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BACKGROUND AND OBJECTIVES Decreased left atrial appendage (LAA) emptying velocity in transesophageal echocardiography (TEE) is related with higher incidence of thrombus and increased risk of stroke. Patients with valve disease are at higher risk of thrombus formation before and after surgery. The aim of this study was to investigate the role of 4-dimensional cardiac computed tomography (4DCT) to predict the risk of thrombus formation. METHODS Between March 2010 to March 2015, total of 62 patients (mean 60±15 years old, male: 53.2%) who underwent 4DCT and TEE for cardiac valve evaluation before surgery were retrospectively included in the current study. Fractional area change in TEE view and emptying velocity at left atrial appendage in TEE view (VeTEE) were measured. Ejection fraction (EF) of left atrial appendage in computed tomography (EFCT) was calculated by 4DCT with full volume analysis. The best cut-off value of EFCT predicting presence of spontaneous echo contrast (SEC) or thrombus was evaluated, and correlation between the parameters were also estimated. RESULTS SEC or thrombus was observed in 45.2%. EFCT and VeTEE were significantly correlated (r=0.452, p

Background and objectives Transcatheter aortic valve replacement (TAVR) has been reported as a good alternative for surgical aortic valve replacement in patients with small aortic annulus. Head-to-head comparisons of different transcatheter aortic valves in these patients are insufficient. We compared the outcomes after TAVR between two different types of recent transcatheter aortic valves (self-expanding vs. balloon-expandable) in patients with small aortic annulus. Methods A total of 70 patients with severe aortic stenosis and small annulus (mean diameter ≤23 mm or minimal diameter ≤21 mm on computed tomography) underwent TAVR with either a self-expanding valve with supra-annular location (n=45) or a balloon-expandable valve with intra-annular location (n=25). The echocardiographic hemodynamic parameters after TAVR and 1-year follow-up were compared. Results Between the self-expanding and balloon-expandable valve-treated patients, the clinical outcomes including permanent pacemaker implantation (11.1% vs. 8.0%), acute kidney injury stage 2 or 3 (4.4% vs. 4.0%), and major vascular complication (4.4% vs. 0.0%) were similar without all-cause mortality, stroke, and life-threatening bleeding during 30-day follow-up. Compared with the balloon-expandable valve-treated patients, the self-expanding valve-treated patients presented larger effective orifice area (EOA) (1.46±0.28 vs. 1.75±0.42 cm², p=0.002) and indexed EOA (0.95±0.21 vs. 1.18±0.28 cm²/m², p=0.001), whereas mean aortic valve gradient (11.7±2.9 vs. 8.9±5.2 mmHg, P=0.005) and incidence of ≥moderate prosthesis-patient mismatch (36.0% vs. 8.9%, p=0.009) were lower. These hemodynamic differences were maintained at 1-year follow-up. Conclusions TAVR with self-expanding valves was associated with superior hemodynamic outcomes compared with balloon-expandable valves in patients with small aortic annulus.

Background and Objectives Clinical data for Korean patients with bicuspid aortic valve (BAV) that underwent aortic valve (AV) surgery are currently limited. Methods Data for 1,160 consecutive adult BAV patients who underwent AV surgery from 2000 to 2014 in 4 tertiary referral centers were retrospectively analyzed. A standard case report form was used for clinical and echocardiographic parameters. Results Mean age at the time of AV surgery was 59±13 years. The most common cause of AV surgery was aortic stenosis (AS, 892 [77%]), followed by aortic regurgitation (AR, 199 [17%]), and infective endocarditis (69 [6%]). AS showed a skewed peak in the aged population and was the predominant cause of AV surgery (87%) in patients ≥50 years of age, whereas AR (46%) and active infective endocarditis (19%) were more common in younger patients (p

Constrictive pericarditis is an uncommon post-inflammatory disorder characterized by a variably thickened, fibrotic, and frequently calcified, pericardium. Etiology of the constriction can occur for many reasons. Although foreign bodies are not the common cause of constrictive pericarditis, the long-term presence of foreign bodies, like bullets, is presumed to cause chronic constrictive pericarditis even after a very long asymptomatic period. A 69-year-old patient with atrial flutter was admitted to the hospital. A cardiac computed tomography showed a bullet located adjacent to the right atrium. The transthoracic echocardiography showed a thickened pericardium and septal bouncing motion, which were compatible with constrictive pericarditis. The history of the patient revealed an injury by gunshot during the Korean War in 1950. Radiofrequency ablation of the atrial flutter was performed, and after ablation, the bullet was removed surgically. The patient was discharged home after surgery without complications.

Background and Objectives We investigated echocardiographic predictors: left ventricular (LV) geometric changes following aortic valve replacement (AVR) according to the late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMR) in patients with severe aortic stenosis (AS) and preserved LV systolic function. Subjects and Methods We analyzed 41 patients (24 males, 63.1±8.7 years) with preserved LV systolic function who were scheduled to undergo AVR for severe AS. All patients were examined with transthoracic echocardiography (TTE), CMR before and after AVR (in the hospital) and serial TTEs (at 6 and 12 months) were repeated. Results The group with LGE (LGE+) showed greater wall thickness (septum, 14.3±2.6 mm vs. 11.5±2.0 mm, p=0.001, posterior; 14.3±2.5 mm vs. 11.4±1.6 mm, p

Background and Objectives: In patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease, complete revascularization (CR) for non-culprit lesions is not routinely recommended. The aim of this study was to compare the clinical outcomes of multivessel compared with infarct-related artery (IRA)-only revascularization in patients undergoing primary percutaneous coronary intervention (PCI) for STEMI. Subjects and Methods: From the Korean Acute Myocardial Infarction Registry (KAMIR) database, 1,094 STEMI patients with multivessel disease who underwent primary PCI with drug-eluting stents were enrolled in this study. The patients were divided into two groups: culprit-vesselonly revascularization (COR, n=827) group; multivessel revascularization, including non-IRA (MVR, n=267) group. The primary endpoint of this study included major adverse cardiac events (MACEs), such as death, myocardial infarction, or target or nontarget lesion revascularization at one year. Results: There was no difference in clinical characteristics between the two groups. During the one-year follow-up, 102 (15.2%) patients in the COR group and 32 (14.2%) in the MVR group experienced at least one MACE (p=0.330). There were no differences between the two groups in terms of rates of death, myo cardial infarction, or revascularization (2.1% vs. 2.0%, 0.7% vs. 0.8%, and 11.7% vs. 10.1%, respectively; p=0.822, 0.910, and 0.301, respectively). The MACE rate was higher in the incompletely revascularized patients than in the completely revascu larized patients (15% vs. 9.5%, p=0.039), and the difference was attributable to a higher rate of nontarget vessel revascular ization (8.6% vs. 1.8%, p=0.002). Conclusion: Although multivessel angioplasty during primary PCI for STEMI did not reduce the MACE rate compared with culprit-vessel-only PCI, CR was associated with a lower rate of repeat revascularization after multivessel PCI. (Korean Circ J 2011;41:718-725)

Background and Objectives The plasma concentration of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) is a st-rong prognostic indicator for patients with heart failure (HF) across all stages of the condition. Several clinical trials have de-monstrated convincingly that neurohormonal modulation on the renin angiotensin system (RAS) decreases plasma NT-pro-BNP level and results in favorable outcomes. But there are still limited comparative data on the neuro-hormonal modulatory effects of two RAS inhibitors: angiotensin converting enzyme inhibitor and angiotensin receptor blocker. Subjects and Methods This study was a prospective, multi-center, randomized, open-label, controlled, and non-inferiority study involving 445 patients with left ventricular ejection fraction (LVEF) less than 45%. Patients were assigned to receive either valsartan (target dose of 160 mg bid) or enalapril (target dose of 10 mg bid) for 12 months. We compared plasma NT-pro-BNP, high sensitive C-reactive protein (hs-CRP) level and echocardiographic parameters before and after treatment with valsartan or enalapril. Results: The NT-pro-BNP and hs-CRP levels were significantly decreased after 12 months of treatment with valsartan and enalapril. The percentage change was similar between both groups. LVEF improved and left ventricular internal dimensions were decreased in both groups, and there were no significant differences between two groups. Conclusion Valsartan is as effective on improving plasma NT-pro-BNP level as enalapril in patients with stable chronic HF.

Background and objectives Left ventricular hypertrophy (LVH) is associated with poor cardiovascular outcomes. Heavy aortic calcification exacerbates arterial stiffness, which consequently heightens left ventricular (LV) afterload. We assessed the usefulness of aortic calcification for predicting adverse cardiovascular outcomes and to determine whether the relationship, if any, differed as a function of LVH. Methods The analytic sample was comprised of a total of 487 individuals 65 years of age or older. Thoracic aorta calcium score (TACS) was measured by coronary computed tomography, and patients were stratified according to the median (TACS, 446 mm³). LVH obtained from echocardiography was defined as LV mass index >115 g/m² for men and >95 g/m² for women. Cox regression reporting hazard ratios (HRs) with 95% confidence intervals (CIs) was performed to predict the risk for the composite study endpoint, defined as cardiac death, admission for heart failure, obstructive coronary artery disease (CAD) requiring revascularization, or stroke. Results A total of 39 composite events (8.0%) occurred during a median follow-up of 65 months (interquartile range [IQR], 17-89 months). For those with LVH, the concurrent presence of high TACS appeared to be an independent predictor (HR, 4.51; 95% CI, 1.71-11.88; p=0.002) for the composite study endpoint. Other combined LVH and TACS subgroups were not associated with significant factors for predicting the composite study endpoint (p>0.050, all). Conclusion TACS provides robust predictive utility for a composite of cardiovascular events and cardiac death in persons with LVH. This finding was less pronounced in those with a relatively healthy myocardium, defined by the absence of LVH.

Transcatheter aortic valve implantation (TAVI) has shown favorable outcomes in patients with severe symptomatic aortic valve stenosis who are at high surgical risk or are unsuitable candidates for open heart surgery. However, concerns exist over treating patients who have previously undergone mitral valve surgery due to the potential interference between the mitral prosthetic valve or ring and the TAVI device. In this case report, we present a patient with symptomatic severe aortic stenosis and previous mechanical mitral valve replacement who was successfully treated with TAVI using a CoreValve.

Background and Objectives: We assessed the ability of portable echocardiography (with contrasts) to clearly delineate the cardiac structure, and evaluated the impact of its use on the diagnosis and management of critically ill patients in Korea. Subjects and Methods: We prospectively enrolled 123 patients (mean age 66±16 years), who underwent portable transthoracic echocardiography (with contrast) for image enhancement at 12 medical centers. The quality of the global left ventricular (LV) images, the number of the regional LV segments visualized, the ability to visualize the LV apex and the right ventricle (RV), and any changes in the diagnostic procedure and treatment strategy were compared before and after the contrast. Results: Of the 123 patients, 52 (42%) were using mechanical ventilators. The amount of poor or uninterpretable images decreased from 48% to 5% (p

Background and Objectives Screening strategies for aortic aneurysm (AA) according to risk factors and ethnicity are controversial. This study explored the prevalence of AA and determined whether screening is necessary in a population of multiple risk factors. Subjects and Methods From June, 2012 to April, 2013, 542 consecutive elderly (≥65 years) male hypertensive patients without a history of AA were prospectively enrolled. After excluding 15 patients (2.8%) with aortic valve surgery, 30 patients (5.5%) with suboptimal computed tomography (CT) images, the remaining 496 patients (age 73±5 years) comprised the study population. Maximal diameters of the thoracic and abdominal aorta were measured using non-contrast CT. Results The prevalence of thoracic AA (TAA, diameter ≥40 mm) and abdominal AA (AAA, diameter ≥30 mm) was 36.5% (181/496) and 6.0% (30/496), respectively. In the multivariate logistic regression analysis, determinants for TAA were age {odds ratio (OR) 1.059, 95% confidence interval (CI) 1.018-1.101, p=0.005}, dyslipidemia (OR 0.621, 95% CI 0.418-0.923, p=0.018), body surface area (OR 11.92, 95% CI 2.787-50.97, p=0.001), diastolic blood pressure (OR 1.029, 95% CI 1.009-1.049, p=0.004) and AAA (OR 3.070, 95% CI 1.398-6.754, p=0.005). In contrast, AAA was independently associated with dysplipidemia (OR 2.792, 95% CI 1.091-7.143, p=0.032), current/past smokerfs (OR 4.074, 95% CI 1.160-14.31, p=0.028), and TAA (OR 3.367, 95% CI 1.550-7.313, p=0.002). Conclusion The prevalence of AA was significant and TAA was more prevalent than AAA in elderly Korean males with hypertension. Future research should establish distinct screening strategies for TAA and AAA according to risk factors and ethnicity.

Aneurysm of the sinus of Valsalva that causes dissection of the interventricular septum is an extremely rare entity. In this report we describe a case of aneurysm of the sinus of Valsalva dissecting into the interventricular septum, from the base to mid septum, after aortic valve replacement. After the diagnosis was made by transthoracic echocardiography and magnetic resonance imaging, the patient was successfully treated with surgical sealant-mediated occlusion of the aneurysmal sac and cardiac resynchronization therapy used for the first time.

Background and Objectives: The Mayo clinic quadratic (MCQ) glomerular filtration rate (GFR) equation accurately estimates the GFR when the presence of kidney disease is unknown. The aim of this study is to evaluate the usefulness of the MCQ GFR equation for predicting contrast-induced nephropathy (CIN) in patients with angina pectoris and who are undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI). Subjects and Methods: One hundred seven patients diagnosed with stable or unstable angina and who had normal serum creatinine levels (SCr

Thrombolytic therapy during cardiopulmonary resuscitation is not routinely recommended, but 50-70% of cardiac arrests are caused by either acute myocardial infarction or massive pulmonary embolism. Thrombolytic therapy can be a reasonable treatment modality for a patient suffering with cardiac arrest in an emergency situation and whose diagnosis is not known. We report here on a case with cardiac arrest and the diagnosis was not known. The patient was refractory to conventrional cardiopulmonary resuscitation, and he was treated with a bolus injection of a thrombolytic agent. He recovered completely without complications. (Korean Circ J 2007;37:663-665)

Background and Objective: Ventricular arrhythmia is an important cause of death in patients suffering with idiopathic dilated cardiomyopathy (IDCM). The decreased uptake or increased "washout" of 123 I-metaiodobenz- ylguanidine (MIBG)-derived radioactivity is associated with a worse prognosis or severe disease in patients with cardiac diseases. Subjects and Methods: Forty patients (28 men, mean age: 56.5±13.0 years) with angiographi- cally proven IDCM were studied and divided into 2 groups: the patients with clinically documented ventricular tachycardia (VT) and IDCM (group A; 17 patients), and the patients without VT, but with IDCM (group B; 23 patients). The normal control group (7 men, mean age 62.4±7.9) was compared theses patients. 123 I-MIBG was evaluated by the early (15 min) and delayed (3hours) uptake, the heart to mediastinum uptake (H/M) ratio and the global and regional washout ratio (WOR) that was defined as the (early H uptake-delayed H uptake)/early H uptake. The clinical variables, echocardiographic parameters and 123 I-MIBG-derived parameters were compared among three groups. Results: There were no significant differences in age and the echocardiographic parameters between the groups A and B. A significant negative correlation was present between the early inferior wall H/M ratio and the LVEDD (Spearman's correlation, r=-0.412, p=0.08), and the early inferior H/M ratio and the LVESD (Spearman's correlation, r=-0.463, p=0.03). Only the delayed lateral wall uptake was significantly lower in group A than that in group B (23.3±5.3 versus 27.8±8.4, respectively p=0.042). The regional WOR was not statically different among the three groups. Conclusion: Cardiac 123 I-MIBG SPECT partially reflects the vulnera- bility for the occurrence of VT in patients suffering with IDCM. These results support the feasibility of using cardiac 123 I-MIBG SPECT as a prognostic tool in IDCM patients. (Korean Circulation J 2007;37:510-516)

Background and Objectives:Percutaneous coronary intervention (PCI) for unprotected left main coronary artery (LMCA) stenosis is a promising technique in the drug-eluting stent era. However, there is a lack of data as to the impact of the lesion location in the LMCA on the procedural and postprocedural outcomes. The aim of this study is to evaluate the effect of lesion location on the procedural and postprocedural outcomes. Subjects and Methods: From July 2003 to January 2006, we enrolled 82 patients (Males: n=49), who underwent PCI for unprotected LMCA stenosis at Yeungnam University Medical Center, Keimyung University Dong-san Hospital and In-je University Baik Hospital in Busan. The patients were divided into two groups according to the lesion location. Group 1 (n= 38) was defined as those patients who had a significant stenosis in the ostium and/or body. Group 2 (n=44) was defined as those patients had a left main coronary lesion involving a bifurcation. All the patients had a sirolimus eluting stent (Cypher, Cordis) deployed into the LMCA stenosis. Stenting techniques such as the T, crush and kissing stent techniques for treating the LMCA were used at the discretion of the operator and according to the characteristics of the lesion location. The in-hospital outcomes were compared between the two groups and followup coronary angiography was performed after 6 months; the major adverse cardiac events (MACE) and restenosis were analyzed between the two groups. Results:The baseline characteristics between the two groups were not statistically different. The procedural outcomes showed that for the stenting methods, the conventional stent technique was the only one used in all cases of Group 1, but the kissing, T stenting and Crush techniques were also used in Group 2 (p=0.001). The clinical outcomes showed that that there was no statistical difference for the in-hospital MACEs between the two groups, but for the out-of hospital MACEs at 6 month, the target lesion revascularizatin rates, including PCI or bypass graft operation, in Group 1 were higher than those in Group 2 (0% vs 13.6%, respectively p=0.043). Both groups had one cardiac death each (2.3% vs 2.6% respectively) and there was 1 MACE in Group 1 and 7 MACEs in Group 2 (2.6% vs 16%, respectively, p=0.045). The angiographic outcomes at 6 month showed that all 8 significant restenosis cases were included in Group 2 (18%, 9.7% in the total population); the restenosis site was the left circumflex artery in all cases. Conclusion:PCI with using drug eluting stents in the left main lesion showed favorable short term outcomes in selected patients. The lesion location is also an important factor for the clinical and angiographical outcomes. (Korean Circulation J 2007;37:419-424)

Background and Objectives:Atrial dilatation contributes to the inducibility of atrial fibrillation (AF) by changing the atrial electrophysiological properties. There has been no report regarding the electrophysiologic data of the left atrium (LA), where the most significant electrophysiological impact might be expected to occur in case of mitral stenosis (MS). We investigated the electrophysiological changes after reduction of the LA pressure in patients who were undergoing percutaneous balloon mitral commissurotomy (PBMC). Subjects and Methods:We studied 26 patients (21 women, age range: 50±12 years) with MS, including 7 sinus rhythm (SR) patients. The effective refractory period (ERP), the monophasic action potential duration (MAPD90), and the conduction time (CT) were measured simultaneously in both atriums at 600, 500, 400 and 300 ms of drive cycle length (DCL). The restitution slope (RS) was also calculated by the S1S2 method. The atrial fibrillation cycle length (AFCL) and dominant frequency (DF) for the cases of AF were also calculated. All the measurements were repeated after PBMC. Results: The mean LA pressure was significantly reduced after PBMC in both the AF and SR patients (17.0±5.5 mmHg vs 10.4±4.0 mmHg, respectively, p

Background and Objectives：Measurements obtained using an intracoronary electrocardiogram (IC-ECG) reflect the electrical activity in various regions of the myocardium. This technique can be easily used in the catheterization laboratory during percutaneous coronary intervention (PCI) procedures. Furthermore, IC-ECG could be used to evaluate myocardial viability in patients with acute myocardial infarction (AMI). The aim of this study was to evaluate the usefulness of IC-ECG in predicting the microvascular integrity and late improvement of left ventricular (LV) function after primary PCI in patients with AMI. Subjects and Methods：A total of 78 patients (62 male, 16 female) who underwent primary PCI with stent implantation were enrolled in this study. After the implantation of the stent, IC-ECG was recorded from the tip of an insulated angioplasty guidewire before and after balloon occlusion of the infarct-related artery. The IC-ECG was obtained from the inferior and inferolateral areas in inferior wall MI, or apex and apical anterior wall regions in anterior wall MI. Significant ST segment elevation was defined as a further ST segment elevation of ≥0.2 mV at 80 msec after the J-point in comparison to the baseline value. The microvascular integrity of the myocardium was evaluated by myocardial contrast echocardiography (MCE) one day after the PCI was performed. Six months later, all of the patients were followed up by echocardiography and the wall motion score index (WMSI) and ejection fraction (EF) were measured. Results：Significant ST elevation was noted in 47 patients (Group A) after coronary occlusion. There was no significant change in the other 31 patients (Group B). MCE showed microvascular perfusion in 41 patients in group A (87%) and in four patients in group B (13%) (p

Background and Objectives:Percutaneous coronary intervention (PCI) of unprotected left main coronary artery (LMCA) stenosis is a promising approach during this era of drug-eluting stents. However, there is no available hemodynamic data on these type patients during the performance of LMCA stenting. The purpose of this study was to determine the risk factors affecting hemodynamic stability during LMCA stenting, and to evaluate whether hemodynamic support such as inotropics or intra-aortic balloon pump (IABP) is needed, based on the risk factors. Subjects and Methods:From July 2003 to January 2006, we enrolled 92 study patients (Male=55) who had visited Yeungnam University Hospital, Keimyung University Dongsan Hospital and InJe University Baik Hospital in Busan and they were all were diagnosed with angiographically detected unprotected LMCA stenosis. Group 1 (n=69) included those patients who did not need hemodynamic support during PCI. Group 2 (n=23) included patients who needed hemodynamic support during PCI. All patients had stents deployed in the LMCA lesions without hemodynamic support; the clinical, angiographic and procedural outcomes were compared between the two groups after the procedure. Results:The baseline patient characteristics were not statistically different between the two groups. On univariate analysis, Group 2 had more patients diagnosed with acute myocardial infarction (AMI) than Group 1 (40% vs. 15%, respectively, p=0.014). Group 1 had a greater frequency of an increased left ventricular (LV) ejection fraction than Group 2 (60±10 vs. 47±11, respectively, p=0.01). Regarding the lesion location in the LMCA, Group 2 had relatively more lesions at bifurcated locations than Group 1 (44% vs. 78%, respectively, p=0.004). Group 2 required more complex techniques to repair lesions, such as kissing or crush stenting, than did Group 1 (19% vs. 48%, respectively, p=0.006). Multivariate logistic regression analysis showed that the presence of AMI (Odds Ratio (OR)=3.74, p=0.014), a complex stenting procedure such as kissing or crushing (OR=3.99, p=0.006), a bifurcated lesion (OR=4.58, p=0.004) and poor LV function (OR=9.95, p= 0.0001) were independent risk factors for hemodynamic instability during LMCA stenting. Conclusion:The most important risk factor for hemodynamic instability during LMCA stenting was LV function. Therefore, preparation for hemodynamic support, including IABP before the procedure, is necessary for the high risk patients. (Korean Circulation J 2007;37:108-112)

Background and Objectives:The traditional indexes of heart rate (HR) variability may lack the ability to detect subtle, but important changes in HR behavior. Nonlinear heart rate variability (HRV) analysis methods that are based on chaos theory can reveal subtle abnormalities in the HR dynamics of patients with cardiovascular diseases. Therefore, we tested the validity of nonlinear analysis methods as markers to differentiate normal and abnormal HR dynamics in the cardiovascular disease state. Subjects and Methods:One-hundred patients were studied: 70 patients with left ventricular dysfunction (LVD), including 40 post-myocardial infarct patients (PMI) and 30 di- lated cardiomyopahty patients (DCM), and 30 age and gender-matched controls. One-hour, 6-hours (day and night each) and 24 hours of R-R interval data from 24-hour Holter recordings were subjected to the conventional time and frequency-domain analysis. The ApEn, short-term (α 1) and long-term (α2) scaling exponents of the detrended fluctuation analysis (DFA) and the power-law exponent (β) were also measured. Results:Conven- tional linear measures did not show a significant difference except for the VLF, lnLF and the LF/HF ratio between the controls and the LVD patients. Among the analyzed parameters, β, β2 and α1 were the most powerful dis- criminators. The β of the normal and LVD patients was -1.10±0.29 and -0.70±0.40, respectively (p

Background and Objectives:According to the MADIT II criteria, a low left ventricular ejection fraction (LVEF) is one of the most important predicting factors for sudden cardiac death (SCD) in post myocardial infarction (PMI) patients, and it is a reasonable indication for ICD implantation. The aim of this study is to reveal the incidence and the prognostic value of the non-invasive parameters and whether the MADIT II criteria for ICD implantation can be applied to Korean PMI patients. Subjects and Methods:During the period from January 2001 to June 2005, 640 PMI survivors were included in this study. The incidence of an abnormal SAECG, premature ventricular complex (PVC) counts ≥10/hr, non-sustained ventricular tachycardia (NSVT) on ambulatory ECG and a low (≤30%) LVEF were studied and used as risk stratification markers for later adverse arrhythmic events. Results:The incidence of PVCs ≥10/hr and NSVT on the ambulatory ECG was 14.3% and 7.5%, respectively. 29 patients (4.9%) had a LVEF of less than 30%. Arrhythmic events occurred in 9 of the 29 patients (31%). SCD or adverse arrhythmic events occurred in 42 of the 640 patients. The percentage of patients who were using β-blocker was lower than that in the MADIT II study group (55% vs 70%, respectively). In the adverse arrhythmic event (+) group, the percentage of β-blocker use was significantly lower than that in the arrhythmic event (-) group (32.5% vs 58%, respectively). Conclusion:The MADIT II criteria and PVCs ≥10/hr or NSVT on the ambulatory ECG can be suggested as the indications for implanting an ICD in Korean PMI patients. The use of β-blocker is important for preventing adverse arrhythmic events. (Korean Circulation J 2006;36:431-436)

A 52-year-old woman, who was suffering from aplastic anemia, presented with the clinical features of severe heart failure. The transthoracic echocardiogram showed a heterogeneous, huge mass on the base of the posterior mitral valve. We guessed that the mass would be a benign neoplasm and probably myxoma, and we decided upon surgical resection. After tumor resection, an unexpected result of the histopathology was a high grade osteosarcoma. The other studies that were done after we had the diagnosis could not reveal any evidence of metastatic malignancy. (Korean Circulation J 2006;36:764-766)

Background and Objectives:Stent thrombosis (ST) after a successful drug-eluting stent (DES) implantation has been reported in around 1% of clinical trials. However, the incidence of ST with a DES in practice is not well known. Here, we evaluated the possible causes of ST encountered in four Korean hospitals. Subjects and Methods:Between March 2003 and December 2003, 450 patients were treated using a DES in the four study hospitals. We reviewed the clinical and procedural characteristics of 8 patients that experienced ST after a successful DES implantation. Results:Eight patients (1.8%), who were administered antiplatelet medication, experienced ST, with a mortality of 50% at the 2 month follow-up. ST occurred within 7 days in all patients, with the exception of one, with an occurrence 37 days after intervention. Initially, all patients were diagnosed as having acute coronary syndrome. Direct PTCA was performed in 3 patients (38%). Severe calcification or a thrombus was noted in 6 (67%) of 9 lesions. In all cases, no GPIIbIIIa inhibitors were used prior to the DES implantation. Incomplete lesion coverage and incomplete stent expansion appeared in 7 (88%) cases. Conclusion:Our study demonstrated that full expansion of the DES and complete lesion coverage must be accomplished, with high pressure inflation or use of cutting balloon preferably under IVUS guidance, for the prevention of ST. Those patients with acute coronary syndrome might warrant intensive antiplatelet therapy, including GPIIbIIIa inhibitors. (Korean Circulation J 2005;35:163-171)

Background and Objectives:Nicorandil is a potassium channel opener, and it has been known to have a cardioprotective effect against ischemia/reperfusion injury. However, the exact mechanisms of the effect are not known. In the previous studies on cardioprotection, administration of nicorandil was started early during the coronary occlusion. Therefore, it is not clear whether nicorandil can also be beneficial when it is administered from the time of coronary recannalization. Materials and Methods:We studied 15 cats that had their chests surgically opened (8 nicorandil cats and 7 control cats). The proximal portion of the left anterior descending artery (LAD) was occluded with ligation for 90 minutes, then it was recannalized for 60 minutes. Intravenous injection of nicorandil was started at the time of recannalization of the artery (a bolus of 100 μg·kg-1 plus an infusion at a rate of 10 μg·kg -1 ·min -1 ). At each stage of the experiments, the risk area and myocardial perfusion were assessed using color microspheres and myocardial contrast echocardiography. The size of the infarction was evaluated by postmortem triphenyltetrazolium chloride staining. Myocardial contrast echocardio- graphy was performed with Pulse Inversion Harmonic Imaging (Sonoace9900, Medison). Results:The risk area during coronary occlusion was 18.8±12.6% in the nicorandil group and 19.3±9.6% in the control group (p=NS). The perfusion defect immediately after and 1 hour after reperfusion was 13.0±8.7% and 8.4±7.6%, respectively, in nicorandil group, and 16.7±11.1% and 13.4±8.8%, respectively, in the control group, (p=NS between groups). Myocardial blood flow in the LAD territory during occlusion immediately after and 1 hour after reperfusion was 56±31%, 73±31% and 69±28%, respectively, of the normal myocardium in the nicorandil group, and 65±20%, 101±75% and 77±42%, respectively, in the control group (p=NS between groups). The postmortem infarction size was 8.1±9.6% in the nicorandil group and 7.7±7.5% in the control group (p=NS). Conclusion:With administration of nicorandil from the time of recannalization in the ischemia/reperfusion injury model, we could not find any significant cardioprotective effect. The cardioprotective effect of nicorandil may be associated with preconditioning before reperfusion. (Korean Circulation J 2005;35:88-93)

Background and Objectives：It is known that ventricular fibrillation (VF) can be enhanced by sympathetic activity and antagonized by vagal activity, and that the kinetics of electrical restitution is a key determinant of VF induction or maintenance. However, little is known about the effects of autonomic stimulation on electrical restitution. Therefore, we studied the effect of sympathetic (SS) and vagus nerve stimulation (VS) on the electrical restitution and VF induction. Materials and Methods：A monophasic action potential (MAP) was simultaneously recorded from the endocardium and epicardium of the left ventricle in 12 open chest canine hearts. The restitution kinetics were studied using a single ventricular extra-stimuli (S2), following a 15 beat drive train (300 ms), down to the effective refractory period (ERP). S2-MAPD was plotted against the preceding diastolic intervals, fitted to exponential curves and the maximum restitution slope (Smax) measured. The VF threshold (VFT) was determined as the minimum current that would induce VF with rapid pacing (50×50 ms). Parameters were studied at the baseline (control) and separately during VS and SS. Results：SS increased the Smax of the endocardium (1.14±0.37 vs. 0.80±0.25, p

Background and Objectives:Heart rate variability (HRV) analysis, by conventional measures, for predicting the risk of atrial fibrillation (AF) has inherent shortcomings. Recently, nonlinear HRV analysis methods have been developed to reveal heart rate dynamics not evident from usual HRV measures. The purpose of this study was to test the hypothesis"heart rate dynamics are altered before the spontaneous onset of paroxysmal AF (PAF)" using algorithms derived from symbolic dynamics based on nonlinear system theory. Subjects and Methods: This study included 34 subjects (30 males, 59±9 years): 17 PAF patients and 17 gender and age-matched con- trols, who underwent 24-hour Holter ECG. The dynamics of one hour of normal sinus rhythm before the onset of AF were assessed using 4 different symbolization algorithms, and quantified by Shannon entropy (SE) and Renyi entropy (RE). Results:The SE, RE and Error-corrected SE (ECSE) were larger in the PAF than the con- trol patients when the raw R-R data was assessed (Algorithm I). However, when reconstructed time series, ex- pressed as the time difference between 2 successive R-R interval, were analyzed (Algorithm II, III and IV), the entropy of the PAF patients were consistently smaller than those of the controls. Of the 4 different symboliza- tion algorithms, algorithms II and III showed a significant difference in the SE, ECSE and RE between the PAF and the control patients (p

Libman-Sacks endocarditis is characterized by noninfectious vegetations on the cardiac valves of patients with systemic lupus erythematosus (SLE). Valvular abnormalities are found in about one third of patients with primary anitiphospholipid syndrome. SLE patients, with antiphospholipid antibodies, have a higher prevalence of valvular involvement than those without these antibodies. A 29 year old man was referred for evaluation of severe orthopnea. He presented with the clinical features of multi-organ failure (heart, lung and kidney). His serological and immunological findings were typical of a SLE flare up. His level of anticardiolipin antibody (IgG) was highly increased and his lupus anticoagulant was positive. A blood culture revealed no growth of bacterial organism. Transthoracic and transesophageal echocardiography showed non-mobile, verrucous vegeta- tions on the anterior leaflet of the mitral valve, with moderate mitral regurgitation. (Korean Circulation J 2003;33

Of the congenital coronary artery fistulae, the multiple coronary artery microfistulae, arising from the left and right coronary artery emptying into the left ventricle, are very rare. Little is known about their anatomic and clinical features, especially in apical hypertrophic cardiomyopathy. The clinical findings are heterogeneous, but include, in most cases, a history of typical or atypical angina pectoris. A 67 year old woman was referred for evaluation of chest pain on exertion, and a shortness of breath. The electrocardiographic and echocardiographic findings were typical of apical hypertrophic cardiomyopathy. Coronary arteriography showed normal epicardial coronary arteries, but multiple coronary artery-left ventricular microfistulae arising from the left and right coronary arteries. Transthoracic Doppler echocardiography, using a high frequency transducer, with a low Nyquist limit, demonstrated multiple coronary artery-left ventricular microfistulae just beneath the apical impulse window. (Korean Circulation J 2003;33 (4):338-342)

Background and Objectives:The pulmonary veins and surrounding ostial areas frequently house focal triggers or reentrant circuits critical to the genesis of atrial fibrillation (AF). The purpose of this study was to assess the efficacy of pulmonary vein isolation, aided by intraoperative radiofrequency catheter ablation, for the treatment of AF associated with mitral valvular heart disease. Subjects and Methods:32 consecutive patients with AF associated with mitral valvular disease, requiring mitral valvular replacement or valvuloplasty were included. We divided these patients into two groups. The first group, PVI, consisted of 16 patients that had mitral valvular operations with intraoperative radiofrequency pulmonary vein isolation, and the other 16 patients, the controls, had mitral valvular operation only. The conversion rate to sinus rhythm and other clinical data were compared between the two groups. Results:Circumferential pulmonary vein isolation, with radiofrequency catheter ablation, was achieved in an average of 15±3 min. There were no mortalities or morbidities associated with this procedure. In the immediate postoperative period, the conversion rate to normal sinus rhythm in the PVI group was significantly higher than in the controls (81% vs. 37.5% p=0.016). After 21±4 weeks of follow up, the sinus rhythm maintenance rates in PVI group was also significantly higher than those of the control group (75% vs. 31.2% p=0.01). Conclusion:Circumferential pulmonary vein isolation, aided by intraoperative radiofrequency catheter ablation, is simple and effective for the treatment of chronic atrial fibrillation associated with mitral valvular disease. (Korean Circulation J 2002;32(7):596-603)