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Young Moo Ro

Publications and source records attributed to Young Moo Ro.

At least 19 recordsLinked to original sources
PubMed2006

Epicardial ablation of ventricular tachycardia associated with isolated ventricular noncompaction.

A 52-year-old man presented with sudden onset of palpitations and dizziness. Echocardiogram confirmed the diagnosis of isolated noncompaction of ventricular myocardium with moderated systolic dysfunction, and the electrocardiogram (ECG) revealed ventricular tachycardia (VT), of which the focus seemed to match an area of prominent left ventricular noncompaction on the 12-lead surface ECG. Through the activation mapping from the endo- and epicardium, simultaneously, a discrete potential preceding the QRS during VT was observed at the anterolateral epicardial wall. He subsequently underwent radiofrequency ablation, and VT was successfully eliminated.

Cardiomyopathies↗
PubMed2006

Decrease in plasma adiponectin concentrations in patients with variant angina pectoris.

BACKGROUND: Plasma adiponectin is decreased in patients with coronary artery diseases, especially in patients with acute coronary syndrome (ACS). However, the correlation between plasma adiponectin and variant angina pectoris (VAP) has not been verified. Plasma adiponectin concentrations between VAP and other coronary artery diseases was compared in the present study. The association between plasma adiponectin concentration and VAP was also investigated. METHODS AND RESULTS: Plasma adiponectin concentrations in the VAP group (n=101) were compared with those of the ACS group (n=117), the stable angina pectoris group (n=108), and the normal coronary group (n=81). Plasma adiponectin concentrations in VAP and ACS were significantly lower than that of the normal coronary group (6.6+/-5.4 vs 5.2+/-4.0 vs 9.0 +/-6.2 microg/ml, p<0.001, respectively). Multivariate analysis indicated that plasma adiponectin (odds ratio (OR) 0.735, 95% confidence interval (CI) 0.621-0.855, p=0.011), smoking (OR 2.012, 95% CI 1.210-3.880, p=0.020), and age (OR 0.976, 95% CI 0.957-0.997, p=0.022) correlated independently with the development of VAP. CONCLUSIONS: Our results suggest that a decrease in plasma adiponectin concentration might be associated with the development of VAP.

Adiponectin↗
PubMed2005

The usefulness of three-dimensional multidetector computed tomography to delineate pericardial calcification in constrictive pericarditis.

Constrictive pericarditis is a rare heart disease but potentially curable with pericardiectomy. Conventional image modalities such as echocardiography, CT and MRI have been used as useful diagnostics for constrictive pericarditis. However, they have limitations in delineating accurate extent of calcified pericardium three-dimensionally (3-D) to aid the surgical management to release the constricted chambers. We present a patient with typical severe extensive myopericardial calcifications visualized by 3-D multidetector CT who was successfully treated by pericardiectomy.

Calcinosis↗
PubMed2005

Transdifferentiation of mesenchymal stem cells into cardiomyocytes by direct cell-to-cell contact with neonatal cardiomyocyte but not adult cardiomyocytes.

Recent studies have demonstrated that direct cell-to-cell interaction is one of the microenvironment factors for transdifferentiation of adult stem cells into cardiomyocytes. We investigated whether transdifferentiation of mesenchymal stem cells (MSCs) into cardiomyocytes was dependent on developmental stages of cocultured cardiomyocytes, and direct cell-to-cell interaction was essential for transdifferentiation. MSCs were isolated from adult rat and cocultured in four different ways: (1) with neonatal cardiomyocytes, (2) with adult cardiomyocytes, (3) with neonatal cardiomyocytes on the cell culture inserts, and (4) with the conditioned medium from neonatal cardiomyocytes. After 5 days of coculture with neonatal cardiomyocytes, 9.40+/-1.15% of 1,1'-dioctadecyl-1-3,3,3',3'-tetramethylindocarbocyanine perchlorate labeled MSCs expressed sarcomeric-alpha-actinin. Immunocytochemistry showed that only these MSCs expressed the cardiac markers and were not observed with other coculture condition as well as conditioned medium. Calcein-AM labeling of cardiomyocytes showed gap junctional communication between 56.1+/-2.0% of MSCs (24 h after labeling, n=5) and neonatal cardiomyocytes. These findings suggest that MSCs are capable of differentiating into cardiomyocytes when directly cocultured with neonatal cardiomyocytes by cell-to-cell interaction, but not with adult cardiomyocytes or conditioned medium.

Animals↗
PubMed2005

Percutaneous coronary intervention with drug-eluting stent implantation vs. minimally invasive direct coronary artery bypass (MIDCAB) in patients with left anterior descending coronary artery stenosis.

The aim of this study was to assess the effects of percutaneous coronary intervention with drug-eluting stents (DESs) versus minimally invasive direct coronary artery bypass (MIDCAB) surgery in the management of patients with proximal left anterior descending (LAD) coronary artery stenosis. Until recent years, despite the advantages of percutaneous transluminal coronary angioplasty (PTCA) with bare metal stent implantation, such as shorter hospital stays and recovery time, MIDCAB showed better results with regard to the need for repeated intervention in the target vessel than PTCA with proximal LAD lesions. Symptomatic patients (n = 189) were randomly assigned to DES group (n = 119) and MIDCAB group (n = 70). Patients with an isolated high-grade lesion (stenosis of > or = 70% of the luminal diameter) in the proximal LAD coronary artery (from the ostium to the first diagonal branch) were included in this study. During the 6-month follow-up period, 1.7% (n = 2) in the DES group needed repeated revascularization procedures for target lesion revascularization compared with 5.9% (n = 4) in the MIDCAB group (P = 0.196). The rates of death and myocardial infarction were similar in both groups [DES 0.0% (n = 0) vs. MIDCAB 2.9% (n = 2), P = 0.135; DES 1.7% (n = 2) vs. MIDCAB 2.9% (n = 2), P = 0.627; respectively] during 6 months of follow-up. In-hospital length of stay was significantly shorter in the DES group compared with the MIDCAB group (5.8 +/- 2.1 days vs. 8.9 +/- 2.6 days; P = 0.001). DES implantation and MIDCAB surgery showed similar rates of myocardial infarction, the need for repeated revascularization, and death during 6 months of follow-up. However, DES implantation resulted in lower average number of hospital stays and similar postoperative complications.

Aged↗
PubMed2005

Chest stab wound-related coronary artery pseudoaneurysm sealed with a polytetrafluoroethylene-covered stent.

We describe a case in which a polytetrafluoroethylene (PTFE)-covered stent was implanted to treat impending rupture of a coronary artery pseudoaneurysm related to a chest stab wound. In this case, transthoracic echocardiography was used to verify the characteristics of the pseudoaneurysm, and we concluded that a PTFE-covered stent may prevent rupture in post-traumatic pseudoaneurysm.

Adult↗
PubMed2005

Clinic blood pressure responses to two amlodipine salt formulations, adipate and besylate, in adult Korean patients with mild to moderate hypertension: a multicenter, randomized, double-blind, parallel-group, 8-week comparison.

BACKGROUND: The commercially available formulation of amlodipine is conjugated with besylate salt to increase water solubility. Recently, a new amlodipine salt formulation has been developed in which the free base of amlodipine is conjugated with a chemically different salt, adipate. OBJECTIVE: The goal of this study was to compare the antihypertensive effect and tolerability of amlodipine adipate with those of amlodipine besylate in patients with mild to moderate hypertension. METHODS: This was a multicenter, randomized, doubleblind, parallel-group study in which patients received 8 weeks of treatment with either amlodipine adipate or amlodipine besylate. The primary efficacy variable was noninferiority of the difference in mean changes from baseline in trough diastolic blood pressure (DBP) after 8 weeks of treatment. Secondary efficacy variables included mean changes in DBP, systolic blood pressure (SBP), and response rate (defined as the proportion of patients whose DBP was <90 mm Hg or whose DBP had decreased from baseline by > or =10 mm Hg). The incidence of adverse events (AEs) was also assessed. RESULTS: Two hundred eleven patients were randomly assigned to receive amlodipine adipate (n = 106) or amlodipine besylate (n = 105). Study patients were primarily female (54.5%), with a mean (SD) age of 52.2 (9.6) years and a mean body weight of 67.1 (10.2) kg; there were no between-group differences in demographic profiles. After 4 weeks of randomized treatment, 58 (27.5%) patients (29 [27.4%] amlodipine adipate, 29 [27.6%] amlodipine besylate) had not achieved a mean DBP <90 mm Hg, and their dose was doubled. Mean DBP changes at 8 weeks were -15.2 (7.3) mm Hg in the amlodipine adipate group and -14.2 (7.4) mm Hg in the amlodipine besylate group (P = NS). Because the 95% CI for the difference in mean DBP changes between groups (-0.53 to 2.55) was within the prespecified lower limit (-4 mm Hg), amlodipine adipate was considered noninferior to amlodipine besylate. Mean SBP changes were -24.9 (12.1) mm Hg in the amlodipine adipate group and -22.0 (14.7) mm Hg in the amlodipine besylate group (P = NS). The response rates were 92.0% for amlodipine adipate and 95.4% for amlodipine besylate (P = NS). The overall incidence of clinical AEs was 20.8% in the amlodipine adipate group and 25.7% in the amlodipine besylate group (P = NS). Drug-related clinical AEs occurred in 5.7% and 12.4% of patients in the respective treatment groups (P = NS). Serum uric acid levels decreased significantly from base-line in both groups (P < 0.001). CONCLUSIONS: Eight weeks of treatment with amlodipine adipate produced significant reductions from baseline in blood pressure in these patients with mild to moderate hypertension. The efficacy of amlodipine adipate was not inferior to that of amlodipine besylate. Tolerability was comparable between the 2 treatment groups.

Adipates↗
PubMed2005

Serially increasing change in lipoprotein(a) concentration has predictive value in acute vascular events.

BACKGROUND: Lipoprotein(a) (Lp(a)) has been regarded in some studies as an independent risk factor of atherosclerotic vascular disease. However, the use of a baseline plasma Lp(a) concentration as a screening tool for future acute vascular events (AVE) is controversial. We therefore investigated whether progressively increasing change in plasma Lp(a) concentration is associated with the development of AVE. METHODS: We investigated prospective analyses of 985 participants (464 women and 521 men) who had either clinically evident vascular disease (VD group, n=443) or its risk factor(s) (RF group, n=542). Blood samples were taken from all participants every six months to measure inflammatory markers such as Lp(a) and C-reactive protein during a 10-year follow-up period. RESULTS: During the follow-up, 223 new cases of myocardial infarction, stroke, and peripheral arterial disease were identified. In the RF group, the relative risk of positive Delta Lp(a) for predicting AVE was 4.36 (95% confidence interval [CI] 1.76-10.85; P=0.002). In the VD group, the relative risk of positive Delta Lp(a) for predicting AVE was 6.35 (95% CI 3.68-10.97; P<0.001). CONCLUSIONS: These results suggest that a progressively increasing change in Lp(a) concentration has a highly significant predictive value in AVE in both the VD and the RF groups.

Adult↗
PubMed2005

Differentiation, engraftment and functional effects of pre-treated mesenchymal stem cells in a rat myocardial infarct model.

BACKGROUND: Mesenchymal stem cells (MSCs) offer a novel therapeutic option in the treatment of acute myocardial infarction. MSCs are able to differentiate into myogenic cells after 5-azacytitdine treatment. However, 5-azacytidine might have genotoxic effects. Recently, it was reported that combined treatment with bone morphogenetic protein-2(BMP-2) and fibroblast growth factor-4(FGF-4) caused cardiac differentiation in non-precardiac mesoderm explants. Therefore, we investigated whether MSCs treated with combined BMP-2 and FGF-4 showed evidence of myogenic differentiation in vitro, and whether these cells resulted in sustained engraftment, myogenic differentiation, and improved cardiac function after implantation in infarcted myocardium. METHODS AND RESULTS: In vitro study: MSCs were treated with BMP-2 + FGF-4 (GF-MSCs) and myogenic phenotype was evaluated immunohistochemically. Cell growth curve was used to compare MSC proliferative capacity between the growth factors and 5-azacytidine treatments. In vivo study: two weeks after coronary artery occlusion, GF-MSCs (n=15), MSCs (n=5) labelled with PKH26 were injected into infarcted myocardium. Control animals (n=5) received a culture medium into the infarcted myocardium. Two weeks after implantation, some engrafted GF-MSCs or MSCs expressed sarcomeric-alpha-actinin and cardiac myosin heavy chain, as was observed in culture. Echocardiography showed that the GF-MSC group had a better (p < 0.05) left ventricular performance than the other groups. CONCLUSION: GF-MSCs induced myogenic differentiation in vitro. Moreover, GF-MSCs engrafted into the infarcted myocardium increased myogenic differentiation, prevented dilation of the infarcted region, and eventually improved heart function.

Animals↗
PubMed2005

Percutaneous coronary intervention versus coronary artery bypass grafting for diabetics with multivessel coronary artery disease: the Korean Multicenter Revascularization Registry (KORR).

This study was designed to assess the relative merits of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in multivessel coronary artery disease (MVCAD), particularly for Korean diabetics. Among 3,279 patients with MVCAD who were recommended for revascularization were enrolled from nine centers in Korea, 2,154 were selected after statistical adjustments for the disparities between two groups. Survival rates were not significantly different for three years between two groups. Among diabetic patients, the three-year mortality rate in PCI group was 1.9-fold higher than that of CABG group, although it was not statistically significant (PCI 19.8%, CABG 11.4%, p=0.14). The three-year mortality rate was similar between the two groups in non-diabetics (PCI 8.3%, CABG 10.0%, p=0.50). The 30-day rate of cerebrovascular event was higher in CABG group, for both diabetic (CABG 3.6%, PCI 0.0%, p<0.001) and non-diabetic patients (CABG 2.4%, PCI 0.0%, p<0.001). Short- and long-term revascularization rates were higher in PCI group than in CABG group. As a conclusion, this Korean registry demonstrates that PCI was associated with comparable survival rates and lower short-term morbidity, but a greater requirement for repeated revascularization compared with CABG in Korean diabetics.

Angioplasty, Balloon, Coronary↗
PubMed2005

Changes of coronary blood flow in vasospastic angina under cold stimulation by transthoracic Doppler echocardiography.

This study was done to evaluate changes of microvascular function under cold stimulation by measuring coronary flow velocities (CFVs) in vasospastic angina (VA) patients using transthoracic Doppler echocardiography (TTDE). 14 patients with VA and 15 healthy controls were included. CFVs were measured at the distal left anterior descending coronary artery by TTDE at baseline and under cold stimulation. Hyperemia was induced by intravenous adenosine infusion (140 microg/kg/min). At baseline, CFVs and coronary flow reserve (CFR) were not different between controls and VA patients. Under cold stimulation, the degree of increment of CFV with adenosine was lower in VA patients than in controls. Comparing baseline with cold stimulation, coronary flow reserve (CFR) increased (3.1+/-0.7 to 3.8 +/-1.0, p=0.06) in controls. In contrast, in VA patients, CFR was decreased (2.8 +/-0.9 to 2.6 +/-0.7, p=0.05) and coronary vascular resistance index markedly increased (0.35 to 0.43, p=0.01). Throughout the study, no patient experienced chest pain or ECG changes. In VA patients, CFR was preserved at baseline, but coronary blood flow increase in response to cold stimulation was blunted and CFR was decreased. These findings suggest that endothelial dependent vasodilation is impaired at the coronary microvascular and the epicardial artery level in VA under cold stimulation.

Adult↗
PubMed2004

5-azacytidine induces cardiac differentiation of P19 embryonic stem cells.

The P19 embryonal carcinoma cell line is a useful model cells for studies on cardiac differentiation. However, its low efficacy of differentiation hampers its usefulness. We investigated the effect of 5-azacytidine (5-aza) on P19 cells to differentiate into a high-efficacy cardiomyocytes. Embryoid-body-like structures were formed after 6 days with 1 mM of 5-aza in a P19 cell monolayer culture, beating cell clusters first observed on day 12, and, the production of beating cell clusters increased by 80.1% (29 of 36-wells) after 18 days. In comparison, the spontaneous beating cells was 33.3% (12 of 36-wells) for the untreated control cells. In response to 1 mM of 5-aza, P19 cells expressed bone morphogenetic protein-2 (BMP-2), BMP-4, Bmpr1a and Smad1 at day 6 or 9, and also cardiac markers such as GATA-4, Nkx2.5, cardiac troponin I, and desmin were up-regulated in a time-dependent manner after induction of BMP signaling molecules. Immunocytochemistry revealed the expression of smooth muscle a-actin, sarcomeric a-actinin, cardiac myosin heavy chain, cardiac troponin T and desmin, respectively. The proportion of sarcomeric a-actinin positive cells accounted for 6.48% on day 15 after 5-aza exposure as measured by flow cytometry. This study has demonstrated that 5-aza induces differentiation of P19 cells into cardiomyocytes in a confluent monolayer culture in the absence of prior embryoid formation and dimethyl sulfoxide exposure, depending in part on alteration of BMP signaling molecules. These results suggest that 5-aza treatment could be used as a new method for cardiac differentiation in P19 cells.

Animals↗
PubMed2004

Spatial dispersion of action potential duration restitution kinetics is associated with induction of ventricular tachycardia/fibrillation in humans.

INTRODUCTION: Action potential duration restitution (APDR) plays a role in initiation and maintenance of ventricular tachycardia (VT)/ventricular fibrillation (VF). We hypothesized that the steeply sloped APDR and its spatial heterogeneity contribute to VT/VF inducibility in patients with ventricular arrhythmia. METHOD AND RESULTS: After programmed ventricular stimulation (PVS) for evaluation of clinically documented VT, patients (n = 20, 15 male, age 52.5 +/- 9.5 years) were divided into two groups: inducible sustained VT/VF (IVT, n = 10) and noninducible VT/VF (NVT, n = 10). Data were compared with the corresponding results obtained from normal controls (C, n = 10). Right ventricular (RV) monophasic action potential duration at 90% repolarization (APD90) and ventricular effective refractory period (VERP) in the right ventricular apex (RVA) and right ventricular outflow tract (RVOT) were determined. APDR was acquired by scanning diastole with premature ventricular beats during a pacing cycle length of 600 msec (S1-S2) in all patients and by rapid pacing at the cycle lengths that induced APD alternans in three patients. Maximal slopes (Smax) of the APDR curves and DeltaAPD90 (APD90 at S2 400 ms - APD90 at the shortest S2) were measured. VERP and APD90 at each RV site did not differ among the three groups. Smax obtained by S1-S2 (1.6 +/- 0.6) did not differ from Smax obtained by rapid pacing (1.2 +/- 0.7), with a significant correlation noted between these values (r = 0.92, P < 0.01). The IVT group had a higher spatial dispersion of Smax (Smax at RVOT - Smax at RVA) compared to the C group (P < 0.05), with no difference between the NVT group and the IVT or C groups. The IVT group had a higher spatial dispersion of DeltaAPD90 compared to the NVT and C groups (P < 0.01, respectively). Smax at the RVOT (2.7 +/- 1.9) was steeper than that at the RVA (1.9 +/- 1.2, P < 0.05). Inducibility of sustained VT/VF was greater at the RVOT (83.3%) than at the RVA (50.0%, P < 0.05). CONCLUSION: In patients with ventricular arrhythmia, VT/VF is highly inducible under conditions of greater spatial dispersion of ventricular refractoriness and APDR.

Action Potentials↗
PubMed2004

Associations among plasma adiponectin, hypertension, left ventricular diastolic function and left ventricular mass index.

OBJECTIVE: The purpose of this study was to characterize the relationships among plasma adiponectin, essential hypertension, left ventricular diastolic function and left ventricular hypertrophy. METHODS AND RESULTS: Plasma adiponectin concentration was assessed by radioimmunoassay, and body mass index (BMI) was measured in 275 patients (138 women and 137 men). Various echocardiographic parameters such as deceleration time (DT) and isovolumetric relaxation time (IVRT) were measured by using echocardiograms. The authors calculated left ventricular mass index (LVMI) and E/A ratio. Pulse wave velocity (PWV) was calculated by dividing the distance between the left subclavian artery ostium and the tip of the femoral sheath with the time interval between two pulse waves. The plasma adiponectin concentration of the hypertensive group was significantly lower than that of the non-hypertensive group (9.9 +/- 9.8 microg/ml vs. 12.9 +/- 9.5 microg/ml, p = 0.019). PWV in the hypertensive group was 12.0 +/- 3.9 m/s compared with 9.3 +/- 2.8 m/s in the normotensive group (p < 0.001). LVMI in the hypertensive group was 135.1 +/- 35.4 g/m2 compared with 100.5 +/- 18.7 g/m2 in the normotensive group (p < 0.001). E/A ratio (0.8 +/- 0.3 vs. 1.1 +/- 0.4, p = 0.041) was lower in the hypertensive group. DT (200.0 +/- 61.2 ms vs. 177.3 +/- 40.8 ms, p = 0.048) and IVRT (106.9 +/- 25.4 vs. 91.3 +/- 27.6 ms, p = 0.243) were higher in the hypertensive group. Plasma adiponectin showed an inverse correlation with LVMI (r = -0.525; p < 0.001) and PWV (r = -0.557; p < 0.001), IVRT (r = -0.485; p = 0.008), and showed a positive correlation with E/A ratio (r = 0.359; p < 0.001). Multiple regression analyses showed that PWV and plasma adiponectin were able to explain the 73.3% of LVMI variability (r = 0.856; p < 0.001). CONCLUSION: The results suggest that a decrease in plasma adiponectin concentration is associated with the progression of left ventricular hypertrophy with diastolic dysfunction.

Adiponectin↗
PubMed2004

Early assessment of myocardial contractility by contrast-enhanced magnetic resonance (ceMRI) imaging after revascularization in acute myocardial infarction (AMI).

BACKGROUND: Recent studies have demonstrated that the size and shape of the hyperenhanced areas on contrast-enhanced magnetic resonance imaging (ceMRI) were nearly identical to areas of irreversible injury, as defined by histochemical staining. We compared the transmural extent of infarct (TEI), as defined by ceMRI, to the initial ECG findings for acute myocardial infarction (AMI), and we also assessed functional contractility according to TEI. METHODS: 12 patients who presented with their first myocardial infarction underwent cine and ceMRI 4 weeks later after their successful revascularization. TEI and wall thickening were determined by using a 30-segment model. RESULTS: Infarction was observed in 81 (23.9%) segments, of which 46 segments (56.8%) had abnormal wall motion and 35 segments (43.2%) had normal wall motion. Of the 35 segments, 33 (94.3%) had subendocardial infarction. 17 segments had infarct of less than 25% of the wall thickness, and all of them had normal wall motion. On the other hand, 11 segments had infarct of more than 75% of wall thickness, of which 11 (100%) had abnormal wall motion. None of segments with nearly transmural infarction were observed in non ST-elevation AMI. The majority of the segments with infarct had non-transmural infarction (87.5%), even if the segments were in ST-elevation AMI (76.1%). Infarct size, as defined by ceMRI, was strongly correlated with peak CK-MB and Troponin-T (r = 0.96, p < 0.001, r = 0.91, p < 0.001, respectively). CONCLUSION: TEI defined by ceMRI is inversely related to the contractility after revascularization in AMI. We were able to predict the future contractile function of segments with infarction using ceMRI before revascularization.

Contrast Media↗
PubMed2003

Gene expression profiling of oxidative stress on atrial fibrillation in humans.

Atrial Fibrillation (AF) is thought be caused by oxidative stress. Oxidative stress at the cellular level results from many factors, including exposure to alcohol, medications, cold, toxins or radiation. In this study we investigated gene transcriptional profiles on the human myocardial tissues from AF and oxidative stress conditions. Right atrial appendages were obtained from AF patients (n = 26) undergoing the Maze procedure, and from control patients (n = 26) who were in normal sinus rhythm and undergoing coronary artery bypass graft operation. To examine the effects of oxidative stress on AF, we used radioactive complementary DNA (cDNA) microarrays to evaluate changes in the expression of 1,152 known genes. This technology, which monitors thousands of genes simultaneously, gives us a better picture of the interactions between AF and oxidative stress. Total RNAs prepared from the retrieved tissues were used to synthesize 33P-labeled cDNAs by reverse transcription and hybridized to cDNA microarrays. Gene expression profiles showed that 30 genes were upregulated and 25 were downregulated in AF patients compared with control patients. Moreover, comparison rank analysis revealed that the expression of five genes related to reactive oxygen species (ROS)-including flavin containing monooxygenase 1, monoamine oxidase B, ubiquitin specific protease 8, tyrosinase-related protein 1, and tyrosine 3-monooxygenase-increased by more than 2.0 of the Z-ratio, and two genes related to antioxidants including glutathione peroxidase 1, and heme oxygenase 2-decreased to the Z-ratio levels of < or = -2.0. Apparently, a balanced regulation of pro- and anti-oxidation can be shifted toward pro-oxidation and can result in serious damage similar to that of human AF. Western blotting analysis confirmed the upregulation of tyrosinase-related protein 1 and tyrosine 3-monooxygenase and the downregulation of heme oxygenase 2. These results suggested that the gene expression pattern of myocardial tissues in AF patients can be associated with oxidative stress, resulting in a significant increase in ROS. Thus, the cDNA microarray technique was useful for investigating transcription profiles in AF. It showed that the intracellular mechanism of oxidative stress plays a pivotal role in the pathologic progression of AF and offers novel insight into potential treatment with antioxidants.

Atrial Appendage↗
PubMed2002

Action potential duration restitution kinetics in human atrial fibrillation.

OBJECTIVES: We undertook this study to determine whether human atrial fibrillation (AF) relates to steeply sloped action potential duration restitution (APDR) kinetics and whether the spatial nonuniformity of APDR promotes persistence of AF. BACKGROUND: A steeply sloped APDR curve is known to be an important determinant of the induction of more complex action potential duration (APD) dynamics and fibrillation. METHODS: Patients with chronic atrial fibrillation (CAF) (n = 18), paroxysmal atrial fibrillation (PAF) (n = 14) and normal control subjects (n = 9) were studied. The monophasic action potential duration at 90% repolarization (APD(90)) and the effective refractory period (ERP) were measured at six sites in the right atrium. After AF was electrically converted, APDR was assessed by delivering a single extrastimulus after a train of stimuli at a cycle length of 600 ms (S(1)S(2)) at six different sites of the right atrium, as well as rapid pacing at cycle lengths that induced APD alternans. RESULTS: The APD(90) and ERP in patients with CAF were shorter than those in patients with PAF and control subjects (p < 0.05); however, the dispersions of APD(90) and ERP in each group were similar. The maximal slopes of APDR by S(1)S(2) and rapid pacing in patients with CAF (1.2 +/- 0.4 and 1.7 +/- 0.2) and PAF (1.1 +/- 0.4 and 1.3 +/- 0.4) were higher than those in control subjects (0.5 +/- 0.3 and 0.8 +/- 0.2, respectively; p < 0.01). The maximal slope obtained by S(1)S(2) did not differ from that obtained by rapid pacing in any group. The inter-regional difference of the maximal slope in patients with CAF (1.6 +/- 0.4, p < 0.05) was greater than that in patients with PAF (1.2 +/- 0.3, p = NS vs. control) and control subjects (0.4 +/- 0.2). CONCLUSIONS: Atrial fibrillation was related to steeply sloped (>1) APDR kinetics. The spatial dispersion of APDR in patients with chronic AF was greater than that of patients with paroxysmal AF and control subjects, indicating that the heterogeneity of APDR of the atrium plays an important role in the persistence of AF.

Action Potentials↗