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1.
Pharmacogenomics J ; 17(6): 494-500, 2017 12.
Article in English | MEDLINE | ID: mdl-27503578

ABSTRACT

Using population pharmacokinetic analysis (PPK), we attempted to identify predictors of S-warfarin clearance (CL(S)) and to clarify population differences in S-warfarin pharmacokinetics among a cohort of 378 African American, Asian and white patients. Significant predictors of CL(S) included clinical (age, body weight and sex) and genotypic (CYP2C9*2,*3 and *8) factors, as well as African American ethnicity, the median CL(S) being 30% lower in the latter than in Asians and whites (170 versus 243 and 250 ml h-1, P<0.01). The plasma S-warfarin (Cp(S)) time courses following the genotype-based dosing algorithms simulated using the PPK estimates showed African Americans with CYP2C9*1/*1 and any of the VKORC1 genotypes would have an average Cp(S) at steady state 1.5-1.8 times higher than in Asians and whites. These results indicate warfarin dosing algorithms should be evaluated in each respective ethnic population. Further study of a large African American cohort will be necessary to confirm the present findings.


Subject(s)
Anticoagulants , Asian People/genetics , Black or African American/genetics , Cytochrome P-450 CYP2C9/genetics , Vitamin K Epoxide Reductases/genetics , Warfarin , White People/genetics , Algorithms , Anticoagulants/administration & dosage , Anticoagulants/blood , Cohort Studies , Dose-Response Relationship, Drug , Female , Genotype , Humans , Male , Metabolic Clearance Rate/genetics , Middle Aged , Models, Biological , Pharmacogenomic Testing , Pharmacogenomic Variants , Polymorphism, Single Nucleotide , Warfarin/administration & dosage , Warfarin/blood
2.
Int J Clin Pract ; 65(8): 852-7, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21762309

ABSTRACT

BACKGROUND: Despite the ability of tissue Doppler imaging (TDI) to detect left ventricular (LV) systolic and diastolic myocardial functions in patients with heart failure, the added value of TDI to clinical variables and conventional echocardiography in predicting the symptoms and outcome of advanced heart failure has not been clearly defined. METHODS AND RESULTS: Two hundred and thirty adult patients diagnosed with congestive heart failure were assigned to study groups based on the New York Heart Association functional classes. Pulsed-wave TDI (PWTDI), including average of peak systolic (Sm), early (Em) and late diastolic (Am) velocities from six mitral annular sites was evaluated. PWTDI was also calculated to create a combined index (EAS index) of diastolic and systolic performances. All patients were followed up for cardiac-related death and hospitalisation as a result of heart failure. Patients with functional class III-IV had a significantly higher EAS index (0.21 ± 0.19 vs. 0.13 ± 0.08, p < 0.05) than those with class I-II and the control (0.10 ± 0.04, p < 0.05). Except for Sm and Em, all conventional echocardiographic Doppler parameters and TDI variables significantly correlated with functional class. Moreover, according to multiple stepwise analysis, EAS index and percentage of chronic renal insufficiency (CRF) were the only two independent predictors of functional class (EAS index, p = 0.006; CRF, p = 0.019). During follow-up (median, 30 months), 93 participants had cardiac events. EAS index, LV mass index and CRF were significant predictors of cardiac mortality and hospitalisation [EAS index, hazard ratio (HR) 4.962, p = 0.006; LV mass index, HR 1.007, p = 0.003; CRF, HR 1.616, p = 0.040]. CONCLUSIONS: The EAS index, which reflects systolic and diastolic performances, is a highly effective means of differentiating between patients with functional class I-II and those with III-IV. The index also correlates with cardiac mortality and hospitalisation for worsening heart failure, thus providing additional value to conventional echocardiographic measures.


Subject(s)
Echocardiography, Doppler/methods , Heart Failure/diagnostic imaging , Aged , Blood Flow Velocity/physiology , Case-Control Studies , Death, Sudden, Cardiac , Diastole , Echocardiography, Doppler/mortality , Female , Heart Failure/mortality , Heart Failure/physiopathology , Hospitalization , Humans , Male , Middle Aged , Observer Variation , Prognosis , Reproducibility of Results , Severity of Illness Index , Survival Analysis , Systole
3.
J Am Coll Cardiol ; 21(7): 1612-21, 1993 Jun.
Article in English | MEDLINE | ID: mdl-8496527

ABSTRACT

OBJECTIVES: A simple technique was designed for radiofrequency ablation therapy of atrioventricular (AV) node reentrant tachycardia. BACKGROUND: This technique was based on the hypothesis that slow pathway conduction reflects conduction through the compact node and its posterior atrial input. METHODS: A total of 100 consecutive patients were studied; there were 37 men and 63 women, with a mean age of 48 +/- 15 years. All 100 patients had induction of sustained tachycardia with (51 patients) or without (49 patients) administration of isoproterenol or atropine, or both. The ablation catheter was initially manipulated to record the largest His bundle deflection from the apex of Koch's triangle. It was then curved downward and clockwise to the area of the compact node when His deflection was no longer visible and the ratio of atrial to ventricular electrogram was < 1. The radiofrequency current was delivered from the 4-mm tip electrode a mean of 5 +/- 7 times at a power of 25 +/- 4 W for a duration of 21 +/- 4 s. The total fluoroscopic time was 19 +/- 11 min. RESULTS: Selective ablation (56 patients) or modification (26 patients) of the slow pathway without affecting anterograde and retrograde fast pathway conduction was achieved in 82 patients. Ablation or modification of both the retrograde fast pathway and the slow pathway but with preservation of anterograde fast pathway conduction was noted in 12 patients. Ablation or modification of the retrograde fast pathway alone or both anterograde and retrograde fast pathway conduction was noted in three patients. Complete AV node block occurred in three patients. Seventy-three patients had no induction of echo beats or tachycardia and 24 patients had induction of a single echo beat after ablation. Follow-up study was performed in 62 patients 76 +/- 18 days after ablation. Thirty-nine patients had no induction of echo beats or tachycardia, 22 had induction of echo beats alone and 1 patient had induction of sustained tachycardia. CONCLUSION: Selective ablation of the slow AV node pathway can be achieved by a simple procedure with a high success rate and few complications.


Subject(s)
Atrioventricular Node/surgery , Catheter Ablation/methods , Tachycardia, Atrioventricular Nodal Reentry/surgery , Adolescent , Adult , Aged , Aged, 80 and over , Atrioventricular Node/physiopathology , Catheter Ablation/adverse effects , Electrocardiography , Female , Heart Block/etiology , Humans , Male , Middle Aged , Tachycardia, Atrioventricular Nodal Reentry/physiopathology , Treatment Outcome
4.
J Am Coll Cardiol ; 20(4): 884-95, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1527299

ABSTRACT

OBJECTIVES: A comprehensive electrophysiologic study followed by selective radiofrequency ablation from three sites was performed in patients with atrioventricular (AV) node reentrant tachycardia to better delineate the nature of the tachycardia circuit. BACKGROUND: We postulated that the retrograde fast pathway is the anterior superficial group of transitional cells and the slow pathway is the compact node with its posterior input of transitional cells. Twenty-three consecutive patients were studied. In nine, the atria could be dissociated from the tachycardia by delivery of an atrial extrastimulus during tachycardia. METHODS: Radiofrequency ablation was performed with three approaches. The anterior approach was designed to interrupt the anterior superficial atrial input to the compact node, the posterior approach to interrupt the posterior atrial input to the compact node and the inferior approach to destroy the compact node itself. RESULTS: Selective ablation of the retrograde fast pathway was achieved in seven patients, six with the anterior and one with the inferior approach. Anterograde fast pathway conduction was not affected, whereas retrograde fast pathway conduction was either abolished or markedly depressed. None had induction of echoes or tachycardia after ablation. Selective ablation of the slow pathway was successful in 13 patients, 1 with anterior, 3 with posterior and 9 with inferior approaches. In these 13 patients, both anterograde and retrograde fast pathway conduction were not affected, the dual pathway physiology was abolished and the tachycardia was not inducible after ablation. Ablation of both the retrograde fast pathway and the slow pathway occurred with the inferior approach in three patients. CONCLUSIONS: We conclude that the retrograde fast pathway is likely to be the anterior superficial group of transitional cells, whereas the slow pathway is the compact node and its posterior input of transitional cells. A barrier seems to exist between the atrium and the tachycardia circuit. In a broad view of the AV node structure, the tachycardia circuit is confined to the node.


Subject(s)
Atrioventricular Node/physiopathology , Electrocoagulation/methods , Tachycardia, Atrioventricular Nodal Reentry/physiopathology , Tachycardia, Atrioventricular Nodal Reentry/surgery , Atrial Function/physiology , Atrioventricular Node/surgery , Cardiac Catheterization , Cardiac Pacing, Artificial/methods , Electrocardiography/methods , Female , Humans , Intraoperative Care/methods , Male , Middle Aged , Radio Waves , Tachycardia, Atrioventricular Nodal Reentry/diagnosis
5.
J Am Coll Cardiol ; 30(5): 1339-45, 1997 Nov 01.
Article in English | MEDLINE | ID: mdl-9350937

ABSTRACT

OBJECTIVES: This study demonstrates that exercise-provocable tachycardia resembling right ventricular outflow tract tachycardia may originate from the anterobasal left ventricle. BACKGROUND: Reentry is the operative mechanism of idiopathic left ventricular tachycardia, with a QRS complex of right bundle branch block and superior axis that is responsive to verapamil but not adenosine. Whether some mechanism other than reentry is operative in some idiopathic left ventricular tachycardias is unclear. METHODS: In 4 of 53 consecutive patients with idiopathic left ventricular tachycardia, the tachycardia was sensitive to adenosine. These four patients were women 63, 61, 61 and 31 years old and were the subjects of the present study. RESULTS: In all four patients, spontaneous tachycardia was related to exercise or emotional stress. The tachycardia displayed atypical left (one patient) or right (three patients) bundle branch block with an inferior axis and marked variation in cycle length. An intravenous bolus of adenosine triphosphate (10 to 20 mg) terminated tachycardia in all four patients. Tachycardia was terminated or prevented in three patients given intravenous or oral verapamil. Atrial or ventricular incremental or extrastimulus testing induced tachycardia in all four patients (three with, one without isoproterenol infusion). Electrically induced tachycardia also demonstrated marked variation in cycle length, which ranged from 230 to 390 ms. Entrainment was not demonstrable with overdrive pacing from multiple sites. Endocardial mapping during tachycardia revealed that the earliest activations were registered 25, 40, 35 and 50 ms before onset of the QRS complex, respectively, from the anterior aspect of the left ventricle just below the mitral annulus, adjacent to the left ventricular outflow tract. High frequency Purkinje spikes were not recorded at this site. Radiofrequency current delivered to this site successfully ablated the tachycardia in three of the four patients. CONCLUSIONS: Exercise-provocable, catecholamine-mediated, verapamil-responsive, adenosine-sensitive ventricular tachycardia may arise from the anterobasal left ventricle adjacent to the outflow tract.


Subject(s)
Tachycardia, Ventricular/physiopathology , Adenosine/therapeutic use , Adult , Anti-Arrhythmia Agents/therapeutic use , Electrocardiography , Electrophysiology , Female , Humans , Middle Aged , Tachycardia, Ventricular/drug therapy
6.
J Am Coll Cardiol ; 30(4): 1024-31, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9316534

ABSTRACT

OBJECTIVES: This study sought to assess the possibility of ablating verapamil-responsive idiopathic left ventricular tachycardia at a site distant from the tachycardia exit and thus to define the tachycardia circuit. BACKGROUND: The nature of the reentry circuit in idiopathic left ventricular tachycardia is unclear. If the circuit is of considerable size, then it should be possible to ablate the tachycardia at a site distant from the exit site. METHODS: Electrophysiologic studies and radiofrequency ablation were performed in 27 consecutive patients with verapamil-responsive idiopathic left ventricular tachycardia. In all 27 patients, the tachycardia exit site was defined as the site where the earliest Purkinje potential was recorded > or = 25 ms before the onset of the QRS complex during the tachycardia and where the pace map QRS complex resembled that during the tachycardia. A potential ablation site other than the exit site was then sought around the midseptum, proximal to the exit site. At such sites the tachycardia could be terminated transiently by pressure applied to the catheter tip, without induction of ventricular ectopic beats. RESULTS: The potential ablation site, other than the tachycardia exit site, was identified in seven male patients (mean [+/-SD] age 31 +/- 12 years, range 13 to 52). Application of the radiofrequency current at this site resulted in termination of the tachycardia within 1 to 5 s (mean 2.9 +/- 1.6), and successful ablation of the tachycardia was achieved in all seven patients (success rate 100%, 95% exact confidence interval 0.5898 to 1). The mean distance between the ablation site and the tachycardia exit site was 3.1 +/- 0.7 cm (range 2.0 to 4.0). A presystolic Purkinje spike was recorded 14 +/- 5 ms (range 8 to 20) before the onset of the QRS complex during the tachycardia. During the follow-up period of 24 +/- 11 months (range 12 to 39), there was no recurrence of tachycardia in these seven patients. CONCLUSIONS: Successful ablation of idiopathic left ventricular tachycardia can be achieved at sites away from the tachycardia exit site in some patients. This finding suggests that the reentry circuit is likely to be of considerable size, encompassing the middle, inferior and lower aspects of the left interventricular septum.


Subject(s)
Catheter Ablation/methods , Heart Conduction System/physiopathology , Heart Conduction System/surgery , Tachycardia, Ventricular/physiopathology , Tachycardia, Ventricular/surgery , Action Potentials , Adolescent , Adult , Catheter Ablation/standards , Electrocardiography , Female , Follow-Up Studies , Heart Conduction System/pathology , Heart Septum/pathology , Heart Ventricles/pathology , Humans , Male , Middle Aged , Recurrence , Tachycardia, Ventricular/pathology , Treatment Outcome
7.
J Am Coll Cardiol ; 33(2): 376-84, 1999 Feb.
Article in English | MEDLINE | ID: mdl-9973017

ABSTRACT

OBJECTIVES: The main objective of this study was to characterize the phenomenon of variation in the P-QRS relation during atrioventricular node reentry tachycardia. BACKGROUND: Variation of P-QRS relation during tachycardia has been observed occasionally in atrioventricular node reentry tachycardia. However, the incidence, the characteristics and the mechanisms of this phenomenon have not been investigated previously. METHODS: Retrospective analysis was performed in 311 consecutive patients with slow-fast form and 108 patients with atypical or multiple form of atrioventricular node reentry tachycardia to examine whether variation of P-QRS relation with changes in AH, HA and AH/HA (A = atria; H = His bundle) ratio occurred during tachycardia. RESULTS: A total of 28 patients, 8 with slow-fast and 20 with atypical or multiple tachycardias, were found to manifest this phenomenon. There were 6 males and 22 females, with an average age of 38+/-16 years. In 10 patients, this phenomenon occurred transiently following electrical induction of the tachycardia. In 15 patients, changes in AH, HA and AH/HA ratio were associated with the occurrence of Wenckebach or 2:1 block proximal to the His bundle (H) recording site without interruption of the tachycardia. In nine patients, three with nonsustained tachycardia and six after administration of adenosine triphosphate, this phenomenon was observed at the termination of the tachycardia. This phenomenon was usually accompanied by a mild lengthening of the tachycardia cycle length. CONCLUSIONS: Variation of P-QRS relation with or without block may occur during atrioventricular node reentry tachycardia, especially in atypical or multiple-form tachycardias. It was postulated that decremental conduction in the distal common pathway, which exists between the distal link of the reentry circuit and the H, is primarily responsible for this phenomenon.


Subject(s)
Electrocardiography , Heart Rate , Tachycardia, Atrioventricular Nodal Reentry/physiopathology , Adenosine Triphosphate/administration & dosage , Adenosine Triphosphate/therapeutic use , Adolescent , Adult , Aged , Aged, 80 and over , Atrioventricular Node/physiopathology , Bundle of His/physiopathology , Cardiac Pacing, Artificial , Child , Female , Follow-Up Studies , Humans , Injections, Intravenous , Male , Middle Aged , Retrospective Studies , Tachycardia, Atrioventricular Nodal Reentry/therapy
8.
Am J Cardiol ; 71(13): 1174-80, 1993 May 15.
Article in English | MEDLINE | ID: mdl-8480643

ABSTRACT

The presence of multiple accessory pathways was noted in 24 of 210 consecutive patients (12 males and 12 females aged 15 to 77 years [mean +/- SD 43 +/- 16]) with the Wolff-Parkinson-White syndrome who underwent electrophysiologic study and radiofrequency ablation. Six had 3 and 18 had 2 accessory pathways. There were 25 manifest and 29 concealed accessory pathways. The location of the accessory pathways was in the left free wall in 22, the right free wall in 17, the left posterior portion of the ventricular septum in 8, the right posterior portion of the ventricular septum in 6, and the midseptum in 1. The success rate of accessory pathway ablation and the fluoroscopic time in these 24 patients with multiple accessory pathways were 89% and 78 +/- 66 minutes, respectively, whereas they were 98% (p < 0.01) and 36 +/- 37 minutes (p = 0.01) in the 186 patients with a single accessory pathway. The mean applications, the power level of the radiofrequency current and the application duration in these 24 patients were 21 +/- 22, 30 +/- 3 W, and 27 +/- 10 seconds, respectively. In the 186 patients with a single accessory pathway, they were 9 +/- 12 applications (p = 0.02), 30 +/- 4 W (p = NS) and 26 +/- 9 seconds (p = NS), respectively. Seventeen of the 24 patients had a follow-up electrophysiologic study 89 +/- 40 days after ablation, and 2 (12%) had resumption of a right and left accessory pathway conduction.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Catheter Ablation , Heart Conduction System/surgery , Wolff-Parkinson-White Syndrome/physiopathology , Wolff-Parkinson-White Syndrome/surgery , Adolescent , Adult , Aged , Electrocardiography , Female , Follow-Up Studies , Humans , Male , Middle Aged , Treatment Outcome
9.
Am J Cardiol ; 81(4): 500-3, 1998 Feb 15.
Article in English | MEDLINE | ID: mdl-9485145

ABSTRACT

Clinical and electrophysiologic parameters were analyzed to define the factors potentially related to tachycardia recurrences in 79 patients undergoing successful radiofrequency ablation of idiopathic right or left ventricular tachycardia. It was found that the endocardial activation time at the successful ablation site was the only independent predictor of tachycardia recurrences.


Subject(s)
Catheter Ablation , Tachycardia, Ventricular/surgery , Adolescent , Adult , Aged , Aged, 80 and over , Child , Electrocardiography , Female , Follow-Up Studies , Humans , Male , Middle Aged , Recurrence , Tachycardia, Ventricular/physiopathology , Treatment Failure
10.
Am J Cardiol ; 73(1): 50-6, 1994 Jan 01.
Article in English | MEDLINE | ID: mdl-8279377

ABSTRACT

Fourteen patients (5%) with an intermediate septal accessory pathway were identified among 283 consecutive patients with the Wolff-Parkinson-White syndrome who had electrophysiologic study and radiofrequency ablation therapy. Nine were women and 5 were men (mean age 33 +/- 13 years). The resting electrocardiogram showed ventricular preexcitation in 8 patients and normal PR interval in 6. Anterograde and retrograde mapping studies revealed that the accessory pathway was para-Hisian in 11 patients and paranodal in 3. The accessory pathway was successfully ablated in 10 patients (9 para-Hisian and 1 paranodal) and damaged in 1 (para-Hisian). Treatment of 3 patients was complicated by transient atrioventricular (AV) block, of 1 by intermittent second-degree AV block, and of another by permanent complete AV block requiring implantation of a permanent pacemaker. Six patients underwent a follow-up electrophysiologic study 84 +/- 55 days after ablation; none had induction of tachycardia even after isoproterenol infusion. It is concluded that radiofrequency ablation therapy for intermediate septal accessory pathway is feasible. However, the success rate is only modest (71%), whereas complications with heart block (36%) or complete right bundle branch block (29%) are high. Thus, the procedure should be reserved for patients with life-threatening or troublesome symptomatic tachyarrhythmias.


Subject(s)
Catheter Ablation , Wolff-Parkinson-White Syndrome/surgery , Adolescent , Adult , Catheter Ablation/adverse effects , Electrocardiography , Electrophysiology , Female , Heart Block/etiology , Humans , Male , Middle Aged , Treatment Outcome , Wolff-Parkinson-White Syndrome/physiopathology
11.
Chest ; 107(1): 41-5, 1995 Jan.
Article in English | MEDLINE | ID: mdl-7813307

ABSTRACT

An electrophysiologic study followed by transcatheter radiofrequency ablation therapy was performed in two adult patients with a permanent form of junctional tachycardia. Both patients had no structural heart disease and exhibited a normal resting ECG. The P wave during tachycardia was negative in leads 1, 3, and aVF, biphasic over V6, and positive in V1 and aVL in both patients, while the P-R/R-P interval ratio during tachycardia was 0.82 and 0.36, respectively, in both patients. Both patients displayed an eccentric atrial activation sequence with the earliest atrial activation occurring at the distal coronary sinus and a decremental retrograde conduction property during incremental ventricular pacing, suggesting the presence of a concealed slowly conducting left free wall accessory pathway. The tachycardia used the normal atrioventricular pathway for anterograde conduction and the concealed show left accessory pathway for retrograde conduction. It was terminated following adenosine administration in both patients; termination of tachycardia was due to a block in the retrograde accessory pathway in one patient and due to a block in the atrioventricular node in the other patient. Radiofrequency ablation was performed by the retrograde transaortic approach. The radiofrequency f4p4ent was delivered to the site of the earliest atrial activation during tachycardia at the ventricular aspect of the mitral annulus. The successful ablation site had a ventriculoatrial (VA) interval of 120 and 130 ms, respectively, and was located at the posterolateral and lateral aspects of the mitral annulus. Following ablation, there was no VA conduction; however, conduction through the normal atrioventricular pathway was noted during isoproterenol infusion in both patients. There was no induction of tachycardia. This study demonstrates that the permanent form of junctional tachycardia in adults can incorporate a concealed left free wall accessory pathway with a decremental property. Radiofrequency ablation therapy is effective and safe in this form of arrhythmia.


Subject(s)
Catheter Ablation , Heart Conduction System/physiopathology , Tachycardia, Supraventricular/surgery , Adult , Cardiac Pacing, Artificial , Electrocardiography , Female , Humans , Male , Tachycardia, Paroxysmal/physiopathology , Tachycardia, Paroxysmal/surgery , Tachycardia, Supraventricular/physiopathology
12.
Chest ; 106(3): 963-5, 1994 Sep.
Article in English | MEDLINE | ID: mdl-7915980

ABSTRACT

Head-up tilt test was done in a 27-year-old man with recurrent syncope of unexplained cause. Severe sinus bradycardia and hypotension accompanied by light-headedness, cold sweating, and nausea occurred at 80 degrees head-up position during 4 micrograms/min isoproterenol infusion. Oral propranolol, 160 mg/d, in four divided doses, effectively prevented the above-mentioned abnormal vasovagal reflexes; diltiazem was only partially effective while disopyramide, aminophylline, or atropine was ineffective in preventing the abnormal vasovagal reflexes induced by head-up tilt with isoproterenol infusion. However, the patient experienced ten episodes of syncope in 2 weeks after he was discharged from the hospital on a regimen of atenolol, 50 mg/d. His symptoms ameliorated immediately after discontinuation of atenolol therapy and he became free of severe symptoms while receiving fludrocortisone. Thus, we have documented a patient with worsening of vasovagal syncope after beta-blocker therapy.


Subject(s)
Adrenergic beta-Antagonists/adverse effects , Syncope/complications , Adult , Electrocardiography/drug effects , Fludrocortisone/therapeutic use , Humans , Male , Posture , Recurrence , Syncope/diagnosis , Syncope/drug therapy
13.
Chest ; 105(3): 937-8, 1994 Mar.
Article in English | MEDLINE | ID: mdl-8131568

ABSTRACT

Electrophysiologic study and radiofrequency ablation therapy were performed in a 28-year-old male patient with the Wolff-Parkinson-White syndrome and electrocardiographic manifestation of concertina phenomenon. His bundle recordings showed a sinus cycle length of 720 = ms with a cyclic variation of QRS morphologies of every 3 beats and an antidromic atrial echo following the last fully preexcited QRS complex. After successful radiofrequency ablation of a left posterior accessory pathway, spontaneous 3:2 atrioventricular nodal Wenckebach periodicity was noted and the mechanism of the concertina phenomenon was unraveled.


Subject(s)
Atrioventricular Node/physiopathology , Electrocardiography , Heart Block/physiopathology , Wolff-Parkinson-White Syndrome/physiopathology , Adult , Cardiac Pacing, Artificial , Catheter Ablation , Heart Block/diagnosis , Humans , Male , Wolff-Parkinson-White Syndrome/diagnosis , Wolff-Parkinson-White Syndrome/surgery
14.
Int J Cardiol ; 54(1): 33-40, 1996 Apr 19.
Article in English | MEDLINE | ID: mdl-8792183

ABSTRACT

Radiofrequency ablation therapy was conducted in 86 consecutive children and young patients with a mean age of 14 +/- 3 years (range = 3-18). Fifty-two patients had Wolff-Parkinson-White syndrome, one had re-entry tachycardia incorporating a nodoventricular fiber, 22 had atrioventricular node re-entry tachycardia, two had atrial tachycardia and nine had idiopathic ventricular tachycardia. Radiofrequency ablation was successful in 50 of the 52 patients (96%) with Wolff-Parkinson-White syndrome and the one with nodoventricular fiber. Radiofrequency modification of the atrioventricular node using the inferior approach was successful in eliminating atrioventricular node re-entry tachycardia in 20 of the 22 patients (91%). Radiofrequency ablation in the two patients with atrial tachycardia was unsuccessful. Of the nine patients with idiopathic ventricular tachycardia, eight from the left ventricle and one from the right ventricular outflow tract, eight were successfully ablated (88%). Follow-up over a period ranging from 1 to 46 months (21 +/- 13) revealed a recurrence of tachycardia in seven patients; a late electrophysiological study in 38 patients revealed the induction of tachycardia in 11 patients (seven with accessory pathway-mediated tachycardia, three with atrioventricular node re-entry tachycardia and one with idiopathic ventricular tachycardia). All 11 patients were successfully ablated by a second trial. In conclusion, radiofrequency ablation therapy is effective and safe in pediatric patients with supraventricular and ventricular tachycardia and should be considered as the therapy of choice in this group of patients.


Subject(s)
Catheter Ablation , Tachycardia, Supraventricular/surgery , Tachycardia, Ventricular/surgery , Adolescent , Catheter Ablation/adverse effects , Child , Child, Preschool , Female , Humans , Male , Prognosis , Tachycardia, Supraventricular/physiopathology , Tachycardia, Ventricular/physiopathology
15.
J Formos Med Assoc ; 92(4): 330-5, 1993 Apr.
Article in English | MEDLINE | ID: mdl-8104580

ABSTRACT

Four apolipoprotein B (apoB) genetic polymorphisms, the AluI, XbaI, MspI and EcoRI restriction fragment length polymorphisms (RFLPs), were analyzed for 162 individuals in Taiwan by polymerase chain reaction. Allele frequency determination revealed that this population has 0.86 AluI- (A-), 0.99 XbaI- (X-), 1.0 MspI+ (M+), and 0.98 EcoRI+ (E+) alleles. Major genotypes were A-/A- (0.75), X-/X- (0.98), M+/M+ (1.0) and E+/E+ (0.96). There were 0.22 A-/A+, 0.02 X-/X+ and 0.04 E+/E- heterozygous genotypes and one minor homozygous A+/A+ (0.03) genotype. The XbaI allele frequency is similar to that found in the Japanese population (XbaI- 0.96), but is significantly different from that in Caucasians (XbaI- 0.31-0.54). Significant differences (p < 0.001) between the Taiwanese and Caucasians were also observed for the AluI, EcoRI and MspI RFLP alleles of the apoB gene. More heterozygous genotypes are observed in Caucasians than in the Taiwanese.


Subject(s)
Apolipoproteins B/genetics , Polymorphism, Restriction Fragment Length , Adult , Aged , Asian People , Base Sequence , DNA , Gene Frequency , Humans , Middle Aged , Molecular Sequence Data , Taiwan , White People
16.
J Formos Med Assoc ; 99(5): 367-74, 2000 May.
Article in English | MEDLINE | ID: mdl-10870325

ABSTRACT

BACKGROUND AND PURPOSE: Apolipoprotein (APO) A1-CIII genes are linked within a 2.6-kb region on human chromosome 11. ApoA1 is the main component of high-density lipoprotein (HDL), and apoCIII inhibits lipoprotein lipase activity. Genetic variations in APOA1-CIII may affect the function of apoA1/apoCIII and plasma lipid/lipoprotein levels, and thus, the risk of developing atherosclerosis. This study compared the frequency distributions of genetic variations in APOA1-CIII genes and their influence on plasma lipid concentrations in Taiwanese patients with coronary artery disease (CAD) and in healthy controls. METHODS: Six restriction site variations (RSVs) of the APOA1-CIII gene complex were investigated by DNA amplification using polymerase chain reaction and restriction enzyme digestion in 229 control subjects and 131 CAD patients during the period from 1992 through 1996. The blood lipid profiles of these subjects were also determined. RESULTS: Thirty-seven distinct six-RSV genotypes were observed. Separate comparisons of the frequency distributions of the six genetic variations showed no significant differences between CAD patients and controls subjects, but the combined six-RSV-genotypes showed different frequency distributions between these two groups. Nine of the 37 six-RSV genotypes were found only in the CAD patients and higher frequencies of two of these types were observed in the CAD patients than in healthy controls. The effects of these genetic variations were on high-density lipoprotein cholesterol in women (for MspIB, PstI, SstI and PvuII RSV) and total cholesterol (for PvuII RSV), low-density lipoprotein cholesterol (for XmnI RSV), and apolipoprotein B (for MspI and SstI RSV) levels in men in the control group. Elevated plasma apoCIII concentration was significantly associated with an increased plasma triglyceride level and body mass index in the control group (P < 0.0001). CONCLUSIONS: Analysis of the frequency distribution of six RSVs of the APOA1-CIII gene complex in Taiwanese CAD patients and control subjects showed that the effect of genotype on plasma lipid levels was gender-specific and that the apoCIII level was closely associated with plasma triglyceride level and body mass index.


Subject(s)
Apolipoprotein A-I/genetics , Apolipoproteins C/genetics , Body Mass Index , Polymorphism, Genetic , Triglycerides/blood , Alleles , Apolipoprotein C-III , Apolipoproteins C/blood , Chromosome Mapping , Female , Genotype , Humans , Male
17.
J Formos Med Assoc ; 98(6): 403-9, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10443063

ABSTRACT

Appropriate control of blood pressure has been shown to reduce morbidity and mortality in patients with hypertension. Losartan potassium, a selective antagonist of the angiotensin II type 1 (AT1) receptor, has been shown to lower blood pressure in patients with hypertension. The purpose of this study was to compare the efficacy and tolerability of losartan and extended-release (ER) felodipine in Taiwanese patients with mild to moderate hypertension. Patients with mild to moderate hypertension (sitting diastolic blood pressure, 95-115 mm Hg) were enrolled in this prospective, randomized, parallel study. Sitting blood pressure, heart rate, adverse reactions, and serum biochemistry values were assessed during 2 weeks of placebo and 12 weeks of active treatment. Each patient received 50 mg of losartan or 5 mg of felodipine ER once daily, and the dosage was adjusted to double the initial level at week 6 if necessary. Of the 44 patients randomly allocated to receive losartan (n = 23) or felodipine (n = 21) therapy, 37 completed the study; three patients in the losartan group and four in the felodipine group withdrew because of adverse experiences, or were lost to follow-up. The mean reductions in sitting diastolic blood pressure at 6 and 12 weeks were significant with both losartan (-8.6 and -11.38 mm Hg, respectively) and felodipine (-9.2 and -10.69 mm Hg, respectively), and did not differ significantly between the two groups. Both losartan and ER felodipine were well tolerated by patients. However, the ER felodipine group had a significantly higher rate of drug-related flushing than the losartan group (24% vs 0%, p = 0.022). The results indicate that once-daily administration of losartan is as effective and well tolerated as once-daily ER felodipine in blood pressure reduction.


Subject(s)
Antihypertensive Agents/therapeutic use , Felodipine/therapeutic use , Hypertension/drug therapy , Losartan/therapeutic use , Adult , Aged , Analysis of Variance , Delayed-Action Preparations , Female , Humans , Male , Middle Aged , Prospective Studies
18.
J Formos Med Assoc ; 89(5): 413-7, 1990 May.
Article in Zh | MEDLINE | ID: mdl-1977855

ABSTRACT

A total of 103 cases with ocular involvement of Behcet's disease, seen over a period of 19 years (1970 to 1988), were collected from the ophthalmological departments of 6 major medical centers in Taiwan. The yearly number of patients who first visited these hospitals from 1979 through 1983 was about 5 cases and about 14 cases from 1984 to 1988. The domiciles of the patients were most commonly (51.5%) in Northern Taiwan. All 103 patients were Chinese, of which 78 (75.7%) were men and 25 (24.3%) were women; the male to female ratio was 3.1. Extraocular symptoms of Behçet's disease, major or minor, and their frequencies among these patients included; oral ulcers, 97.1%, skin lesions, 74.8%; genital ulcers, 61.2%; arthritis, 47.6%; gastrointestinal lesions, 14.6%; epididymitis, 5.8%; central nervous system lesions, 2.9%; vascular lesions, 1.9%; pulmonary lesions, 2.9% and urinary lesions, 4.9%. Fifty-one (49.5%) patients were of the complete type and 52 (50.5%) of the incomplete type. The peak distribution of ages at the onset of the ocular lesions, was from 20 to 40 years. As for visual prognosis, 37.9% of the 198 diseases eyes had a visual acuity of 0.5 or better, 9.1% between 0.5 and 0.1, 25.3% between 0.1 and 0.01 and 27.8% were 0.01 or worse. In 24 (12.1%) eyes, the vision was completely lost. In HLA studies, a significantly increased incidence of HLA-A26 (p less than 0.01) and HLA-B51 (p less than 0.001) was found.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Behcet Syndrome/epidemiology , Eye Diseases/epidemiology , Adolescent , Adult , Behcet Syndrome/diagnosis , Behcet Syndrome/drug therapy , Child , Female , Humans , Male , Middle Aged , Taiwan/epidemiology
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