A novel pacing manoeuvre to diagnose atrial tachycardia.

AIMS: Currently used diagnostic manoeuvres at the electrophysiology study do not always allow for consistent identification of atrial tachycardia (AT), either because of inapplicability of the technique or because of low predictive value and specificity. The aim of this study was to determine whether overdrive atrial pacing during paroxysmal supraventricular tachycardia (SVT) with the same cycle length from both the high right atrium and the coronary sinus can accurately identify or exclude AT by examining the difference between the V-A intervals of the first returning beat of tachycardia between the two pacing sites. METHODS AND RESULTS: Fifty-two patients were included; 24 patients with atrioventricular nodal re-entry tachycardia (AVNRT), 13 patients with atrioventricular re-entry tachycardia (AVRT), and 15 patients with AT. Comparing the 37 non-AT patients with the 15 AT patients, there was a highly significant difference between the mean V-A interval difference, (delta V-A) 2.1 +/- 1.8 ms (range 0-9 ms) vs. 79.1 +/- 42 (range 22-267 ms) (P < 0.001), respectively. None of the patients in the non-AT group had a delta V-A > 10 ms. In contrast, all 15 patients with AT had a delta V-A interval >10 ms. Thus, the diagnostic accuracy of the delta V-A interval cut-off of >10 ms was 100%, with a 95% confidence interval of 93.1-100% for AT. In 11 (73%) of the 15 AT patients, the standard ventricular overdrive pacing manoeuvre was not possible. In 14 of the 15 patients (93%) in the AT group, standard atrial overdrive pacing showed variable V-A intervals, correctly diagnosing AT. In all 52 patients, this measurement was repeated during pacing from the other location. In five patients from the AT group, the result of the second attempt was different from the result of the first attempt. CONCLUSION: We found that atrial differential pacing during paroxysmal SVT without termination of tachycardia and the finding of variable returning V-A interval was highly sensitive and specific for the diagnosis of AT. The manoeuvre can be easily performed in all patients with SVT and is highly reproducible. It is a useful adjunct to the currently available ventricular and atrial pacing manoeuvres.

Bipolar transurethral resection in saline--an alternative surgical treatment for bladder outlet obstruction?

PURPOSE: The transurethral resection in saline system uses bipolar energy for transurethral prostate resection, thus, avoiding the need for glycine irrigation and its associated complications. We compared the clinical efficacy and safety of bipolar transurethral resection in saline and of monopolar transurethral prostate resection for symptomatic benign prostate hyperplasia. MATERIALS AND METHODS: From January 2005 to June 2006, 238 consecutive patients with symptomatic benign prostate hyperplasia were randomized into a prospective, controlled trial comparing the 2 treatment modalities. Patient demographics, operative time, hospital stay and complications were noted. Serum hemoglobin and electrolytes were determined in all patients immediately before and after the endoscopic procedure. RESULTS: During 18 months 120 patients were randomized to the conventional transurethral prostate resection group and 118 were randomized to the transurethral resection in saline group. Patient profiles, weight of resected prostatic tissue and duration of hospitalization were similar in the 2 groups. The decrease in serum sodium and serum chloride was statistically significantly greater in the transurethral prostate resection group than in the transurethral resection in saline group (each p = 0.05). The transurethral resection in saline procedure required significantly more time (mean 56 vs 44 minutes, p <0.01). There was 1 case (0.8%) of transurethral resection syndrome in the transurethral prostate resection group but none in the transurethral resection in saline group. Postoperative bleeding did not significantly differ between the 2 groups. Clot retention was observed in 6 (5%) and 4 patients (3%) in the transurethral prostate resection and transurethral resection in saline group, respectively. Two repeat interventions were required in the transurethral prostate resection group. CONCLUSIONS: The bipolar transurethral resection in saline system is as efficacious as monopolar transurethral prostate resection but it is safer than the latter because of the lesser decrease in postoperative hypernatremia and the smaller risk of transurethral resection syndrome. However, probably due to technical reasons, transurethral resection in saline operative time is significantly longer.