Subclavian venoplasty by the implanting physicians in 373 patients over 11 years.

BACKGROUND: The need to add a lead(s) despite subclavian/innominate obstruction is increasing. Subclavian venoplasty may be a good alternative to the commonly employed options; however, there are few reports in the literature, and all are by interventional radiologists. OBJECTIVE: To describe the procedural details, results and safety of venoplasty by implanting physicians in a large group of consecutive patients. METHODS: Safety, lead function and success were established from review of the procedure reports and clinical complications in 373 consecutive venoplasty patients from 1999-2010. Procedural details were obtained by review of the angiograms (venograms) and procedural flow charts of 152 consecutive patients from 2004-2007. RESULTS: Venoplasty was successful in 371 of 373 patients without damage to the existing leads and without clinical complications. Total angiographic occlusion was demonstrated in 65% of cases by peripheral venogram, but in only 20% of cases by contrast injection at the site of obstruction; 86% were crossed with a hydrophilic wire. Microdissection and excimer laser were used to cross three of the four wire-refractory occlusions. Obstruction was both central and peripheral in 22.1% of cases and central only in 17%. The time required to cross the obstruction and perform venoplasty was 13 ± 21 minutes. A noncompliant balloon was successful in most, but an ultranoncompliant balloon was required in 13% of cases. Contrast extravasation was common during crossing of a total obstruction and also was observed with balloon rupture on three occasions, but was not clinically significant. CONCLUSIONS: Subclavian venoplasty is a safe, practical lead-management option that can be used by implanting physicians.

Efficacy of atrial antitachycardia pacing using the Medtronic AT500 pacemaker in patients with congenital heart disease.

Patients with congenital heart disease are vulnerable to atrial tachyarrhythmias, especially after atrial surgeries. We evaluated the efficacy of atrial arrhythmia detection and antitachycardia pacing (ATP) using the Medtronic AT500 pacemaker in 28 patients with congenital heart disease (age 30 +/- 18 years). Of 15 patients with atrial arrhythmias, 14 had atrial tachycardia events that were appropriately detected. ATP was enabled for 167 treatable episodes, successfully converting 90 (54%). Rhythms classified as ventricular tachycardia were detected 127 times, yet most were actually atrial or sinus tachycardia with 1:1 atrioventricular conduction. Atrial tachycardias in congenital heart disease are amenable to ATP algorithms in the AT500 pacemaker.

The effect of atrial pacing therapies on atrial tachyarrhythmia burden and frequency: results of a randomized trial in patients with bradycardia and atrial tachyarrhythmias.

OBJECTIVES: The Atrial Therapy Efficacy and Safety Trial (ATTEST) was a prospective, randomized study to evaluate preventive pacing and antitachycardia pacing (ATP) in patients with symptomatic atrial fibrillation (AF) or atrial tachycardia (AT). BACKGROUND: The effect of the combination of atrial prevention and termination algorithms on AT/AF burden and frequency in pacemaker patients is unknown. METHODS: A DDDRP pacemaker (AT500, Medtronic Inc., Minneapolis, Minnesota) with three atrial preventive pacing algorithms and two ATP algorithms was implanted in 368 patients. Patients were randomized one-month post-implant to all prevention and ATP therapies ON or OFF and followed for three months. The OFF group had DDDR pacing at a lower programmed rate of 60 ppm. The AT/AF burden and frequency were determined from daily device counters in 324 patients treated according to protocol. RESULTS: In 17,018 episodes with stored electrograms, appropriate detection was confirmed in 17,004 (99.9%). The median percentage of atrial pacing was 98% in the ON group versus 75% in the OFF group (p < 0.001). Using device-defined criteria for successful termination, ATP terminated 8,590 (54%) of 15,789 treated episodes. The median AT/AF burden during the three-month study period was 4.2 h/month ON versus 1.1 h/month OFF (p = 0.20). The median AT/AF frequency was 1.3 episodes/month ON versus 1.2 episodes/month OFF (p = 0.65). System-related, complication-free survival at four months was 90.2% (Kaplan-Meier estimate). CONCLUSIONS: This DDDRP pacemaker is safe, has accurate AT/AF detection, and provides ATP with 54% efficacy as defined by the device. The atrial prevention and termination therapies combined did not reduce AT/AF burden or frequency in this patient population.