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Author's summary As COVID-19 spreads worldwide, cardiac injury in patients infected with COVID-19 becomes a significant concern. Thus, this study investigates the impact of several electrocardiogram parameters and disease severity in COVID-19 patients. The deceased patients showed increased dispersion of QTc and Tpe-c compared with surviving patients (78.2±41.1 vs. 40.8±24.6 ms and 60.2±37.3 vs 40.8±24.5 ms, both p, Background and Objectives As the coronavirus disease 2019 (COVID-19) spreads worldwide, cardiac injury in patients infected with COVID-19 becomes a significant concern. Thus, this study investigates the impact of several electrocardiogram (ECG) parameters and disease severity in COVID-19 patients. Methods Seven medical centers in Daegu admitted 822 patients with COVID-19 between February and April 2020. This study examined 267 patients among them who underwent an ECG test and evaluated their biochemical parameters like C-reactive protein (CRP), log N-terminal pro-B-type Natriuretic Peptide (NT-proBNP), cardiac enzyme, and ECG parameters (heart rate, PR interval, QRS interval, T inversion, QT interval, and Tpe [the interval between peak to end in a T wave]). Results Those patients were divided into 3 groups of mild (100 patients), moderate (89 patients), and severe (78 patients) according to clinical severity score. The level of CRP, log NT-proBNP, and creatinine kinase-myocardial band were significantly increased in severe patients. Meanwhile, severe patients exhibited prolonged QT intervals (QTc) and Tpe (Tpe-c) compared to mild or moderate patients. Moreover, deceased patients (58; 21.7%) showed increased dispersion of QTc and Tpe-c compared with surviving patients (78.2±41.1 vs. 40.8±24.6 ms and 60.2±37.3 vs. 40.8±24.5 ms, both p

Atrial tachycardias (ATs) from noncoronary aortic cusp (NCC) uncovered after radiofrequency ablation for atrial fibrillation (AF) are rarely reported. This study was conducted to investigate the prevalence and clinical characteristics of NCC ATs detected during AF ablation and compare their characteristics with de novo NCC ATs without AF.Consecutive patients who underwent radiofrequency catheter ablation for AF were reviewed from the multicenter AF ablation registry of 11 tertiary hospitals. The clinical and electrophysiological characteristics of NCC AT newly detected during AF ablation were compared with its comparators (de novo NCC AT ablation cases without AF).Among 10,178 AF cases, including 1,301 redo ablation cases, 8 (0.08%) NCC AT cases were discovered after pulmonary vein isolation (PVI; 0.07% in first ablation and 0.15% in redo ablation cases). All ATs were reproducibly inducible spontaneously or with programmed atrial stimulation without isoproterenol infusion. The P-wave morphological features of tachycardia were variable depending on the case, and most cases exhibited 1:1 atrioventricular conduction. AF recurrence rate after PVI and NCC AT successful ablation was 12.5% (1 of 8). Tachycardia cycle length was shorter than that of 17 de novo ATs from NCC (303 versus 378, p=0.012). No AV block occurred during and after successful AT ablation.Uncommon NCC ATs (0.08% in AF ablation cases) uncovered after PVI, showing different characteristics compared to de-novo NCC ATs, should be suspected irrespective of P-wave morphologies when AT shows broad propagation from the anterior interatrial septum.

BACKGROUND AND OBJECTIVES The prognostic impact of left axis deviation (LAD) on clinical outcomes in acute heart failure syndrome (AHFS) with left bundle branch block (LBBB) is unknown. The aim of this study was to determine the prognostic significance of axis deviation in acute heart failure patients with LBBB. METHODS Between March 2011 and February 2014, 292 consecutive AHFS patients with LBBB were recruited from 10 tertiary university hospitals. They were divided into groups with no LAD (n=189) or with LAD (n=103) groups according to QRS axis

Background and Objectives The aging population is rapidly increasing, and atrial fibrillation (AF) is becoming a significant public health burden in Asia, including Korea. This study evaluated current treatment patterns and guideline adherence of AF treatment. Methods In a prospective observational registry (COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation [CODE-AF] registry), 6,275 patients with nonvalvular AF were consecutively enrolled between June 2016 and April 2017 from 10 tertiary hospitals in Korea. Results The AF type was paroxysmal, persistent, and permanent in 65.3%, 30.0%, and 2.9% of patients, respectively. Underlying structural heart disease was present in 11.9%. Mean CHA2DS2-VASc was 2.7±1.7. Oral anticoagulation (OAC), rate control, and rhythm control were used in 70.1%, 53.9%, and 54.4% of patients, respectively. OAC was performed in 82.7% of patients with a high stroke risk. However, antithrombotic therapy was inadequately used in 53.4% of patients with a low stroke risk. For rate control in 192 patients with low ejection fraction (

The efficacy and safety of catheter ablation for the management of atrial fibrillation (AF) has been improved in recent years. Radiofrequency (RF) catheter ablation for maintaining sinus rhythm is superior to the current antiarrhythmic drug therapy in selected patients. Pulmonary vein isolation (PVI) is the cornerstone of various catheter ablation strategies. It is well recognized that pulmonary vein (PV) antrum contributes to the AF initiation and/or perpetuation. Since PV stenosis is a complication of ablation within a PV, the ablation site for PVI has shifted to the junction between the left atrium and the PV rather than the ostium of the PV. However, PV reconnection after ablation is the major cause of recurrence of AF. The recovery of PV conduction could be caused by anatomical variations such as the failure to produce complete transmural lesion or gaps at the ablation line due to the transient electrophysiologic effects from the RF ablation. In this review, we discussed several factors to be considered for the achievement of the best PVI, including clinical aspects and technical aspects.

BACKGROUND AND OBJECTIVES This study was performed to describe clinical characteristics of patients with left ventriculars (LV) dysfunction and implantable cardioverter-defibrillator (ICD), and to evaluate the effect of ICD therapy on survival in Yeongnam province of Korea. SUBJECTS AND METHODS From a community-based device registry (9 centers, Yeongnam province, from November 1999 to September 2012), 146 patients with LV dysfunction and an ICD implanted for primary or secondary prophylaxis, were analyzed. The patients were divided into two groups, based on the etiology (73 with ischemic cardiomyopathy and 73 with non-ischemic cardiomyopathy), and indication for the device implantation (36 for primary prevention and 110 for secondary prevention). The cumulative first shock rate, all cause death, and type and mode of death, were determined according to the etiology and indication. RESULTS Over a mean follow-up of 3.5 years, the overall ICD shock rate was about 39.0%. ICD shock therapy was significantly more frequent in the secondary prevention group (46.4% vs. 16.7%, p=0.002). The cumulative probability of a first appropriate shock was higher in the secondary prevention group (p=0.015). There was no significant difference in the all-cause death, cardiac death, and mode of death between the groups according to the etiology and indication. CONCLUSION Studies from this multicenter regional registry data shows that in both ischemic and non-ischemic cardiomyopathy patients, the ICD shock therapy rate was higher in the secondary prevention group than primary prevention group.

A contralateral bundle branch block (BBB) aberration during tachycardia with a preexisting BBB strongly suggests the presence of ventricular tachycardia. We report on a middle-aged, female patient presented with wide QRS tachycardia. The patient had orthodromic atrioventricular tachycardia with a left BBB aberration in the presence of a preexisting right BBB due to an abnormal His-Purkinje system. We learned that the contralateral BBB aberration with supraventricular tachycardia could be seen when the His-Purkinje system was abnormal.

Treatment of cardiac disease via the epicardium fell under the domain of cardiac surgery due to the need for an open thoracotomy. Since an open thoracotomy is invasive in nature and has the potential for complications, a minimally invasive and percutaneous approach would be more attractive for suitable patients. The recent success of epicardial ablation of refractory arrhythmia via the percutaneous pericardial approach has increased the potential for delivery of epicardial therapies. Epicardial ablation has increased the success and safety since anti-coagulation and transseptal catheterization for left atrial arrhythmias is not required. The pericardial space has also been used to deliver therapy for several cardiac diseases. There are reports on successful delivery of drugs and their efficacy. Even though there was a wide range of efficacies reported in those studies, the reported complication rates are strikingly low, which suggests that direct delivery of drugs to the epicardium via the pericardial space is safe. Furthermore, recent animal studies have supported the feasibility of epicardial delivery of biological agents, including genes, cells, and even genetically engineered tissue for therapeutic purposes. In conclusion, percutaneous pericardial cannulation of closed pericardial space can play a significant role in providing non-surgical therapy for cardiovascular diseases. However, it requires skills and operator experiences. Therefore, there is need to further develop new tools, safer techniques, and effective procedure environment before generalizing this procedure.

Several cases of stent strut fractures (SSFs) have recently been reported following drug-eluting stent (DES) implantation Although SSF is a rare complication, it has been suggested to be a cause of restenosis. To date, a number of cases of stent fracture have been associated with sirolimus-eluting stents and they occurred from 2 days to about 2 years after the initial procedure. We report here on a case of paclitaxel-eluting stent fracture at the time of stent placement in a calcified coronary lesion. (Korean Circ J 2008;38:387-389)

Background and Objectives: Long-term right ventricular (RV) apex pacing has been associated with left ventricular (LV) systolic dysfunction. However, pacing in the RV outflow tract (RVOT) is associated with a narrower QRS duration and may have a more normal LV activation in comparison to RV apical (RVA) pacing. We hypothesized that RVOT pacing is associated with less mechanical dyssynchrony compared to RVA pacing and that it also more closely resembles mechanical activation in normal controls with a narrow QRS. Subjects and Methods: We studied 9 patients with RV pacing, 9 with left bundle branch block (LBBB), and 15 normal controls with a narrow QRS. In the RV pacing group, we paced from the RVA and RVOT. At the end of each pacing train, we obtained echocardiographic images in the apical 4- and 2-chamber views and obtained the following parameters: the compression/expansion crossover point (CEP) for myocardial strain and the time from QRS onset to the CEP in the strain image. The degree of dyssynchrony was evaluated using the dispersion and standard deviation of CEP times in 12 segments of the LV. Results: Significant dyssynchrony was observed in the RVOT pacing group compared to the group with normal QRS. No significant difference was observed in LV mechanical dyssynchrony among the RVOT pacing, RVA pacing, and LBBB groups. Conclusion: RVOT pacing is associated with significant LV dyssynchrony. Although the RVOT has been recommended as an alternative site for pacing, this approach may have adverse effects on long-term LV function. (Korean Circ J 2008;38:590-595)

Background and Objectives:Sirolimus-eluting stents (SESs) have a considerably lower optimal minimal stent area (MSA) threshold compared to bare metal stents (BMSs). In the SIRIUS IVUS sub study, the absolute optimal stent expansion (OSE) of SESs was described as ≥5.0 mm. The purpose of this study was to evaluate the impact of the OSE on long-term outcomes following SES implantation using absolute IVUS criteria. Subjects and Methods:The study included 157 patients (BMS: 57; SES; 100), who underwent 6-month follow-up angiography and 18-month clinical follow-up after bare metal stent or drug-eluting stent (DES) implantation. According to the absolute measurement IVUS criteria, patients were divided into two groups: OSE and non-OSE. The IVUS criteria for OSE were MSA ≥6.5 mm for BMS implantation and MSA ≥5.0 mm for SES implantation. Results:Angiographic binary restenosis was higher in the non-OSE than the OSE group with BMS (33.3% vs. 11.4%; p

Background and Objectives：Arterial stiffness assessed non-invasively with the aortic pulse wave velocity (PWV) has been associated with atherosclerosis in the coronary arteries and also cardiovascular mortality. The aim of this study was to determine whether arterial stiffness may predict the severity of coronary artery disease (CAD). Subjects and Methods：We enrolled 106 consecutive, symptomatic patients (males: 71 (67%), mean age: 57.0±10.5 years) who underwent coronary angiography. The extent of the CAD was defined by single or multiple vessel disease according to the number of coronary vessels with a ≥50% narrowing, the lesion type according to the AHA/ ACC guidelines, and a modified stenosis scoring system. Arterial stiffness was characterized by measurement of the carotid-radial PWV. In addition, such cardiovascular risk factors as the body mass index, hypertension, smoking, LDL-and HDL-cholesterol, ejection fraction (EF), left ventricle mass index (LVMI), pulse pressure, plasma homocysteine and C-reactive protein (CRP) were evaluated. Results：The carotid-radial PWV in multiple vessel CAD was faster than in single vessel CAD and the normal arteries (10.33±1.46 vs. 8.76±1.65 m/sec, respectively, p< 0.001). On the univariate analysis, the extent of the CAD, as expressed as a modified stenosis score, was associated with the total cholesterol, LDL-cholesterol, the EF and the PWV. However, on the multivariate analysis, the extent of CAD was associated with the carotid-radial PWV (p

Background and Objectives:Compared to bare metal stent, drug-eluting stent has improved the clinical and angiographic outcomes for de novo, simple lesions. In real world clinical practice, we often encounter more complex, long lesions, which increase the rate of restenosis and cardiovascular events. The aim of this study was to evaluate the clinical and angiographic outcome of sirolimus-eluting stent (SES) for the treatment of very long lesions in real world clinical practice. Subjects and Methods:We implanted multiple SESs (>40 mm in total length) in 113 de novo lesions in 113 patients. The average length of the implanted stents was 58±14 mm (range: 41-112 mm) and a mean of 2.2 stents were implanted in each lesion and the average stent diameter was 3.0 ±0.3 mm. Results:Procedural and angiographic success were achieved in all the patients without death or coronary artery bypass surgery. Non-Q wave MI (CK-MB≥ 3 times the normal value) developed in 13 patients (11.5%). Two patients experienced late stent thrombosis after discharge (1.8%). The major adverse cardiac events (MACE)-free survival was 94% at 12 months. There were two sudden cardiac deaths. Six months follow up angiography was performed on 76 patients (67%) and angiographic binary restenosis developed in 7 patients (9.2%). All of them were the focal type in-stent restenosis and these were found to be located at the distal stents. Conclusions:In conclusion, long lesion coverage with SESs is feasible with a favorable mid-term outcome in real world clinical practice. (Korean Circulation J 2006;36:490-494)

Background and Objectives：Coffee is one of the most popular beverages in the world. Caffeine is one of the substances contained in coffee and it is well known to increase blood pressure and the peripheral vascular resistance, in part because it stimulates the sympathetic nervous system. Arterial stiffness is an important factor for the performance of the cardiovascular system and it is an independent prognosticator of cardiovascular disease. We investigated the acute effect of caffeine on arterial stiffness in young healthy subjects. Subjects and Methods：We enrolled 20 young healthy subjects, who were randomly divided two groups. The caffeine group (10 subjects, 4 males, mean age: 23.3±1.1 years) received 520 mL caffeinated coffee and the control group (10 subjects, 4 males, mean age: 23.1±1.3 years) received 520 mL water. The arterial stiffness was evaluated by the carotid-radial pulse wave velocity and the augmentation index as corrected by heart rate (75 bpm), and all the hemodynamic measurements were obtained at baseline, 30, 60, 120 and 180 minutes after ingestion of the coffee or water. Results：Arterial stiffness measured by carotid-radial pulse wave velocity increased progressively from 9.4±1.2 m/sec at baseline to 11.5± 1.6 m/sec (p

Background and Objectives:From a clinical standpoint, coronary artery disease in blood vessels measuring 2.5 mm to 2.75 mm, as accessed by quantitative coronary angiography (QCA), has been classified as a small vessel disease, and it is treated with percutaneous coronary intervention (PCI). The aim of this study was to evaluate the discrepancy of vessel size between intravascular ultrasound (IVUS) and QCA, and its late outcome before and after stent implantation in patients with small coronary artery disease (2.5-2.75 mm). Subjects and Methods:We enrolled 135 patients having 143 lesions who underwent IVUS-guided PCI. Twenty-three patients (26 lesions) were in the small vessel (SV, ≤2.75 mm) group and 112 patients (128 lesions) were in the large vessel (LV, >2.75 mm) group. We evaluated the IVUS and QCA parameters’ association with mortality, acute myocardial infarction (AMI) and target vessel revascularization (TVR) at the 1 year follow-up. Results:On QCA, the pre-interventional reference vessel diameters and post-stent minimal lumen diameters in the SV group were smaller than those in the LV group. The discrepancy of vessel size between IVUS and QCA at the reference site was larger in the SV group than that in the LV group (1.44 mm vs. 0.92 mm, respectively p

A coronary pseudostenosis is a characteristic angiographic image, which may appear as coronary winkles, or intussusceptions, due to a stiff guidewire during coronary interventions. Intravascular ultrasound (IVUS) plays a role in ruling out severe coronary stenosis, coronary dissections, thrombus or coronary spasm. We report a case of coronary pseudostenosis, which occurred during coronary interventions, diagnosed by intravascular ultrasound.

Background and Objectives:An elevated serum homocysteine level is a risk factor of atherosclerosis. The relationship between homocysteine and antioxidant vitamins, and other cardiovascular risk factors, and between cardiovascular patients and controls, were evaluated. Subjects and Methods:The study population consisted of 146 patients, with objectively first diagnosed ischemic heart disease, and 146 healthy sex and age matched controls. The serum levels of homocysteine, folate, vitamin B12 and vitamin B6 were measured. The correlation between the serum levels of homocysteine and those of folate, vitamin B6 and vitamin B12 were also evaluated. Results:The serum homocysteine concentrations were significantly higher in the cardiovascular patients than in the matched controls (13.35±0.51 mmol/l vs. 11.43±0.37 mmol/l, p=0.003). However, there was no significant difference between the stable angina, unstable angina and myocardial infarction subgroups. From a multivariate analysis, the elevated homocysteine level was still associated with a low folate level (patient group;r=-0.380, p=0.000, control group;r=-0.229, p=0.000). The measured vitamin B12 level showed no correlation with the homocysteine level in the cardiovascular patients, but did in the controls (R=0.066, p

Background and Objectives:Adiponectin is an adipocyte derived plasma protein that is known to have an anti-atherogenic effect. Low plasma adiponectin concentrations are found in obesity, diabetes and coronary artery disease. The measurement of the plasma adiponectin level is helpful in the assessment of the risk for coronary artery disease. The intercellular adhesion molecule (ICAM)-1 is associated with the atherosclerotic inflammatory response. An elevated ICAM-1 concentration is associated with increased risk of future coronary events, independent of other risk factors. The relationships between serum adiponectin and ICAM-1 levels and the progression of coronary artery stenosis with instent restenosis of previous stent sites were analyzed. Subjects and Methods:83 patients who had percutaneous transluminal coronary angioplasty and stent insertion were enrolled. The initial angiographic finding was compared with that at the 6 month follow up. The serum adiponectin and ICAM-1 level were measured with the plasma lipid profiles prior to percutaneous coronary intervention. These biochemical parameters were analyzed according to the progression of coronary artery stenosis (≥10%) and instent restenosis (≥50%). Results:In the coronary artery stenosis progression group, there were significantly lower adiponectin (3.91±1.24 μg/mL vs. 4.66±1.36 μg/mL, p=0.03) and higher ICAM-1 levels (199.16±79.13 ng/mL vs. 150.54±63.65 ng/mL, p=0.03). The instent restenosis group also showed lower adiponectin (3.99±1.22 μg/mL vs. 4.33±1.38 μg/mL) and higher ICAM-1 (195.17±68.45 ng/mL vs. 171.47±80.48 ng/mL) levels, but without statistical significance. Conclusion:The serum adiponectin and ICAM-1 levels are related to the progression of coronary artery stenosis. However, further study will be required to confirm the relationships between the serum adiponectin and ICAM-1 levels and instent restenosis. (Korean Circulation J 2004; 34(9):837-844)

Background and Objectives:In dialysis patients, the cardiovascular mortality is 10 to 20 times higher than that in the general population. The increased arterial stiffness in patients with end-stage renal disease (ESRD) is an independent predictor of all-cause mortality. The arterial stiffness and atherosclerotic markers were evaluated in patients with ESRD treated with and without hemodialysis (HD) or peritoneal dialysis (PD). Subjects and Methods:14 hemodialysis (mean dialysis duration 19.6 months), 14 peritoneal dialysis (mean dialysis duration 26.1 months) and 14 patients with ESRD prior to initiation of dialysis, and 27 age-sex matched controls were enrolled. The calculated central pulse pressure, plasma homocysteine, serum C-reactive protein, left ventricular mass index and aortic pulse wave velocity (PWV) were measured. Results:Patients with ESRD treated with and without dialysis had greater increases in their arterial stiffness and advanced atherosclerosis compared with the controls. However, there was no difference in the arterial stiffness and atherosclerotic markers before and after the dialysis treatment, or in the dialysis modality (HD, PD) of patients with ESRD. In a multiple regression model, PWV in patients with ESRD was explained by the level of plasma homocysteine (β=0.396;p=0.027). Conclusion:Atherosclerosis and arterial stiffness in patients with ESRD may not be affected by dialysis treatment or modality. In patients with ESRD, the level of plasma homocysteine is independently associated with arterial stiffness. (Korean Circulation J 2004;34(9):865-873)

Background and Objectives:Congenital long QT syndrome (LQTS) is a genetic disease that brings prolongation of the QT interval on an electrocardiogram and leads to syncope and sudden death by a fatal ventricular arrhythmia. In Korea, there have been studies about the clinical characteristics and treatment of LQTS, but there are no studies for the molecular and biological evaluation of its genetic mutation. Subjects and Methods:Six nationwide university hospitals and laboratories segregated DNA from the blood of 10 patientsdiagnosed with LQTS to analyze the genetic mutation. Results:Nine out of ten individuals were female. Eight showed genetic mutations. Three had an abnormality in the KvLQT1, 6 in the HERG and 2 had abnormalities in both KvLQT1 and HERG. None had abnormalities in KCNE1 and 2 showed no abnormalities in KvLQT1, HERG or KCNE1. Conclusion:Congenital LQTS shows various genetic mutations, and this indicates the necessity for further organized study in more individuals for confirmation of the relationship between the results of clinical diagnosis and genetic analysis. (Korean Circulation J 2004;34(8):813-819)

Background and Objectives:In radiofrequency catheter ablation (RFCA), it is an essential point to understand the characteristics of local electrograms at arrhythmic focus. However controversy exists as whether the unipolar or bipolar electrogram is superior in detecting arrhythmic focus. Subjects and Methods:We evaluated the characteristics of unipolar and bipolar electrograms at ventricular tachycardia (VT) origin. Electroanatomical mapping and RFCA were performed in 6 patients with idiopathic VT. 22 sites were enrolled and 6 of them were successful sites. We analyzed the relationship between surface and local electrograms in accordance with success or failure. We also analyzed the morphology of local electrograms. Results:At successful sites of RFCA, point of unipolar onset (22.86±10.82 msec vs 5.47±26.31 msec, p

Commotio cordis is sudden death due to a non-penetrating chest wall impact in the absence of structural injury to the heart and chest wall. It usually occurs during sports games, like baseball, ice-hockey and soft balls, in young children. When objects (baseball, hockey puck, etc) strike the chest, a fatal arrhythmia like ventricular fibrillation can occur. We report a case of ventricular fibrillation that occurred after a light blunt trauma to the chest wall. (Korean

A single coronary artery is a rare congenital anomaly. The right coronary artery, originating from distal left circumflex, is an extremely rare variety of a single coronary artery. Our report is accompanied by a brief review of the literature.

Numerous central nervous system disorders can produce various electrocardiographic abnormalities due to vagal stimulation. These common abnormalities may include:QT prolongation, a large and inverted T wave and a prominent U wave etc. Sinus bradycardia and atrioventricular block have rarely been reported. We experienced a case of sick sinus syndrome, which was associated with a subarachnoid hemorrhage and subdural hematoma following a head trauma. (Korean Circulation J 2003;33 (12):1151-1154)

Background and Objectives:For the past 10 years, VDD pacemakers have been substituted for DDD pacemakers, due to their ease of implantation and follow up. The degree of AV synchrony and associated factors were evaluated in the patients with VDDR pacemakers. Subjects and Methods:Twenty one patients, 10 males and 11 females, were enrolled. The mean age of the patient was 56 years. In the supine position, the atrial sensing threshold and cardiac cycle data were checked to evaluate the AV synchrony with a programmer. If the AV synchrony was less than 90%, it was considered improper synchronization. Results:The measured P wave amplitudes were 2.33 and 1.22mV at implant and follow up, respectively. From the follow up cardiac cycle data, the percentage of ventricular pacing only (Vp), atrial sensing and ventricular pacing (AsVp) and the total percentage of AV synchronization (PAS) were 21.38, 76.33 and 77.77%, respectively. Inadequate AV synchrony was observed in 11 patients. The causes were the absence of a minimal tracking limit, a faster pacing rate than the patient’s resting rate, atrial fibrillation, sinus node dysfunction, atrial under sensing and functioning of the rate adaptive function in 4, 3 and 1 each, respectively. After rectifying the causes, the cardiac cycle data improved from 32.83 to 5.17% for the Vp, from 62.67 to 91.5% for the AsVp and from 65.52 to 94.38% in the PAS, all with statistical significance. Conclusion:For proper AV synchrony, it is necessary to carefully manipulate, not only the P wave sensitivity, but also several other of the pacemaker parameters. (Korean Circulation J 2003;33 (8):709-714)

Background:Coronary sinus catheterization is important in electrophysiological studies. However the morphologic feature of the coronary sinus and its significance in patients with supraventricular tachycardia (SVT) have not been determined. During diagnostic electrophysiological studies, coronary sinus catheterization was easier in patients with atrioventricular nodal reentry tachycardia (AVNRT) than in patients with atrioventricular reentry tachycardia (AVRT). Therefore, we studied coronary sinus morphology in patients with SVT and compared AVNRT and AVRT patients. Methods:The size and shape of the coronary sinus were measured in 13 patients who underwent retrograde coronary sinus venogram during electrophysiologic study between May and June 1996. The diagnosis was 7 cases of AVNRT, 2 of Wolff-Parkinson-White syndrome and 4 of concealed bypass tracts (mean age, 40 years:male vs female, 1:1.2). Results:The mean coronary sinus ostial diameter was 10.4±2.0 mm;for AVNRT, it was 11.4±2.2 mm, and for AVRT it was 9.3±1.0 mm in left anterior oblique projection (p=0.031). The mean coronary sinus-to-spine angle was 82.6±17.4°:AVNRT 95.4±24.4° and AVRT 67.7±15.2° in anterior posterior projection (p=0.035). Conclusion:The coronary sinus ostial diameter of AVNRT patients was significantly larger than that of AVRT patients. This finding may have important implications for arrythmia pathogenesis in such patients. (Korean Circulation J 1998;28(4):620-625)

Background:Measurement of echocardiographic mitral valve area(MVA) is a useful non-invasive method of estimating the stenotic mitral valve area. This study was undertaken to evaluate the accuracy of echocardiographic MVA measurements by comparing MVAs measured by the planimetric and the pressure half-time method versus direct MVA measurement by using a cone shaped device specifically made for direct measurement of MVA. Methods and Results:The study population consisted of 22 consecutive patients from August 1993 to February 1996. All the patients underwent 2D planimetry and Doppler echocardiographic MVA measurements before and after valve replacement surgery;direct measurement also was performed after surgery. Five patients(22.7%) had normal sinus rhythm, and the rest of the patients had atrial fibrillation. Two-dimensional echocardiographic examinations were attempted in 22 patients, and adequate measurements were obtained in 21 of the patients studied. Mean mitral valve area were 0.99±0.32cm ranged from 0.42 to 1.68cm on 2D planimetry method, 0.93±0.32cm ranged from 0.42 to 1.68cm on Doppler pressure half-time method, 1.17±0.20cm ranged from 0.93 to 1.68cm on direct measurement of mitral valve area after surgery. 2D planimetry method(r=0.621, p=0.003, SE=0.165), pressure half-time method(r=0.454, p=0.003 SE=0.187), and transmitral peak velocity (r=-0.480, p=0.026, SE=0.189) was relatively well correlate with operative mitral valve area. There was relatively good agreement between direct and 2D planimetric measurements and between