Feasibility and Safety of Two French Electrode Catheters in the Performance of Electrophysiological Studies

The aim of this study was to analyze prospectively the feasibility and safety of using 2 Fr versus 6 Fr standard electrode catheters for diagnostic electrophysiological study. Methods: Two hundred and five consecutive patients were randomized to receive the 6 Fr approach (3 quadripolar, 6 Fr, electrode catheters inserted through the left or right femoral vein and placed in the high right atrium, right ventricular apex, and His bundle area) or the 2 Fr approach (3 quadripolar, 2 Fr, electrode catheters inserted through a single, 7 Fr, triple lumen, guiding catheter and positioned at the same sites as the 6 Fr approach). Results: Introduction time was shorter in the 2 Fr group (133.3 ± 65 s, range 87–669 s) than in the 6 Fr group (242.8 ± 91.8 s, range 168–1024 s, P < 0.001). The overall fluoroscopy time was longer in the 2 Fr group (141.2 ± 40.1 s, range 78–312 s) than in the 6 Fr group (126.4 ± 39.7 s, range 58–341 s, P = 0.009). However in the last 100 patients there was no more difference between the two groups (137.6 ± 28.2 s vs 128.4 ± 23.2 s, P = 0.07). There was no significant difference between 2 Fr and 6 Fr groups in the mean atrial (5.9 ± 2.2 mV, range 2.2–11.3 mV, vs 6.1 ± 2.3 mV, range 2.4–12.4 mV, P =0.57) and ventricular (5.6 ± 2.1 mV, range 1.9–9.7 mV, vs 5.7 ± 2.2 mV, range 2.3–10.5 mV, P = 0.66) activation potential amplitudes recorded during sinus rhythm, or in the rate of stable His bundle potential recording (P = 0.3), and catheter dislodgment (P = 0.54). The overall number of complications was significantly higher in the 6 Fr group than in the 2 Fr group (29 vs 5, P = 0.001), as well as the number of entry site related complications (3 vs 12, P = 0.02) and catheter manipulation related complications (2 vs 17, P < 0.001). Conclusions: The results of this study show that the use of 2 Fr electrode catheters reduces the rates of entry site and catheter manipulation related complications during EPS. Despite their small size, these catheters allow quick and precise positioning of the electrode.     

Diagnostic Clues From the Surfaee ECG to Identify Idiopathic (Fascicular) Ventricular Tachycardia: Correlation with Electrophysiologic Findings

ECG in Idiopathic Fascicular VT. Introduction : An RS interval > 100 msec in precordial leads has been recently described for the diagnosis of ventricular tachycardia (VT). The aim of this study was to assess the value of this criterion when applied to patients with right bundle branch block pattern, left-axis deviation (fascicular) VT sensitive to verapamil.
Methods and Results : Eleven patients (mean age 31 ± 11 years; range 16 to 51) had a mean heart rate of 164 ± 37 beats/min (range 107 to 230) during VT, The QRS complex axis was -92°± -15° (range -80 to -115). The mean QRS duration was 121 ± 9 msec (range 105 to 140). The mean RS interval was 67 ± 9 msec (range 60 to 80). Fusion beats were present in 2 patients (18%), and AV dissociation confirmed by electrophysiologic study was found on ECG in 8 (73%) of 11. During tachycardia, the QRS-H'interval was 19 ± 10 msec (range 10 to 30) in 6 of 11 patients. In seven patients, a fast, unique (or double) presystolic potential lasting 32 msec (range 12 to 40) occurring before the onset of the QRS complex was found at the site of origin of VT, localized in the inferior apical left ventricular septum. In all cases, VT was successfully treated by catheter ablation.
Conclusion : A wide QRS complex tachycardia with right bundle branch block and left-axis deviation sensitive to verapamil observed in a young patient without structural heart disease should not be confused with supraventricular tachycardia with aberrancy but rather suggests the presence of fascicular VT. As opposed to VT associated with structural heart disease, the RS interval is < 80 msec in all precordial leads in all cases. Independent of this parameter, AV dissociation detectable on surface ECG has a sensitivity of 73%, which increases to 82% in the presence of fusion beats.     

Heart Rate Turbulence in Chagas Disease

RIBEIRO, A.L.P., et al. : Heart Rate Turbulence in Chagas Disease. Heart rate turbulence (HRT) quantifies the biphasic response of the sinus node to ventricular premature complexes (VPCs) and is a powerful electrocardiogram related risk predictor. VPCs are frequent in Chagas disease, a potentially lethal illness, and can hamper the analysis by conventional methods of autonomic heart control. The aim of the study was to examine HRT in patients with Chagas disease. Chagas disease patients and healthy controls (group   0, n = 11   ) without other diseases were submitted to a standardized protocol, including electrocardiogram, echocardiography, and 24-hour Holter monitoring. Chagas disease patients were divided according to their left ventricular systolic function: normal (group   1, n = 103   ) and reduced ejection fraction (group   2, n = 23   ). Two HRT indices, turbulence onset (TO) and turbulence slope (TS), were calculated and compared among groups after adjustment for covariates like the prevalence of VPCs and the mean heart rate. Chagas disease patients had significantly altered TO (group 1: −0.0186, group 2: −0.0126) and TS (group 1: 10.844, group 2: 7.870) values in comparison with controls (TO − 0.0256, TS 19.829);   P < 0.001   for both comparisons. In conclusion, HRT data may be useful in the electrocardiographic analysis of autonomic heart control in Chagas disease. Its prognostic value remains to be determined. (PACE 2003; 26[Pt. II]:406–410)     

The Automatic Implantable Cardioverter/Defibrillator; Transesophageal Atrial Pacing Discloses the Potential for Erroneous Discharges

We report the occurrence of erroneous discharge from an implanted automatic cardioverter/defibrillator during transesophageal atrial pacing. Transesophageal pacing was performed as part of a study protocol on the inducibility of ventricular tachycardia from the atrium in patients with ischemic heart disease. At an induced heart rate of 166 beats per minute (a value just above the cut-off rate of the device), the cardioverter/defibrillator was triggered. This observation suggests that transesophageal atrial pacing could be utilized to disclose the potential for spurious discharges in the event of fast atrial rhythms in patients with the automatic implantable cardioverter/defibrillator.     

A Double-Blind, Randomized, Comparative Study of Two Type A Botulinum Toxins in the Treatment of Primary Axillary Hyperhidrosis

BACKGROUND Botulinum toxin (BTX) is an effective treatment for primary axillary hyperhidrosis. In this study we used two toxins not bioequivalent: BOTOX (Allergan, Inc.) and Dysport (Beaufour Ipsen Biotech).
OBJECTIVE The objective was to compare the efficacy, safety, and tolerability of BOTOX and Dysport in the treatment of primary axillary hyperhidrosis using a conversion factor of 1:3, respectively.
METHODS In a double-blind, randomized prospective study, 10 patients with primary axillary hyperhidrosis and sweat production exceeding 50 mg/minute received 50 U of BOTOX in one axilla and 150 U of Dysport in the other. We performed Minor's test and gravimetry at 0 days, at 15 days, and monthly for 1 year.
RESULTS No significant difference was observed in the sweating quantity at baseline. After 1 month all patients had achieved success for both axillae. The sweat rate was reduced by a mean of 97.7% for BOTOX and 99.4% for Dysport, without statistical difference. The duration of benefits was similar between both toxins, with a mean of 260 days for BOTOX and 290 days for Dysport, without statistical difference. The longest symptom-free interval was 12 months (5 patients, 55.6%).
CONCLUSIONS BOTOX and Dysport presented similar levels of safety and efficacy in the treatment of primary axillary hyperhidrosis when a conversion factor of 1:3 was used.     

EVENT-RELATED POTENTIALS ELICITED BY INFREQUENT NON-TARGET STIMULI IN YOUNG CHILDREN OF ALCOHOLICS: FAMILY HTSTORY AND GENDER DIFFERENCES

This article analyses the visual and auditory event-relatedpotentials (ERPs) elicited by infrequent non-target stimuliin young children with alcoholic fathers. The aim was to studythe characteristics of the ERP waves specifically evoked bystimuli which capture the attention of the subject in youngones at risk for alcoholism, and to assess the effect of samplefactors which can modulate these characteristics, namely familyhistory of alcoholism and gender. There were no differencesrelated to risk for alcoholism on the auditory ERPs. However,males and females with a multigenerational family history ofalcoholism showed significant differences on visual ERP latencies,although different waves were affected for each gender. Femalesshowed a larger latency of the visual frontal negative wave,Nc, and males showed a larger latency of the visual parietocentralP300 wave.     

Inhibition of cholesteatoma migration in vitro with all-trans retinoic acid

Retinoids have recently become of interest to clinicians because of their ability to inhibit migration and proliferation of premalignant squamous cells while enhancing growth and proliferation of normal cells. An in vitro investigation was undertaken to determine whether retinoic acid exhibits similar inhibitory effects on cholesteatoma cells. Cholesteatoma specimens were obtained intraoperatively from 10 patients undergoing mastoidectomy or revision mastoidectomy for chronic ear disease. Cholesteatoma explant growth and en mass migration were observed daily, and topographic maps were constructed at various time intervals to quantify rate and direction of explant migration in the presence or absence of all-trans retinoic acid. Before all-trans retinoic acid administration, explants migrated very rapidly (1 to 2 mm/day). A maximum threefold inhibition of migratory rate occurred, with explants exposed to 0.1 μmol/L retinoic acid when compared with controls. A sixfold maximum inhibition was observed at higher retinoic acid concentrations (5 μmol/L). On removal of all-trans retinoic acid, twofold and fourfold increases in migratory rates were observed. The direction of explant migration varied significantly for long periods of time and appeared not to be affected by retinoic acid. This investigation suggests that all-trans retinoic acid has an inhibitory effect on cholesteatoma cell migration. Retinoids may have a role in controlling cholesteatoma disease in the future. (Otolaryngol Head Neck Surg 1996;114:768-76.)     

Temporary Atrial Pacing in the Prevention of Postoperative Atrial Fibrillation

Background: Atrial fibrillation (AF) is a common complication after coronary artery bypass grafting (CABG). Since its prevention with prophylactic drug therapy has limited success, alternative approaches are desirable. This study examined the efficacy of atrial or biatrial pacing, compared with no pacing, on the incidence of AF after isolated CABG.
Methods: From August 2002 to September 2004, 240 patients underwent CABG. After surgery, right and left atrial epicardial pacing wires were implanted for 72 hours of temporary pacing. Patients were randomly assigned to one of three groups: no pacing (control group), right atrial (RA), and biatrial (BiA) pacing. Cardiac rhythm was monitored continuously during intensive care, or daily on the ward. The primary endpoints of this study were an episode of AF occurring up to 72 hours after CABG and the risk factors correlated with this event.
Results: Atrial and BiA pacing significantly lowered the incidence (1.25% vs 25%, P = 0.001) of AF episodes, and were both correlated (odd ratio 0.038; 95% confidence interval 0.005–0.29) with a decrease in rates of postoperative AF. Multivariable analysis identified older age (odd ratio 1.074; 95% confidence interval 1.024–1.12) and no pacing as independent risk factors of postoperative AF.
Conclusions: Temporary right atrial or biatrial pacing after CABG significantly decreased the postoperative incidence of AF. Multivariable analysis identified older age and no pacing as predictors of AF occurrence .     

Biventricular Pacing via a Persistent Left Superior Vena Cava: Report of Four Cases

GASPARINI, M., et al .: Biventricular Pacing via a Persistent Left Superior Vena Cava: Report of Four Cases. Persistence of left superior vena cava (LSVC) is an uncommon finding during pacemaker implantation, which may be particularly relevant in performing LV transvenous pacing. Rarely, it is further complicated by the presence of atresia of the coronary sinus ostium (CSO). This article reports the authors experience with biventricular pacing (Biv-P) in this unusual clinical setting. From October 1999 to April 2002, 158 patients underwent biventricular pacing. In four of them (mean age 62.2 years), the presence of a persistent LSVC draining into the coronary sinus (CS) was detected at implantation, associated with atresia of the CSO in two patients. A common characteristic was the angiographic finding of a large CS with few tributaries. The LV leads were successfully positioned in the middle cardiac vein in three patients and in a posterolateral vein in one patient. All vessels were large and their cannulation via downstream CS catheterization required the lead to be manipulated through sharp angles. Mean fluoroscopic exposure and procedural times were not significantly different from the overall Biv-P population. In all patients, at a mean follow-up of 11 months, sensing and capture threshold remained stable and a significant decrease in NYHA functional class and increase in LVEF were noted. The direct lead placement in large CS tributaries in the presence of persistent LSVC was feasible and safe. The leads remained stable up to a mean follow-up of nearly 1 year. (PACE 2003; 26[Pt. II]:192–196)