Clinical characteristics and prognosis of Korean patients with ventricular tachycardia / 대한내과학회지

BACKGROUND: Although the determination of etiology is crucial for the management of ventricular tachycardia (VT), there have been few studies on the epidemiology and clinical characteristics of patients with ventricular tachycardia in Korea. Previous studies on Western populations have shown that ischemic VT is the most common type arrhythmia; however, the incidence of ischemic heart disease in Korea is lower than in Western culture. The purpose of this study was to determine the clinical characteristics and prognosis of Korean patients with VT. METHODS: From January 1999 to December 2002 patients who were diagnosed with VT by ECG or confirmed by electrophysiological studies were enrolled. Hospital records were reviewed for the clinical characteristics which included: demographic features, underlying disease, clinical presentation, ECG features and prognosis in 136 patients who visited our emergency room or out patient clinic. RESULTS: There were 100 men and 36 women (mean age 51.517.6). The most common presenting symptom was palpitation (56.6%), which was followed by chest pain and syncope. The most common type of VT was idiopathic VT (54.4%); ischemic VT was found in 29 cases (21.3%) and dilated or hypertrophic cardiomyopathy in 16 cases (11.8%). For all types of VT, the idiopathic VT showed the best prognosis and cardiac function (p<0.05). RFCA (Radiofrequency catheter ablation) was the best treatment option for treatment of idiopathic VT (p<0.05). CONCLUSIONS: These findings suggest that idiopathic VT may be the most common type of VT in Korean patients; it usually originates form either the right ventricular outflow tract (RVOT) or the LV. The response to treatment and prognosis was poor in VT patients who had underlying heart disease; however, the prognosis was excellent for those with idiopathic VT.

Follow-up of a Group of Patients with Automatic Implantable Defibrillator

BACKGROUND AND OBJECTIVES: Several randomized studies have shown that the implantable cardioverter-defibrillator (ICD) is a very effective treatment modality for the primary and secondary preventions of sudden cardiac death. The purpose of this study was to analyze our initial experience of ICD implantation in patients who had experienced syncope or sudden cardiac death between 1997 and 2004. SUBJECTS AND METHODS: Between Aug. 1997 and Feb. 2004, 28 patients who had undergone an ICD implantation at the Yonsei Cardiovascular Center were retrospectively analyzed. RESULTS: There were 28 patients (24 men, 4 female), with a mean age of 48+/-13.1 (21-74) years. ICD implantation was performed in 2 and 26 patients for the primary and secondary preventions of sudden cardiac death. Eight patients (28.6%) had neither a structural heart disease nor an electrical disease, but 8 (28.6%) had Brugada Syndrome. Twelve patients (42.8%) presented with structural heart disease. The most frequent documented clinical arrhythmia was ventricular fibrillation, which occurred in 11 patients (39.3%). During the mean follow-up of 29.3 months, the were 60 events of tachyarrhythmia triggered shock; 25 of these were from inappropriate shock due to atrial fibrillation (1 6), sinus tachycardia (6) and farfield T wave sensing (3). Two patients died: one of stomach cancer and the other died suddenly without DC shock. An autopsy revealed a moderate amount of bloody pericardial effusion, but unknown hemodynamic significance. CONCLUSION: The implant of an ICD is an effective measure for the secondary prevention of sudden cardiac death. Dual-chamber ICD is desirable for the prevention of inappropriate ICD shock for supraventricular tachyarrhythmias.

Differential Diagnosis of Wide QRS Tachycardia by Electrocardiogram

BACKGROUND AND OBJECTIVES: The differential diagnosis of a regular tachycardia, with a wide QRS complex(> or =20 msec) n the 12-lead electrocardiogram(CG), remains an important challenge. Despite the information available on electrocardiography in patients with ventricular tachycardia(T) nd supraventricular ventricular tachycardia, with aberrant conduction or pre-existed bundle branch block(ide-QRS SVT); the data from Korean is limited. The purpose of this study was to report on the differential diagnostic criteria.SUBJECTS AND METHODS: The clinical and electrocardiographic characteristics of 150 patients(5.8%) ith VT, and 78(4.2%) ith wide-QRS SVT, were evaluated. RESULTS: n atrioventricular(V) issociation was found in 44.7%(7/150) f the VTs, which is very useful in differential diagnosis. In the RBBB patterns, a monophasic R, or a biphasic, wave(R, RS), in the V1 lead, were present in 49.0 and 40.6% of VTs, respectively, and an R/S ratio of less than 1, in the V6 lead, was present in 89.6% of VTs. In the LBBB patterns, the duration of the R wave(gt; or =0 msec), the interval from the Q wave to the nadir of the S wave(> or =0 msec) nd the notching of the S wave, in the V1 lead, were present in 61.1, 87.0 and 31.3% of VTs, respectively. When an algorithm, using the AV dissociation and morphological criteria for a VT in the V1 and V6 leads, was tested for differentiation, the sensitivity and specificity were 96.7 and 93.6%, respectively. CONCLUSION: A more accurate, correct, diagnosis of wide-QRS tachycardia can be made by using a stepwise approaching method consisting of AV dissociation and morphological criteria for VT in the V1 and V6 leads.

A Clinical Study on Anti-Hypertensive Effect and Safety of Telmisartan (Micardis ) in Mild to Moderate Hypertensive Patients

BACKGROUND AND OBJECTIVES: Telmisartan (Micardis ), a selective type I angiotensin II receptor blocker, has recently been introduced as a new antihypertensive agent. We evaluated its anti-hypertensive effect and safety in mild to moderate hypertensive patients. MATERIALS AND METHODS: Telmisartan, 40 mg, was started once a day over the 4 week period in 45 patients with mild to moderate hypertension (35 male, mean age : 54.9 +/- 8.7 years). The dose was maintained in the patients whose blood pressures were controlled below 140/90 mmHg for the following 4 weeks. In those patients whose blood pressures did not fell below 140/90 mmHg, the dose was doubled to 80 mg per day for the following 4 weeks. Blood pressures were assessed at the 8th week of administration. For safety evaluation, laboratory tests were performed before and after treatment with telmisartan. Changes in heart rate and electrocardiogram were also observed. RESULTS: 1) The mean blood pressures in the sitting position were 161.6 +/- 14.7 mmHg(systolic) and 102.4 +/- 4.3 mmHg (diastolic) before treatment, which were lowered to 139.5 +/- 15.8 mmHg and 90.2 +/- 8.0 mmHg repectively after 8 weeks of treatment(p0.05). 3) Laboratory tests revealed no significant abnormality by the treatment with telmisartan. 4) No significant side effects were observed during the treatment period. CONCLUSION: Telmisartan, 40 mg or 80 mg, once a day induced significant reduction in systolic and diastolic blood pressures without significant side effects in the patients with mild to moderate hypertension. Telmisartan is thought to be a well tolerated and effective antihypertensive medicine.

Radiofrequency Catheter Ablation of Atrial Tachycardia

Radiofrequency catheter ablation (RFCA) has been established as an effective and safe treatment modality for atrioventricular nodal reentrant tachycardia and WPW syndrome. Surgical ablation or direct current catheter ablation had been performed to cure focal atrial tachycardia (AT), however, these treatments had limitations such as the need of open thoracotomy or the risk of barotrauma. RFCA could be an effective treatment modality for cure of AT. We performed RFCA for AT in 22 patients (male 13, mean age 38.1+/-15.4 years) among 831 patients who underwent electrophysiologic study between Jul. 1996 and May. 1999. Clinical pattern of tachycardia was paroxysmal (17 patients) or incessant (mean duration of symptoms, 41.1+/-42.3 months). Associated cardiac diseases were tachycardia-mediated cardiomyopathy (3 patients), aortic stenosis (1 patient) and ventricular septal defect with pulmonic stenosis (1 patient). AT was induced by programmed electrical stimulation in 17 patients: AT in the other 5 patients was incessant. The RFCA was successful in 17 patients (77.3%). The mean interval between atrial electrogram of mapping catheter and P wave of surface ECG was -53.5+/-24.9msec in 17 successful sites. Fractionated atrial activities were invariably found in the successful sites. Successful sites of RFCA for right AT were around coronary sinus ostium (5), crista terminalis (4), lower portion of sinus node (1), inferior portion of tricuspid annulus (1), and His area (1), respectively. In left AT, lateral portion near atrioventricular groove (2), inferoposterior portion (2) and near left atrial appendage (1) were successful site. During follow-up (mean 23 months), one patient had recurrence (recurrence rate 5.9%). RFCA for AT is an effective and curative treatment in selected cases.

A Clinical Study on Anti-Hypertensive Effect and Safety of Candesartan Cilexetil (Atacand) in Mild to Moderate Hypertensive Patients

BACKGROUND AND OBJECTIVES: Candesartan cilexetil (Atacand ), a selective type I angiotensin II receptor blocker, has recently been introduced as a new antihypertensive agent. We evaluated its anti-hypertensive effect and safety in mild to moderate hypertensive patients. MATERIALS AND METHODS: Candesartan cilexetil, 8 mg or 16 mg, was administered once a day over 8 weeks period in the patients with mild to moderate hypertension (25 male, 26 female, mean age: 53.5+/-1.2 years). For safety evaluation, laboratory tests were performed before and after treatment with candesartan cilexetil. Changes in blood pressure, heart rate and electrocardiogram were also observed. RESULTS: 1) The mean blood pressures in the sitting position were systolic 164.1+/-2.1 mmHg and diastolic 106.3+/-0.8 mmHg before treatment, which were lowered to 135.4+/-2.0 mmHg and 89.1+/-1.1 mmHg, repectively after 8 weeks of treatment (p0.05). 4) Laboratory tests revealed no significant abnormality by the treatment with candesartan cilexetil. 5) Left ventricular hypertrophy by ECG criteria detected in 3 cases disappeared after treatment with candesartan cilexetil. 6) No significant side effects were observed during the treatment period. CONCLUSION: Candesartan cilexetil, 8 mg or 16 mg, once a day is an effective and well tolerated antihypertensive treatment. It has a significant dose-dependent antihypertensive effect.

A Case of Torsades de Pointes Induced by Cisapride

Torsades de pointes, a polymorphic ventricular tachycardia associated with prolonged QT interval, is a well-known life-threatening arrhythmia, which has been found to be induced by various causes such as drugs, electrolyte imbalances, and severe bradycardia. Cisapride is a gastrointestinal prokinetic drug, which is widely used to treat gastroesophageal reflux disease or other functional gastrointestinal disorders. Cisapride can cause torsades de pointes and cases of torsedes de pointes induced by cisapride have been reported in other countries. Cases of torsades de pointes associated with antihistamine drugs have been reported in Korea, however, cisapride-induced torsades de pointes case has not been reported. We report a case of 31 year-old female patient who experienced repeated loss of consciousness due to cisapride-induced torsades de pointes.

Implantable Cardioverter-Defibrillator (ICD) Therapy: Initial Clinical Experience in 6 Patients

Sudden cardiac death accounts for approximately half of all cardiovascular mortality in the industrialized countries and ventricular tachyarrhythmia is the most common mechanism for this event. Implantable cardioverter-defibrillator (ICD) has been effectively used for prevention of sudden cardiac death in patients with life-threatening ventricular tachyarrhythmias since 1980. Clinical experience with ICD device now exceeds 100,000 implants worldwide and the number of implantation is increasing. In Korea, there is also increasing trend of ICD implantation. The authors report the initial experience of of ICD implantation in 6 patients who had high risk of sudden cardiac death.

Efficacy and Safety of Atorvastatin in Patients with Elevated LDL-cholesterolemia

BACKGROUND AND OBJECTIVES: HMG-CoA reductase inhibitors have been used for a decade to lower LDL cholesterol levels and to improve cardiovascular diseases and clinical outcomes. This study was designed to evaluate the clinical efficacy and safety profiles of atorvastatin, a new HMG-CoA reductase inhibitor, in patients with elevated LDL-cholesterolemia. MATERIAL AND METHODS: Eighty three patients who had high 12-hour fasting serum LDL-cholesterol level (> or =145 mg/dl and or =145 mg/dl and TG < or =400 mg/dl were assigned to receive atorvastatin 10 mg once daily for 4 weeks. After 4 weeks, the dose was continued for 4 weeks in each individual if serum LDL-cholesterol was maintained below 130 mg/dL. For each individual whose serum LDL-cholesterol was above 130 mg/dL, the dose was doubled (20 mg/day) and administered for 4 weeks. Serum AST, ALT and CPK were also measured in addition to blood chemistry tests for lipid profiles at 4 and 8 weeks for safety assessment. RESULTS: 1) The total study population who completed the whole protocol was composed of 46 patients (23 male, 23 female, mean age 54 years). 2) At 4 weeks, the reduction by mean percent change from the baseline in LDL-cholesterol was -44.8% (from 182.3+/-3.4 mg/dl to 99.7+/-2.9 mg/dl). The fixed goal of LDL-cholesterol less than 130 mg/dl was achieved by 95.8%. 3) At 4 weeks, the mean percent change from the baseline in TC, TG, HDL-C, LDL/HDL-C and ApoB were -32.3%, -17.4%, +9.6%, -48.5% and -36.6%, respectively. 4) At 8 weeks, the mean percent change from the baseline in LDL-cholesterol was -43.0% (from 182.3+/-3.4 mg/dl to 103+/-2.4 mg/dl). The fixed goal of LDL-cholesterol less than 130 mg/dl was achieved by 91.3% of the whole patients. 5) At 8 weeks, the mean percent change from the baseline in TC, TG, HDL-C, LDL/HDL-C and ApoB were -31.3%, -22.6%, +13.7%, -48.8% and -35.9%, respectively. 6) No serious side effects were observed during the whole period. CONCLUSION: Atorvastatin is highly effective and safe in modulating lipid profiles favorably (lower LDL-Cholesterol, lower TG, elevate HDL-Cholesterol), in patients with serum lipid abnormality.

The Inhibitory Effect of Triflusal (Disgren)on the Platelet Aggregation in Healthy Volunteers: Impedance Method with the Whole Blood

BACKGROUND: Antiplatelet drugs play an important role in the prevention and treatment of coronary artery diseases. Triflusal, an antiplatelet drug structually related to acetylsalicylic acid, selectively inhibits the cyclooxygenase of platelet and thromboxane A2 formation. However there is a controversy about the clinical dosage and the quantitative evaluation of the platelet antiaggregatory effect of triflusal. In this study we have evaluated the platelet antiaggregatory effect and cost-effective dosage of triflusal in the whole blood of healthy volunteers. METHODS: Using the whole blood of 50 healthy people, we performed a baseline platelet aggregation function test induced by adenosine diphosphate (ADP) and collagen. The subjects were subdivided into 3 treated groups (300 mg, 600 mg, 900 mg). We compared the platelet aggregation effect between the baseline results and 2 weeks after triflusal administration. RESULTS: Triflusal inhibited the platelet aggregation induced by ADP and collagen in the 600 mg administration group most effectively. The platelet aggregation induced by collagen was inhibited dose-dependently. The definite inhibitory responders (% inhibition > or = 25) for platelet aggregation induced by collagen were more common than those induced by ADP (33% vs 27% in 300 mg, 71% vs 53% in 600 mg, 78% vs 39% in 900 mg). There were no serious clinical side-effects except gastrointestinal trouble. One volunteer in the 900 mg treated group discontinued the treatment due to epigastric pain. CONCLUSION: We conclude that triflusal has a dose-dependent inhibitory effect on platelet aggregation induced by collagen and that the most effective dosage for platelet antiaggregation effect is 600 mg per day.

The Inhibitory Effect of Triflusal (Disgren)on the Platelet Aggregation in Healthy Volunteers: Impedance Method with the Whole Blood

BACKGROUND: Antiplatelet drugs play an important role in the prevention and treatment of coronary artery diseases. Triflusal, an antiplatelet drug structually related to acetylsalicylic acid, selectively inhibits the cyclooxygenase of platelet and thromboxane A2 formation. However there is a controversy about the clinical dosage and the quantitative evaluation of the platelet antiaggregatory effect of triflusal. In this study we have evaluated the platelet antiaggregatory effect and cost-effective dosage of triflusal in the whole blood of healthy volunteers. METHODS: Using the whole blood of 50 healthy people, we performed a baseline platelet aggregation function test induced by adenosine diphosphate (ADP) and collagen. The subjects were subdivided into 3 treated groups (300 mg, 600 mg, 900 mg). We compared the platelet aggregation effect between the baseline results and 2 weeks after triflusal administration. RESULTS: Triflusal inhibited the platelet aggregation induced by ADP and collagen in the 600 mg administration group most effectively. The platelet aggregation induced by collagen was inhibited dose-dependently. The definite inhibitory responders (% inhibition > or = 25) for platelet aggregation induced by collagen were more common than those induced by ADP (33% vs 27% in 300 mg, 71% vs 53% in 600 mg, 78% vs 39% in 900 mg). There were no serious clinical side-effects except gastrointestinal trouble. One volunteer in the 900 mg treated group discontinued the treatment due to epigastric pain. CONCLUSION: We conclude that triflusal has a dose-dependent inhibitory effect on platelet aggregation induced by collagen and that the most effective dosage for platelet antiaggregation effect is 600 mg per day.

Repositioning of Pacemaker Generator due to Therapeutic Radiation: A Tunneling Method

Therapeutic ionizing radiation can damage the permanent pacemaker. Reimplantation of pacemaker should be considered when the pacemaker site is included in the radiation field. We report a case of successful repositioning of preexisting pacemaker generator and leads with subcutaneous tunneling method across the sternum instead of insertion of new leads in a female patient with breast cancer who had DDD pacemaker.

Ablation of manifest left free wall accessory pathways with polarity reversal mapping: ventricular approach

Polarity reversal mapping for localization of the left free wall accessory pathway (AP) at the atrial insertion site has been shown to be effective for successful ablation, but this technique requires atrial septal puncture. We evaluated the safety, efficacy, and reproducibility of two dimensional polarity reversal mapping at the ventricular insertion site of the accessory pathway without atrial septal puncture in symptomatic patients with manifested left free wall AP. Polarity reversal mapping under the mitral annulus by transaortic approach was performed in 10 consecutive patients with conventional ablation catheter (6 French, 4 mm tip, 2 mm interelectrode distance), during sinus rhythm or atrial pacing. A low set high, bandpass filter (0.005-400Hz) was used. Radiofrequency (RF) ablation was performed at the site of ventricular electrocardiogram polarity reversal during sinus rhythm. Polarity reversal was identified in all patients at the ventricular side of the mitral annulus. Ablation was successful in all patients without complications. The procedure time was 86.0 +/- 21.1 min, the fluoroscopic exposure time was 16 +/- 12 min, the number of RF applications was 8 +/- 6, the power level 21 +/- 7 watts, and the time to initial AP block was 3.0 +/- 0.9 sec. Polarity reversal mapping is a safe and efficient technique at the ventricular insertion site. This technique might be complementary to the currently-utilized activation mapping technique.

Electrophysiologic Characteristics of Successfully Ablated Midseptal Accessory Pathway

BACKGROUND: Catheter ablation using radiofrequency energy has been established as the most important mode of treatment in patients with accessory pathway. However the ablation of midseptal accessory pathways had been recognized as being more difficult to ablate than other located pathway because of the low incidence and the difficult localization of ablation site. This paper describes the electrophysiologic characteristics of successfully ablated midseptal accessory pathway using radiofrequency energy. METHOD: Routine electrophysiologic studies were performed in 13 patients with midseptal accessorypathway. Guided by the recording of VA interval, the ablation catheter was positioned in all patients in an area bounded anteriorly by the tip electrode of the His bundle catheter and posteriorly by the coronary sinus ostium. Local electrograms during orthodromic atrioventricular reentrant tachycardia or right ventricular apical pacing were compared for 13 patients with midseptal accessory pathway and consequent 13 patients with posteroseptal accessory pathway. RESULT: 13 patients with midseptal accessory pathway; eight with constant Wolff-Parfinson-White syndrome, one with intermittent Wolff-Parkinson-White syndrome and four with concealed bypass track underwent attempts at ablation of their pathway using radiofrequency energy. 11 accessory pathways were successfully ablated without complication during the firstsession. A second attempt at ablation was made in two patients with success(one; recurred case, the other one; failed case at the first session). In the surface 12-Lead ECG, all eight patientswith constant Wolff-Pakinsin-White syndrome had not shownen Qrs complex at lead 3. Two patient with midseptal accessory pathway had transient left bundle branch block during orthodromic tachycardia. The VA interval during left bundle branch block was not change compared to that during narrow complex tachycardia in both. In all patients with midseptal accessory pathway, the VA interval in his bundle electrogram were almost similar to that in the coronary sinus ostial electrogram, which was not observed in the patients with posteroseptal accessory pathway. CONCLUSION: We suggest that VA interval during orthodromic tachycardia and right ventricular apcial pacing is the most reliable market for identifying midseptal accessory pathway, especially distinguishing from posteroseptal accessory pathway.

A Case Report of Percutaneous Transluminal Angioplasty with Stenting in

Percutaneous transluminal angioplasty(PTA) was first described by Dotter and Jukins in 1964 and subsequently modified by Gruentzig and Hoff in 1974. PTA has proved a safe and effective treatment for focal atherosclerotic disease of the aorta and its major extremity branches. The complications of PTA of the peripheral vessels are less frequent and less serve than those associated with the comparable surgical procedure. Intestinal angina is a clinical syndrome compromising postprandial abdominal pain, nausea, vomiting, diarrhea, weight loss, and eventually fear of eating. The syndrome is thought to be due to visceral ischemia, with stenosis or occlusion of the three visceral arteries being necessary for the syndrome to occur. Although the first report of mesenteric PTA appeared in 1980, the series of PTA with stenting of the visceral arteris reported in the literature have been small or included limited follow-up. We report a case of a intestinal angina due to superior mesenteric arterial stenosis. A 69-year-old male complained of serve postprandial pain, chronic diarrhea for 1 year. PTA with stening in superior mesenteric artery results in recannulation of obstructed artery and relief of symptom.

Cathrter Aboation of The Posteroseptal Accessory Pathways

BACKGROUND: The ablation of accessory pathways(APs) using radiofrequency(RF) energy has been establihed as a primary modality of treatment for atrioventricular reentranr tachycardia with probrn safety and high rate of success. However, the ablation of posteroseptal(PS) APs had been recognized as being more difficult to ablate than those in other location because of the complex three dimensional anatony of the posterior apace, and multifarious approaches have been proposed. We analyzed electrophysiologic characteristics and results of catheter ablation of 70 consecutive patients, who underwent RF ablation of PS APs with or without booster direct current(DC) shock. METHODS: Teh AP location was confirmed to be in the PS region, ablation was attepmted at the atrial aspect of the tricuspid annulus adjacent to the coronary sinus ostium, within the coronary sinus in couding middle cardiac vein, or underneath the mitral annulus close to the septum using retrograde transaortic approach if deemed necessory. A continuous, unmodulated sine wave radiofr-equency generator was used as the source of energy for ablation. The site was considered optimal for ablation when the electrogram obtained from the ablation catheter had one or more of the following characteristics : (1) short VA intervals with an A : V ratio of