Reversal of pulmonary vein remodeling after catheter ablation of atrial fibrillation.

BACKGROUND: Pulmonary veins (PV) and the atria undergo electrical and structural remodeling in atrial fibrillation (AF). This study aimed to determine PV and left atrial (LA) reverse remodeling after catheter ablation for AF assessed by chest computed tomography (CT). METHODS: PV electrophysiologic studies and catheter ablation were performed in 63 patients (68% male; mean ± SD age: 56 ± 10 years) with symptomatic AF (49% paroxysmal, 51% persistent). Chest CT was performed before and 3 months after catheter ablation. RESULTS: At baseline, patients with persistent AF had a greater LA volume (91 ± 29 cm(3) vs. 66 ± 27 cm(3); P = 0.003) and mean PV ostial area (241 ± 43 mm(2) vs. 212 ± 47 mm(2); P = 0.03) than patients with paroxysmal AF. There was no significant correlation between the effective refractory period and the area of the left superior PV ostium. At 3 months of follow-up after ablation, 48 patients (76%) were AF free on or off antiarrhythmic drugs. There was a significant reduction in LA volume (77 ± 31 cm(3) to 70 ± 28 cm(3); P < 0.001) and mean PV ostial area (224 ± 48 mm(2) to 182 ± 43 mm(2); P < 0.001). Patients with persistent AF had more reduction in LA volume (11.8 ± 12.8 cm(3) vs. 4.0 ± 11.2 cm(3); P = 0.04) and PV ostial area (62 mm(2) vs. 34 mm(2); P = 0.04) than those who have paroxysmal AF. The reduction of the averaged PV ostial area was significantly correlated with the reduction of LA volume (r = 0.38, P = 0.03). CONCLUSIONS: Catheter ablation of AF improves structural remodeling of PV ostia and left atrium. This finding is more apparent in patients with persistent AF treated by catheter ablation.

Parahisian pacing: technique, utility, and pitfalls.

Several observations and maneuvers in the electrophysiology (EP) laboratory are employed to identify whether retrograde ventriculoatrial conduction is via the atrioventricular (AV) node or an accessory pathway. Parahisian pacing is a unique maneuver where there is no change in the position of the catheter, the position of the stimulating electrode, nor the cycle length for pacing, but rather the pacing output is varied. The primary value for parahisian pacing is to distinguish between a septal accessory pathway and AV nodal conduction. However, more nuanced but just as reliable interpretation is possible to also help identify free-wall accessory pathways, intermittently conducting pathways, multiple accessory pathways, and various combinations of pathway and AV nodal retrograde conduction. In this review, we discuss the importance of correct technique and explain with examples some uncommon, yet instructive, findings when performing parahisian pacing.

No increased bleeding events with continuation of oral anticoagulation therapy for patients undergoing cardiac device procedure.

BACKGROUND: Switching warfarin for heparin has been a practice for managing periprocedural anticoagulation in high-risk patients undergoing device-related procedures. We sought to investigate whether continuation of warfarin sodium therapy without heparin bridging is safe and, when it is continued, the optimal international normalized ratio (INR) without increased bleeding risk at time of device-related procedure. METHODS AND RESULTS: We retrospectively studied 766 consecutive patients taking warfarin long term who underwent device-related procedures. Patients were grouped by treatment: discontinued warfarin (-warfarin, n = 243), no interruption of warfarin (+warfarin, n = 324), and discontinued warfarin with heparin bridging (+heparin, n = 199). The study primary endpoint was systemic bleeding or formation of moderate or severe pocket hematoma within 30 days of the procedure. Thirty-one (4%) patients had bleeding events, including pocket hematoma in 29 patients. The bleeding events occurred more often for +heparin (7.0%) than -warfarin (2.1%) or +warfarin (3.7%, P = 0.029). For +warfarin group, INR of 2.0-2.5 at time of procedure did not increase bleeding risk compared with INR less than 1.5 (3.7% vs 3.4%; P = 0.72), but INR greater than 2.5 increased the bleeding risk (10.0% vs 3.4%; P = 0.029). Concomitant aspirin use with warfarin significantly increased bleeding risk than warfarin alone (5.6% vs 1.4%, P = 0.02). Median length of hospitalization was significantly shorter for +warfarin than +heparin (1 vs 6 days; P < 0.001). CONCLUSION: Continuation of oral anticoagulation therapy with an INR level of <2.5 does not impose increased risk of bleeding for device-related procedures, although precaution is necessary to avoid supratherapeutic anticoagulation levels.

Three new tools for parathyroid surgery: expensive and unnecessary?

BACKGROUND: The intraoperative quick parathyroid hormone assay, the intraoperative gamma probe, and endoscopic parathyroidectomy are three very new techniques developed to facilitate parathyroid surgery. Some hospitals do not have the necessary equipment, and many, like ours, continue to operate in the time-honored way. STUDY DESIGN: We performed a retrospective chart review of 34 such operations, done with the use of Sestamibi scans, but entirely without the newer modalities. RESULTS: Four-gland exploration was carried out on all patients. Operative times ranged from 15 to 165 minutes, with a mean of 47 minutes, and incision lengths ranged from 2 to 3 cm, with a mean of 2.8 cm. There was no mortality, no reoperation, and no vocal cord or recurrent laryngeal nerve injury. Our cure rate was 100%, as determined by a fall in postoperative calcium and parathormone levels. CONCLUSIONS: In our view, the intraoperative parathyroid hormone assay, gamma probe, and endoscopic parathyroidectomy add an entirely unnecessary cost to an operation that can be completed satisfactorily with a preoperative Sestamibi scan and a thorough four-gland exploration.