Predictors of Severe or Moderate Coronary Artery Disease in Asymptomatic Individuals with Extremely Low Coronary Calcium Scores

PURPOSE: To evaluate predictors of severe or moderate coronary artery disease (CAD) in individuals with zero or very low (<10) coronary artery calcium (CAC) scores. MATERIALS AND METHODS: The 1175 asymptomatic persons with zero or very low (<10) CAC scores were analyzed for CAD stenosis using coronary computed tomography angiography. Moderate and severe CADs were defined as having more than 50% and more than 70% stenosis in any of the major coronary arteries, respectively. Age, gender, body mass index, hypertension, type II diabetes, dyslipidemia, lipid profile, creatinine, and smoking status were evaluated as predictors for moderate and severe CAD. RESULTS: In the study population, moderate and severe CADs were found in 7.5% and 3.3%, respectively. Among evaluated risk factors, age [odds ratio (OR) 1.04, 95% confidence interval (CI) 1.02−1.07, p<0.001], current smoking status (OR 3.12, 95% CI 1.82−5.34, p<0.001), and CAC 1−9 (OR 1.80, 95% CI 1.08−3.00, p=0.024) were significantly associated with moderate CAD. Meanwhile, age (OR 1.05, 95% CI 1.02−1.08, p=0.003), low high density lipoprotein (HDL) (OR 0.96, 95% CI 0.93−0.99, p=0.003), and current smoking status (OR 2.34, 95% CI 1.14−5.30, p=0.022) were found to be significantly associated with severe CAD. Improvement of discrimination power for predicting severe CAD was observed when smoking and HDL cholesterol were serially added into the age model. CONCLUSION: Smoking showed significant correlations with moderate or severe CAD, and low HDL cholesterol also proved to be a predictor of severe CAD in asymptomatic individuals with extremely low CAC scores.

Cardiovascular Events of Electrical Cardioversion Under Optimal Anticoagulation in Atrial Fibrillation: The Multicenter Analysis

PURPOSE: Electric cardioversion has been successfully used in terminating symptomatic atrial fibrillation (AF). Nevertheless, largescale study about the acute cardiovascular events following electrical cardioversion of AF is lacking. This study was performed to evaluate the incidence, risk factors, and clinical consequences of acute cardiovascular events following electrical cardioversion of AF. MATERIALS AND METHODS: The study enrolled 1100 AF patients (mean age 60+/-11 years) who received cardioversion at four tertiary hospitals. Hospitalizations for stroke/transient ischemic attack, major bleedings, and arrhythmic events during 30 days post electric cardioversion were assessed. RESULTS: The mean duration of anticoagulation before cardioversion was 95.8+/-51.6 days. The mean International Normalized Ratio at the time of cardioversion was 2.4+/-0.9. The antiarrhythmic drugs at the time of cardioversion were class I (45%), amiodarone (40%), beta-blocker (53%), calcium-channel blocker (21%), and other medication (11%). The success rate of terminating AF via cardioversion was 87% (n=947). Following cardioversion, 5 strokes and 5 major bleedings occurred. The history of stroke/transient ischemic attack (OR 6.23, 95% CI 1.69-22.90) and heart failure (OR 6.40, 95% CI 1.77-23.14) were among predictors of thromboembolic or bleeding events. Eight patients were hospitalized for bradyarrhythmia. These patients were more likely to have had a lower heart rate prior to the procedure (p=0.045). Consequently, 3 of these patients were implanted with a permanent pacemaker. CONCLUSION: Cardioversion appears as a safe procedure with a reasonably acceptable cardiovascular event rate. However, to prevent the cardiovascular events, several risk factors should be considered before cardioversion.

Mid-Septal Hypertrophy and Apical Ballooning; Potential Mechanism of Ventricular Tachycardia Storm in Patients with Hypertrophic Cardiomyopathy

Medically refractory ventricular tachycardia (VT) storm can be controlled with radiofrequency catheter ablation (RFCA), however, it may be difficult to control in some patients with hemodynamic overload. We experienced a patient with intractable VT storm controlled by hemodynamic unloading. The patient had mid-septal hypertrophic cardiomyopathy with an implantable cardioverter defibrillator (ICD) back-up. Because of the severe mid-septal hypertrophy, his left ventricle (LV) had an hourglass-like morphology and showed apical ballooning; the focus of VT was at the border of apical ballooning. Although we performed VT ablation because of electrical storm with multiple ICD shocks, VT recurred 1 hour after procedure. As the post-RFCA monomorphic VT was refractory to anti-tachycardia pacing or ICD shock, we reduced the hemodynamic overload of LV with beta-blockade, hydration, and sedation. VT spontaneously stopped 1.5 hours later and the patient has remained free of VT for 24 months with beta-blockade alone. In patients with VT storm refractory to antiarrhythmic drugs or RFCA, the mechanism of mechano-electrical feedback should be considered and hemodynamic unloading may be an essential component of treatment.

A Case of Severe Pulmonary Thromboembolism in a Young Male With Klinefelter Syndrome

A young male patient diagnosed with Klinefelter syndrome was admitted to our hospital via the emergency room with chief complaints of acute chest pain and dyspnea. Pulmonary thromboembolism was diagnosed from his chest CT images. His symptoms improved after he underwent thrombolysis and anticoagulation treatment. Klinefelter syndrome has a tendency towards hypercoagulability due to hormonal imbalance and one or more inherited thromophilic factors. Thus, Klinefelter syndrome patients with a past medical history of venous thromboembolism require continuous oral anticoagulation therapy for a period of at least six months.

Long-Term Outcome of Single-Chamber Atrial Pacing Compared with Dual-Chamber Pacing in Patients with Sinus-Node Dysfunction and Intact Atrioventricular Node Conduction

PURPOSE: The optimal pacing mode with either single chamber atrial pacemaker (AAI or AAIR) or dual chamber pacemaker (DDD or DDDR) is still not clear in sinus-node dysfunction (SND) and intact atrioventricular (AV) conduction. MATERIALS AND METHODS: Patients who were implanted with permanent pacemaker using AAI(R) (n = 73) or DDD(R) (n = 113) were compared. RESULTS: The baseline characteristics were comparable between the two groups, with a mean follow-up duration of 69 months. The incidence of death did not show statistical difference. However, the incidence of hospitalization for congestive heart failure (CHF) was significantly lower in the AAI(R) group (0%) than the DDD(R) group (8.8%, p = 0.03). Also, atrial fibrillation (AF) was found in 2.8% in the AAI(R) group, which was statistically different from 15.2% of patients in the DDD(R) group (p = 0.01). Four patients (5.5%) with AAI(R) developed AV block, and subsequently switched to DDD(R) pacing. The risk of AF was lower in the patients implanted with AAI(R) than those with DDD(R) [hazard ratio (HR), 0.84; 95% confidence interval, 0.72 to 0.97, p = 0.02]. CONCLUSION: In patients with SND and intact AV conduction, AAI(R) pacing can achieve a better clinical outcome in terms of occurrence of CHF and AF than DDD(R) pacing. These findings support AAI(R) pacing as the preferred pacing mode in patients with SND and intact AV conduction.

Prevalence, Predictive Factor, and Clinical Significance of White-Coat Hypertension and Masked Hypertension in Korean Hypertensive patients

BACKGROUND: The prevalence and clinical significance of white-coat hypertension (WCHT) and masked hypertension (MHT) are unknown in Koreans. Here we measure the frequency of WCHT and MHT in hypertensive subjects and identify the epidemiologic and/or clinical factors that predict it in Korean subjects. METHDOS: This study is a retrospective analysis of a random sample from February 2004 to October 2005. All patients had measurements of blood pressure (BP) in the clinic and 24-hour ambulatory blood pressure monitoring (ABPM). Subjects were classified into four groups on the basis of daytime ambulatory BP and clinic BP level: 1) Normotension (NT), 2) MHT, 3) WCHT, and 4) sustained hypertension (SHT). RESULTS: For all 967 patients, the mean clinic BP was 157.7+/-22.0/ 95.3+/-13.1 mmHg, and the mean daytime ambulatory BP was 136.4+/-15.0/ 86.2+/-10.7 mmHg. The NT, MHT, WCHT, and SHT groups consisted of 51 (5.3%), 55 (5.7%), 273 (28.2%), and 588 (60.8%) subjects, respectively. The left ventricular mass index was significantly higher in SHT than in the other groups, and was positively correlated with BP, especially ABPM. Compared with NT, the factors associated with MHT were younger age, male gender, higher BMI, clinic BP > or =130 mmHg, and alcohol consumption. Compared with SHT, the factors associated with WCHT were female gender, lower BMI, and clinic BP < 150 mmHg. CONCLUSIONS: WCHT and MHT were prevalent in the hypertensive population. ABPM was more predictive of target organ damage than clinic BP, and could be useful in identifying subjects at risk for WCHT and MHT.

Clinical observation of cardiac myxoma / 대한내과학회지

BACKGROUND: Cardiac myxoma is uncommon, even though accounts for 50% of primary cardiac tumor, histologically benign disease but may be lethal because of its strategic position. It has diverse clinical manifestations mimicking various diseases, which can be described under the three headings: constitutional, obstructive and embolic and the diagnosis can be easily missed unless clinician has high index of suspicion. A correct diagnosis is made before operation with the development of echocardiography. We reviewed our clinical experience in diagnosis and management of 21 cases of myxomas from 1985 to 2000. METHODS: There were 4 males (19%) and 17 females (81%). Their ages ranged from 17 to 66 years (mean 42.2 years). All the patient's medical records on their clinical features, laboratory findings, chest X-rays, electrocardiograms, echocardiographic findings, operative findings and postoperative follow-up were reviewed. RESULTS: Seventeen cases (81%) of the myxomas originated in left atrium and four (19%) in right atrium. Most common symptom was that of intracardiac obstruction such as dyspnea or dyspnea on exertion (62%). Fatigue which accounted for most of the constitutional symptom found in 38% of the 21 patients while embolism accounted for 38%. In all patients, echocardiography was used for diagnosis and the diagnostic accuracy of echocardiography was 100%. All patients received surgical treatment and immediate postoperative complications occurred in seven patients (33%). Among them, serious complications were found in two cases and one expired due to congestive heart failure. Follow-up duration ranged from 2 months to 15 years. There was no recurrence or other problem in all patients during the follow-up period. CONCLUSION: Although clinical suspicion is difficult due to the nonspecific presentation of myxoma, the diagnosis can be made easily with echocardiographic examination in all cases and surgical excision of myxoma may be curative with good long-term result.

Changes of Aortic Morphology after Aortic Dissection Evaluated by CT Angiography

BACKGROUND AND OBJECTIVES: In aortic dissection (AD), CT angiography (CTA) is useful both in initial diagnosis and long term follow-up. In this study, we used CTA to evaluate the morphologic changes of aorta after AD. SUBJECTS AND METHODS: We reviewed the initial and follow-up CTA images of 43 patients with AD. The diagnoses were double-lumen dissection (n=13), intramural hematoma (n=11), and residual dissection after surgery (n=19). The duration of CTA follow-up was 3.3+/-1.9 years (range 7 - 89 months). After reviewing the CTA images of the thoracic aorta level, and of the upper and lower abdominal aorta levels, we compared the areas of total lumen, true lumen and false lumen and the area ratio of true/total lumen. RESULTS: Changes in luminal areas were greatest in the thoracic aorta, where both the true lumen area and the ratio of true/total lumen area increased. Subgroup analysis revealed that although the total lumen area increased significantly in the classic AD group, no changes were noted in the ratio of true/total lumen area. Only the increase in false lumen area (from 5.8 cm 2 to 9.0 cm 2) was significant (p=0.036). In patients with intramural hematoma, a decrease in total lumen area and an increase in the ratio of true/total lumen area were noted. CONCLUSION: In classic AD, false lumen dilatation occurs with false lumen enlargement, whereas in intramural hematoma total aorta size decreases with any increase in the ratio of true/total lumen area.

Vitamin C Improves The Age-Related Impairment of Endothelium-Dependent Vasodilation in Elderly

BACKGROUND: Aging is associated with increased cardiovascular risk and firmly established as a risk factor for the development of atherosclerosis. However the exact mechanism of age-related damage to the arterial wall and its relation to the atherosclerotic process are not well known.The endothelium plays an important role for the regulation of vascular tone and the endothelial function is impaired in the presence of risk factors early in the process of atherosclerosis. Assessment of endothelial function appears to be a valuable tool for the diagnosing and therapeutic monitoring of coronary artery disease. Anti-oxidants are known to improve endothelial dysfunction in atherosclerosis patients. The aim of this study was, (1) to evaluate the endothelial function in elderly, (2) to investigate whether vitamin C administration has benefit on the endothelial function in elderly. METHODS: The endothelial function was estimated using venous occlusion plethysmography(VOP) in 7 elderly and 7 young healthy volunteers. The strain guage was connected to plethysmograph to record the forearm volume change. A rapid cuff inflator was used to inflate the arm cuff to 40 mmHg instantaneuosly thus occluding venous return from the forearm. The measurement of forearm volume change was repeated for 7 times each stage. The change of the forearm blood flow(FBF) was measured with the acetylcholine infusion through brachial artery and also with intra-arterial vitamin C. RESULTS: Endothelium-dependent vasodilatation was significantly impaired in the elderly group compared to the young group(321 +/-17% in elderly group vs 509 +/-81%, mean+/-SEM) Forearm blood flow response to acetylcholine was significantly enhanced with inraarterial infusion of vitamin C in elderly group(321+/-17% in elderly group vs 78% in vitamin C) Coinfusion of L-NMMA, an inhibitor of nitric oxide synthase, blunted forearm blood flow response to acetylcholine. CONCLUSIONS: Even though the mechanisms leading to drpressed endothelial function in elderly remains to be elucidated, our study shows that vitamin C result in demonstrable improvement by a mechanism that is probably related to antioxidant activity.

The Incidence of Coronary Artery Stenosis in Patients with Valvular Heart Disease

BACKGROUND AND OBJECTIVES: his study was performed in order to assess the incidence of coronary artery stenosis in patients with valvular heart disease (VHD) in Korea and its correlation with coronary risk factors and to investigate the need for coronary angiography in this subgroup of patients with VHD before surgery. SUBJECTS AND METHODS: atients with rheumatic mitral VHD (n=375) and isolated aortic VHD (n=187) who underwent cardiac catheterization and coronary angiography at Seoul National University Hospital between January, 1991 and December, 2000 were enrolled in the study. Significant coronary artery stenosis on angiography was defined as stenosis of more than 50% of the luminal diameter. In each patient the presence of the following coronary risk factors were recorded:moking, diabetes mellitus, hypertension and total cholesterol concentration. RESULTS: n patients with rheumatic mitral VHD, the incidence of significant coronary artery stenosis was 5.6% and was correlated significantly with age, hypertension and smoking. Significant coronary artery stenosis was not found in patients below 50 years of age. In patients with isolated aortic VHD, the incidence of significant coronary artery stenosis was 9.1% and was correlated significantly with age. Significant coronary artery stenosis was not found in patients below 45 years of age. CONCLUSION: he incidence of coronary artery stenosis in VHD was very low and showed a general distribution in older ages in Korea. These results suggest that coronary angiography, a routine evaluation before valve surgery in younger patients who have neither risk factors nor angina pectoris, should be performed selectively in patients older than 45 years with consideration of the cost and risk of the procedure.