWS), mean velocity of circumferential fibre shortening (Vcfc), and contractile reserve (change of ratio Vcfc/ESWS after dobutamine administration) were also determined at the same period. RESULTS Treatment with GH produced a significant reduction in plasma TNF-alpha (7.8+/-1.1 vs 5.5+/-0.9pg/ml, P=0.013), IL-6 (5.7+/-0.5 vs 4.7+/-0.4pg/ml, P=0.043), GM-CSF (27.3+/-1.7 vs 23.3+/-1.8pg/ml, P=0.042), sGM-CSFR (4.0+/-0.4 vs 3.2+/-0.4ng/ml, P=0.039), MCP-1 (199+/-5 vs 184+/-6pg/ml, P=0.048), sICAM-1 (324+/-34 vs 274+/-27ng/ml, P=0.008) and sVCAM-1 (1238+/-89 vs 1043+/-77ng/ml, P=0.002) in DCM patients. A significant increase in ratios IL-10/TNF-alpha (1.9+/-0.3 vs 3.5+/-0.9, P=0.049), IL-10/IL-6(2.6+/-0.6 vs 3.2+/-0.5, P=0.044) and TGF-beta2/TNF-alpha (3.1+/-0.6 vs 4.4+/-0.6, P=0.05) was alsofound with GH therapy. A significant reduction in ESWS (841+/-62 vs 634+/-48gr/cm(2), P=0.0026) and LV end-systolic volume index (LVESVI, 128+/-12 vs 102+/-12ml, P=0.035) as well as a significant increase in posterior wall thickness (PWTH, 9.2+/-0.5 vs 10.3+/-0.6mm, P=0.034), contractile reserve (0.00029+/-0.0001 vs 0.00054+/-0.0001circ*cm(2)/gr*s, P=0.00028) and VO2max (15.3+/-0.7 vs 17.1+/-0.9ml/kg/min, P=0.002) were observed after GH administration. Good correlations were found between GH-induced increase in contractile reserve and the increases in VO2max (r=0.63, P=0.028), IL-10/TNF-alpha (r=0.69, P=0.011) and TGF-beta2/TNF-alpha (r=0.58, P=0.046) ratios, as well as the reduction in plasma TNF-alpha levels (r=-0.86, P=0.0004). CONCLUSIONS GH administration modulates beneficially circulating cytokine network and soluble adhesion molecules in patients with DCM, whilst enhancing contractile reserve and diminishing LV volumes. These GH-induced anti-inflammatory effects may be associated with the improvement in LV contractile performance and exercise capacity as well as with the reverse of LV remodelling of patients with DCM.

Provocation of Neurocardiogenic Syncope by Clomipramine Administration During the Head-Up Tilt Test in Vasovagal Syndrome

OBJECTIVES We sought to test the hypothesis that activation of the serotonergic system in patients with vasovagal syndrome during the head-up tilt test provokes syncope. BACKGROUND Central serotonergic activation participates in the pathogenesis of neurocardiogenic syncope. Drugs increasing serotonin (5-HT) in the central nervous system have not been tested as drug challenges during the head-up tilt test with clomipramine (Clom-HUT). METHODS The serotonergic re-uptake inhibitor clomipramine was infused (5 mg in 5 min) at the start of Clom-HUT in 55 patients (mean age 40 +/- 17 years) with a positive history of recurrent neurocardiogenic syncope and in 22 healthy control subjects (mean age 46 +/- 15 years). Blood samples were taken at 0, 5, 10 and 20 min for estimation of plasma prolactin and cortisol as neuroendocrine indicators of central serotonergic responsivity. All subjects had been previously tested with a basic 60 degrees head-up tilt test (B-HUT) for 30 min, and if negative, isoproterenol infusion was given at the end of the test. RESULTS Twenty-nine (53%) of the 55 patients and none of the 22 control subjects had a positive result in the B-HUT. With Clom-HUT, the proportion of patients who experienced a positive response increased to 80% (n = 44), although this happened to only one control subject. Prolactin and cortisol plasma levels increased significantly in the positive Clom-HUT patient group only. CONCLUSIONS The results indicate an increased responsivity of the central serotonergic neural system in subjects with vasovagal syndrome, the activation of which leads to sympathetic withdrawal. The use of clomipramine infusion with the tilt test seems to considerably improve its diagnostic value.

Central Serotonergic Responsiveness in Neurocardiogenic Syncope A Clomipramine Test Challenge

BACKGROUND Central serotonergic mechanisms appear to participate in the pathogenesis of recurrent neurally mediated syncope. The aim of the study was to investigate the responsiveness of the central serotonergic system by measuring the prolactin and cortisol responses to intravenous administration of the serotonin reuptake inhibitor clomipramine. METHODS AND RESULTS Twenty subjects free of any medical treatment were tested. Twelve had a history of recurrent syncopal attacks and positive tilt test (patient group, mean age 47+/-18 years, 8 men); 8 subjects without syncope and a negative tilt test result served as control subjects (mean age 49+/-10 years, 5 men). Twenty-five milligrams of clomipramine was administered intravenously within 15 minutes, and blood samples were taken at 0, 15, 30, 45, and 60 minutes. Two days later, a tilt test was performed at 60 degrees for 30 minutes and blood samples were taken at 0, 10, 20, and 30 minutes. During the clomipramine challenge, plasma prolactin levels increased in both groups. The levels at 30 minutes were higher in the patient group compared with the control group (17.3+/-7.2 vs 9.3+/-7.6 ng/mL, P=0.05). Similar results were observed for cortisol at 30 minutes (172+/-15 vs 118+/-21 ng/mL P=0. 04) and at 45 minutes (189+/-20 vs 116+/-23 ng/mL, P=0.03). The tilt test was positive in 8 (67%) out of 12 of the patient group and negative in all control subjects. In the samples taken during the tilt test, significant increases in prolactin and cortisol were observed only in the subjects with positive tilt test results. CONCLUSIONS Patients with a history of neurocardiogenic syncope show a higher responsiveness of the central serotonergic system to clomipramine challenge. The results support the view that central serotonergic mechanisms are involved in the pathophysiology of the syndrome.

Cardiac denervation after radiofrequency ablation of supraventricular tachycardias.

Inappropriate sinus tachycardia and atrial arrhythmias have been reported after radiofrequency ablation. Previous studies have suggested that cardiac denervation is a possible explanation for these rhythm disturbances. The aim of this study was to investigate possible alterations in autonomic innervation of the heart after ablation using the techniques of heart rate variability (HRV) analysis and metaiodobenzylguanidine (I-123 MIBG) scintigraphy. The subjects of this study were 30 consecutive patients aged 25 to 40 years, without structural heart disease, who underwent radiofrequency ablation of atrioventricular nodal slow pathways, and posteroseptal and left lateral accessory pathways because of symptomatic recurrent reentrant tachycardias. Time and frequency domain analysis of HRV after ablation revealed a significant reduction in the indexes of the mean of all 5-minute standard deviation of RR intervals (p = 0.042), low frequency (p = 0.0005), and total frequency (p = 0.008) compared with preablation values in the group of patients who underwent atrioventricular nodal slow pathway ablation. Patients who underwent ablation of a posteroseptal accessory pathway also had significant attenuation of the indexes of standard deviation about the mean RR interval (p = 0.03), standard deviation of 5-minute mean RR intervals (p = 0.006), and low-frequency (p <0.0001), and high-frequency (p <0.0001) components. Significant I-123 MIBG map defects, indicating efferent cardiac sympathetic denervation, were also found in the same groups of patients: atrioventricular nodal group (p = 0.0024), posteroseptal accessory pathway group (p = 0.0007). None of the above changes in HRV and 123-I MIBG scintigraphy were seen in patients who underwent ablation of left lateral accessory pathways. We conclude that radiofrequency ablation in the anterior, mid-, and posterior regions of the low intraatrial septum may disrupt sympathetic fibers located in these regions, causing cardiac sympathetic denervation. The density of these fibers appear to be less along the left atrioventricular groove.

Hormonal Responses During Tilt-Table Test in Neurally Mediated Syncope

The hormonal profile during tilt testing was examined in syncopal patients. An increase in the growth hormones cortisol and prolactin was found during syncope, suggesting an implication of central serotonergic activation.

Antiinflammatory Effects of Cardiac Resynchronization Therapy in Patients with Chronic Heart Failure

Background: Cardiac resynchronization therapy (CRT) pacing has been proposed as an additional treatment to medical therapy to improve heart failure patients with left ventricular asynchrony. The aim of this study was to evaluate the influence of CRT treatment on proinflammatory cytokines in patients with heart failure.

Head-up tilt test with clomipramine challenge in vasovagal syndrome--a new tilt testing protocol.

PURPOSE The aim of the study was to randomly compare clomipramine, used as a challenge-agent during head-up tilt test, with isoproterenol, used in the conventional test, in patients with vasovagal syndrome. SUBJECTS AND METHODS The serotonergic re-uptake inhibitor clomipramine was infused (5mg in 5min) at the start of head-up tilt test (Clom-HUT) in 126 patients (mean age 41+/-16 years) with positive history of recurrent neurocardiogenic syncope, and in 54 healthy control subjects (mean age 46+/-15 years). All subjects had also been tested with a conventional 60 degrees head-up tilt test (Con-HUT) for 30 min and, if negative, isoproterenol infusion was performed at the end of the test. The two tests were performed in a random order with a 24-h interval between them. RESULTS Fifty-two of the 126 patients (41%) and two of the 54 controls had a positive response to Con-HUT. In the Clom-HUT the proportion of patients who experienced a positive response increased to 83% (105 subjects), while this happened only to four control subjects. The predictive accuracy of Clom-HUT increased compared to Con-HUT from 58 to 86%, respectively. CONCLUSION The results indicate an increased responsiveness of central serotonergic neural system in subjects with vasovagal syndrome, the activation of which leads to sympathetic withdrawal. The use of clomipramine infusion during tilt test seems to improve considerably its diagnostic value.

Growth hormone-induced reduction of soluble apoptosis mediators is associated with reverse cardiac remodelling and improvement of exercise capacity in patients with idiopathic dilated cardiomyopathy.

Objective Recent experimental and clinical data indicate that abnormal inflammatory and apoptotic processes contribute to the progression of chronic heart failure (CHF). We sought to study the effects of growth hormone (GH) on circulating soluble apoptosis mediators, and to investigate whether these GH-induced anti-apoptotic effects are associated with the reduction of left ventricular (LV) volumes and attenuation of exercise intolerance in idiopathic dilated cardiomyopathy (IDC) patients. Methods Plasma tumour necrosis factor-α (TNF-α), its soluble receptors sTNFRI and sTNFRII, and plasma apoptosis mediators soluble Fas (sFas) and sFas Ligand (sFAsL) were measured (enzyme-linked immunosorbent assay) in 12 IDC patients (NYHA III; LVEF: 24±2%) before and after a 3-month subcutaneous administration of GH 4IU every other day (randomized, crossover design). Peak oxygen uptake (VO2max), as well as LV volume indices, wall thickness, and endsystolic wall stress (ESWS) were also determined at the same period. Results Treatment with GH produced a significant reduction in plasma TNF-α (7.8±1.1 versus 5.5±0.9 pg/ml, P<0.02), sTNFRI (4.0±0.4 versus 3.3±0.3 ng/ml, P<0.05), sTNFRII (2.8±0.3 versus 2.4±0.2 ng/ml, P<0.05), sFas (4.7±0.7 versus 3.3±0.5 ng/ml, P<0.05) and sFasL (33.5±9.7 versus 20.2±6.2 pg/ml, P<0.01). A significant reduction in ESWS (841±62 versus 634±48 g/cm2, P<0.01), LV end-systolic volume index (LVESVI, 128±12 versus 102±12 ml/m2, P<0.001) and LV end-diastolic volume index (LVEDVI, 228±16 versus 200±18ml/m2, P<0.01) as well as a significant increase in VO2max (15.3±0.7versus 17.1±0.9 ml/kg per min, P<0.01) were also observed in the patient population after GH administration. Significant correlations were found between the GH-induced decrease of sTNFRII and sFasL and respective reduction of LVESVI. Conclusion Growth hormone administration reduces circulating TNF system and soluble apoptosis mediators in patients with IDC. These GH-induced anti-apoptotic effects may be associated with the improvement in exercise capacity as well as with the reverse of LV remodelling in patients with CHF and IDC. Eur J Cardiovasc Prev Rehabil 12: 164–168

Effect of biventricular pacing on heart rate variability in patients with chronic heart failure

Biventricular pacing is emerging as a long‐term therapy for symptomatic heart failure. Analysis of heart rate variability (HRV) has become an important predictive tool in this syndrome.

Baroreflexes in Vasovagal Syncope: Two Types of Abnormal response

FLEVARI, P.P., et al.: Baroreflexes in Vasovagal Syncope: Two Types of Abnormal Response. Heart rate changes to hypotensive stimuli (baroreceptor sensitivity [BRS]) and forearm blood flow (FBF) reduction during head‐up tilt are mediated by arterial and cardiopulmonary baroreceptors. Regarding baroreflexes in neurocardiogenic syncope (NCS), an apparent variation exists in findings reported in the literature. This may be due to the existence of different types of response. This study included 39 patients with NCS and positive tilt test and 26 normal subjects with negative test. Patients were grouped according to the type of tilt test response (mixed, cardioinhibitory, vasodepressor). BRS was noninvasively assessed in the supine position as an estimate of arterial baroreceptor sensitivity. As an estimate of cardiopulmonary baroreceptor reactivity, FBF was measured by venous occlusion plethysmography in the supine position and every 2.5 minutes during the first 15 minutes of tilt. BRS was related to percent of FBF changes. BRS was impaired in syncopal patients relative to controls (7.2 ± 0.9 vs 10.4 ± 0.3 ms/mmHg, P = 0.01), especially in vasodepressive type (4.9 ± 1.0 ms/mmHg, P = 0.0001). FBF changes during tilt were subnormal in NCS, ascribed to two different patterns: one, characterized by impaired vasoconstriction (FBF during tilt showing < 10% mean reduction relative to baseline, especially in vasodepressive type) and another, characterized by a great variability across time (unstable response, especially in cardioinhibitory type). In controls, BRS was related to the percent of FBF changes after 2.5, 5, and 10 minutes of tilt (P values 0.0001, 0.004, and 0.008). In patients, BRS was uncoupled from FBF changes. In conclusion, baroreflexes in NCS are impaired, unstable, and disorganized. Impairment predominates in the vasodepressive type and instability in the cardioinhibitory. The results of this study are indicative of more than one baroreflex‐mediated response types.