Changes in Atrioventricular Node Physiology Following Slow Pathway Modification in Patients with AV Nodal Re-entrant Tachycardia: The Hypothetical Suggestion of Mechanism of Noninducibility of AVNRT

BACKGROUND AND OBJECTIVES: In cases of radiofrequency catheter ablation (RFCA) for patients with atrioventricular nodal re-entrant tachycardia (AVNRT), complete elimination of slow pathway is not always achievable. Furthermore, in situations of the so-called modified slow pathway, the underlying mechanism of tachycardia elimination remains unclear. SUBJECTS AND METHODS: Patients who underwent RFCA for AVNRT, and showed persistence of dual atrioventricular nodal physiology but no induction of AVNRT after ablation were enrolled. We measured electrophysiologic parameters before and after the ablation procedure. RESULTS: The study subjects included 31 patients (39% men; mean age 43±19 years). The RR interval, Wenckebach cycle length of AV node, slow pathway effective refractory period, maximal AH interval of fast pathway and slow pathway showed no significant changes before and after ablation. However, fast pathway effective refractory period (360±67 vs. 304±55, p<0.001) and differences between slow pathway effective refractory period and fast pathway effective refractory period (90±49 vs. 66±35, p=0.009) were decreased after slow pathway ablation. CONCLUSION: We suggest a possible relationship between the mechanism of tachycardia elimination in AVNRT and an alteration of the re-entrant circuit by removal of the atrial tissue in Koch's triangle. This may be a critical component of providing the excitable gap for the maintenance of tachycardia rather than the electrical damage of slow pathway itself.

Type 4 dual left anterior descending coronary artery

No abstract available.

Complete Atrioventricular Block-Induced Torsade de Pointes, Manifested by Epilepsy

Complete atrioventricular (AV) block is frequently regarded as a cause of informed syncopal attacks, even though the escape rhythm is maintained. Torsade de pointes (TdP) may be a significant complication of AV block associated with QT prolongation. Here, we report the case of a 42-year-old female who was referred to our hospital due to recurrent seizure-like attacks while taking anti-convulsant drugs at a psychiatric hospital. TdP with a long QT interval (corrected QT = 0.591 seconds) was observed on an electrocardiogram (ECG) taken in the emergency department. The patient's drug history revealed olanzapine as the suspicious agent. Even after the medication was stopped, however, the QT interval remained within an abnormal range and multiple episodes of TdP and related seizure-like symptoms were found via ECG monitoring. A permanent pacemaker was thus implanted, and the ventricular rate was set at over 80 beats/min. There was no recurrence of tachyarrhythmia or other symptoms.

Effects of Combined Therapy with Ezetimibe Plus Simvastatin After Drug-Eluting Stent Implantation in a Porcine Coronary Restenosis Model

The aim of this study was to examine the anti-proliferative and anti-inflammatory effects of ezetimibe/simvastatin (E/S) after drug-eluting stent (DES) implantation in a porcine coronary restenosis model. Pigs were randomized into two groups in which the coronary arteries (23 pigs) had DES. Stents were deployed with oversizing (stent/artery ratio 1.3:1) in porcine coronary arteries. Fifteen pigs were taken 10/20 mg of E/S and eight pigs were not taken E/S. Histopathologic analysis was assessed at 28 days after stenting. In neointima, most inflammatory cells were lymphohistiocytes. Lymphohistiocyte count was not different between two groups (337+/-227 vs. 443+/-366 cells, P=0.292), but neointima area was significantly smaller (1.00+/-0.49 mm2 vs. 1.69+/-0.98 mm2, P=0.021) and percent area stenosis was significantly lower (23.3+/-10% vs. 39+/-19%, P=0.007) in E/S group compared with control group. There were no significant differences in fibrin score (1.99+/-0.79 vs. 1.81+/-0.88, P=0.49), endothelial score (1.75+/-0.66 vs. 1.80+/-0.59, P=0.79), and the percent of endothelium covered lumen (43+/-21% vs. 45+/-21%, P=0.84) between E/S group and control group. Combined therapy with ezetimibe and simvastatin inhibits neointimal hyperplasia, but does not inhibit inflammatory infiltration and arterial healing after DES implantation in a porcine coronary restenosis model.

The Significance of Repetitive Ventricular Responses Induced by Radiofrequency Energy Application for Idiopathic Left Ventricular Tachycardia

In radiofrequency (RF) ablation for idiopathic left ventricular tachycardia (ILVT), the termination of tachycardia during RF ablation is considered a hallmark of success. However, in cases of patients with difficulty of induction of ventricular tachycardia (VT), the evaluation of procedural success can be problematic. We have observed thermal responses reflected as ventricular rhythm change to RF energy delivered on sinus rhythm for ILVT. We therefore describe the significance of repetitive ventricular responses. The study subjects were 11 ILVT patients for whom RF energy was delivered during sinus rhythm because of difficulty in re-induction of tachycardia. During each energy delivery, we focused on the occurrence of repetitive ventricular responses especially exhibiting a similar morphology to clinical VT. The repetitive ventricular responses were noted in 10 of 11 patients. Two patients received a second procedure due to the recurrence of ILVT. The mean follow-up period was 36.2+/-12.8 months. The clinical course of the remaining patients was favorable and without recurrence of ILVT. Based on the favorable clinical outcomes, ablation-induced repetitive ventricular responses with similar QRS morphology to clinical ILVT are useful markers for selecting an ablation site and could be used as an additional mapping method, termed as "thermal mapping".

Successful Radiofrequency Catheter Ablation for Wolff-Parkinson-White Syndrome Within the Neck of a Coronary Sinus Diverticulum

Posteroseptal accessory pathways are often associated with coronary sinus diverticula. These diverticula contain myocardial coats which serve as a bypass tract. We report a 54-year-old woman who underwent radiofrequency (RF) catheter ablation for Wolff-Parkinson-White (WPW) syndrome. The surface electrocardiography (ECG) demonstrated pre-excitation, indicating a posteroseptal accessory pathway. A catheter ablation via a transaortic approach failed to ablate the accessory pathway. Coronary sinus venography revealed the presence of a diverticulum near the ostium. An electrogram in the neck of the diverticulum showed the coronary sinus myocardial extension potential, which was successfully ablated by delivery of RF energy.

Effect of Cardiac Nerve Growth Factor in Acute Myocardial Infarction in Human

BACKGROUND AND OBJECTIVES: It has been demonstrated that the concentration of plasma nerve growth factor (NGF) effects nerve sprouting. In addition, the relationship between plasma NGF concentration and the occurrence of ventricular tachyarrhythmia (VT) has been reported in animal models of myocardial infarction (MI). However, the causal relationship between NGF and VT remains unclear in humans. The aim of the current study was to determine whether NGF is increased in patients with MI. In addition, the relationship between the concentration of plasma NGF and the inducibility of VT was evaluated. SUBJECTS AND METHODS: We studied 15 patients with stable angina pectoris (SA) and 30 patients with an acute MI (AMI). The patients in the AMI group were divided into VT occurrence (n=14) and non-VT occurrence groups (n=16). Thirty-four patients suspected to have VT underwent programmed electrical stimulation (PES) and were divided into an idiopathic VT group (n=24) and an induced VT with PES {healthy control (C) group; n=10}. Plasma NGF concentrations were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The plasma concentrations of the AMI group were significantly increased compared to the C group {median (interquartile range), 18.9 (8.7) vs. 10.3 (12.5) pg/mL, p<0.05} and the patients with SA {18.9 (8.7) vs. 15.1 (6.7) pg/mL, p<0.05}, but not significantly different from those in the idiopathic VT group {median (interquartile range), 18.9 (8.7) vs. 18.7 (8.5) pg/mL, p=0.89}. There was no significant difference in the plasma NGF concentrations between the C and SA groups {10.3 (12.5) vs. 15.1 (6.7) pg/mL, p=0.18}. In the AMI patients, there was no significant difference in the plasma NGF concentrations between patients with VT and those without VT {18.5 (6.7) vs. 21.2 (10.2) pg/mL, p=0.25}. CONCLUSION: The plasma NGF concentrations were increased in patients with an AMI compared to patients with SA and Cs.

Complete Fracture of Sirolimus-Eluting Stent in a Saphenous Vein Graft to Left Anterior Descending Artery

Coronary stent fractures have been suggested as a potential new mechanism of restenosis. The mechanical properties of stents were designed not only to prevent vessel recoil, but also to resist the mechanical stress of vessel movement over millions of cardiac cycles. We present a case in which mechanical stress may have contributed to the fracture of a stent implanted in a saphenous vein graft (SVG) to the left coronary artery. The patient was admitted due to chest pain 2 years after receiving a coronary artery bypass graft. A coronary angiography revealed the culprit vessel to be the SVG to the left coronary artery. The graft was stenosed and was stented with a sirolimus-eluting stent. A 6-month follow-up coronary angiography revealed 80% in-stent restenosis with stent fracture. We re-intervened by balloon angioplasty. This is the first report of sirolimus-eluting stent fracture combined with restenosis of SVG in Korea.

A case of congenital bilateral coronary-to-right ventricle fistula coexisting with variant angina

A coronary arteriovenous (AV) fistula consists of a communication between a coronary artery and a cardiac chamber, a great artery or the vena cava. It is the most common anomaly that can affect coronary perfusion. Yet bilateral involvement of a coronary fistula, constitutes an uncommon subgroup of coronary AV fistulas. We herein report on a case of bilateral coronary AV fistula that was coexistent with variant angina originating from the distal right ventricular branch of the right coronary artery and the distal septal branch of the left anterior descending artery, and the latter drained into the right ventricle.

Hemorrhagic pericarditis with cardiac tamponade after percutaneous coronary intervention associated with the use of abciximab

Glycoprotein (GP) IIb/IIIa inhibitors, such as abciximab, are used as adjunctive therapy for percutaneous coronary intervention (PCI) in high-risk non-ST-elevation myocardial infarction (NSTEMI) and in ST-elevation myocardial infarction (STEMI), although their effects when used for STEMI are less clear. As the use of GP IIb/IIIa inhibitors becomes more widespread, determining the risks associated with them becomes more important. The major risks associated with the use of GP IIb/IIIa inhibitors are the potential for major bleeding and thrombocytopenia. This is the first reported case in Korea of hemorrhagic pericarditis resulting in cardiac tamponade associated with the use of abciximab, a commonly used GP Ilb/IIa inhibitor, following PCI.

A Case of ST-Segment Elevation Myocardial Infarction Mimicking Stress-Induced Cardiomyopathy

ST-segment elevation myocardial infarction (STEMI) is a disease decribed by typical chest pain, ST-segment elevation on eletrocardiogram, elevated cardiac enzymes, along with wall motion abnormality under echocardiographic findings, and it is caused by vulnerable plaques. However, stress induced cardiomyopathy (SICM) may show similar clinical symptoms, but specific echocardiographic findings (i.e. transient left ventricular regional wall motion abnormalities with peculiar apical ballooning appearance) and normal coronary angiography may differentiate it from STEMI. Therefore, one may mistake STEMI for SICM, and lead to serious error in diagnosis and treatment of the disease. We report a case of STEMI mimicking SICM, and suggest an idea to approach the patient with SICM.

The Relationship of the LV Systolic Function, the LV Dimension and the LV Mass to QT Dispersion in Stable Angina Patients who are with or without Significant Coronary Stenosis / 대한흉부외과학회지

BACKGROUND: The aim of this study was to investigate the relationship of the left ventricular (LV) systolic function, the LV dimension and the LV mass with the QT dispersion in patients with stable angina, and we also wanted to compare this relationship between patients with and without significant coronary stenosis on coronary angiography. MATERIAL AND METHOD: 174 patients complained of typical angina and they had no associated ST segment or cardiac enzyme abnormalities. The patients were divided into 2 groups based on the results of coronary angiography: the patients with angiographic coronary stenosis > or =50% made up group I (n=101), and the patients with angiographic coronary stenosis <50% made up group II (n=73). An echocardiogram for assessing the LV ejection fraction (EF), the LV dimension and the LV mass and a 12-lead electrocardiogram for assessing the QT dispersion were performed before the coronary angiography. RESULT: The QT dispersion was significantly greater in group I than that in group II (39.8 ms vs. 33.3 ms; p<0.05). For all the patients, all the parameters of LV dimension and LV mass had statistically positive correlation to the QT dispersion, but the LV mass was the only independently significant parameter that was correlated with the increased QT dispersion (p<0.05). For group I, none of the echocardiographic parameters had significant correlation with the QT dispersion. However, the LV dimension and LV mass had significantly positive correlation with the QT dispersion, and the LV mass was also the only independently significant parameter that was correlated with increased QT dispersion in group II (p<0.05). CONCLUSION: Our study demonstrated a significantly positive correlation of the QT dispersion to the LV dimension and the LV mass in patients with stable angina. These findings are present only in patients without significant coronary stenosis.

A Case of Bilateral Coronary to Pulmonary Artery Fistulas Associated With Severe Aortic Regurgitation

Coronary artery fistula (CAF) is a rare form of congenital anomalies of the coronary arteries, and this is usually discovered by chance during coronary angiography. However, this type of fistula can cause important coronary morbidity and mortality leading to angina, syncope, congestive heart failure, myocardial infarction and sudden death. Bilateral CAFs are even rarer, and especially when combined with valvular heart disease. The coincidence of CAF with aortic regurgitation is relatively rare and this might sometimes cause myocardial ischemia. We present here a case of bilateral coronary-pulmonary artery fistulas that arose from the first diagonal branch of the left anterior descending artery and the conal branch of the right coronary artery combined with severe aortic regurgitation, and this all caused myocardial ischemia.

Noninvasive Pacemaker Stress Echocardiography as a Screening Test for Coronary Artery Disease in Patients With Atypical Angina and Permanent Pacemaker

BACKGROUND AND OBJECTIVES: Making the noninvasive diagnosis of coronary artery disease in patients with a permanent pacemaker is difficult because of the inability to interpret electrocardiograms and the low specificity of perfusion scintigraphy. We evaluated the diagnostic accuracy of noninvasive pacemaker stress echocardiography (PASE) as a screening test for coronary artery disease in patients with atypical angina and a permanent pacemaker. SUBJECTS AND METHODS: This a prospective study, and transthoracic stress-pacing echocardiography was performed on 15 patients (9 men and 6 women; age, mean age: 71.1+/-11.0 years) with atypical angina and a permanent pacemaker. All the patients underwent noninvasive pacemaker-stress echocardiography by external programming (pacing the heart rate up to 150 beats per minute). Coronary angiography was performed on the 8 patients with positive PASE results. Significant coronary artery disease was defined as > or =70% stenosis in at least one major coronary artery. RESULTS: The echocardiographic images were interpretable for all the patients. No significant side effects were observed. The left ventricular systolic function was preserved in all the patients (left ventricular ejection fraction; 63.5+/-8%). Only 5 (62.5%) of 8 patients showed significant coronary artery disease, as documented by coronary angiography. CONCLUSION: Noninvasive PASE is a simple, rapid, safe and diagnostically efficient test for detecting coronary artery disease in patients with atypical angina and a permanent pacemaker. Larger studies are necessary to validate our findings.

Chest Pain due to Coronary Artery Vasospasm after Aortic Valve Replacement Surgery: A case report / 대한흉부외과학회지

Coronary artery vasospasm results in transient, abrupt chest pain that's due to the increased vasomotor tone of the coronary artery, and this can cause myocardial ischemia. We report here on one case of the right coronary artery vasospasm after aortic valve replacement surgery, and this was due to severe aortic regurgitation.

Clinical features and prognostic factors in Korean patients hospitalized for coronary artery disease (Catholic Heart Care Network Study) / 대한내과학회지

BACKGROUND: Coronary artery disease (CAD) has recently become one of the major causes of mortality and morbidity in Korea. However, not much epidemiologic and demographic data has yet been reported. The purpose of this study was to investigate the clinical features as well as the prognostic factors of patients with CAD. METHODS: We prospectively enrolled 1,665 consecutive patients with CAD who had been admitted to the Catholic University Hospitals from December 1999 to April 2003. RESULTS: Acute myocardial infarction (AMI) was the most common cause of admission (n=715, 42.9%). Dyslipidemia, hypertension and smoking were the most common risk factors. More than 70% of the patients who underwent percutaneous coronary intervention (PCI) received stent implantation. A total of 965 (612 males) patients were followed at least for 6 months (the mean follow-up duration was 23.8+/-12.2 months). The incidence rates of major adverse cardiac events (MACE: cardiac death, acute myocardial infarction, target vessel revascularization) and cardiac death were 15.1% (n=146) and 2.2% (n=21), respectively. There was no difference in overall survival between the patients treated with medical therapy and those treated with PCI. By Cox regression analysis, the independent prognostic factors for MACE were PCI (95% CI: 1.75-4.85; p<0.01) and multivessel disease (95% CI: 1.03-2.04; p<0.05), and the independent prognostic factors for cardiac death were medical therapy (95% CI: 1.08-14.41; p<0.05) and old age (95% CI: 1.13-16.13; p<0.05). CONCLUSIONS: There was no difference in overall survival between the patients treated with medical therapy and those treated with PCI. However, PCI was superior to medical therapy for preventing death of the patients with acute coronary syndrome.

The Association Between Current Helicobacter pylori Infection and Coronary Artery Disease

BACKGROUND: The role of Helicobacter pylori (H. pylori) in the pathogenesis of coronary artery disease (CAD) is still controversial, and the relation between current H. pylori infection and CAD has not been fully examined. This study evaluated the relation between H. pylori infection as confirmed by gastroduodenoscopic biopsy and CAD. METHODS: We determined the presence of H. pylori infections, via gastroduodenoscopy, in 88 patients of the normal coronary angiographic group and also in 175 patients of the CAD group, and the latter patients had more than 50% coronary stenosis angiographically demonstrated. We excluded those patients with a history of previous H. pylori eradication and/or malignancy. A small piece of tissue from the antrum, which was obtained by gastroduodenoscopic biopsy, was stained by Warthin-starry silver stain. We defined a negative staining result that there was no stained tissue in the sample and the stained tissue was also positive for H. pylori infection. RESULTS: There was no significant difference, except for gender, age, smoking and high density lipoprotein cholesterol (HDL-c), of the demographic and laboratory characteristics between the groups. Twenty seven (30.7%) patients of the normal control group and 71 (40.6%) patients of the CAD group were positive of H. pylori infection, yet there was no statistical difference. We angiographically followed up the 80 patients of the CAD group who were treated by percutaneous coronary intervention (PCI) at 6 to 9 months after their primary intervention. Twenty two (37.9%) of the 58 patients of the H. pylori negative group and 10 (45.5%) of the 22 patients of the H. pylori positive group were treated with reintervention, but reintervention was also not significantly different between the group with H. pylori infection and the group without the infection. CONCLUSIONS: These data indicated that H. pylori infection had a modest influence on CAD and progressive atheroma, but the showed a tendency to increase. Further studies are needed to evaluate the relationship between H. pylori infection and CAD.

A Case of Stress-Induced Cardiomyopathy Related with the Postpartum Period

Stress-induced cardiomyopathy is a relatively rare, unique entity that has only recently been widely appreciated. It characterized by transient left ventricular regional wall motion abnormalities (with a peculiar apical ballooning appearance), chest pain or dyspnea, ST-segment elevation and/or T wave inversion and minor elevations of the cardiac enzyme levels. The patients in the previous series were usually women over 50 years of age and a triggering event was identified in most cases; these included severe emotional distress or an acute medical illness. Although reports of single episodes of stress-induced cardiomyopathy are not infrequent in the recent medical literature, we report here on a case of stress-induced cardiomyopathy in a young women, and this was related with the post-partum period as a stressful condition.

Inhibition of Neointima Formation by Anti-Vascular Endothelial Growth Factor and Receptor-1 Peptides in a Balloon-Injured Rat Carotid Artery

BACKGROUND AND OBJECTIVES: Vascular endothelial growth factor (VEGF) is a potent endothelial cell-specific mitogen. This study was undertaken to test the hypothesis that the neointima hyperplasia induced by a balloon injury is inhibited by blocking VEGF and VEGF receptor-1 (VEGFR-1) with anti-VEGF peptides. Materials and Methods: Anti-VEGF RRKRRR peptide (dRK6) and anti-VEGFR-1 peptide (anti-flt-1) were synthesized at Pohang University of Science and Technology, Korea. Male Sprague-Dawley rats, weighing 300-350 g, were subcutaneously injected 0.5 mg/kg of dRK6 or 0.5 mg/kg of anti-flt-1, dissolved in phosphate buffer solution, 2 days before induction of a carotid balloon-injury, and then daily in the same manner post carotid balloon injury for 2 weeks. RESULTS: Neointima formation was suppressed in both the dRK6 and anti-flt-1 groups compared to that in the untreated controls at 2 weeks post carotid balloon-injury (neointimal area; control group 0.44+/-0.09 mm2, dRK6 group 0.25+/-0.05 mm2, anti-flt-1 group 0.19+/-0.05 mm2, p<0.01). Anti-flt-1 peptide and dRK6 reduced the numbers of proliferative bromodeoxyuridine-labeled cells in the neointima (control group 16.4+/-10.6%, dRK6 group 3.7+/-2.1%, anti-flt-1 group 5.9+/-3.4%, p<0.05). In addition, an inflammatory response, as determined by monocyte chemoattractant protein-1 and interleukin-6 upregulation, which was evident in the controls, was inhibited by both dRK6 and anti-flt-1. CONCLUSION: This study suggests anti-vascular endothelial growth factor peptides can reduce the inflammation and neointima formation in balloon injured rat carotid arteries.

Brain Tumor is a Rare Cause of both Bradycardia and Seizure

The association between brain tumors and cardiac asystole has rarely been reported in the medical literature. This potentially life-threatening symptom has usually been observed to arise from left temporal lobe brain tumors. Yet previously published papers have shown that cardiac asystole and bradycardia, as manifestations of epilepsy, originate from the frontal lobe of the brain. Although syncope is a common presenting symptom of a brain tumor, bradycardia and complete atrioventricular (AV) block, as the first signs of a brain tumor, have been only sporadically documented in the literature. We report here on a patient with recurrent complete AV blocks that were followed by syncope as an expression of seizures that may have arose from a brain tumor; this tumor was most likely a meningioma in the right frontal lobe. The patient required the subsequent placement of a permanent pacemaker. In conclusion, cardiac asystole may be a potentially life-threatening symptom of frontal lobe lesion of the brain. The frontal lobe may play a role in the autonomic regulation of cardiovascular responses.