Physiologic Pacing for Atrial Fibrillation Prevention in Sinus Node Disease: Long-Term Results

Background: Physiologic pacing has been demonstrated to be effective in preventing atrial fibrillation recurrences in patients with sinus bradycardia. Aim of the study was to evaluate long-term incidence of atrial fibrillation in a large population of patients affected by sinus node disease receiving physiologic pacing. Furthermore, predictors of arrhythmia recurrence and effect of pacing mode were investigated.
Population: Four hundred twenty-five patients (220 Male, 77 ± 9 years) were retrospectively analyzed: implanted system was AAI in 20.5% and DDD in 79.5%. Thirty-four percent had atrial fibrillation before implant.
Results: Follow-up lasted on average 51 ± 36 months (median 42, range 1 month–18 years). Sixty-six percent were on antiarrhythmic drug therapy. After 5 years, 89% survived, 74.5% had at least one episode of atrial fibrillation, 39.9% were submitted to electrical cardioversion, 67.2% were hospitalized because of cardiac causes, 33.3% developed permanent atrial fibrillation. Primary conduction system disease and valvular heart disease were independent predictors for atrial fibrillation recurrence. Preimplant atrial fibrillation predicted arrhythmia recurrence during the follow-up, but it did not predict development of permanent atrial fibrillation. AAI pacing, when compared with DDD, was associated to a lower rate of atrial fibrillation recurrences (AAI 28.7%, DDD 53.3%, P < 0.001).
Conclusion: In spite of expected benefits of physiologic pacing, the development of atrial fibrillation and permanent atrial fibrillation were quite common. The additional benefits of multifunction pacemakers designed to prevent and treat atrial fibrillation should be evaluated in controlled studies.     

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)     

Atypical chronic lymphocytic leukaemia witht(ll;14)(ql3;q32): karyotype evolution and prolymphocytic transformation

Summary. In order to define better the cytological and clinical features of atypical B-cell chronic lymphocytic leukaemia (B-CLL) with t(ll;14)(ql3;q32), sequential morphologic immunological and cytogenetic studies were performed in seven patients belonging to a series of 72 consecutive cases presenting with a diagnosis of CLL or atypical CLL according to the FAB criteria. Cytologic diagnosis in these seven patients with t(ll;14) was typical CLL in two cases presenting with < 10% large lymphocytes (LL) and prolymphocytes (PL) and atypical CLL in five cases in which LL and PL comprised between 10% and 55%. The diagnosis was supported by histologic findings on bone marrow biopsy (five cases) or splenectomy specimens (two cases). A progressive increase of peripheral LL and PL was observed, resulting in a switch of FAB diagnosis over a 6-60-month period from typical CLL into atypical CLL in two cases and from atypical CLL into prolymphocytic leukaemia in five cases. Immunophenotyping showed a mature B-cell phenotype with CD19, CD22, CD24 positivity and CD10 negativity in all patients. A bright-staining pattern for surface immunoglobulins (SIg) was detected in 6/7 cases, CD5 positivity in 6/7 cases, and CD23 positivity in 1/7 cases. The FMC-7 monoclonal antibody was positive in >40% cells in 5/6 cases. Chromosome changes in addition to t(11; 14) were seen in five cases; in two cases unbalanced translocations involving the 3q21 chromosome region, resulting in partial trisomy for the long arm of chromosome 3, were detected early in the course of the disease. Karyotype evolution that was associated with disease progression occurred in 3/6 assessable patients. Comparison of these findings with similar data from 65 B-CLL patients without t(ll;14) showed that atypical morphology, switch of FAB diagnosis during the course of the disease, and karyotype evolution were more frequently seen in cases with t(ll;14) (5/7 v 15/65 cases, P = (V015, 7/7 v 7/65 cases, P < 0-0001, and 3/6 v 5/45 assessable cases, P= 0-04, respectively). The frequency of positivity for CD2 3 and bright SIg staining differed significantly in the two groups. It is concluded that t(ll;14) identifies a cytologically atypical subset of B-CLL, characterized by frequent cytologic and cytogenetic evolution and by a distinct immunological profile, sharing some biological features with mantle cell lymphoma.