Early improvement of left ventricular ejection fraction by cardiac resynchronization through His bundle pacing in patients with heart failure.

AIMS: Permanent His bundle pacing (p-HBP) can correct intraventricular conduction disorders and could be an alternative to traditional cardiac resynchronization therapy (CRT) via the coronary sinus. We describe the short-term impact of HBP on left ventricular ejection fraction (LVEF) and improvement of left intraventricular synchrony. METHODS AND RESULTS: This prospective descriptive study, performed from January 2018 to February 2019, included patients with left bundle branch block (LBBB) and an CRT indication who were resynchronized by p-HBP. We used the Medtronic C315 His catheter or a combination of the CPS-Direct-Universal introducer, CPS-AIM™-Universal subselector (Abbot), and SelectSecure™ MRI-SureScan™ 3830 lead. Correction of the LBBB by HBP had been previously checked. At 1 month of follow-up, we analysed the quantification of LVEF and measurement of the delay of the septal wall with the posterior wall as a parameter of intraventricular synchrony. We included 48 patients with LBBB and an indication for CRT. With HBP, we corrected the LBBB in 81% of patients (n = 39), and we achieved cardiac resynchronization through permanent HBP in 92% of these patients (n = 36). Left ventricular ejection fraction and intraventricular mechanical resynchronization improved in all patients, which was demonstrated by echocardiography through the improvement of the delay of the septal wall with the posterior wall from 138 ms (range 131-151) to 41 ms (19-63). CONCLUSION: There is early improvement after p-HBP in LVEF and left ventricular electromechanical synchronization in patients with LBBB, heart failure, and an indication for CRT.

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.

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.

Cardiac resynchronization therapy in non-ischemic cardiomyopathy: a comparative non-randomized study of His Bundle pacing versus biventricular pacing.

BACKGROUND: Cardiac resynchronization therapy (CRT) via permanent His bundle pacing (pHBP) has gained acceptance globally, but robust studies comparing pHBP-CRT with classic CRT are lacking. In this study, we aimed to compare the improvement in left ventricular ejection fraction (LVEF) after pHBP-CRT versus classic CRT. METHODS: This was a single-center study comparing a prospective series of pHBP-CRT with a historical series of CRT via classic biventricular pacing (BVP). Patients with non-ischemic cardiomyopathy, baseline LVEF < 35%, left bundle branch block (LBBB), and CRT indications were selected. RESULTS: Fifty-one patients underwent classic CRT and 52 patients underwent pHBP-CRT. In the classic CRT group, the median (interquartile range) basal LVEF was 30% (IQR, 29-35%) before implantation and 40% (35-48%) at follow-up. In the pHBP-CRT group, the median basal LVEF was 30% (28-34%) before implantation and 55% (45-60%) at follow-up, with significant differences between both modalities at follow-up (p = 0.001). The median long term His recruitment threshold with LBBB correction was 1.25 (1-2.5) V at 0.4 ms in cases of pHBP-CRT, compared to a left ventricular coronary sinus threshold of 1.25 (1-1.75) V in cases of classic CRT (p = 0.48). After CRT, the median paced QRS was 135 (120-145) ms for pHBP-CRT versus 140 (130-150) ms for BVP-CRT (p = 0.586). CONCLUSIONS: The improvement in LVEF was superior with pHBP-CRT than with classic CRT. The thresholds at follow-up were similar in both groups.

Electrical and mechanical cardiac resynchronisation by novel direct his-bundle pacing in a heart failure patient.

Efficacy of standard cardiac resynchronisation therapy (CRT) by biventricular pacing via coronary sinus depends on the target site for left ventricular (LV) pacing, which in a not insignificant number of patients is limited by anatomical constraints. Direct His-bundle pacing (DHBP) is considered an alternative method of pacing for patients requiring cardiac stimulation in order to obviate detrimental effects of right ventricular pacing on LV function. However, its role in CRT has not been investigated, with scarce number of cases recently reported. We present a case of a heart failure patient in whom CRT was considered and treated by DHBP. In addition to electrical resynchronisation and optimal clinical response, echocardiography showed successful ventricular mechanical synchrony. To our knowledge, these latter findings are for the first time described in the setting of CRT by DHBP.

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.

[Permanent His-bundle pacing in patients with infra-Hisian atrioventricular block]. / Estimulación hisiana definitiva en pacientes con bloqueos infrahisianos.

INTRODUCTION AND OBJECTIVES: Permanent His-bundle pacing is effective in patients with supra-Hisian atrioventricular block. We report our experience in patients with infra-Hisian atrioventricular block. METHODS: The study involved selected patients referred for syncope and intraventricular conduction disturbance, infra-Hisian atrioventricular block, with left ventricular dyssynchrony and no coronary sinus access. All patients underwent electrophysiological study to evaluate infra-Hisian atrioventricular conduction, both at baseline and after flecainide administration. We selected patients with an indication for permanent pacing in whom His-bundle pacing produced a narrow QRS complex. Leads were implanted in the right atrium, in the bundle of His, and at the apex of the right ventricle, and connected to the atrial, left ventricular, and right ventricular terminals, respectively, of a biventricular pacemaker generator. All pacemakers were programmed in DDD mode with a left ventricle-right ventricle interval of 80 ms. RESULTS: Between February and December 2004, seven patients met the study's inclusion criteria. The His-bundle lead was implanted successfully in five. The His-bundle pacing threshold remained stable in two patients, whereas it increased in three. During follow-up, at between 2 and 12 months, no lead dislodgement or failure to capture was observed. Echocardiography did not disclose any deterioration in ventricular function, or any worsening of or new valvular incompetence, but showed that ventricular dyssynchrony had disappeared in previously affected patients. CONCLUSIONS: His-bundle pacing is the only pacing mode capable of inducing a physiologically normal ventricular contraction. It can be used in some patients with infra-Hisian atrioventricular block.

[Progress in cardiac pacing]. / Novedades en estimulación cardiaca.

This review article summarizes the fundamental principles of radiological protection for interventional cardiologists. In addition, the scientific articles on cardiac pacing that have had the greatest impact in the last year are also summarized. Two cardiac pacing techniques are described: His-bundle pacing and cardiac contractility modulation.

The potential and reality of permanent his bundle pacing.

Right ventricular apex pacing can have deleterious effects. Our aims were to investigate how many patients referred for permanent pacing were suitable candidates for permanent His bundle pacing, and to determine the proportion in whom such pacing was successful. All cases of suprahisian block and most cases of infrahisian block (71.4%) were corrected by temporary His bundle pacing. However, permanent His bundle pacing was achieved in only 55% of cases in which it was attempted, and in only 35.4% of all possible cases.

Cardiac resynchronization through selective His bundle pacing in a patient with the so-called InfraHis atrioventricular block.

We present a case of infraHis AV block in which selective His bundle pacing with His-ventricular conduction through the conduction system was accomplished. While further investigations are developed, this approach may be an alternative for cardiac resynchronization in cases of difficult coronary sinus access.