Magnetocardiographic mapping of QRS fragmentation in patients with a history of malignant tachyarrhythmias

BACKGROUND

The identification of patients at increased risk for ventricular tachycardia or ventricular fibrillation (VT/VF) and sudden cardiac death has consequences for therapeutic options and thus may reduce mortality in patients with coronary artery disease (CAD).

HYPOTHESIS

We hypothesized that the intra-QRS fragmentation in magnetocardiographic recordings is increased in patients with CAD and with a history of VT/VF.

METHODS

Multichannel magnetocardiography (MCG) was carried out in 34 healthy controls, 42 patients with CAD without a history of VT/VF, and 43 patients with CAD and with a history of VT/VF. The intra-QRS fragmentation was quantified by a new fragmentation score. Its spatial distribution was investigated using two-dimensional (2-D) contour maps according to the sensor position of the 49-channel magnetogradiometer.

RESULTS

Patients with CAD and with a history of VT/VF had significantly increased QRS fragmentation compared with patients with CAD without VT/VF or controls (72.9+/-37.5, 48.5+/-14.3, and 42.5+/-7.8, respectively: p <0.05). The area of high fragmentation in 2-D contour maps was twice as large in patients with than in those without a history of VT/VF (represented by the number of MCG channels with high fragmentation: 26.3+/-15.5 vs. 12.4+/-9.9, p<0.0001). Patients prone to VT/VF could be identified with a sensitivity of 64% and a specificity of 90%.

CONCLUSION

In patients with CAD and with a history of VT/VF, intra-QRS fragmentation is increased and the area of high fragmentation in 2-D contour maps is enlarged. These findings may be helpful in identifying patients with CAD at risk for malignant tachyarrhythmias.

High molecular weight adiponectin correlates positively with myeloperoxidase in patients with type 2 diabetes mellitus

Adiponectin (APN) is present in human plasma as a low molecular weight (LMW), a middle molecular weight (MMW) and a high molecular weight form (HMW). As a support to determine properties such as anti-atherogenic or atherogenic effects, recent clinical studies suppose to determine the ratio of each APN multimer to total APN but not the absolute plasma concentration of APN. In the present study, the correlation of APN and its multimers with myeloperoxidase (MPO), an enzyme with pro-inflammatory properties, was examined in patients with type 2 diabetes mellitus. MPO and APN serum levels were assessed in 49 patients with type 2 diabetes mellitus at the beginning and at the end of an anti-diabetic treatment. After treatment a significant increase in the ratio of HMW to total APN (from 0.43+/-0.16 to 0.59+/-0.14, p<0.05) was found. Before treatment, HMW-APN was correlated positively with MPO (r=0.314, p<0.05). Moreover, a positive correlation was observed between the increased HMW ratio and MPO during treatment (r=0.304, p<0.05). HMW-APN correlates positively with MPO in patients with type 2 diabetes. Therefore, HMW-APN may exert possible pro-inflammatory effects in type 2 diabetes.

Diadenosine polyphosphates Ap3A and Ap4A, but not Ap5A or Ap6A, induce proliferation of vascular smooth muscle cells

Depending on the number of phosphate groups, diadenosine polyphosphates (ApnA, Ap3A, Ap4A, Ap5A and Ap6A) differ in properties such as proliferation, apoptosis, vasoconstriction and vasodilatation of vascular smooth muscle cells (VSMCs). Possible signaling pathways leading to effects such as proliferation are still unknown. This study examined the proliferative effects of diadenosine polyphosphates on VSMCs and their intracellular pathways. Proliferation of VSMCs was measured by the cell count and [(3)H] thymidine incorporation. Phosphorylation of the MAP kinases ERK1/2 was determined by Western blotting. Single-cell [Ca(2+)](i) measurements were done to determine the influence of [Ca(2+)](i) on intracellular signaling. Stress fiber formation was assessed by fluorescence microscopy to detect an influence of G alpha(12). Ap3A and Ap4A, but not Ap5A or Ap6A, were shown to increase proliferation of VSMCs by activating P2Y receptors, which leads to stimulation of the Ras-Raf-MEK-ERK1/2 cascade. Ap3A- and Ap4A-induced activation of the MAP kinases ERK1/2 was dependent on a signaling pathway that included the EGF receptor, PKC, PLCbeta and the increase of [Ca(2+)](i). In conclusion, Ap3A and Ap4A, but not Ap5A or Ap6A, induce proliferation of VSMCs by a signaling pathway that begins with activation of P2Y receptors and leads to stimulation of the MAP kinases ERK1/2.

Low-dose treatment with atorvastatin leads to anti-oxidative and anti-inflammatory effects in diabetes mellitus

We investigated whether atorvastatin, given in a dose to low to influence the lipid profile, has any effect on oxidative stress, inflammation and endothelial function under streptozotocin-induced diabetic conditions. Diabetes mellitus was induced in male Sprague Dawley rats by a single injection of streptozotocin. Rats were treated chronically with atorvastatin (50 mg/kg/day; p.o.) or vehicle until day 48 and compared with controls. NAD(P)H activity, protein expression nuclear factor-kappaBp65 (NF-kappaBp65) and phosphorylation of the extracellular signal-regulated kinase (ERK1/2) were assessed in the quadriceps muscle. Protein and mRNA levels of intracellular and vascular adhesion molecules (ICAM-1, VCAM-1) and cytokines were measured by Taqman or immunohistochemistry staining, respectively. Endothelial function was investigated in vivo using the autoperfused hind limb model. Diabetic groups displayed similar severe hyperglycemia. Untreated diabetic rats showed enhanced NAD(P)H activity, activation of the ERK1/2/NF-kappaBp65-pathway, enhanced expression of cytokines and cellular adhesion molecules and impaired vascular function. Low-dose therapy by atorvastatin did not alter the lipid profile but led to a reduction of NAD(P)H activity (-28%, P<0.05) associated with reduced protein expression of NF-kappaBp65 (-53%, P<0.05) and phosphorylation of its regulator mitogen-activated protein kinase (MAPK) ERK1/2 in diabetic rats. Also inflammatory markers were reduced after atorvastatin treatment indexed by reduced mRNA expression of VCAM-1 (-24%), tumor necrosis factor alpha (-59%) and interleukin 1beta (-50%) and reduced ICAM-1 (-81%) and VCAM-1 (-74%) positive staining. These beneficial effects were associated with improved endothelium-dependent vasodilatation (maximal vasodilatation: +101%; P<0.05). Lipid-independent anti-oxidative and anti-inflammatory effects of low-dose atorvastatin involving the ERK1/2/NF-kappaB-pathway are sufficient to improve endothelial function under experimental diabetic conditions.

Platelet activation in diabetic microangiopathy

Platelet activation and hyperreactivity are known to be associated with a rapid development and progression of diabetic angiopathy. The present study attempts to clarify whether IDDM patients without diabetic complications have an increased platelet activation and whether in vivo platelet activation is altered in the presence of diabetic microangiopathy. Platelet activation was assessed by flow cytometry analysis in 50 healthy controls (c) and in 41 patients with insulin-dependent diabetes mellitus (IDDM type 1) who were screened for diabetic complications. Sixteen of these patients (0) showed no evidence of microangiopathic organ lesions as assessed by an established standard battery of clinical tests, whereas the other 25 patients had diabetes derived microvascular complications (dmc). Patients with macroangiopathy were ruled out. Platelet activation was evaluated by flow cytometric detection of four activation-dependent platelet surface markers (lysosomal GP53, thrombospondin, P-selectin and ligand-induced binding site-1 of GPIIb-IIIa). A higher percentage of thrombospondin-positive platelets was detected in the IDDM patients without complications: 8.6 +/- 0.9% (0) vs 6.1 +/- 0.4% (c) vs 5.4 +/- 0.4% (dmc), P < 0.05, respectively. A decrease in GP53-, P-selectin-, and LIBS-1-positive platelets was observed in the IDDM group with dmc: for GP53 17.4 +/- 1.0% (dmc) vs 23.4 +/- 1.0% (c), P < 0.05; for P-selectin 5.5 +/- 0.6% (dmc) vs 8.0+/-0.7% (c), P < 0.01 and for LIBS-1 8.3 +/- 0.9% (dmc) vs 15.8 +/- 1.3% (c), P < 0.01. No differences in these markers were found in controls and IDDM patients without complications. In addition, no correlations were found between the glucose metabolism and platelet activation. These findings indicate (i) that the platelet system is pre-activated in IDDM , and (ii) that an increased consumption of activated platelet may occur in the vessels of IDDM patients with diabetic microangiopathy.

The role of the renal kallikrein-kinin system in diabetic nephropathy

PURPOSE OF REVIEW

Diabetic nephropathy is one of the most common complications in diabetes mellitus. Multiple pathogenic mechanisms are now believed to contribute to this disease, including inflammatory cytokines, autacoids and oxidative stress. Numerous studies have shown that the kallikrein-kinin system may be involved in these mechanisms. This review focuses on recent research advance on the potential role of the kallikrein-kinin system in the development of diabetic nephropathy, and its clinical relevance.

RECENT FINDINGS

A collection of recent studies has shown that angiotensin-converting enzyme inhibitors, which inhibit angiotensin II formation and degradation of bradykinin, and vasopeptidase inhibitors attenuated the development of diabetic nephropathy in experimental animals and clinical settings. The role of the kallikrein-kinin system in diabetes is further supported by findings that diabetic nephropathy is worsened in diabetic mice lacking bradykinin B2 receptors. Although long-acting bradykinin B2 receptor agonists have been shown to have renal protective effects, their therapeutic benefits have not been well studied.

SUMMARY

Current experimental investigations demonstrated that pharmacological intervention of the kallikrein-kinin system improved renal conditions in diabetes mellitus. These findings suggest that the kallikrein-kinin system may be a therapeutic target in preventing and treating diabetic nephropathy.

Angina Pectoris und ST-Hebungen nach Chemotherapie mit 5-FU

We report on the case of a 64 year old male who received chemotherapy for a metastatic squamous cell carcinoma of the oropharynx. The chemotherapeutic regimen consisted of 5-fluorouracil (5-FU) and cisplatin. Six hours after completion of the first 24 h continuous infusion of 5-FU, the patient developed severe chest pain accompanied by vegetative symptoms and a pronounced ST-elevation of the precordial leads. Under the suspicion of an acute anterior myocardial infarction an immediate coronary angiogram was performed, demonstrating a total occlusion of the left anterior descending (LAD) coronary artery close to the left main stem. The other coronary arteries appeared smooth. After the intracoronary administration of nitroglycerine, the LAD reopened spontaneously without any residual stenosis, paralleled by complete relief of all symptoms. Therefore, 5-FU induced coronary spasm was diagnosed. After initial therapy with intravenous nitrate followed by oral calcium channel blocker, the patient remained free of symptoms and no rise in cardiac enzymes were noted. The chemotherapeutic regimen was changed to cisplatin plus docetaxel. No new attacks of chest pain occurred and the antivasospastic therapy could be stopped without further events.

Overview on chronic viral cardiomyopathy/chronic myocarditis

Myocarditis is most often induced by cardiotropic viruses and often resolves with minimal cardiac remodelling and without discernable prognostic impact. Acute myocarditis has a highly diverse clinical presentation (asymptomatic, infarct-like presentation, atrioventricular (AV)-block, atrial fibrillation, sudden death due to ventricular tachycardia, fulminant myocarditis with severely depressed contractility). Progression of myocarditis to its sequela, dilated cardiomyopathy (DCM), has been documented in 20% of cases and is pathogenically linked to chronic inflammation and viral persistence. Persistence of cardiotropic viruses (enterovirus, adenovirus) constitutes one of the predominant aetiological factors in DCM. Additionally, circulating autoantibodies to distinct cardiac autoantigens have been described in patients with DCM, providing evidence for autoimmune involvement. Since clinical complaints of myocarditis and DCM are unspecific, a positive effect of any specific therapy depends on an accurate biopsy-based diagnosis and characterization of the patients with histological, immunohistological and molecular biological methods (PCR), which have developed into sensitive tools for the detection of different viruses, active viral replication, and myocardial inflammation. The immunohistochemical characterization of infiltrates has supported a new era in the diagnosis of myocardial inflammation compared with the Dallas criteria, which has led to a new entity of secondary cardiomyopathies acknowledged by the WHO, the inflammatory cardiomyopathies (DCMi). Immunohistochemically quantified lymphocytes significantly better reflect troponin levels and correlate with findings by anti-myosin scintigraphy compared with the histological analysis. Furthermore, the orchestrated induction of endothelial cell adhesion molecules (CAMs) in 65% of DCM patients has confirmed that CAM induction is a prerequisite for lymphocytic infiltration in DCMi. The combination of these immunohistological with molecular biological diagnostic techniques of virus analysis allows a further classification of dilated cardiomyopathy by differentiating the disease entity in subgroups of virus-positive and virus-negative patients with or without cardiac inflammation. Further analysis of the predominant Th1-/Th2-immune response may provide additional prognostic information on the natural course of the disease. This differential analysis improves the clinical management of patients and is an indispensable prerequisite for the development of specific antiviral or immunomodulatory treatment strategies.

Anti-viral treatment in patients with virus-induced cardiomyopathy

Ongoing viral persistence in the myocardium is associated with an adverse prognosis of cardiomyopathy eventually resulting in a reduced capacity for work and thus it is associated with enormous social costs. Experimental and clinical data highlight that an imbalance of the cytokine network and a defect in the cytokine-induced immune response may constitute major causes leading to the development of virus persistence and progression of myocardial dysfunction. Reversibility of cardiac impairment during the early stages of the disease and the arising chance of specific treatment options demand early diagnosis and treatment of the disease. Our pilot data on anti-viral treatment using INF-beta showed beneficial clinical effects and suggest that some of the ventricular dysfunction and wall motion abnormalities resolved after elimination of the responsible agents. The data also suggest that elimination of cardiotropic viruses and associated clinical effects may occur even in DCM patients presenting with a long history.

[Cardiomyopathies. I: classification of cardiomyopathies--dilated cardiomyopathy]

Cardiomyopathies are common causes of heart failure and sudden cardiac death. According to the WHO classification, "specific" cardiomyopathies are differentiated from "idiopathic" cardiomyopathies. Thus, this classification is primarily based on pathophysiological characteristics. The diagnostic spectrum in cardiomyopathies comprises the entire spectrum of non-invasive and invasive cardiological examination techniques. The exact verification of certain cardiomyopathies necessitates additionally investigations. For example, immunohistological and molecular biological investigations of endomyocardial biopsies may confirm inflammatory cardiomyopathy, which is often induced by viruses. Several studies have shown that specific immunomodulatory treatment options can halt the progressive course of the disease. Several gene mutations have been identified in genetic/familial dilated cardiomyopathy. First-degree relatives should be screened for early stages. Primary prevention of sudden cardiac death shows increasing superiority of the implantable defibrillator compared with pharmacological approaches (i.e. amiodarone).

Leistungsknick, Thoraxschmerz und Polyserositis bei einem 35-jährigen Patienten mit antikonvulsiver Therapie

We report on a rare case of a late-onset drug-induced lupus erythematosus. A 35 year old male patient complained about dyspnea, chest pain and reduced physical activity for three months. His medical history consisted of epilepsy treated with carbamazepine for 20 years. After diagnosis of a large pericardial effusion and percardiocentesis (1200 ml) the diagnosis of viral perimyocarditis was suspected. Under antiphlogistic treatment the symptoms vanished initially. Four weeks later the pericardial effusion recurred and a livedo reticularis became evident. A structural or infectious heart disease, in particular viral myocarditis, was ruled out invasively. Serologic testing revealed antinuclear antibodies and antibodies against histones without presence of antibody against ds-DNA, thereby confirming the diagnosis of carbamazepine-induced lupus erythematodes. After discontinuation of carbamazepine and immunosuppressive medication the patient recovered completely.

Transluminale Bergung intravasaler Fremdk�rper

Patients with central venous lines or implanted Hickman catheters and port systems, suffer catheter embolization in 0.1-2.8% of the cases due to material fatigue or medical malpractice. In a 58-year-old vascular surgery patient, a central venous line catheter fragment was successfully retrieved from the pulmonary artery using a snare catheter via a transfemoral approach. From this case, we discuss the incidence, clinical aspects, diagnosis and interventional therapy of catheter embolization.

[Diabetic cardiopathy: pathogenesis, diagnosis and therapy]

Diabetes mellitus is one of the most widespread metabolic diseases in Western industrial countries with increasing prevalence due to a progressively aging population that is also characterized by increasing obesity and a sedentary life style. Cardiovascular conditions are the major prognostic complications of diabetes. Cardiologically, diabetic cardiopathy may become manifest on different structural and functional levels of the heart. Disorders may involve the micro- and macrocirculation (angiopathy), ventricular function (cardiomyopathy) and the intracardial nervous system (autonomous neuropathy). The following survey summarizes the cardiovascular risk with particular attention to the pathogenesis, diagnostics and therapy of diabetes mellitus related coronary disease and diabetic cardiomyopathy.

Effect of adventitial VEGF165 gene transfer on vascular thickening after coronary artery balloon injury

OBJECTIVE

Experimental studies have provided evidence that neovascularization is an important feature of plaque growth, and angiogenic gene therapy may, therefore, increase plaque growth. This study examined the effect of local (peri)adventitial vascular endothelial growth factor165 (VEGF) gene transfer on vascular thickening after coronary balloon injury.

METHODS

Two coronary arteries of 15 pigs were subjected to balloon injury followed by either (peri)adventitial VEGF165 or beta-galactosidase (LacZ) plasmid/liposome-mediated gene transfer via needle injection catheter. At days 3, 14 and 28, histologic sections of coronary arteries were analyzed.

RESULTS

Transferred VEGF165 gene and increased adventitial neovascularization were detected in coronary arteries after balloon injury and VEGF injection. The mean intima+media (I+M) area increased after coronary balloon injury and VEGF (1.13+/-0.17 and 2.54+/-0.52 mm(2)) or LacZ (1.37+/-0.19 and 2.96+/-0.41 mm(2)) gene transfer, with no significant difference between both groups at 3 and 28 days, respectively. No significant difference in I+M neovascularization was observed at day 28 between the treatment groups (microvessel area density 0.24+/-0.08% with VEGF and 0.26+/-0.14% with LacZ, respectively). I+M endothelial cell proliferation index ranged from 7% to 22% (VEGF) and 18% to 24% (LacZ).

CONCLUSIONS

Catheter-mediated (peri)adventitial VEGF165 gene transfer induces adventitial neovascularization but not an increase of vascular thickening/I+M growth and vascularization in a porcine model of coronary artery injury.

[Differentiation between vital heart muscle tissue and infarct scar using magnetocardiography]

Magnetocardiography provides touchless information about myocardial excitation propagation and repolarization. This evolving diagnostic technique has been used so far to risk-stratify patients in terms of sudden cardiac death and to detect myocardial ischemia. We evaluated its potential to assess myocardial viability in patients with coronary artery disease. Magnetocardiography was performed using a shielded prototype 49-channel LTS SQUID system. A specific algorithm was developed to calculate automatically a set of magnetocardiographic parameters. Regional myocardial viability was determined using 18F-labeled fluoro-2-deoxyglucose positron emission tomography. We found that magnetocardiography may contribute essentially to discriminate between viable myocardium and infarct scar.