Left Main Coronary Angioplasty: Assessment of a "Risk Score" to Predict Acute and Long-Term Outcome

Due to the recent emergence of adjunctive techniques such as cardiopulmonary bypass support, left main angioplasty may become more routinely applied in the near future. In order to choose the best possible therapy, a precise risk assessment will be desirable. Twenty-two left main angioplasties were thus reviewed and patients were divided in two groups according to a risk score adapted from a previously published jeopardy score. Group I included patients with a risk score ≤ 6 and group II patients with a risk score > 6. A cutoff criterion of six points was chosen because it represents the maximal amount of myocardium put at jeopardy from a single coronary stenosis. The success rate of the procedure was 77% and was similar in both groups. Of the 12 patients in group I, two patients underwent in-hospital bypass surgery and one of them died. Among the ten patients of group II, one sustained a myocardial infarction, three underwent acute surgery, and one patient died postoperatively. After a mean follow-up of 41 months, the total mortality rate was 17% in group I and 30% in group II. The long-term event-free survival rate was 75% in group I and 10% in group II (P = 0.004). The risk score was found to be a potentially important predictor of sustained success (long-term success: 4.4 ± 2.9 vs no long-term success: 8.3 ± 3.4; P = 0.01), although sophisticated statistical analysis was limited by the small number of patients. Thus, in patients with a low risk score, angioplasty seems to be an appropriate treatment while it appears that surgery should remain the standard therapy for patients with a calculated high risk score. However, the clinical significance of this new risk score remains to be determined with more elaborate statistical analysis applied to a larger number of patients.     

Regional Disparities of Endocardial Atrial Activation in Paroxysmal Atrial Fibrillation

Previous experimental data suggest that atrial activity is homogeneously distributed during paroxysmal atrial fibrillation (AFib). Little is known about this in human paroxysmal AFib. Methods : Twenty-five men and two women (mean age 49 ± 11 years; five with structural heart disease) with paroxysmal AFib for a mean 5 ± 6.2 years despite the use of a mean of 3.6 ± 1.7 antiarrhythmic drugs underwent atrial mapping. The right atrium was divided into four regions: posterior (intercaval), lateral, anterior, and septal. A 14-pole catheter was positioned to assess complex electrical activity defined as the duration of continuous electrical activity or electrograms with FF intervals < 100 ms for 60 seconds (expressed as percentage of time). In addition, the left atrium (divided into three regions: posterior, anterior, and septal) was explored in 12 patients with a multipolar catheter. Results : The complex electrical activity time between all the regions explored was significantly different. In the right atrium, the septa] (74%± 32%; P = 0.02) and the posterior (63%± 32%; P = 0.04) areas were significantly more disorganized than the lateral (22%± 23%) and anterior (21 %± 26%) regions. In the left atrium, complex electrical activity was predominant and widely distributed (posterior: 87%± 11%; septal: 65%± 27%) except in the appendage area (anterior region: 18%± 14%). Conclusions : Quantitative assessment of complex electrical activity in both atria in humans shows heterogeneous temporal and spatial distribution. This may have implications for guiding catheter ablation of AFib.     

Radiation Exposure During Radiofrequency Catheter Ablation for Atrial Fibrillation

MACLE, L., et al. : Radiation Exposure During Radiofrequency Catheter Ablation for Atrial Fibrillation. RF catheter ablation of paroxysmal atrial fibrillation (PAF) is associated with prolonged fluoroscopy. The procedural duration and fluoroscopic exposure to patients and medical staff were recorded and compared among 43 ablation procedures for PAF, 20 for common atrial flutter, and 16 for accessory pathways. Patient radiation exposure was measured by dosimeters placed over the xyphoid, while that of physicians and nurses was measured by dosimeters placed outside and inside the lead apron. The mean fluoroscopy time was   57 ± 30   minutes for PAF,   20 ± 10   minutes for common flutter, and   22 ± 21   minutes for accessory pathway ablation. The patient median radiation exposure was 1110μSv for PAF, compared with 500 μSv for common flutter and 560 μSv for accessory pathway ablation (P < 0.01). The median radiation exposure to physician and nurse inside the lead apron were, respectively, 2 μSv and 3 μSv for PAF, 1 μSv and 2 μSv for common flutter, and <0.5 μSv and 3 μSv for accessory pathway ablations. RF catheter ablation for PAF was associated with prolonged fluoroscopy times and a twofold higher radiation exposure to the patient and physician compared with other ablation procedures. Assuming 300 procedures/year, radiation exposure to the medical staff was below the upper recommended annual dose limit. (PACE 2003; 26[Pt. II]:288–291)     

Tilt Table Testing of Young Adult Patients: Improved Speed and Sensitivity Using an Isoproterenol Bolus and a Continuous 60° Tilt

The tilt table is a diagnostic device used to induce vagal syncope and determine etiology. Sensitivity enhancing techniques, such as the administration of isoproterenol, can be applied to children and young adults to compensate for the otherwise low sensitivity (20%-30%) observed in that population. This study describes an improved test that offers a simplified approach while decreasing the amount of time involved by up to 50%, without compromising sensitivity. This 45-minute procedure relies on sensitization with isoproterenol administered as a 2- to 8-μg bolus instead of a continuous infusion. The isoproterenol is injected at the 30th minute of a 45-minute 60° tilt test without returning the patient to the supine position. In this study, the isoproterenol bolus tilt test was found to be "positive" in 24 of 30 patients reporting unexplained syncope: 10 cases before the 30th minute (11.2 ± 8.4 min) and 14 cases after administration of 5.1 ± 1,9 μg of isoproterenol.     

Cost Analysis of Catheter Ablation for Paroxysmal Atrial Fibrillation

WEERASOORIYA, R., et al. : Cost Analysis of Catheter Ablation for Paroxysmal Atrial Fibrillation . RF ablation for paroxysmal atrial fibrillation (PAF) is a curative treatment, which when successful, eliminates the need to take antiarrhythmic drugs, be anticoagulated, and have recurrent physician visits or hospital admissions. The authors performed a retrospective cost comparison of RF ablation versus drug therapy for PAF. The study population consisted of 118 consecutive patients with symptomatic, drug refractory PAF who underwent   1.52 ± 0.71   RF ablation procedures (range 1–4) for PAF. During a follow-up of 32 ± 15 weeks, 85 (72%) patients remained free of clinical recurrence in absence of antiarrhythmic drugs. The cost of RF ablation was calculated in the year 2001 euros on the basis of resource use. The mean cost of pharmacologic treatment prior to ablation was 1,590 euros/patient per year. The initial cost of RF ablation for PAF was 4,715 euros, then 445 euros/year. After 5 years, the cost of RF ablation was below that of ongoing medical management, and continued to diverge thereafter. RF catheter ablation may be a cost-effective alternative to long-term drug therapy in patients with symptomatic, drug refractory PAF. (PACE 2003; 26[Pt. II]:292–294)     

The Value of DDD Pacing in Patients with an Implantable Cardioverter Defibrillator

Although the beneficial effects of DDD pacing are well known, currently available ICDs provide only fixed rate ventricular antibradycardia pacing. In a consecutive series of 139 patients with ICDs, we have analyzed the need for antibradycardia pacing and the indications for DDD pacing. We also report our initial experience with the Defender 9001 (ELA Medical, France) DDD-ICD. Out of 139 patients, 25 (18%) were in need of antibradycardia pacing. Ten patients already had a pacemaker at the time of ICD implantation and ten other patients had a conventional pacemaker indication at that time. Five patients became pacemaker dependent during a follow-up of 20 ± 8 months. The disorders necessitating pacemaker therapy were high degree AV conduction disturbances in 72%, sick sinus syndrome in 12%, and AF with a slow ventricular response in 16% of patients. Based upon current indications, DDD pacing was indicated in 20 (80%) of 25 patients. The Defender 9001 DDD-ICD (ELA Medical) was used in two patients with ischemic cardiomyopathy and pacemaker syndrome with VVI pacing. Cardiac output during DDD pacing increased by 36% in one patient with an increase in VO₂ max during exercise of 29%. The other patient showed an increase in cardiac output of 50% with DDD pacing, and, while unable to exercise with VVI pacing, had a VO_2max of 24 mL/kg per minute during DDD pacing. Up to 18% of our ICD patients are in need of antibradycardia pacing. Of these pacemaker dependent patients, 80% have an indication for DDD pacing. Our first clinical experience with a DDD-ICD confirms the hemodynamic benefit of AV synchronous pacing in ICD patients with pacemaker syndrome.