Ticlopidine in the prevention of thrombus formation after percutaneous transluminal coronary angioplasty (PTCA).

We studied the additive effect of ticlopidine to aspirin compared with aspirin in the prevention of thrombus formation after PTCA in two groups of 21 patients who underwent PTCA at Her Majesty's Cardiac Centre, Siriraj Hospital from January to April 1993. Patients in both groups were comparable in baseline patient data and characteristics of angiographic lesions. There was no difference in angiographic outcome including the presence of intracoronary thrombus between the two groups. We concluded that ticlopidine had no additive effect to aspirin in the prevention of thrombus formation after PTCA.

Effectiveness of percutaneous transluminal coronary angioplasty for patients with unstable angina.

We have reported a series of patients with unstable angina successfully treated with PTCA. It can be performed safely with a high success rate in a selected population.

Hyperhomocysteinemia in patients with coronary artery disease.

Hyperhomocysteinemia has been recognized as a risk factor of atherosclerosis. This study was aimed to measure the risk of coronary artery disease in patients with hyperhomocysteinemia. Age, HDL level, tHcy level and history of DM were independent risk factors for coronary artery disease. The level of tHcy of 11.0 mmol/L provides the best sensitivity and specificity of predicting coronary artery disease.

Homocysteine and restenosis after percutaneous coronary intervention.

Numerous clinical studies in Western and Asian countries suggest that individuals with elevated blood levels of homocysteine have an increased risk of atherosclerosis, myocardial infarction, cerebral infarction, and deep vein thrombosis. Homocysteine is also known to induce both atherogenic and thrombogenic mediators in cultured vascular cells so that homocysteine may influence the damage of endothelial cells, promote smooth muscle cell growth, induce atherogenic mediators and thrombus formation after coronary angioplasty. The association between homocysteine and restenosis after percutaneous coronary intervention (PCI) has been discussed. In this study, the relationship between plasma homocysteine levels and restenosis after PCI to investigate whether plasma homocysteine levels may be a predictor of restenosis after PCI was examined. One hundred consecutive patients who underwent successful PCI were enrolled and plasma homocysteine level was measured in all patients prior to PCI. Plasma for homocysteine level was obtained in 99 of 100 patients who had angioplasty. The mean plasma homocysteine concentration in the enrolled patients was 13.61 +/- 6.04 micromol/L. The minimum and maximum of plasma homocysteine were 4.40 micromol/L and 50.00 micromol/L, respectively. In healthy subjects, the normal reference range of homocysteine level is 5-15 micromol/L However, recent data suggest that some patients may be at increased cardiovascular and cerebrovascular risk at levels as low as 12 micromol/L. For this reason, both cut off points of homocysteine level > or = 15 micromol/L or > or = 12 micromol/L to identify the high homocysteine level group were used. Of 99 patients, high homocysteine level (> or = 15 micromol/L) was established in 9 patients with restenosis versus 20 patients without restenosis. If the cut off point of homocysteine level > or = 12 micromol/L was used, high homocysteine level was established in 14 patients with restenosis versus 39 patients without restenosis. From both cut off points of homocysteine level, there was no correlation between plasma homocysteine level and the restenosis group. (p>0.05).

Serum lipoprotein (a) level and restenosis after percutaneous coronary intervention.

Restenosis is regarded as the result of a combination of various pathological events. The mechanisms are complex and not completely understood. In this study, the authors focused on the lipoprotein (a) (Lp (a)). It is one of the novel risk factors in atherosclerotic vascular disease. Numerous clinical studies suggest that individuals with elevated blood levels of Lp (a) have been shown to be associated with atherosclerotic vascular disease. However, whether a high serum concentration of Lp (a) affects restenosis after PCI remains controversial. In this study, the relationship between serum Lp (a) levels and restenosis after PCI was examined to investigate whether serum Lp (a) levels may be a predictor of restenosis after PCI. Of the 100 patients studied, 31 patients (31%) were classified as the restenosis group and 69 patients (69%) the non-restenosis group. Both groups did not significantly differ in serum concentration of total cholesterol, triglyceride, HDL-C, and LDL-C. The mean serum Lp (a) concentration in patients with restenosis was 41.50 +/- 34.99 mg/dL compared with a mean serum Lp (a) concentration of 29.87 +/- 25.47 mg/dL in those without restenosis. There was no statistical significance of Lp (a) level between the restenosis and non-restenosis groups (p=0.06). In healthy subjects, the normal reference range of serum Lp (a) concentration is below 30 mg/dL. From this reference, if a cut off point of serum Lp (a) concentration equal to 30 mg/dL or above to identify high Lp (a) level group was used. High serum Lp (a) level was established in 15 patients with restenosis versus 21 patients without restenosis. From this cut off point of serum Lp (a) level, the authors did not find a correlation between serum Lp (a) level and the restenosis group. (p=0.08).

Short-term effects of atenolol in patients with dilated cardiomyopathy.

Dilated cardiomyopathy is a common cause of heart failure with systolic dysfunction. Medications used to treat this condition are usually for symptomatic relief. We studied the effect of atenolol in heart failure caused by dilated cardiomyopathy in a double blinded randomized fashion. There were 17 males and 5 females. All patients underwent right and left heart catheterization, coronary angiography, endomyocardial biopsy, exercise testing and doppler echocardiography. By 3 months, atenolol significantly reduced resting and exercise heart rate and pulmonary capillary wedge pressure. There was no difference in exercise capacity. We conclude from this study that atenolol improve hemodynamic condition in patients with dilated cardiomyopathy without improving exercise capacity during this short observation period.

Results of rapid two-stage arterial switch operation in patients with transposition of the great arteries: one-year postoperation.

The rapid two-stage arterial switch operation is an alternative therapy for patients with simple transposition of the great arteries who present beyond the neonatal period and have low left ventricular pressure. It provides normal ventricular function compared to the atrial switch operation. Between July 1994 and February 1997, there were 13 such infants who had rapid two-stage arterial switch operation performed at Siriraj Hospital. There was 1 late death (11 months after the operation). All 12 survivors (mean age 22.4 +/- 5.7 months) were clinically evaluated and had echocardiography performed at 14.8 +/- 4.9 months after the operation. All were asymptomatic. Echocardiogram revealed a residual small atrial septal defect (1 case), small ventricular septal defect (1 case), mild supravalvar neopulmonary stenosis (2 cases), bicuspid neoaortic valve without stenosis (2 cases), dilated neoaortic sinus of Valsalva (6 cases, 50%) and mild neoaortic insufficiency (11 cases, 91.7%). The left ventricular function was hyperdynamic after pulmonary artery banding and significantly decreased to normal level at the time of study (shortening fraction of 43.8 +/- 10.7 vs 29.2 +/- 3.8%, respectively, p = 0.0005). The wall thickness was significantly increased after pulmonary artery banding and decreased overtime (0.48 +/- 0.08 vs 0.32 +/- 0.05 cm, respectively, p < 0.0005). The left ventricular dimension was significantly increased both after pulmonary artery banding and at the time of study (2.06 +/- 0.42 vs 3.32 +/- 0.30 cm, respectively, p < 0.0005). The left ventricular mass was significantly increased after pulmonary artery banding and at the time of study (21.79 +/- 7.79 vs 33.08 +/- 7.40 g/m2, respectively, p = 0.0005). The mortality and morbidity of rapid two-stage arterial switch operation are low. However, long-term follow-up should be monitored.

Short and long term mortality after acute myocardial infarction as predicted by two-dimensional echocardiography.

We have non-invasively determined the extent of the acute myocardial insult shortly after admission in a large group of patients with acute myocardial infarction. There appeared a fairly sharp distinction between patients with low and high likelihood of in-hospital death and one year mortality on the basis of echocardiographic findings. The use of wall motion score index and ejection fraction in the prediction of short term mortality (in-hospital death) is good, but the prediction of long term mortality is not that good, since several patients survived up to one year even with high wall motion score index (greater than 2.2) or low ejection fraction (less than or equal to 35%) on admission. One-year survival is high up to 90 per cent in patients with low wall motion score index or high ejection fraction on admission.

Limitation of transthoracic echocardiography in the diagnosis of congenital heart diseases.

Nowadays, it has been widely accepted that echocardiography is the most efficient, non invasive diagnostic tool to diagnose congenital heart diseases. However, cardiac catheterization remains the gold standard to diagnose and obtain hemodynamic data prior to cardiovascular surgery. In order to find out the accuracy of transthoracic echocardiography in relation to the anatomical diagnosis of congenital heart diseases, 175 consecutive patients who underwent diagnostic cardiac catheterization during January 1999 to December 1999 were reviewed. All of them had complete echocardiographic studies prior to the procedure. The male to female ratio was 1.06:1. The median age at the time of echocardiography was 3.36 (0.01-28.8) years old. The indications of the cardiac catheterization were to demonstrate cardiovascular anatomy 64 per cent, to obtain pulmonary artery pressure and pulmonary vascular resistance 13.7 per cent, and to get both information 22.3 per cent. Tetralogy of Fallot (23.4%) was the most frequent cardiac malformation, followed by complex congenital heart diseases (22.3%), simple left to right shunt (12%), pulmonary atresia with ventricular septal defect (8.6%), tricuspid atresia (5.7%), simple d-transposition of great arteries (4%), etc. From cardiac catheterization; 49 cases (28%) revealed additional data which were surgically important, 3 cases (1.7%) resulted in different diagnoses, and 3 cases (1.7%) revealed additional information which was not surgically important. Inadequate imaging technique (36 cases, 65.5%) and limitation of technique (19 cases, 34.5%) were the reasons for missing anatomical findings of transthoracic echocardiography. Age at the time of echocardiography was not a significant factor affecting the accuracy. Persistent left superior vena cava, multiple aorto-pulmonary collateral arteries, pulmonary artery anatomy, and coronary artery anatomy were the most frequent cardiac lesions misdiagnosed by transthoracic echocardiography that were somewhat surgically important. The incorrect echocardiographic diagnoses were aorto-pulmonary window, patent ductus arteriosus, and vascular ring. Thorough and extensive echocardiographic scanning coupled with cooperative or adequately sedated patients by an experienced operator using an efficient echocardiographic machine might improve the accuracy of transthoracic echocardiography in the diagnosis of congenital heart diseases.

Effect of atenolol on symptomatic ventricular arrhythmia without structural heart disease.

Ventricular arrhythmia (VA) from right ventricular outflow tract (RVOT) is a common problem. Symptomatic patients are usually treated with beta-blockers. There is little data on the systematic evaluation of the drug efficacy. The objectives of this study were 1) To determine proportion of exercise induced ventricular arrhythmia among patients with symptomatic ventricular arrhythmia and 2) to determine the response to beta blockers and the correlation between the response to betablockers and exercise induced VA. We prospectively studied 46 consecutive patients with symptomatic ventricular arrhythmia. Patients recorded their symptom scores underwent exercise testing and 24-hour ambulatory monitoring before treatment and 1 month after atenolol. Exercise induced ventricular arrhythmia was demonstrated in 28 per cent of patients with symptomatic ventricular arrhythmia. Atenolol improves symptoms, decreases PVC count from ambulatory monitoring, increases exercise duration and suppresses malignant form of VA during exercise. These effects are at a similar extent in both groups of patients: those with and without exercise induced VA. However, the effect on ventricular arrhythmia suppression during exercise of atenolol was seen only in patients with increased PVC during exercise. In conclusion, atenolol is a good option in treating patients with symptomatic VA from RVOT regardless of the pattern of PVC response to exercise. Atenolol can suppress PVC during exercise testing better in patients with exercise induced VA compared to those without.

Reliability of Thai version of SF-36 questionnaire for the evaluation of quality of life in cardiac patients.

Quality of life is an important measurement of medical outcomes. Reliability of a Thai version of the SF-36 questionnaire has never been reported. The objective of this study was to determine the reliability of a Thai version of the SF-36 questionnaire in cardiac patients. We developed a Thai version of the SF-36 questionnaire and tested it in 212 cardiac patients. Reliability of the Thai version of the SF-36 questionnaire was assessed by internal consistency using Cronbach's Alpha statistic and inter-item correlation. We demonstrated that Cronbach's Alpha coefficient of every aspect of QOL exceeded 0.7, and all inter-item correlation exceeded 0.4. In conclusion, the Thai version of the SF-36 questionnaire is a valuable tool in assessing medical outcomes and medical research in Thai patients with cardiac disease. Whether it can be used in other diseases remains unknown.

Impaired fasting glucose, diabetes mellitus and coronary risk factors.

The authors conducted a prevalence survey of impaired fasting glucose and diabetes mellitus in 3,615 Shinawatra employees, and we also determined various risk factors of coronary artery disease such as blood pressure level, body mass index and serum lipids. The prevalence of impaired fasting glucose and diabetes mellitus were 1.7 per cent and 0.8 per cent respectively. The prevalences were more common in males and increased with increasing age. Coronary risk factors were higher in impaired fasting glucose (IFG) and diabetes mellitus (DM) when compared with normal glucose levels. There were also significant differences between impaired fasting glucose and diabetes mellitus, except for pulse pressure, serum cholesterol level, LDL-cholesterol level and HDL-cholesterol level.

Regular exercise and cardiovascular risk factors.

Physical inactivity has been counted as a risk factor for coronary artery disease. Regular exercise has also been reported to reduce risk of cardiovascular disease and its risk factors. We surveyed 3615 subjects for their conventional risk factors of coronary disease and for the frequency of their exercise. We found that subjects who had regular exercise were more likely to have lower triglyceride and resting heart rate. HDL cholesterol was higher in the group of subjects who had regular exercise. There was no difference in fasting plasma glucose, total cholesterol or blood pressure levels between those who had and those who did not have regular exercise.

Obesity and risk factors of coronary heart disease in healthy Thais: a cross-sectional study.

Association between obesity and conventional risk factors for coronary artery disease is well established. Obesity is currently considered an independent risk for coronary artery disease. The relationship between body mass index (BMI) and fasting plasma lipids and glucose and blood pressures in non-obese subjects is not established. The authors studied relationships between BMI and lipids, and glucose, and blood pressure levels in healthy a population. The authors measured the weights and heights of 3,615 employees of a company during a routine yearly health examination. There were 1,250 males aged 31.3 +/- 6.6 and 2,365 females aged 29.3 +/- 4.9 years old. The average BMI for males and females were 23.5 +/- 3.6 and 20.1 +/- 3.0 respectively. The levels of total cholesterol (Chol), LDL-cholesterol, and triglyceride (TG), fasting plasma glucose (FPG) had a positive relationship with BMI (r = 0.22, 0.26, 0.41, 0.20; p < 0.001). HLD-cholesterol had a negative correlation with BMI (r = -0.36, p < 0.001). Both systolic (SBP) and diastolic (DBP) blood pressures had a positive correlation with BMI. The association persisted after all values were adjusted by age and sex. BMI has a significant positive relationship with the conventional risk factors for coronary artery disease and a negative relationship with HDL-cholesterol.

Utility of intraoperative transesophageal echocardiogram in congenital heart disease.

Intraoperative transesophageal echocardiogram (TEE) has improved the perioperative outcome in adult patients. The purpose of the current study was to assess the benefit of intraoperative TEE in patients with congenital heart disease undergoing surgical correction (repair). The results of the patients who had consecutively undergone intraoperative TEE during their congenital heart surgery between January 1998 to June 2000 were reviewed. There were 104 patients (whose ages ranged from one week old to 50 years old (median 5 years old) and their weights from 3 kg to 79 kg (median 15 kg). A significant impact was said to have occurred if these findings prompted a change in surgical procedure following a prebypass study or rebypass for repair of a residual defect. Prebypass TEE had a significant impact in seven patients (6.7%). TEE could be used as a guide to help repair in three patients. The postbypass TEE examination had a significant impact in 15 patients (14.4%). Of these 15 patients, eight were detected primarily by TEE examination. The group of patients in whom TEE had the most significant impact was in patients who had surgery related to the repair of the atrioventricular valve (complete or partial atrioventricular (AV) canal repair, Ebstein's anomaly; 9 out of 22 patients; 41%). A less significant impact was found in surgery for other complex congenital defects (single ventricle or complete transposition of great arteries; eight out of 46 patients; 17.4%). TEE had limited impact in simple congenital lesion. Intraoperative TEE is valuable in the perioperative care of patients with congenital heart defects. We found the most benefit in patients with complete or partial AV canal and Ebstein's anomaly.

Reversibility of tachycardiomyopathy after successful radiofrequency catheter ablation: intermediate results.

Left ventricular function in patients with tachycardia induced cardiomypopathy can improve after cessation of the arrhythmia. We reported the intermediate results of 10 patients, 6 men and 4 women, with tachycardiomyopathy who successfully underwent radiofrequency catheter ablation (RFCA) for incessant tachycardia. Three had right atrial tachycardia, 5 ventricular tachycardia (2 and 3 from the right and left ventricles, respectively), 1 atrial flutter and 1 right accessory pathway. During the mean follow-up period of 19 months (range 11-38 months), one patient, right atrial tachycardia, had recurrence and reablation was successfully done without recurrence. Left ventricular ejection fraction, endsystolic and diastolic diameters from echocardiography gradually improved from 35 per cent, 51 and 61 mm to 58 per cent, 36 and 52 mm, respectively (p<0.001). The mean duration of reversibility was 7 months (range 1-15 months). There was no recurrence of tachycardiomyopathy after the return of left ventricular function. Conclusion, RFCA can terminate tachyarrhythmia and lead to significant improvement of left ventricular diameters and systolic function in patients with tachycardia induced cardiomyopathy.

Radiofrequency catheter ablation for frequent premature ventricular contractions: a preliminary report of 15 cases.

Between February 1995 and March 1997, 15 patients, 13 women and 2 men, underwent radiofrequency catheter ablation (RFCA) for symptomatic frequent premature ventricular contractions (PVC's). The mean age was 43.3 +/- 11.9 years. Thirteen patients (86.7%) had right PVC's and the remainder had both right and left PVC's. RFCA were done under local anesthesia, using both earliest endocardial activation time and pace mapping in complement. The immediate success rate was 14/15 (93%) with only minor complications in 2 patients (13.3%). The fluoroscopic and procedure times were 40.6 +/- 24.0 and 170.7 +/- 81.2 minutes, respectively. From the Holter monitoring, total PVC count, per cent of PVC per total heart beat in 24 hours and couplets count were significantly reduced, (more than 90%, p < 0.05), by RFCA. Triplets and repetitive ventricular tachycardia were totally abolished. During the follow-up period of 10.1 +/- 7.5 months, 2 patients (14.3%) had recurrences of right PVC's within 2 weeks after ablation. Reablation was successfully done in both patients without recurrence, giving the final success rate of 93 per cent. In conclusion, RFCA could be safely performed with a high success rate in patients with symptomatic frequent PVC's. It can be considered an alternative treatment in patients resistant to medical therapy.

Left ventricular hypertrophy: relationship of echocardiographic and electrocardiographic findings in idiopathic dilated cardiomyopathy.

Diagnosis of left ventricular hypertrophy is important in patients with cardiac disease. To test the correlation of echocardiographic and electrocardiographic findings for diagnosis of left ventricular hypertrophy in Idiopathic Dilated Cardiomyopathy (IDC), 18 patients with proven IDC were examined. There were 15 males and 3 females, ages ranged from 22-60 years (mean 43 +/- 10.7). LV mass index ranged from 134.4-421.2 g/m2 (mean 187.8 +/- 68.6). All 18 patients had LVH by echocardiography but only 10 patients (55.6%) had LVH by using ECG Romhilt-Estes scoring system. The correlation between echocardiographic and electrocardiographic findings for diagnosis LVH was not significant (r = 0.026; p = 0.935) and echocardiography was better than electrocardiography for diagnosis of LVH in IDC.

Radiofrequency catheter ablation in pediatrics: experience at Siriraj Hospital.

UNLABELLED: Tachyarrhythmia is one of the life threatening cardiac electrophysiology problems in children. It also affects quality of life of the patients. Radiofrequency catheter ablation (RFCA) has made a significant impact in the treatment of tachyarrhythmia since 1989. The present report is the first and largest report in Thai children. There have been 24 RFCA procedures in 21 children since it was initially performed at Siriraj Hospital from January 1996 to December 1999. The electrophysiology studies and medical records were analyzed retrospectively. Median age and weight at the time of the procedure were 11 (1.1-13) years old and 38.8 (6.8-78.2) kg respectively. The presenting symptoms were palpitation 66.7 per cent, presyncope 16.7 per cent, congestive heart failure and cardiogenic shock 8.3 per cent, syncope 4.2 per cent, and chest pain 4.2 per cent. Median duration of symptom was 3.5 (0.1-8.0) years. The underlying cardiac arrhythmias were Wolff Parkinson White (WPW) syndrome 50 per cent, concealed accessory pathway 16.7 per cent, atrioventricular node re-entry tachycardia (AVNRT) 16.7 per cent, atrial ectopic tachycardia (AET) 12.5 per cent, and WPW with AVNRT 4.2 per cent. The median fluoroscopy time and procedure time were 25 (4-145) minutes and 125 (60-320) minutes respectively. The median tachycardia cycle length was 332.5 (220-460) seconds. The immediate success rate was 21/24 (87.5%) procedures. The procedural complication was 1/24 (4.2%). Two patients (8.3%) had recurrences of tachycardia and were successfully controlled with antiarrhythmic drugs. CONCLUSION: RFCA is a safe, effective, and curative procedure with high success rate for pediatric tachyarrhythmias.

Comparison of supraventricular tachycardia from concealed bypass tract and Wolff-Parkinson-White syndrome.

Supraventricular tachycardia (SVT) is a common problem. There are 2 types of accessory atrioventricular pathway (AP) causing SVT: one can conduct antegradely (WPW syndrome) and another can conduct only in a retrograde direction (concealed bypass tract or CBT). There are little data of the significance and difference of the two types in Thailand. The objectives of this study were to compare characteristics of patients, accessory pathways and outcome of radiofrequency catheter ablation (RFCA) between the 2 types of accessory pathways. We reviewed the electrophysiology report of patients with supraventricular tachycardia from the accessory pathway who were referred for RFCA. There were 74 males and 74 females at a mean age of 37 years. CBT accounts for 44 per cent of SVT from AP. Compared to CBT, WPW syndrome was more in the right-sided location, more associated with heart disease, a higher number of accessory pathways, more inducible atrial fibrillation and more difficult to do ablation. However, the overall success rate of RFCA was similar. Although the recurrence rate was 8.4 per cent, all patients with recurrence were successfully reablated. We concluded from this study that RFCA is a highly effective method for the treatment for both forms of accessory pathway although there are some differences between WPW syndrome and CBT.