Role of autonomic tone in facilitating spontaneous onset of typical atrial flutter

OBJECTIVES

This study sought to study the change in autonomic tone that precedes the initiation of paroxysmal atrial flutter.

BACKGROUND

An abrupt change in the autonomic tone of the heart is an important initiating factor in the pathogenesis of ventricular tachyarrhythmias and paroxysmal atrial fibrillation. Whether the autonomic tone has a role in the initiation of paroxysmal atrial flutter has not been reported.

METHODS

Holter electrocardiographic recording was used to investigate the changes in heart rate variability before the onset of paroxysmal atrial flutter.

RESULTS

A total of 12 patients with paroxysmal atrial flutter were analyzed. An increase in the normalized value of the low frequency (LF) component and the LF/high frequency (HF) ratio and a decrease in the normalized value of the HF component began at 6 min before the onset of episodes of paroxysmal atrial flutter, which indicated that sympathovagal balance had shifted to more sympathetic predominance.

CONCLUSIONS

An increase in sympathetic modulation or vagal withdrawal, or both, may facilitate the initiation of atrial flutter.

Clinical and laboratory correlation of acute Henoch-Schönlein purpura in children

The clinical and laboratory features of 72 children with Henoch-Schönlein purpura (HSP) were examined to determine if there were associations between the laboratory indices--including white blood cell (WBC) counts, serum C-reactive protein (CRP) levels, platelet (PLT) counts--and the clinical manifestations of acute HSP. Marked leukocytosis (WBC > 15,000/mm3), elevation of serum CRP levels (> 10 mg/L) and thrombocytosis (PLT > 400 x 10(3)/mm3) were associated with gastrointestinal (GI) bleeding, but not associated with abdominal pain in the absence of GI bleeding. None of the three parameters was associated with arthritis and nephritis. Elevated serum CRP levels alone was associated with prolonged hospital course, and may serve as an indicator of disease severity in patients with HSP. GI bleeding did not occur in patients with normal WBC counts, serum CRP levels, PLT counts (0/19), but occurred in 21.7% (5/23), 50% (8/16), and 85.7% (12/14) in patients with only one, two of the three and all three laboratory abnormalities, respectively. Patients with GI bleeding had higher mean WBC, PLT counts and serum CRP levels than those with abdominal pain in the absence of GI bleeding, and than those without abdominal pain. Routine measurement of these parameters is warranted to monitor children with acute HSP.

Long-term outcome of radiofrequency catheter ablation for typical atrial flutter: risk prediction of recurrent arrhythmias

INTRODUCTION

Little is known about the predictors of recurrent atrial flutter or fibrillation after successful radiofrequency ablation of typical atrial flutter. In addition, there is only limited evidence suggesting that elimination of atrial flutter would modify the natural history of atrial fibrillation in patients who experienced both of these arrhythmias. The aims of the present study were to investigate the long-term results of radiofrequency catheter ablation and to examine the predictors for late occurrence of atrial fibrillation in a large population with typical atrial flutter.

METHODS AND RESULTS

The study population consisted of 144 patients (mean age 56 +/- 18 years) with successful ablation of clinically documented typical atrial flutter. In the first 50 patients, successful ablation was defined as termination and noninducibility of atrial flutter; for the subsequent 94 patients, successful ablation was defined as achievement of bidirectional isthmus conduction block and no induction of atrial flutter. The clinical and echocardiographic variables were analyzed in relation to the late occurrence of atrial flutter or fibrillation. Over the follow-up period of 17 +/- 13 months, 14 (9.7%) patients had recurrence of typical atrial flutter. In the first 50 patients, 8 (16%) had recurrence of atrial flutter, compared with only 6 (6%) of the following 94 patients. Patients with incomplete isthmus block had a significantly higher incidence of recurrent atrial flutter than those with complete isthmus block (6/16 vs 0/78, P < 0.0001) in the following 94 patients. There was no predictor for recurrence of atrial flutter after successful ablation as determined by univariate and multivariate analysis. Although successful ablation of atrial flutter eliminated atrial fibrillation in 45% of patients with a prior history of atrial fibrillation, 31 (21.5%) of 144 patients undergoing this procedure developed atrial fibrillation during the follow-up period. Univariate analysis revealed that three clinical variables were related to the occurrence of atrial fibrillation: (1) the presence of structural heart disease; (2) a history of atrial fibrillation before ablation; and (3) inducible sustained atrial fibrillation after ablation. By multivariate analysis, only a history of atrial fibrillation and inducible sustained atrial fibrillation could predict the late development of atrial fibrillation after atrial flutter ablation.

CONCLUSION

Radiofrequency catheter ablation of typical atrial flutter is highly effective and associated with a low recurrence rate of atrial flutter, but atrial fibrillation continues to be a long-term risk for patients undergoing this procedure. The presence of structural heart disease and prior spontaneous or inducible sustained atrial fibrillation increases the risk of developing atrial fibrillation.

Atrioventricular node reentrant tachycardia in patients with a prolonged AH interval during sinus rhythm: clinical features, electrophysiologic characteristics and results of radiofrequency ablation

Among a consecutive series of 600 patients who underwent radiofrequency catheter ablation for AV node reentrant tachycardia, 14 patients (age 29-76 years) had a prolonged AH interval during sinus rhythm (172 +/- 18 ms, range 140 to 200). Seven of them had unsuccessful ablation during the previous ablation sessions. Eight patients with anterograde dual AV node pathway physiology received anterograde slow pathway ablation, and the other 6 patients without dual-pathway physiology received retrograde fast pathway ablation. All patients had successful elimination of AV nodal reentrant tachycardia after a mean of 4 +/- 4 radiofrequency applications, power level 36 +/- 6 watts and a pulse duration of 42 +/- 4 seconds. The postablation AH interval remained unchanged. During a follow-up period of 25 +/- 13 months, one patient who received slow pathway ablation developed 2:1 AV block with syncope. As compared with the other 586 patients without a prolonged AH interval, these 14 patients had significantly poorer anterograde AV nodal function and lower incidence of anterograde dual AV node physiology (P < 0.01). We concluded that slow pathway ablation in patients with dual pathway physiology, and retrograde fast pathway ablation in patients without dual pathway physiology were effective and safe in patients with a prolonged AH interval. However, delayed onset of symptomatic AV block is possible and careful follow-up is necessary.

Idiopathic monomorphic ventricular tachycardia: clinical outcome, electrophysiologic characteristics and long-term results of catheter ablation

Ventricular tachycardia (VT) without structural heart disease or any identifiable predisposing causes for arrhythmia is an uncommon but well-recognized clinical entity. The purpose of this study is to assess the results of catheter ablation therapy and the long-term outcome of patients with idiopathic monomorphic VT in a large patient group. Sixty-one consecutive patients (male/female=40/21; mean age 38+/-16 years) with idiopathic VT underwent electrophysiologic study and an attempt of catheter ablation therapy. The 'left VT' group included 31 patients with QRS morphology of right bundle branch block during VT suggestive of the VT originating from the left ventricle (LV), and the 'right VT' group consisted of 30 patients with QRS morphology of left bundle branch block with normal or right frontal axis deviation suggestive of VT arising from right ventricular outflow tract (RVOT). Idiopathic left VT has sustained VT during the clinical attacks, baseline electrophysiologic study or after isoproterenol infusion; it can be entrained by overdrive ventricular pacing, terminated by verapamil, but not by adenosine (except one case with VT focus at left ventricular free wall). Catheter ablation was successful in 22 (84%) of 26 patients, with recurrence rate of 9%. The successful ablation sites were located at LV inferior-apical septum (16 patients), mid-septum (three patients), high septum (two patients) and high anterior wall (one patient). In the right VT group, 20 (67%) of 30 patients presented clinically repetitive monomorphic VT. Most of the idiopathic right VT (22/30) required isoproterenol to facilitate induction of VT, and were sensitive to both verapamil and adenosine. Successful catheter ablation was achieved in 21 (84%) of 25 patients, with recurrence rate 19%. The successful ablation sites were located at RVOT-septum in 18 patients, and RVOT-free wall in three patients. During a mean follow-up period of 29.2+/-21.7 months (range 1-76 months) after hospital discharge, all patients were alive but one left VT case died of non-cardiovascular cause. We concluded that idiopathic left side and right side VTs have their distinct clinical, electrophysiologic and electropharmacological characteristics suggestive of different underlying mechanisms, and both have a benign prognosis. Furthermore, catheter ablation can be effective in eliminating idiopathic VT originating from the right ventricular outflow tract and left ventricle.

Identification of fiber orientation in left free-wall accessory pathways: implication for radiofrequency ablation

Previous reports on the anatomic discordance between atrial and ventricular insertion sites of left free-wall accessory pathways were limited and their findings were controversial. The purpose of this study was to explore the fiber orientation and related electrophysiologic characteristics of left free-wall accessory pathways. The study population comprised 96 consecutive patients with a single left free-wall accessory pathway (33 manifest and 63 concealed pathways), who underwent electrophysiologic study and radiofrequency catheter ablation using the retrograde ventricular approach. The atrial insertion site of the accessory pathway was defined from the cinefilms as the site with the earliest retrograde atrial activation bracketed on the coronary sinus catheter during tachycardia, and the ventricular insertion site was defined as the site where successful ablation of the pathway was achieved. Forty-two patients (44%) had their atrial insertion sites 5-20 mm (10 +/- 3 mm) distal to the ventricular insertion sites (proximal excursion), 30 (31%) patients had their atrial insertion sites 5-20 mm (12 +/- 3 mm) proximal to the ventricular insertion sites (distal excursion), and 24 (25%) patients had directly aligned atrial and ventricular insertion sites. Retrograde conduction properties, including 1:1 VA conduction and effective refractory period, were significantly poorer in the pathways with proximal excursion (302 +/- 67, 285 +/- 61 ms respectively) than in those with distal excursion (264 +/- 56, 250 +/- 48 ms respectively) or direct alignment (272 +/- 61, 258 +/- 73 ms respectively). Accessory pathways at the more posterior location had a significantly higher incidence of proximal excursion (P = 0.006), and those at the more anterior location had a higher incidence of distal excursion (P = 0.012). In conclusion, a wide variation in fiber orientations and related electrophysiologic characteristics was found in left free-wall accessory pathways. This may have important clinical implications for radiofrequency ablation.

Acetaminophen overdose in children and adolescents

From 1982 to 1997, 12 Chinese children were admitted to Chang Gung Memorial Hospital with acetaminophen overdose. Six subjects (one young child, and five adolescents) developed liver damage which was severe in three cases (AST > 1000 IU/L). Acetaminophen-induced liver function abnormalities were characterized by elevation of transaminase levels with ALT higher than AST(6/6), coagulopathy(5/6), thrombocytopenia (1/6), but absence of jaundice(6/6). Fortunately, none of the six patients with liver damage developed fulminant liver failure, and all recovered completely. Acetaminophen overdose can cause significant morbidity in children and adolescents. Caretakers should be well instructed to give the drug correctly. So far, acetaminophen is still considered as the drug-of-choice for antipyresis in pediatric practice. However, multicentered collaborative study is necessary to determine whether acetaminophen intoxication causes less hepatic failure in Chinese children than in Western children.

Serum osteocalcin levels of normal children in Taiwan

Osteocalcin is mainly secreted by osteoblasts, and then diffuses into blood which can be detected by several experimental methods. This study determined the osteocalcin level by solid phase fluorescent immunosorbent assay (Pharmacia CAP; Sweden), a well-established and accurate laboratory method for determining the minor concentration of substances in blood. A total of 332 healthy children were enrolled in the study, including 176 boys and 156 girls ranging in age from one to fifteen years. It was concluded that (1) quantitative osteocalcin (OCs) value varies between 30.2 to 41.0 ng/ml; (2) there is an incremental tendency in both sexes until puberty; (3) girls generally have a higher osteocalcin level than boys before mid-puberty (2-12 years old). The differences are statistically significant.

Characterization of low right atrial isthmus as the slow conduction zone and pharmacological target in typical atrial flutter

BACKGROUND

Previous electrophysiological studies in patients with typical atrial flutter suggested that the slow conduction zone might be located in the low right atrial isthmus, which is a path formed by orifice of inferior vena cava, eustachian valve/ridge, coronary sinus ostium, and tricuspid annulus. The conduction characteristics during atrial pacing and responses to antiarrhythmic drugs of this anatomic isthmus were unknown.

METHODS AND RESULTS

Forty-four patients, 20 patients with paroxysmal supraventricular tachycardia (group 1) and 24 patients with clinically documented paroxysmal typical atrial flutter (group 2), were studied. A 20-pole halo catheter was situated around the tricuspid annulus. Incremental pacing from the low right atrium and coronary sinus ostium was performed to measure the conduction time and velocity along the isthmus and lateral wall in the baseline state and after intravenous infusion of procainamide or sotalol. In both groups, conduction velocity in the isthmus during incremental pacing was significantly lower than that in the lateral wall before and after infusion of antiarrhythmic drugs. Furthermore, gradual conduction delay with unidirectional block in the isthmus was relevant to initiation of typical atrial flutter. Compared with group 1, group 2 had a lower conduction velocity in the isthmus and shorter right atrial refractory period. Procainamide significantly decreased the conduction velocity, but sotalol did not change it. In contrast, sotalol significantly prolonged the atrial refractory period with a higher extent than procainamide. After infusion of procainamide, the increase of conduction time in the isthmus accounted for 52+/-19% of the increase in flutter cycle length, and 5 of 12 patients (42%) had spontaneous termination of typical flutter. After infusion of sotalol, typical flutter was induced in only 6 of 12 patients (50%) without significant prolongation of flutter cycle length.

CONCLUSIONS

The low right atrial isthmus with rate-dependent slow conduction properties is critical to initiation of typical human atrial flutter. It may be the potentially pharmacological target of antiarrhythmic drugs in the future.

Atrioventricular node reentrant tachycardia in patients with a long fast pathway effective refractory period: clinical features, electrophysiologic characteristics, and results of radiofrequency ablation

Twenty-two patients (group 1) with AV node reentrant tachycardia and a baseline fast pathway effective refractory period (ERP) > or = 500 msec were compared with 30 consecutive patients (group 2) with AV node reentrant tachycardia and a fast pathway ERP < 500 msec. Both groups underwent slow pathway ablation. In the patients with complete elimination of slow pathway, the fast pathway ERP and shortest 1:1 conduction cycle length shortened significantly after ablation but was greater in group 1 (n = 14) than in group 2 (n = 21) (125 +/- 78 msec vs 48 +/- 29 msec, p < 0.001 and 103 +/- 72 msec vs 52 +/- 30 msec, p < 0.001, respectively). In group 1, the shortening of fast pathway ERP was correlated to baseline difference between anterograde fast and anterograde slow ERP (r = 0.806, p < 0.001, slope = 1.08), and the shortening of fast pathway shortest 1:1 conduction cycle length was correlated to baseline difference between anterograde fast and anterograde slow shortest 1:1 conduction cycle length (r = 0.885, p < 0.001, slope = 1.47). During follow-up bradycardia did not develop in any patient and no one required pacing. This shortening of the fast pathway ERP and shortest 1:1 conduction cycle length after complete elimination of slow pathway reduced the concern of subsequent impairment of AV node conduction.

Serial single photon emission computed tomography imaging in patients with cerebral lupus during acute exacerbation and after treatment

Single photon emission computed tomography (SPECT) with [99mTc] HMPAO was performed sequentially every week in 4 patients with systemic lupus erythematosus (SLE), from the acute phase of neurologic involvement until normal cerebral blood flow (CBF) was detected by the scan. SPECT accurately reflects central nervous system (CNS) abnormalities in patients with SLE and correlates with subsequent improvement. Correlated with the patients' rapid clinical improvement, the brain SPECT blood flow scan demonstrated homogeneous distribution in 1 to 9 weeks. In these four patients, the defect in CBF could be reversed by optimal treatment. Brain SPECT blood flow scan may be used as a biologic marker of pathologic activity in the brain of patients with SLE.

Complex electrophysiological characteristics in atrioventricular nodal reentrant tachycardia with continuous atrioventricular node function curves

BACKGROUND

Although typical atrioventricular nodal reentrant tachycardia (AVNRT) with discontinuous AV node function curves has been well studied, there has been a lack of any significant information about AVNRT without evidence of dual AV nodal pathway physiology during atrial extrastimulus testing or atrial pacing.

METHODS AND RESULTS

Group 1 included 9 patients with continuous curves during atrial extrastimulus testing but without a jump (> or = 50 ms) of the atrial-His bundle (AH) interval during incremental atrial pacing. The maximal AH interval during atrial pacing (266 +/- 61 versus 168 +/- 27 ms, P = .007) or extrastimulus testing (290 +/- 60 versus 176 +/- 18 ms, P = .005) shortened significantly after ablation. Antegrade and retrograde AV node properties were similar before and after ablation. Group 2 included 14 patients with continuous curves and a jump of the AH interval during incremental atrial pacing. The atrial pacing cycle length with 1:1 AV conduction and effective refractory period (ERP) of the antegrade AV node increased significantly, whereas the maximal AH interval during atrial pacing (358 +/- 70 versus 203 +/- 28 ms, P = .001) or extrastimulus testing (338 +/- 75 versus 196 +/- 34 ms, P = .002) shortened significantly after ablation. Group 3 included 24 patients with discontinuous curves. The maximal AH interval during atrial pacing or extrastimulus testing and the ERP of the antegrade fast AV node shortened, whereas the ERP of the antegrade AV node increased significantly after ablation. The maximal AH interval before ablation, extent of decrease in maximal AH interval after ablation, ERP of the retrograde AV node before ablation, and tachycardia cycle length were significantly shorter in group 1 than groups 2 and 3.

CONCLUSIONS

In AVNRT with continuous AV node function curves, dual AV nodal pathway physiology may or may not be demonstrated during atrial pacing. Significant shortening of the maximal AH interval during atrial pacing after radiofrequency ablation suggests successful elimination of AVNRT.

Radiofrequency ablation-induced asystole during transaortic approach for a left anterolateral accessory pathway: a Bezold-Jarisch-like phenomenon

We present a case of cardiac asystole induced by radiofrequency catheter ablation of a left anterolateral accessory pathway in a 28-year-old woman with Wolff-Parkinson-White syndrome who was experiencing recurrent palpitation. Radiofrequency current applied on the ventricular aspect of the mitral annulus corresponding to the aforementioned site provoked profound slowing of the sinus rate preceded by disappearance of the preexcitation, and then asystole ensued. The proposed causal mechanism was a reflexogenically mediated hypotension-bradycardia syndrome (Bezold-Jarisch-like phenomenon) through stimulation of either nearby vagal afferent pathways or sensory terminal receptors at the ablation site.

Sulphasalazine therapy in chronic uveitis of children with chronic arthritis

Four children with chronic arthritis (3 juvenile rheumatoid arthritis and 1 juvenile ankylosing spondylitis) and poorly controlled chronic uveitis, were given sulphasalazine (SASP) therapy for a mean period of 3.3 years. Three patients showed an excellent response, as evidenced by a reduction of inflammatory cells in the anterior chamber of the eyes and improvement of visual acuity. The response occurred after a mean of 7.7 weeks. These data suggested SASP therapy may have a role in the treatment of chronic anterior uveitis in children with chronic arthritis.

Chronic granulomatous disease: a case report

Chronic granulomatous disease is an uncommon inherited disease with presentations of frequent pyogenic and fungal infections. In this disease, the phagocytes ingest pathogens, but the ingested microorganisms can not be killed because the cells lack the ability to convert oxygen into superoxide using the enzyme known as NADPH oxidase. We report on a patient who had experienced frequent lymphadenopathy and bacterial infections since childhood. In addition to his history of repeated bacterial infections, diagnosis was also based on abnormal findings in immunologic tests including the nitroblue tetrazolium test assay, analysis of chemiluminescence and detection of hydrogen peroxide using flow cytometry. He received prophylactic treatment with antibiotics, and the condition remained stable during a six-month follow-up period.

Electrophysiologic characteristics and radiofrequency catheter ablation in atrioventricular node reentrant tachycardia with second-degree atrioventricular block

INTRODUCTION

Detailed electrophysiologic study of AV nodal reentrant tachycardia (AVNRT) with 2:1 AV block has been limited.

METHODS AND RESULTS

Six hundred nine consecutive patients with AVNRT underwent electrophysiologic study and radiofrequency catheter ablation of the slow pathway. Twenty-six patients with 2:1 AV block during AVNRT were designated as group I, and those without this particular finding were designated as group II. The major findings of the present study were: (1) group I patients had better anterograde and retrograde AV nodal function, shorter tachycardia cycle length (during tachycardia with 1:1 conduction) (307 +/- 30 vs 360 +/- 58 msec, P < 0.001), and higher incidence of transient bundle branch block during tachycardia (18/26 vs 43/609, P < 0.001) than group II patients; (2) 21 (80.8%) group I patients had alternans of AA intervals during AVNRT with 2:1 AV block. Longer AH intervals (264 +/- 26 vs 253 +/- 27 msec, P = 0.031) were associated with the blocked beats. However, similar HA intervals (51 +/- 12 vs 50 +/- 12 msec, P = 0.363) and similar HV intervals (53 +/- 11 vs 52 +/- 12, P = 0.834) were found in the blocked and conducted beats; (3) ventricular extrastimulation before or during the His-bundle refractory period bundle could convert 2:1 AV block to 1:1 AV conduction.

CONCLUSIONS

Fast reentrant circuit, rather than underlying impaired conduction of the distal AV node or infranodal area, might account for second-degree AV block during AVNRT. Slow pathway ablation is safe and effective in patients who have AVNRT with 2:1 AV block.

Results of radiofrequency ablation in patients with clinically documented, but noninducible, atrioventricular node reentrant tachycardia and orthodromic atrioventricular reciprocating tachycardia

Among 1,281 patients with symptomatic supraventricular tachycardia, 34 patients (2.7%) with presumed diagnosis of atrioventricular node reentrant tachycardia and orthodromic atrioventricular reciprocating tachycardia did not have inducible tachycardia in the electrophysiologic laboratory. Application of radiofrequency energy to the presumed arrhythmogenic sites could achieve a high success rate, with a low recurrence rate in these patients.

Comparisons of oral propafenone and sotalol as an initial treatment in patients with symptomatic paroxysmal atrial fibrillation

The main goal of this study is to evaluate the safety and efficacy of propafenone versus sotalol as an initial choice of treatment in patients with symptomatic paroxysmal atrial fibrillation (AF), according to a double-blind randomized system. In the oral propafenone group (n = 41), 2 patients (5%) discontinued therapy because of gastrointestinal discomfort in 1 and dizziness in the other. Thirty-one (79%) of the 39 patients who continued the treatment had effective response to oral propafenone (>75% reduction of symptomatic arrhythmic attacks) on a mean dose of 663 +/- 99 mg/day with a decrease in attack frequency from 10 +/- 3 to 2 +/- 1 times per week. In the oral sotalol group (n = 38), 4 patients (11%) discontinued treatment because of dizziness in 2 and symptomatic bradycardia in 2. Twenty-six of the 34 patients (76%) who continued the treatment had effective response to oral sotalol on a mean dose of 200 +/- 57 mg/day with a decrease in attack frequency from 11 +/- 3 to 2 +/- 1 times per week. Comparisons of the results between propafenone and sotalol groups showed a similar incidence of intolerable (2 of 41 vs 4 of 38, p = 0.42) and tolerable side effects (10 of 39 vs 8 of 34, p = 1.0). The attack frequency at baseline (11 +/- 3 vs 10 +/- 4 times per week, p = 0.23) and after treatment (3 +/- 1 vs 3 +/- 2 times per week, p = 0.85) did not differ significantly between the 2 groups. The incidence of effective response to drugs was also similar (31 of 39 vs 26 of 34, p = 0.78). Furthermore, the decrease of symptom scores (-32 +/- 8% vs -29 +/- 7%, p = 0.18) and percentage decrease of ventricular rate (-15 +/- 4% vs -18 +/- 4%, p = 0.10) during AF were also similar between the 2 groups. In conclusion, oral propafenone and sotalol are equally effective and safe in preventing attacks and alleviating symptoms of paroxysmal AF.

Effect of high intensity drive train stimulation on dispersion of atrial refractoriness: role of autonomic nervous system

OBJECTIVES

This study evaluated the effect of high intensity drive train (S1) stimulation on the atrial effective refractory period (ERP) and its relation to the autonomic nervous system.

BACKGROUND

High intensity S1 stimulation was demonstrated to shorten the ventricular ERP and to increase dispersion of refractoriness. These effects may be due to local release of neurotransmitters. The response of the atrium and ventricle to neurotransmitters was different. The effects of high intensity S1 stimulation at the atrial tissue were evaluated.

METHODS

Forty patients without structural heart disease were studied. In group 1, 20 patients, the atrial ERP was measured at 0, 7, 14, 21 and 28 mm away from the S1 site under both twice diastolic threshold and high intensity (10 mA) S1 stimulation. The same protocol was repeated after sequential administration of propranolol (0.2 mg/kg body weight) and atropine (0.04 mg/kg). In group 2, the other 20 patients, the atrial ERP was studied at three atrial sites (high lateral right atrium [HLRA], right posterior interatrial septum [RPS] and distal coronary sinus [DCS] with twice diastolic threshold and high intensity S1 stimulation at baseline and after sequential autonomic blockade. The three atrial sites were randomly assigned as the S1 location.

RESULTS

In group 1, high intensity S1 stimulation shortened the atrial effective refractory period most prominently at the site of S1: (mean +/- SD) 13.3 +/- 6.4% (p < 0.001), 8.1 +/- 3.8% (p < 0.001), 4.8 +/- 4.3% (p < 0.001), 3.7 +/- 4.7% (p < 0.001) and 0.5 +/- 2.6% at 0, 7, 14, 21 and 28 mm from the S1 site, respectively. The effect of high intensity S1 stimulation was blunted with propranolol and autonomic blockade but persisted after atropine alone. High intensity S1 stimulation also increased dispersion of refractoriness (from 23 +/- 11 ms to 31 +/- 12 ms, p = 0.01), which was eliminated with autonomic blockade. In group 2, high intensity S1 stimulation had similar effects at different locations (ERP shortening of 10.8 +/- 2.7%, 10.8 +/- 2.2% and 12.2 +/- 4.6% at the HLRA, RPS and DCS, respectively). The responses to sequential autonomic blockade were similar to those in group 1. However, high intensity S1 stimulation at HLRA increased dispersion of refractoriness, but at DCS it reduced dispersion of refractoriness.

CONCLUSIONS

High intensity S1 stimulation led to local shortening of the atrial ERP and increased dispersion of refractoriness. These effects were blunted with propranolol and autonomic blockade. High intensity S1 stimulation at the HLRA increased dispersion of atrial refractoriness, whereas the same stimulation at the DCS decreased dispersion of atrial refractoriness.

Electrophysiologic characteristics and radiofrequency catheter ablation of fast-slow form atrioventricular nodal reentrant tachycardia

This study demonstrates that the fast-slow form of atrioventricular nodal reentrant tachycardia is usually catecholamine-sensitive and its electrophysiologic characteristics are significantly different from those of the slow-fast form. However, radiofrequency catheter ablation is a safe and effective treatment for patients with the fast-slow form of atrioventricular nodal reentrant tachycardia.

Radiofrequency catheter ablation of slow pathway in 760 patients with atrioventricular nodal reentrant tachycardia--long-term results

BACKGROUND

Although selective radiofrequency catheter ablation of the slow atrioventricular (AV) nodal pathway has provided a curative therapy for patients with AV nodal reentrant tachycardia, information about the long-term result of radiofrequency catheter ablation in patients with different types of AV nodal reentrant tachycardia was not available. This study was to investigate the long-term effect of selective slow pathway ablation in a large group of consecutive patients with AV nodal reentrant tachycardia.

METHODS

From December 1990 to June 1996, 760 consecutive patients with clinically documented AV nodal reentrant tachycardia received radiofrequency catheter ablation of antegrade and/or retrograde slow AV nodal pathway at this electrophysiologic laboratory. The data of electrophysiologic characteristics and long-term follow-up were collected. The success rate, complication rate and recurrence rate were analyzed.

RESULTS

There were 669 slow-fast form AV nodal reentrant tachycardia, 27 fast-slow form AV nodal reentrant tachycardia, 13 variant form AV nodal reentrant tachycardia, and 51 multiple forms of AV nodal reentrant tachycardia. The electrophysiologic characteristics were different among these four groups. However, radiofrequency catheter ablation attained a 99% success rate in all the four groups with different types of tachycardia. There were 5 accidental injuries to AV conduction. Three of the 5 patients needed implantation of pacemakers. During the follow-up period, there were 14 (1.8%) recurrence of AV nodal reentrant tachycardia. All of the 14 patients had a successful second ablation without recurrence.

CONCLUSIONS

This study demonstrated that radiofrequency catheter ablation of slow pathway was a highly effective treatment modality for patients with various types of AV nodal reentrant tachycardia. Furthermore, the incidence of complication rate and recurrence rate were low in an experienced center.

Long-term results of radiofrequency catheter ablation in patients with Wolff-Parkinson-White syndrome

BACKGROUND

Information about the long-term results of radiofrequency catheter ablation, electrophysiologic characteristics of differently located accessory pathways, and the difference between a single accessory pathway and multiple accessory pathways was limited.

METHODS

Nine hundred and thirty-one patients with 1016 accessory pathways (APs) received electrophysiologic study and radiofrequency catheter ablation between July 1, 1989 and June 31, 1996. Group 1 included 856 (91.9%) patients with a single AP and Group 2 included 75 (8.1%) patients with multiple APs. The follow-up period was 48 +/- 37 months (range, 2 to 84 months).

RESULTS

Nine hundred and thirteen patients (98.1%) had successful ablation with a complication rate of 1.5%. In Group 1, left free wall pathways were ablated with fewer radiofrequency pulses, shorter procedure time, shorter radiation exposure time and a lower recurrence rate than those at other locations. Comparisons between Group 1 and Group 2 showed that the latter had higher incidences of antidromic tachycardia (3% vs 13%, p < 0.05) and atrial flutter/fibrillation (26% vs 37%, p < 0.05). Regarding radiofrequency catheter ablation, Group 2 needed more radiofrequency pulses (8.7 +/- 7.8 vs 5.5 +/- 7.7, p < 0.001), longer procedure time (3.3 +/- 1.4 vs 2.1 +/- 1.0 hours, p < 0.05) and radiation time (49 +/- 27 vs 29 +/- 19 minutes, p < 0.001), and a higher recurrence rate (10.6% vs 3.3%, p < 0.005) than those in Group 1. Thirty-six patients (4%) with recurrence had more right-side pathways than those without recurrence. In addition, difficult ablation (longer procedure time, longer radiation time and more radiofrequency pulses) was associated with a higher recurrence rate.

CONCLUSIONS

These findings demonstrated that a high success rate with a low recurrence and low complication rate of radiofrequency catheter ablation could be achieved in a large population with APs during a long follow-up period.

Determination of subnanogram concentrations of fentanyl in plasma by gas chromatography-mass spectrometry: comparison with standard radioimmunoassay

A method was devised to determine fentanyl plasma concentrations by GC-MS using selected-ion monitoring (SIM) with sufentanil as internal standard. This was compared with a commonly used commercial radioimmunoassay (RIA). Sample preparation for GC-MS involved basification of plasma then extraction using n-butyl chloride followed by concentration to dryness and reconstitution in toluene for chromatography. Using 1-ml plasma samples, the estimated limit of detection of fentanyl was 20 pg/ml. Blood samples for pharmacokinetic studies were split and assayed by GC-MS and RIA which had a limit of detection of 200 pg/ml. Pearson's r (r - 0.80, p < 0.0001) indicated the methods were highly correlated at all plasma concentrations. Owing to the greater sensitivity of the method, GC-MS is recommended over RIA for subnanogram determination of fentanyl in plasma.

Double-blind placebo-controlled study of oxatomide in the treatment of childhood asthma

Oxatomide is an orally active H1-histamine receptor antagonist. It has been demonstrated to have therapeutic efficacy in the treatment of allergic diseases in adults. The aim of this study was to evaluate the efficacy and safety of oxatomide in the treatment of asthma in children. Sixty-four asthmatic children of both sexes, aged between 5 and 16 years, were enrolled in this double-blind, placebo-controlled trial with a duration of 4 months. Patients were randomized chosen to receive either oxatomide with a daily dose of 1 to 2 mg/kg body weight or a placebo twice daily. Clinical evaluations including pulmonary function tests and immunological studies. The patients' impression on the effect of treatment also were recorded during the study. The effects of bronchodilatation and normalizing pulmonary function were observed 2 months after oxatomide treatment. The levels of eosinophil cationic protein and total asthma symptom scores were significantly reduced during treatment with oxatomide. There was no significant change in total IgE or IgG4 before or after treatment in either the treatment or control groups. During the study, two (5.8%) oxatomide treated patients reported slight drowsiness and one (2.9%) reported body weight gain. Routine laboratory tests showed no significant alterations. In conclusion, oxatomide was generally well tolerated in this study and may have the potential of being an effective treatment for childhood asthma.

Electrophysiologic characteristics and radiofrequency catheter ablation in patients with clockwise atrial flutter

INTRODUCTION

Although the mechanism and radiofrequency catheter ablation of counterclockwise (typical) atrial flutter have been studied extensively, information about the electrocardiographic and electrophysiologic characteristics and effects of radiofrequency ablation in patients with clockwise atrial flutter is limited.

METHODS AND RESULTS

Thirty consecutive patients with clinically documented paroxysmal clockwise atrial flutter were studied. Endocardial recordings and entrainment study using a "halo" catheter with 10 electrode pairs in the right atrium were performed. Radiofrequency energy was applied to the inferior vena cava-tricuspid annulus (IVC-TA) and/or coronary sinus ostium-tricuspid annulus (CSO-TA) isthmus to evaluate the effects of linear catheter ablation. Eighteen patients had both counterclockwise and clockwise atrial flutters, and 12 patients had only clockwise atrial flutter. Both forms of atrial flutter had similar flutter cycle lengths (232 +/- 30 vs 226 +/- 25 msec, P = 0.526) but reverse activation sequences. Right atrial pacing at a cycle length 20 msec shorter than the flutter cycle length from the CSO-TA isthmus, IVC-TA isthmus, and the area between the two isthmuses revealed concealed entrainment with stimulus-to-P wave intervals of 32 +/- 19, 95 +/- 14, and 50 +/- 17 msec (P = 0.022) in the counterclockwise form, and 110 +/- 12, 40 +/- 20, and 60 +/- 15 msec (P = 0.018) in the clockwise form. In clockwise atrial flutter, 20 patients with biphasic P waves in the inferior leads had the presumed exit site of slow conduction area located at the low posterolateral right atrium; 10 patients with positive P waves in the inferior leads had the presumed exit site located at the mid-high posterolateral right atrium. Among the 18 patients with both forms of atrial flutter, linear ablation lesions directed at the IVC-TA isthmus eliminated both forms of atrial flutter in 14 patients; in the remaining 4 patients, CSO-TA linear lesions eliminated the counterclockwise form and IVC-TA lesions eliminated the clockwise form. Among the 12 patients with the clockwise form only, CSO-TA linear lesions eliminated flutter in 2 and IVC-TA linear lesions eliminated flutter in 10 patients. Successful ablation was confirmed by creation of bidirectional conduction block in the IVC-TA and/or CSO-TA isthmus during pacing from the proximal coronary sinus and right posterolateral atrium sandwiching the linear lesions. During the follow-up period of 17 +/- 8 months, 2 patients had recurrence of clockwise atrial flutter, 1 patient had new onset of atypical atrial flutter, and 2 patients had new onset of atrial fibrillation.

CONCLUSIONS

Counterclockwise and clockwise atrial flutters may have overlapping slow conduction areas with different exit sites. Radiofrequency catheter ablation using the linear method directed at the IVC-TA and CSO-TA isthmuses was feasible and effective in treating both forms of atrial flutter.

Long-term results of radiofrequency catheter ablation in patients with multiple accessory pathways

Information on the long-term results of radiofrequency catheter ablation in a large group of patients with multiple accessory pathways (APs) was not available. This study included 858 patients with Wolff-Parkinson-White syndrome who underwent electrophysiologic study and radiofrequency catheter ablation: 73 patients (8.5%) had multiple APs. Sixty-six patients had 2 APs, 5 had 3 APs, 1 had 4 APs, and 1 had 5 APs. The most common combination pattern of these pathways were concealed APs (38 patients, 52%). Localization of accessory pathways showed a higher incidence of right free wall (22% vs 11%, p < 0.05), anteroseptal, and midseptal APs (9% vs 5%, p < 0.05) in patients with multiple APs than in patients with 1 AP. The most common anatomic sites for multiple APs were 2 APs in the left wall (21 patients, 28%). Although the success rate was similar (98% vs 99%, p > 0.05), procedure time (3.1 +/- 1.2 vs 2.0 +/- 1.1 hours, p < 0.05) and radiation exposure time (48 +/- 26 vs 29 +/- 19 minutes, p < 0.05) were longer in patients with multiple APs. The recurrence rate was higher in patients with multiple APs (9.5% vs 2.5%, p < 0.05), and the most common site of recurrent APs was in the left free wall (7.2%); in contrast, it was in the right free wall in patients with 1 AP. These findings demonstrated that a high success rate of radiofrequency catheter ablation was found in patients with multiple APs; however, the higher recurrence rate in patients with multiple APs should be considered.

Temperature and impedance monitoring during radiofrequency catheter ablation of slow AV node pathway in patients with atrioventricular node reentrant tachycardia

This study was designed to observe the changes of temperature and impedance and to find the role of temperature control in radiofrequency ablation of slow pathways in patients with AV node reentrant tachycardia. Power, impedance and temperature were measured during each application of radiofrequency energy while the generator was operated in the power control mode. A total of 760 applications were delivered in 76 patients. The success rate was 100% without recurrence during a follow-up period of 8 +/- 3 months. The mean catheter tip temperature associated with successful ablation was 51.3 +/- 5.4 degrees C (range 45 degrees C to 64 degrees C), and significantly higher than the unsuccessful pulses (48.7 +/- 6.2 degrees C, P < 0.05). The mean temperature was 49.8 +/- 3.1 degrees C during accelerated junctional rhythm, significantly higher than the pulses without this rhythm. The mean temperature correlated well with early decrease of impedance (r = 0.71, P < 0.001), and an early decrease of impedance more than 5 ohms had an 87% positive predictive value for adequate tissue heating. These data suggested that, if temperature monitoring was available, setting the target temperature at about 51 degrees C could achieve adequate tissue heating for successful ablation of slow pathway; if not, impedance monitoring with an early decrease of impedance < 5 ohms could predict adequate tissue heating.

Effects of isoproterenol in facilitating induction of slow-fast atrioventricular nodal reentrant tachycardia

This study demonstrates that patients with poorer conduction properties of the anterograde slow and retrograde fast pathways usually need isoproterenol to facilitate induction of atrioventricular nodal reentrant tachycardia. Isoproterenol infusion usually facilitates induction of tachycardia by enhancing the retrograde ventriculoatrial conduction.

Temperature monitoring in radiofrequency catheter ablation of atrial flutter using the linear ablation technique

INTRODUCTION

Information about temperature and impedance monitoring during radiofrequency catheter linear ablation of atrial flutter has not been reported. We proposed that a radiofrequency catheter ablation system using a closedloop temperature control model could decrease the incidence of coagulum formation and shorten the radiation exposure and procedure times compared with those found in a power control model.

METHODS AND RESULTS

Forty patients (8 women and 32 men; mean age 64 +/- 7 years) with atrial flutter were referred for radiofrequency ablation. The patients were randomized into two groups: group I patients underwent radiofrequency catheter linear ablation of atrial flutter using a power control of energy output model; and group II patients underwent the closedloop temperature control model with a target electrode temperature of 70 degrees C. As compared with group II, group I patients had a higher incidence of coagulum formation (12% vs 2%, P < 0.05), temperature shutdown (11% vs 0%, P < 0.01), and impedance shutdown (16% vs 3%, P < 0.01), more radiofrequency applications (7 +/- 3 vs 4 +/- 2, P < 0.01), and longer procedure time (100 +/- 25 vs 75 +/- 23 minutes, P < 0.05) and radiation exposure time (31 +/- 10 vs 20 +/- 7 minutes, P < 0.05) required for successful ablation. Larger deviations of temperature (9.0 degrees +/- 2.4 degrees C vs 5.0 degrees +/- 1.2 degrees C, P < 0.0001) and impedance (9.2 +/- 2.6 omega vs 5.3 +/- 1.6 omega, P < 0.0001) were also found in group I patients compared with those in group II.

CONCLUSIONS

This study demonstrated that a closed-loop temperature control model could facilitate the effects of radiofrequency catheter ablation of the atrial flutter circuit by decreasing coagulum formation, temperature and impedance shutdown, and procedure and radiation exposure times.

Effect of quinapril therapy on blood pressure and serotonin change in patients with mild to moderate hypertension

BACKGROUND

Previous studies have shown that serotonin plays an important role in hypertension because of its vasoconstrictive effect, mediated through serotonergic receptors. Angiotensin-II is a potent vasopressor which facilitates the aggregation of platelets, subsequently releases serotonin. Because quinapril is an angiotensin-converting enzyme inhibitor and could result in a decrease of angiotensin-II, Quinapril was used to treat patients with mild or moderate hypertension in order to observe the change of plasma serotonin.

METHODS

Twenty-two patients, (10 males, 12 females, mean age 45 yrs) without other major medical diseases and secondary causes of hypertension, were selected for this study. High performance liquid chromatography (HPLC) with electrochemical detection was used to detect the plasma serotonin. These patients were given placebos for two weeks before the first dose of quinapril (5 mg). Thereafter, the dosage was adjusted according to the response of blood pressure to a desired value (BP < 140/90 mmHg). At about 14:00 hours on the first day, after the patient had rested for an hour and was in a quiet condition, blood was drawn by venipuncture with heparin as anti coagulant; the plasma serotonin concentration was determined for the baseline value. The plasma serotonin level was rechecked eight weeks later.

RESULTS

It was found that systolic blood pressure began to decrease significantly two weeks after quinapril therapy, and then reached a constant state. Blood pressure decreased from 174/107 mmHg to 134/87 mmHg. Among these 22 patients, there were 14 (65%) whose blood pressure reduced to a normal range. Plasma serotonin also decreased significantly from 4.69 +/- /3.67 ng/ ml to 2.89 +/-2.64 ng/ml (p < 0.05). According to this data, 15 in 22 patients (68%) had reduction of plasma serotonin. There was little correlation between change in blood pressure and change of plasma serotonin; the correlation co-efficiency is only 0.019.

CONCLUSIONS

This study shows that quinapril has an antihypertensive property and serotonin-lowering effect. Since there was no correlation between the change of serotonin and blood pressure, these two actions of quinapril might have been mediated through different mechanisms.

Ileal perforation in Henoch-Schönlein purpura: report of one case

Henoch-Schönlein purpura (HSP) is a systemic vasculitis of unknown cause and abdominal pain is usually complained. Although intussusception and intestinal bleeding may occur, ileal perforation is rare. We present a case of ileal perforation following HSP in which our patient received corticosteroid on the 8th day of clinical course. Attention is focused on assessing the effect of corticosteroid and the relationships among ischemic enteritis, ileal perforation and the usage of steroid.

Electrophysiologic characteristics and anatomical complexities of accessory atrioventricular pathways with successful ablation of anterograde and retrograde conduction at different sites

INTRODUCTION

Catheter ablation may eliminate anterograde and retrograde accessory pathway conduction at closely adjacent but anatomically discrete sites. However, the mechanisms of this discrepancy, the electrophysiologic and anatomical characteristics, and information about systematic study from a large patient population are not available. The purpose of this study was to investigate the electrophysiologic characteristics and anatomical complexities of the accessory pathway in which anterograde and retrograde conduction was successfully ablated at different sites.

METHODS AND RESULTS

Thirty-eight (10.9%) patients (19 men and 19 women; mean age 37 +/- 2.4 years) fulfilling the criteria of having separate ablation sites for anterograde and retrograde conduction were designated as group I, and the other 310 patients (215 men and 95 women; mean age 47 +/- 0.6 years) were designated as group II. The patients with right-sided free-wall pathways had the highest incidence (18.6%) of separate ablation sites. The anatomical distance between anterograde and retrograde directions (left anterior oblique view, 13 +/- 0.6 vs 8 +/- 0.9 mm, P < 0.01; right anterior oblique view, 17 +/- 0.6 vs 5 +/- 0.7 mm, P < 0.01), and incidence of conduction impairment in one direction after successful ablation of another direction (15% vs 78%, P < 0.05) differed significantly between left and right free-wall pathways. The mean distances obtained from left (7 +/- 0.4 vs 14 +/- 0.4 mm, P < 0.05) and right (7 +/- 1.1 vs 15 +/- 0.9 mm, P < 0.05) anterior oblique views were shorter in patients who had impairment of conduction properties than those in patients without impaired conduction after successful ablation of one direction.

CONCLUSIONS

This study showed that anatomical and functional dissociation of the accessory pathway into anterograde and retrograde components was possible. Further study on the relation between electrophysiologic and pathologic characteristics would be helpful to confirm these findings.

The systemic and cerebral kinetics of thiopental in sheep: enantiomeric analysis

Thiopental is used as a racemate (rac-thiopental). Enantiomeric pharmacokinetic differences could therefore influence the onset and duration of anesthesia of rac-thiopental. We studied the systemic and cerebral kinetics of R(+)- and S(-)-thiopental in five adult ewes after a 2-min intravenous infusion of 500 mg rac-thiopental sodium. Systemic kinetic values were determined from the time course of concentrations in arterial plasma; cerebral kinetic values were deduced from the time course of the concentration differences between arterial and superior sagittal sinus blood plasma. Enantiomeric differences were found in both sites, with the (R:S) ratio of thiopental enantiomer blood concentrations initially being > or = 1 then decreasing to < 1 after approximately 60 min. This is consistent with the finding of the mean total body clearance of R(+)-thiopental being 17% (SD 12%) greater than that of S(-)-thiopental (P = .04). Sagittal sinus plasma concentrations of both enantiomers followed closely behind those in arterial plasma and this is consistent with facile bidirectional exchange of thiopental between plasma and brain. No significant differences were found between enantiomers in the rates of brain influx or efflux. Onset and regression of anesthesia occurred while the enantiomer blood concentrations were similar. Hence published pharmacokinetic-pharmacodynamic models of the onset of thiopental effects probably are not significantly compromised by neglecting the enantiomeric duality of thiopental, but models based on its elimination kinetics could be compromised if enantiomeric differences are neglected.

Methotrexate in the treatment of children with chronic arthritis--long-term observations of efficacy and safety

In a study to investigate the efficacy and toxicity of long-term methotrexate (MTX) therapy in children with chronic arthritis, the medical records of 26 children (seven boys and 19 girls) with juvenile rheumatoid arthritis (JRA) were reviewed retrospectively. The patients received MTX therapy for a mean of three years (range, six months to six years). A clinically significant response occurred in 19 children (73.1%): remission in ten (38.5%) and improvement (25% reduction in the number of actively inflamed joints) in nine (34.6%). Concomitant prednisolone therapy was reduced in 13 out of 14 children (93%). Haemoglobin levels and erythrocyte sedimentation rates were statistically significantly improved over baseline after MTX therapy. Six (23%) children experienced toxic effects during MTX therapy. One patient discontinued the MTX treatment after 18 months because of jaundice and raised liver enzymes. It is concluded that the study confirms the efficacy, and acceptable toxicity profile, of MTX given over a period of several years to children with JRA.

Electrophysiologic characteristics, electropharmacologic responses and radiofrequency ablation in patients with decremental accessory pathway

OBJECTIVES

This study sought to characterize the functional properties of decremental accessory atrioventricular (AV) pathways and to investigate their pharmacologic responses.

BACKGROUND

Although decremental AV pathways associated with incessant reciprocating tachycardia have been studied extensively, information about the electrophysiologic characteristics and pharmacologic responses of anterograde and retrograde decremental AV pathways is limited.

METHODS

Of 759 consecutive patients with accessory pathway-mediated tachyarrhythmia, 74 with decremental AV pathways were investigated (mean age 43 +/- 18 years). After baseline electrophysiologic study, the serial drugs adenosine, verapamil and procainamide were tested during atrial and ventricular pacing. Finally, radiofrequency catheter ablation was performed.

RESULTS

Five patients had anterograde decremental conduction over the accessory pathway but had no retrograde conduction. Of the 64 patients with retrograde decremental conduction over the accessory pathway, anterograde conduction over the pathway was absent in 41 (64%), intermittent in 5 (8%) and nondecremental in 18 (28%). In the remaining five patients, anterograde and retrograde decremental conduction over the same pathway was found. The anterograde and retrograde conduction properties and extent of decrement did not differ between anterograde and retrograde decremental pathways. Posteroseptal pathways had the highest incidences of anterograde and retrograde decremental conduction. Intravenous adenosine, procainamide and verapamil caused conduction delay or block, or both, in 10 of 10, 10 of 10 and 4 of 10 of the anterograde and 20 of 20, 20 of 20 and 8 of 20 of the retrograde decremental pathways, respectively. All patients had successful ablation of the decremental pathways without complications. During the follow-up period of 31 +/- 19 months, only one patient experienced recurrence.

CONCLUSIONS

Decremental accessory pathways usually had functionally distinct conduction characteristics in the anterograde and retrograde directions. Their pharmacologic responses suggested the heterogeneous mechanisms of decremental conduction.

Prevalence of HTLV type I infection in Iran: a serological and genetic study

Several publications describe the presence of the human T cell lymphotropic virus type I (HTLV-I) in Jewish individuals born in Mash-had, Iran. We report here the results of HTLV-I serological and genetic studies in the non-Jewish population of Mash-had as well as a neighboring area: Gonbad-Kavous. Seven hundred and seven serum samples from Mash-had (694 healthy individuals and 13 patients with lymphoma) and 90 from Gonbad-Kavous were tested for HTLV antibodies by gelatin particle agglutination assay (PA) and confirmatory Western blots (WBs). Seropositive rates of 3.0% (21 of 694) in Mash-had, 0% (0 of 90) in Gonbad-Kavous, and 100% (13 of 13) in lymphoma cases were observed. HTLV-I DNA sequence were amplified by polymerase chain reaction directly from the fresh PBMCs of seropositive individuals. Phylogenetic analysis of the viral DNA sequence indicated that the HTLV-I present in Mash-had belong to the HTLV-I cosmopolitan clade. Altogether, these data indicate that Mash-had, located in northeastern Iran, is a newly recognized endemic center for HTLV-I.

Co-existence of atrial tachycardia and common atrial flutter: electrophysiological characteristics and radiofrequency catheter ablation

Four patients, who had no prior atrial surgery, underwent radiofrequency ablation for clinically documented typical atrial flutter. In addition to typical atrial flutter re-entrant atrial tachycardia was initiated during electrophysiological study in these four patients. We used earliest atrial endocardial activation and concealed entrainment pace mapping with short stimulus-P interval (< 40 ms) to identify the exit site of slow conduction are of atrial flutter were located at the posteromedial right atrium between the coronary ostium and the tricuspid annulus and those of slow conduction area of atrial tachycardia were located at high lateral right atrium in all four patients. Radiofrequency energy applied to these exit sites successfully eliminated both atrial flutter and atrial tachycardia in these four patients. Typical atrial flutter and re-entrant atrial tachycardia with two distinct re-entrant circuits concomitantly occurring in patients without prior atrial surgery are rare. Radiofrequency ablation can abolish both atrial tachyarrhythmias in the same ablation session.

Poststreptococcal reactive arthritis: report of one case

Poststreptococcal reactive arthritis (PSRA) is a clinical syndrome of reactive arthritis. It is associated with recent streptococcal infections, but could not fulfill the revised Jones criteria for acute rheumatic fever (ARF). The incidence of PSRA cardiac complications to develop was as high as the ARF's developing into rheumatic heart disease. A 9-year-old boy presented with limping gait. He had pain in his left knee for 4 days but no fever. His right knee was swelling with a limitation of movement. A throat culture showed positive growth for group A streptococcus, and consequently antistreptolysin-O serum titer and C-reactive protein were elevated. A synovial fluid examination was turbid but sterile. After 3 days the arthralgia subsided rapidly. A cardiac color Doppler and electrocardiogram showed no evidence of valvular disease. Under the threat of high incidence of rheumatic heart disease in PSRA, we treated this patient with prophylactic antibiotics as acute rheumatic fever. A clinic follow up one year later showed neither sequels nor heart murmur on physical examination.

Congenital erythropoietic porphyria: clinical, biochemical, and enzymatic profile of a severely affected infant

Blistering of light-exposed skin, pink-stained fluorescing diapers, and fluorescing peripheral erythrocytes led to diagnosis of congenital porphyria in an infant born to consanguineous parents. Although massive coproporphyrinuria and coproporphyrinemia initially suggested a coproporphyrinogen oxidase deficiency disorder, excess porphyrins were chiefly of the isomer I series, implicating a uroporphyrinogen III synthase defect. Congenital erythropoietic porphyria was confirmed by demonstration of a profound defect in the activity of the infant's uroporphyrinogen III synthase (4% of the mean value for nine normal controls) and in both parents at approximately 50% of the mean normal activity. Coinheritance of gene defects for either hereditary coproporphyria or erythropoietic protoporphyria in addition to those for congenital erythropoietic porphyria was excluded by demonstrating normal activities of both coproporphyrinogen oxidase and ferrochelatase in the infant. The complicated perinatal and postnatal clinical course and biochemical and enzyme assay data for the infant and his parents are described.

Juvenile dermatomyositis associated with partial lipodystrophy

The case of a child who developed partial lipodystrophy and metabolic abnormalities during treatment of juvenile dermatomyositis is described and discussed.

Parotid lymphangioma. A case report

Parotid lymphangiomas occur rarely in childhood, and they are usually detected in infancy or early childhood. They grow slowly and present as painless, soft fluctuant masses. Rapid enlargement of the mass is usually associated with trauma, infection or hemorrhage into the cysts, and enlargement can lead to severe complications due to mass effect such as tracheal or esophageal compression and facial weakness. We report a case of parotid lymphangioma with clinical presentation of a rapidly enlarging mass in the left parotid region and facial palsy after aspiration of the mass at the age of 10 years. The facial weakness resolved completely when the size of mass decreased spontaneously.

High-performance liquid chromatographic determination of thiopentone enantiomers in sheep plasma

An HPLC method was developed to determine the plasma concentrations of R(+)- and S(-)-thiopentone for pharmacokinetic studies in sheep. The method required separation of the thiopentone enantiomers from the corresponding pentobarbitone enantiomers which are usually present as metabolites of thiopentone. Phenylbutazone was used as an internal standard. After acidification, the plasma sample were extracted with a mixture of ether and hexane (2:8). The solvent was evaporated to dryness and the residues were reconstituted with sodium hydroxide solution (pH 10). The samples were chromatographed on a 100 mm x 4 mm I.D. Chiral AGP-CSP column. The mobile phase was 4.5% 2-propanol in 0.1 M phosphate buffer (pH 6.2) with a flow-rate of 0.9 ml/min. This gave k' values of 1.92, 2.92, 5.71, 9.30 and 11.98 for R(+)-pentobarbitone, S(-)-pentobarbitone, R(+)-thiopentone, S(-)-thiopentone, and phenylbutazone, respectively. At detection wavelength of 287 nm, the limit of quantitation was 5 ng/ml for R(+)-thiopentone and 6 ng/ml for S(-)-thiopentone. The inter-day coefficients of variation at concentrations of 0.02, 0.1 and 8 micrograms/ml were, respectively, 4.8, 4.4 and 3.5% for R(+)-thiopentone and, respectively, 5.0, 4.3 and 3.9% for S(-)-thiopentone (n = 6 each enantiomer). At the same concentrations, the intra-day coefficients of variation from six sets of replicates (measured over six days) were, respectively, 8.0, 8.0 and 8.8% for R(+)-thiopentone and 8.8, 7.4 and 9.6% for S(-)-thiopentone. Linearity over the standard range, 0.01-40 micrograms/ml, was shown by correlation coefficients > 0.998. This method has proven suitable for pharmacokinetic studies of thiopentone enantiomers after administration of rac-thiopentone in human plasma also and would be suitable for pharmacokinetic studies of the pentobarbitone enantiomers.

Human protoporphyria: genetic heterogeneity at the ferrochelatase locus

Inherited deficiency of ferrochelatase results in erythropoietic protoporphyria (EPP). Genetic heterogeneity at the locus for human ferrochelatase was investigated. Analysis of genomic DNA of patients with EPP and of control subjects by restriction endonuclease techniques using ten different enzymes detected polymorphisms only at sites recognized by EcoRI, HincII, PstI and TaqI. None of these polymorphisms alone was specific for expression of the disease since each was observed in control subjects as well. Three of these polymorphisms (at EcoRI, HincII and PstI sites) were always associated, indicating linkage. These and other studies demonstrate that the ferrochelatase gene is markedly heterogeneous. It is not yet clear whether some of the mutations associated with these polymorphisms contribute to expression of EPP.

Sinusitis and bronchial asthma in children

Sinus disease has been assumed to exist in children with respiratory tract allergies. We consecutively evaluated 375 patients (245 male, 130 female) with childhood onset asthma, between 5 and 15 years of age (mean 7.8 years of age). Abnormal Waters radiographs were found in 205 patients (54.7%) which included mucosal wall thickening greater than 6 mm (67.3%), complete opacification (22.9%) and air-fluid levels (9.8%). The level of immunoglobulin (Ig) E was found to be much higher in non-sinusitis asthmatic children than in asthmatic children with sinusitis (1207 IU/mL vs. 644 IU/mL). The IgG, IgA, IgM and erythrocyte sedimentation rate (ESR) values were not significantly different in the two groups. All patients were treated with antibiotics for 3 to 6 weeks. Five patients required surgical intervention after antibiotic treatment had little success. Streptococcus viridans was isolated from 4 patients following surgical aspirates and Peptostreptococcus anaerobius was isolated in only one patient. In conclusion, sinusitis in children may be an aggravating factor for chronic reactive lower airway disease. Optimal treatment may decrease the need of asthmatic medication.

A hereditary C3 deficiency due to aberrant splicing of exon 10

Hereditary C3 deficiency in a 22-year-old woman was studied. Previous works indicated that C3 could not be detected in the serum of such a patient by enzyme immunoassay. In this study, we demonstrated that C3 genes of this patient and her parents have no gross structural aberration. However, C3 mRNA was almost not detectable in the skin fibroblasts of this patient. The activity of the patient's C3 upstream regulatory elements was tested and showed no functional abnormality. Using reverse-transcriptase polymerase chain reaction (RT-PCR) to amplify RNA from LPS-stimulated patient's fibroblasts, two shorter cDNAs within C3 exon 8 to exon 12 were noted. DNA sequence analysis of the RT-PCR products revealed that one deleted 116 nucleotides of the full exon 10 and the other deleted 34 nucleotides in the 3' region of exon 10. A single base substitution (G to T) in the splice donor site of intron 10 was identified. This aberrant splicing involving exon 10 could result in translational pretermination at exon 11. Thus, this mutation provided the molecular basis for the deficiency of C3 in the patient.

Acute pancreatitis: an early manifestation of systemic lupus erythematosus

Acute pancreatitis is thought to be quite uncommon in patients with systemic lupus erythematosus (SLE), especially if it is the initial manifestation of the disease. We report a 13-year-old girl with SLE whose early clinical presentation was acute pancreatitis. The disease was not related to concomitant drug therapy. It was associated with elevated serum and urine amylase levels and pancreatic enlargement by ultrasound assessment. The clinical symptoms and signs subsided after prednisolone treatment.

Thallium myocardial scintigraphy in single left coronary artery

A case of single left coronary artery is presented with the correlation between the results of thallium-201 (T1-201) myocardial single photon emission computed tomography (SPECT) and coronary angiographic findings. The chest pain in this case might be partly secondary to the myocardial ischemia, under stress, which could result from the steal phenomenon to normal perfusion myocardium due to anatomical anomaly of single left coronary artery. Our findings suggest that T1-201 myocardial SPECT could be a useful method for detecting myocardial ischemia in patients with single left coronary artery.

Dermatomyositis and polymyositis in childhood

From January 1, 1981 to December 31, 1992, we experienced nine patients with childhood onset of dermatomyositis and polymyositis. The mean age of disease onset was 12 years (range 7 to 16 years). Seven of them fulfilled the criteria of dermatomyositis, the remaining two were polymyositis. Girls were more predominant than boys in 6:3 ratio. The clinical features included extremities muscle weakness, skin rash, periorbital swelling and dysphagia. Increased muscle enzymes including creatine phosphokinase (CPK) or lactic dehydrogenase (LDH) were all positive in nine patients. All of our nine patients were treated with prednisolone after the diagnosis was established. The duration of treatment ranged from 3 to 65 months (mean: 25.3 months). Two of the nine patients also received immunosuppressive agents, hydroxychloroquine and azathioprine respectively. At present six patients survive without treatment. Two patients continue with corticosteroid and immunosuppressive therapy. One patient died from primary peritonitis, six months after being diagnosed with JDMS. In conclusion our study shows there is a female dominance; monocyclic clinical course is more common; and the prognosis is good in general, in the cases of juvenile dermatomyositis and polymyositis.