Management of a Remnant Electrode in a Patient With Cardioverter-Defibrillator Infection After Refusal of Intravascular Electrode Removal

Treatments of choice for cardiac implantable electronic device (CIED) infections are the removal of the entire CIED system, control of infection, and new device implantation. Occasionally, a complete CIED removal can not be performed for several reasons, such as very old age, severe comobidity, limited life expectancy, or refusal by a patient. We encountered a male patient who developed traumatic CIED infection five years after cardioverter-defibrillator implantation. An intravenous electrode could not be removed by a simple transvenous extraction procedure, and he refused surgical removal of the remnant electrode. After control of local infection, the tips of the electrode were separated and buried between muscles, and the wound was closed with a local flap. CIED infection did not recur for 12 months even without relying on long-term antimicrobial treatment.

The Effects of Macrophage on Neointimal Formation after Balloon or Stent Injury in Hypercholesterolemic Rabbits

BACKGROUND AND OBJECTIVES: The present study investigated differences in the effects of macrophages between neointimal formation after balloon (BI) and that after stent injury (SI) in hypercholesterolemic rabbits. We also studied the relationship between advanced glycation end products (AGE), the receptor for AGE (RAGE), and S100A8/A9 in the inflammatory reaction mediated by macrophages. MATERIALS AND METHODS: Male New Zealand White rabbits fed with a 1% cholesterol diet for 2 weeks underwent balloon dilatation to one iliac artery, and stenting to the contralateral artery. Arteries were harvested at 7, 14, and 28 days after injury. RESULTS: Sizes and cell numbers of neointima were higher in SI than in BI (p0.05). Sizes and cell numbers of neointima in BI and SI increased significantly till 14 days (p0.05). Macrophage numbers increased until 28 days in the media of BI (p=0.003). Macrophage numbers increased at 14 days in the neointima of SI (p=0.001), but decreased at 28 days (p=0.014). Macrophage numbers were not changed in the media of SI. Cell numbers and area were significantly correlated with macrophage numbers in the neointima and media of BI, and in the neointima of SI (p<0.05). RAGE expression was strong in cells adjacent to lumen at 7 and 14 days, and in cells of neointima and media adjacent to internal elastic lamina at 28 days. Expression of RAGE was increased in both macrophage and smooth muscle cells. Macrophages were the predominant cells observed with AGE accumulation. S100A8/A9 was not found. CONCLUSION: There seems to be a difference in effect of macrophages on the formation of neointima after injury between BI and SI. The effects of macrophages appears to be more significant in the neointima of BI. Mechanical arterial injury induces the formation of AGE and overexpression of RAGE in macrophages.

Age-related Contribution of Lp (a) with Coronary Artery Calcification in Patients with Acute Coronary Syndrome: a Potential Role of Metabolic Disorder in Calcified Plaque

Lp (a) and coronary artery calcification (CAC) have recently been reported as predictors of plaque instability, but this is surrounded by much controversy. We investigated the influence of Lp (a) and CAC compared other acute coronary syndrome (ACS) risk factors. 698 patients diagnosed with at least minimal coronary artery obstructive disease from a coronary angiography were randomly selected using SPSS. Lp (a), other lipid profiles and past histories were checked, and CAC semi quantitatively graded on stored fluoroscopic images. The prevalence of CAC was significantly higher in the ACS than the non-ACS group (38.0% vs. 29.9%, p=0.026). The serum level of Lp (a) (26.89 +/- 30.64 vs. 20.85 +/- 21.63, p 35 mg/dl) was higher in the ACS group (24% vs. 15.7%, p 35 mg/dl. In the younger patients ( 60 years), CAC, but not the Lp (a), was an independent risk factor (OR=1.775, p=0.021, 95% CI; 1.090 - 2.890). Both the Lp (a) and CAC were risk factors for ACS, and they had a synergistic effect on its development. In the younger Lp (a), and the older CAC, was the more potent risk factor for ACS, respectively.

Right Ventricular Myxoma Prolapsing into Pulmonary Artery with Significant Obstruction

Obstructive myxoma of the right ventricular outflow tract occurs rarely. A 22-year-old woman presented with a 3-month history of shortness of breath during exertion. Transthoracic echocardiography showed a huge mass in a dilated right ventricle. The mass, which obstructed the right ventricular outflow tract, was attached to the interventricular septum and protruded through the pulmonic valve during systole. The peak and mean systolic pressure gradients across the pulmonic valve were 79.9 and 47.8 mmHg, respectively. At surgery, the origin of the mass was attached to the right ventricular apex on its septal surface. The histopathological findings were characteristic of myxoma. The patient recovered uneventfully.

Hemodynamic Analysis of Coronary Circulation in Angulated Coronary Stenosis Following Stenting

The present study in angulated coronary stenosis used human in vivo hemodynamic parameters and computed simulation, both qualitatively and qualitatively, to evaluate the influence of flow velocity and wall shear stress (WSS) on coronary atherosclerosis, the changes of hemodynamic indices following coronary stenting, and their effect on evolving in-stent restenosis. Initial and follow-up coronary angiographies in patients with angulated coronary stenosis were performed (n=60). The optimal degree of coronary stenting for angulated coronary stenosis had two models, the less than 50% angle changed group (model 1, n=33) and the more than 50% angle changed group (model 2, n=27). This angle change was based on the percentage change of vascular angle between pre- and post-intracoronary stenting. The flow-velocity wave obtained from in vivo intracoronary Doppler study data was used for in vitro numerical simulation. Spatial and temporal patterns of the flow-velocity vector and recirculation area were drawn throughout the selected segment of coronary models. WSS of pre- and post-intracoronary stenting was calculated from three-dimensional computer simulation. As results, follow-up coronary angiogram demonstrated significant difference in the percentage of diameter stenosis between the two groups (group 1: 40.3 +/- 30.2 vs. group 2: 25.5 +/- 22.5%, p < 0.05). Negative shear area on 3D simulation, which is consistent with the re-circulation area of flow vector, was noted on the inner wall of the post-stenotic area before stenting. The negative WSS disappeared after stenting. High spatial and temporal WSS before stenting fell within the range of physiologic WSS after stenting. This finding was more prominent in model 2 (p < 0.01). The present study suggests that hemodynamic forces exerted by pulsatile coronary circulation, termed WSS, might affect the evolution of atherosclerosis within the angulated vascular curvature. Moreover, geometric characteristics, such as the angular difference between pre- and post- intracoronary stenting might define optimal rheologic properties for vascular repair after stenting.

Autoantibody against, Malondialdehyde-Modified Low Density Lipoprotein in Patients with Non-Diabetic Unstable Angina: A Potential Role in Immunologic Reaction of Plaque Instability

The role of autoantibody against oxidized low-density lipoprotein (LDL) in the pathogenesis of atherosclerosis is still unknown. The purpose of this study was to determine whether autoantibodies against malondialdehyde (MDA)-modified LDL are associated with coronary artery disease (CAD) and clinical presentations of CAD in non-diabetic patients without acute myocardial infarction (AMI). We determined the serum levels of autoantibody against MDA-modified LDL by ELISA in 71 patients with angiographically significant CAD (> or = 50% diameter stenosis in at least 1 vessel) and 80 controls without angiographically significant CAD. Among the total 151 subjects, 30 subjects did not have any clinical ischemic event, 90 subjects had stable angina symptoms, and 31 subjects had unstable angina symptoms. The autoantibody titer, expressed mean optical density units, was significantly higher in patients with CAD than in controls (0.177+/- 0.014 versus 0.127+/- 0.011, respectively; p=0.006) and higher in unstable angina group than in stable angina group (0.240+/- 0.025 versus 0.145+/- 0.007, respectively; p < 0.001). By logistic regression analysis, the high autoantibody titer was associated significantly with CAD (P=0.008), independent of age, gender, body mass index, triglyceride concentration, and the ratio of total cholesterol-high density lipoprotein (HDL) cholesterol. In multiple regression analysis, presence of CAD, smoking history and low HDL-cholesterol level were independent factors associated with a increased anti-oxLDL Ab titer. The autoantibody titer was significantly lower in nonsmoker than smoker (p=0.019) and higher in low HDL- cholesterol (< or = 35 mg/dl) group than in high HDL-cholesterol group (p=0.012). Elevated autoantibody titer was associated with CAD and the unstable clinical presentation of CAD. Our results suggest that immune response to oxidized LDL may play a role in the pathogenesis of atherosclerosis and plaque instability.

A Case of Abdominal Aortic Interruption Presented with Secondary Hypertension

Aortic interruption is a very rare disease that can be classified into congenital and acquired aortic interruption. Congenital aortic interruption generally implies an interruption of the aortic arch and no case of congenital abdominal aortic interruption has been reported. Acquired aortic interruption, on the other hand, can be caused by atherosclerosis, thrombosis, saddle embolism, and arteritis such as Takayasu arteritis. We experienced a case of congenital abdominal aortic interruption accompanied by one well-developed collateral flow presented with secondary hypertension in a 28-year-old female patient.

A Case of Thyroid Storm Due to Thyrotoxicosis Factitia / 대한내분비학회지

Thyrotoxicosis factitia, a syndrome that results from a surreptitious ingestion of excess thyroid hormone, has generally been diagnosed in young or middle-aged women who have psychopathological disturbances. An 18-year-old female was admitted to the hospital 24 hours after taking an overdose of more than 50 tablets of synthyroid (levothyroxine, 5mg). She had taken 6 to 9 tablets of synthyroid daily for 6 months for the purpose of weight reduction even though she was not overweight. Because of her stuporous mental state and an acute respiratory failure, she was intubated and treated in the intensive care unit. After careful history taking and after her plasma thyroid hormone levels were determined, we diagnosed a thyroid storm that was caused by a thyrotoxicosis factitia. The laboratory results were, T3 430.0 ng/dL, free T4 70.0 ng/dL, TSH 0.05 IU/mL. Her symptoms improved after treatment by steroids and propranolol. She was discharged 8days after admission. Cases of thyrotoxicosis factitia have been reported very infrequently and, there has been no reports of a thyroid storm due to thyrotoxicosis factitia in Korea. We now report a case of a thyroid storm that resulted from thyrotoxicosis factitia that was caused by the ingestion of a massive dose of thyroid hormone that was takan daily for 6 months. We also present a brief review of the relevant literature.

Potential role of leptin in angiogenesis: leptin induces endothelial cell proliferation and expression of matrix metalloproteinases in vivo and in vitro

Leptin, the product of ob gene, is an endocrine hormone that regulates adipose tissue mass. Recently, leptin has been found to generate a growth signal involving a tyrosine kinase-dependent intracellular pathway and promote angiogenic processes via activation of leptin receptor (Ob-R) in endothelial cells. However, it is not clear how leptin functions to promote multi-step processes involved in the neovascularization at the atherosclerotic plaque. We have examined the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) and Ob-R in human atherosclerotic lesions, leptin-mediated angiogenesis in vivo and in vitro. Immunohistochemical analysis of human atherosclerotic aorta revealed an increased expression of Ob-R in the intima of neorevascularized regions and of both MMPs and TIMPs predominantly in the endothelial lining of intimal neovessels and macrophages/foam cells. In the rat corneal angiogenesis assay, leptin elicited a comparable sensitivity of angiogenic activity to those of vascular endothelial growth factor (VEGF). The immunohistological analysis of the leptin-treated rat cornea showed definitive rises in Ob-R, MMPs and TIMPs expression as well as those of VEGF receptor (VEGFR-1). Leptin (10-40 ng/ml) induced proliferation of the human umbilical vein endothelial cells (HUVECs) and elevation of MMP-2, MMP-9, TIMP-1, and TIMP-2 expression in a dose-dependent manner. Leptin also induced increases of MMP-2, MMP-9, TIMP-1, and Up-regulated the human coronary artery smooth muscle cells (HCASMCs). These findings suggest that leptin, a hormone with pluralistic properties including a mitogenic activity on vascular endothelial cells, plays a role in matrix remodeling by regulating the expression of MMPs and TIMPs. Taken together, our findings further provide evidences for leptin's role as an angiogenesis inducer in the normal organ (rat cornea) and in aberrant vasculature under duress like atherosclerosis.

Evaluation of Residual Renal Function of Chronic Renal Failure at the Initiation of Dialysis / 대한신장학회잡지

The decision to initiate dialysis in a patient with progressive renal disease often depends on the physician's assessment of the patient's subjective symptoms of uremia. Decreased residual renal function and malnutrition at the initiation of dialysis is a strong predictor of subsequent increased relative risk of death on dialysis. In this context, to investigate the residual renal function and nutritional parameters of chronic renal failure patients at the initiation of dialysis, 103 patients with chronic renal failure patients were studied. The residual renal function(estimated GFR) was ascertained by measuring simultaneously the 24-h creatinine and urea clearances and averaging the two values and Krt/V. Nutritional parameters were ascertained by measuring the nPNA, %LBM and serum albumin. The mean estimated GFR was 5.97+/-2.88ml/min, the mean weekly Krt/V was 1.24+/-0.80, the mean %LBM was 61.66+/-22.41 and the mean nPNA was 0.89+/-0.30 g/day/kg. We knew that the time of initiation of dialysis, which was based on the manifestation of symptoms of certain patients in conjunction with selected laboratories indices, was delayed than that of NKF- DOQI recommendation. This study suggests that the timely initiation of dialysis is determined by not clinical symptoms and signs but estimated GFR, krt/V and nPNA.