Exclusion of fluoroscopy use in catheter ablation procedures: six years of experience at a single center.

BACKGROUND: Nonfluoroscopic mapping systems have demonstrated significant reduction of radiation exposure in radiofrequency (RF) catheter ablation procedures. However, their use as only imaging guide is still limited. OBJECTIVE: To evaluate the usefulness of a completely nonfluoroscopic approach to catheter ablation of supraventricular arrhythmias using the Ensite-NavX™ electroanatomical navigation system. METHODS: During 6 years, all consecutive patients referred for RF catheter ablation of regular supraventricular tachycardia (SVT) were admitted for a "zero-fluoroscopy" approach and studied prospectively. The only exclusion criterion was the need to perform a transseptal puncture. RESULTS: A total of 340 procedures were performed on 328 patients (179 men, age 55.7 ± 18.6 years). One hundred fifty-three patients had typical atrial flutter (AFL), 146 had AV nodal reentrant tachycardia (AVNRT), 35 had AV reciprocating tachycardia (AVRT), 4 patients had incisional atrial flutter (IAF), and 2 had focal atrial tachycardia (AT). Procedural success was achieved in 337 of the cases (99.1%). In 322 (94.7%), the procedure was completed without any fluoroscopy use. Mean procedure time was 110.5 ± 51.8 minutes. Mean RF application time was 9.8 ± 12.8 minutes and the number of RF lesions was 16.43 ± 15.8. Only 1 major complication related to vascular access was recorded. During follow-up, there were 12 recurrences (3.5%) (8 patients from the AVNRT group, 4 patients from the AP group). CONCLUSION: RF catheter ablation of SVT with an approach completely guided by the NavX system and without use of fluoroscopy is feasible, safe, and effective.

Direct left ventricular endocardial pacing: an alternative when traditional resynchronization via coronary sinus is not feasible or effective.

BACKGROUND: Biventricular pacing through the coronary sinus (CS) is effective for the treatment of patients with heart failure and left bundle-branch block. However, this approach is not always feasible. Although surgical epicardial lead implantation is an alternative, the technique may be deleterious in some patients. Thus, direct left ventricular (LV) endocardial pacing under local anesthesia may be an option. OBJECTIVE: We describe our technique and analyze the results of direct LV endocardial pacing. METHOD: Fourteen patients with failed resynchronization via CS (April 2006-September 2011) were selected. Using a femoral approach, we performed transseptal puncture and LV mapping, then fixed the active lead where the longest electrical delay was observed; the generator was placed in the anterior thigh. For resynchronization, eight patients with a device previously implanted through the upper veins received a single-chamber generator that was set to the VVT mode to sense the subclavian pacing spike. Six patients received a complete femoral resynchronization system with either a defibrillator or pacemaker. Patients were followed for 6-54 months. RESULTS: The LV lead was successfully implanted in all cases. Two patients experienced excessive bleeding and two died during follow-up. All except one improved at least one New York Heart Association class and experienced improved left ventricle ejection fraction. One patient with recurrent episodes of ventricular fibrillation was asymptomatic. CONCLUSION: Direct LV endocardial pacing is safe and may be a less risky, more efficient alternative than surgical epicardial lead implantation for resynchronization via CS.

Ventricular resynchronization therapy by direct His-bundle pacing using an internal cardioverter defibrillator.

AIMS: Cardiac resynchronization therapy (CRT) has been demonstrated to improve the functional class of patients with refractory heart failure if QRS width is >120 ms. Addition of an internal cardioverter defibrillator diminishes the prevalence of mortality of such patients. The technique for CRT requires selective stimulation of the left ventricle (LV), commonly undertaken through the coronary sinus. This procedure is not always feasible. Direct His-bundle pacing (DHBP) might be an alternative for CRT. METHODS AND RESULTS: Patients were selected from a population with refractory heart failure derived for CRT and internal cardioverter defibrillator insertion. Of those, patients in whom LV stimulation via the coronary sinus was not achievable and DHBP obtained left bundle branch block disappearance were included. Direct His-bundle pacing corrected basal conduction disturbances in 13 of the 16 patients (81%) selected. In four patients in whom DHBP was attempted, the electrode was not successfully fixed. In the nine remaining patients, a definitive resynchronization by DHBP was achieved, with consequent improvement in functional class and parameters of LV function as assessed by echocardiography. CONCLUSION: Direct His-bundle pacing might be an alternative treatment for CRT in selected cases.

Permanent His-bundle pacing: seeking physiological ventricular pacing.

AIMS: Right ventricular apical pacing can have deleterious effects and the His bundle has been widely reported to be an alternative site. This paper presents our experience with permanent His-bundle pacing (HBP). METHODS AND RESULTS: Patients referred for pacemaker implants (regardless of block type) were screened to determine if temporary HBP corrected conduction dysfunctions (threshold < or =2.5 V for 1 ms) and provided infra-Hisian 1:1 conduction of at least 120 s/m. Of the 182 patients selected, HBP corrected conduction dysfunctions in 133 (73%) patients, 42 (32%) of whom were rejected for the permanent procedure due to high thresholds. His-bundle lead implantation was attempted in the remaining 91 patients and was successful in 59 (65% of all attempts, 44% of all possible cases). CONCLUSION: In some patients, permanent HBP may be an alternative to right ventricular apical pacing.

Implante de un desfibrilador biventricular con estimulación endocárdica transeptal de ventrículo izquierdo vía venosa femoral / Implantation via the femoral vein of a biventricular defibrillator with transseptal endocardial left ventricular pacing

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