Clinical phenotype classification to predict risk and optimize the management of patients with atrial fibrillation using the Atrial Fibrillation Better Care (ABC) pathway: a report from the COOL-AF registry.

BACKGROUND: Phenotypic classification is a method of grouping patients with similar phenotypes. AIM: We aimed to use phenotype classification based on a clustering process for risk stratification of patients with non-valvular atrial fibrillation (AF) and second, to assess the benefit of the Atrial Fibrillation Better Care (ABC) pathway. METHODS: Patients with AF were prospectively enrolled from 27 hospitals in Thailand from 2014 to 2017, and followed up every 6 months for 3 years. Cluster analysis was performed from 46 variables using the hierarchical clustering using the Ward minimum variance method. Outcomes were a composite of all-cause death, ischemic stroke/systemic embolism, acute myocardial infarction and heart failure. RESULTS: A total of 3405 patients were enrolled (mean age 67.8 ± 11.3 years, 58.2% male). During the mean follow-up of 31.8 ± 8.7 months. Three clusters were identified: Cluster 1 had the highest risk followed by Cluster 3 and Cluster 2 with a hazard ratio (HR) and 95% confidence interval (CI) of composite outcomes of 2.78 (2.25, 3.43), P < 0.001 for Cluster 1 and 1.99 (1.63, 2.42), P < 0.001 for Cluster 3 compared with Cluster 2. Management according to the ABC pathway was associated with reductions in adverse clinical outcomes especially those who belonged to Clusters 1 and 3 with HR and 95%CI of the composite outcome of 0.54 (0.40, 073), P < 0.001 for Cluster 1 and 0.49 (0.38, 0.63), P < 0.001 for Cluster 3. CONCLUSION: Phenotypic classification helps in risk stratification and prognostication. Compliance with the ABC pathway was associated with improved clinical outcomes.

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 of Wolff-Parkinson-White syndrome: report of 83 cases from Siriraj Hospital.

We described the characteristics of patients and accessory pathway and showed our results of Radiofrequency catheter ablation (RFCA). There were 41 males and 42 females at a mean age of 36 years. Accessory pathway associated with Wolff-Parkinson-White (WPW) syndrome in our population was more prevalent on the right side which is different from previous reports. Most commonly associated heart disease was Ebstein's anomaly. Overall success rate was 96.4 per cent. Right free wall accessory pathway needed a longer procedure time and fluoroscopy time, higher radiofrequency power and more radiofrequency applications compared to other locations. Although the recurrence rate was 12 per cent, all patients with recurrence were successfully reablated. We also described the comparison of our result with previous studies. To our knowledge this is the first report in Thailand with a reasonable number of cases. RFCA is a very effective treatment of WPW syndrome in the Thai population and should be considered in symptomatic patients especially those who are refractory to medication.

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.

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.

The use of cardiac magnetic resonance imaging in coronary artery disease.

A new noninvasive imaging technique, magnetic resonance imaging (MRI), has been developed that has the potential to assess anatomical and functional data of patients with coronary artery disease. None of the other cardiac investigations to date can combine all aspects of information. Cardiac MRI is a challenging task because of the motion of the structure during cardiac contraction and the motion with respiration. We reviewed the technique and the use of cardiac MRI in various aspects. The emerging area in cardiac MRI is the analysis of the plaque morphology information, and the use of the new contrast agents. Further investigation is needed in order for cardiac MRI to achieve a better image information within a shorter period of time.

Prevalence of new coronary risk factors in Thai population.

Many new cardiovascular biomarkers of atherosclerosis have recently been emerging. However, there is a paucity of these data in the Thai population. This study aims to determine the prevalence of these biomarkers of atherosclerosis and the relationship between these new risk factors and other conventional risk factors for atherosclerosis in the healthy Thai population. As a yearly check-up program, we surveyed 3,615 normal healthy populations for their conventional risk factors and some new cardiovascular biomarkers for atherosclerosis. The authors found hyperhomocysteinemia and high level of Lp(a) in 27 per cent and 32 per cent of the cases respectively. Prevalence of recent and past chlamydial infection was found in 30 per cent and 51 per cent respectively.

The use of nonfluoroscopic catheter-based mapping system to perform radiofrequency ablation in complex ventricular tachycardia after cardiac surgery in congenital heart disease: a case report.

A nonfluoroscopic electroanatomical cardiac mapping system (CARTO) integrates anatomical and electrophysiological information to reconstruct a three-dimensional activation map. Information from the CARTO system helps to reveal the mechanism and perform successful ablation in scar re-entry ventricular tachycardia after cardiac surgery. Three-dimensional activation and propagation mapping was performed in a patient with ventricular tachycardia after surgical correction of a double outlet right ventricle. The ventricular tachycardia appeared in two morphologies and were refractory to antiarrhythmic medication including amiodarone. Both ventricular tachycardias were re-entered using the ventriculotomy scar but rotated in different directions. Successful radiofrequency ablation was performed by creating a line of conduction block from the pulmonic valve to the ventriculotomy scar using entrainment mapping and the ablation lesion tagging technique. The CARTO system is useful in mapping and guiding the ablation of complex ventricular tachycardia after surgical correction in congenital heart disease

Myocardial injury after radiofrequency catheter ablation.

Radiofrequency catheter ablation has been a good treatment option for various types of cardiac arrhythmia. However there is concern about myocardial injury associated with radiofrequency catheter ablation. We studied myocardial injury with biochemical markers and echocardiogram in 41 consecutive patients who underwent electrophysiology study (EP study) and radiofrequency catheter ablation (RFCA) at our institute from April to July 2000. The concentration of biochemical markers (CK-MB mass, troponin T and myoglobin) and result of the echocardiograms were analyzed with other characteristics. In 41 patients subjected to EP study with possible RFCA, abnormal levels of troponin T, CK-MB mass and myoglobin were found in 46 per cent, 15 per cent and 44 per cent immediately after procedure, which went up to 64 per cent, 22 per cent and 2 per cent at twenty four hours. Compare to the group with normal troponin T level, the patients with abnormal level at 24 hours after RFCA had a longer procedure time (119+/-44 min. vs 90+/-22 min.), more frequent use of impedance ablation catheters (65% vs 27%), more RF applications (9+/-8 vs 18+/-16) and more ventricular ablation sites (69% vs 9%). The echocardiogram results showed no remarkable abnormality in any patients. Troponin T was the most sensitive marker to detect thermal myocardial injury associated with radiofrequency catheter ablation. Prolonged procedure time, RF applications, the use of impedance ablation catheter and ventricular ablation site were associated with elevated troponin T concentration after RFCA.

Radiofrequency catheter ablation: 5 years experience at Siriraj Hospital.

Between February 1995 to May 2000, 626 consecutive patients underwent radiofrequency catheter ablation for various types of cardiac arrhythmia. The mean age was 41 years, range 1-85 years. Mapping and ablation were guided by intracardiac electrogram and anatomical approaches. The initial success, compliction, recurrent and final success rates are shown below:- [table; see text] Conclusion, RFCA is an effective treatment and should be considered as first line treatment for certain tachyarrhythmia.

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.

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.

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.

Heart rate variability at rest and during mental stress in patients with coronary artery disease: differences in patients with high and low depression scores.

This study tested the hypothesis that coronary artery disease (CAD) patients with high depressed mood scores differ in sympatho-vagal balance during mental stress compared to patients with low depressed mood scores. Using electrocardiographic monitoring, heart variability data from spectral analysis and hemodynamic parameters were obtained prior to and during mental stress from 34 men and 7 women. A public speaking task was used as the mental stressor. Patients were grouped by a median split of their Minnesota Multiphasic Personality Inventory-Depression score. During mental stress, patients with higher depression scores had greater changes in peak heart rate (p < .05) and low frequency to high frequency power ratio (p < 0.05) than patients with lower scores suggesting a shift toward more sympathetic activity during mental stress. These findings may be related to the reported relation between depression and survival risk in patients with CAD.

The relationship between resting systolic blood pressure and cutaneous pain perception in cardiac patients with angina pectoris and controls.

In order to determine the influence of resting systolic blood pressure and stable angina on cutaneous pain perception, we studied 19 male cardiac patients with stable angina and 16 male controls. Pain perception was measured using a suprathreshold evaluation of pain intensity and pain unpleasantness to a series of thermal stimuli. We found that men with higher resting blood pressure had a decrease in the perception of pain intensity and pain unpleasantness. Similarly, we found that patients with stable angina perceived pain as less intense and unpleasant than controls. These differences in pain perception may be associated with different pain mechanisms: in the case of blood pressure, differences in opioid activity and baroreceptor-regulated pain systems; in the case of stable angina, patients may adapt to continued experiences of pain, altering internal frames of reference.

Radiofrequency catheter ablation in type I atrial flutter: preliminary experience of 10 cases.

Common atrial flutter results from macroreentry in the right atrium. Catheter ablation of slow conduction, between tricuspid annulus and inferior vena cava (TA-IVC) or tricuspid annulus and coronary sinus ostium (TA-CS os) has been reported to terminate and prevent recurrence of this arrhythmia. We reported 10 consecutive patients, 7 men and 3 women, who underwent radiofrequency catheter ablation of common atrial flutter. The mean age was 59.4 +/- 11.2 years (range 42-82 years). During the paroxysmal atrial flutter, all patients had palpitation, 4 had dyspnea on exertion, 3 patients had syncope and 1 patient had presyncope. The mean duration of symptoms was 5.7 +/- 4.9 years (range 0.5-13 years). Two patients had dilated cardiomyopathy, 1 Ebstein's anomaly and 1 chronic obstructive pulmonary disease. Four patients (40%) had history of atrial fibrillation (AF) before ablation. The mean cycle length of atrial rhythm was 257.2 +/- 36.6 ms. Ablation was done by anatomical approach and could terminate arrhythmia in 9 patients (90%), 7 from TA-IVC, 2 from TA-CS os without major complication. The mean number of applications was 20.4 +/- 16.9 and turned atrial flutter to normal sinus rhythm in 13.5 +/- 10.7 seconds. Fluoroscopic and procedure times were 38.4 +/- 31.4 and 157.2 +/- 68.8 minutes, respectively. During the follow-up period of 24.0 +/- 28.7 weeks, 2 patients had recurrent atrial arrhythmia, 1 atrial fibrillation and 1 atrial flutter type I, giving the final success rate of 70 per cent. All patients who had recurrence or failure had a history of paroxysmal AF before ablation. In conclusion, radiofrequency catheter ablation in atrial flutter type I, using anatomical approach, is an effective treatment to terminate and prevent this arrhythmia in short term follow-up. It may be considered as an alternative treatment in patients with atrial flutter who were refractory to antiarrhythmic agents.

Heart rate variability in patients with coronary artery disease: differences in patients with higher and lower depression scores.

OBJECTIVE: This study tested the hypothesis that coronary artery disease patients with higher depression scores have lower heart rate variability during daily life. METHOD: Thirty-three men and nine women, ranging in age from 46 to 79, with coronary artery disease and exercise-induced ischemia were studied. The standard deviation of normal R-R intervals (SDNN) and average heart rate were obtained from 24-hour ambulatory electrocardiographic monitoring. Patients were grouped by a median split of the Minnesota Multiphasic Personality Inventory (MMPI-D) score. RESULTS: SDNN was lower (p = .009) and average heart rate was higher (p = .003) in patients with higher depression scores. These relationships remained substantially unaltered after statistically adjusting for the only demographic/clinical factor that varied between the groups: gender. CONCLUSIONS: In comparison to the lower depression score group, those with higher depression scores had lower heart rate variability during daily life. These findings may be related to the reported relationship between depression and survival risk in patients with coronary artery disease.

Association of systolic blood pressure at time of myocardial ischemia with angina pectoris during exercise testing.

In a sample of 306 patients with positive treadmill test results, we found that patients with silent ischemia had a higher systolic blood pressure at onset of ST depression than patients with painful ischemia. We conclude that systolic blood pressure at the time of ischemia influences the experience of angina during exercise in a manner consistent with acute activation of baroreceptors and resulting antinociception.