Funding Acknowledgements
Type of funding sources: None.
Background
Right ventricular apical (RVA) pacing deleterious effects on left ventricular ejection fraction (LVEF) had been demonstrated. Non-apical pacing, such as right ventricular mid-septal (RVMS) and His Bundle pacing, appear as practical alternatives. Our purpose is to evaluate the effect of alternate sites of right ventricular (RV) pacing on left ventricular (LV) function and hemodynamics in patients with bradyarrhythmias.
Methods
We observed 118 patients (age 58±27 years, 64% men) with AV block III, who underwent permanent dual chamber pacemaker implantation. To 72 patients RV lead has implanted the middle area of RV septum (RVMS) and 46 patients’ RV lead has been implanted traditionally to the right ventricular apex (RVA). Color tissue velocity imaging was performed to analyze time to peak systolic velocity (Ts) in a 12 segment model of the LV for each pacing site. Measurements included standard deviation of time to peak systolic velocity (SD-Ts) for all segments, the maximal difference in Ts between any 2/6 basal (Ts-B), any 2/6 mid segments (Ts-M) and maximal Ts difference between any 2/12 segments (Ts-12). Stroke volume was estimated using Doppler velocity time integral (TVI) in the left ventricular outflow tract (LVOT). QRS width for each site was recorded. Measurements were observed by transthoracic echocardiography and electrocardiography before and 12 months after implantation.
Results
Ts-12 was significantly higher with RVA - pacing (107 ms, p=0.003) compared to RVMS - pacing (81 ms) sites. SD-Ts were significantly higher with RVA - pacing (38.5 ms, p=0.01) than RVMS - pacing (28.7 ms). QRS duration was the longest for RVA - pacing (157 ms) while significantly shorter RVMS - pacing (115 ms, p<0.001). LVOT VTI was significantly higher for RVMS - pacing than for RVA (p=0.0014) pacing.
Conclusions
Right ventricular mid-septal pacing may reduce electro-mechanical dyssynchrony compared to RVA pacing and RVMS – pacing to effect better LV function and hemodynamics than RVA pacing in patients with permanent pacemaker implantation.
Objective
This study aims to evaluate long-term results after catheter ablation of atrial fibrillation (AF) in patients with reduced left ventricular ejection fraction (LVEF) and to evaluate sinus rhythm (SR) maintenance, clinical status, and echocardiographic parameters in the long-term follow-up period.
Material and methods
The study included 112 patients (75.5% men, age 59.5±11.5 years) with LV EF <50% underwent radiofrequency catheter ablation for paroxysmal (24%) or persistent (76%) AF. Patients after ablation were followed up for 38.4 (17.7–54.5) months for AF recurrence, functional class, and echocardiographic parameters.
Results
All patients underwent complete antral isolation of the pulmonary veins, and 95 (84.8%) underwent additional linear ablations in the left atrium. During the follow-up period, 48 (42.8%) patients experienced arrhythmia recurrence in the form of AF, atrial flutter, or ectopic atrial tachycardia. Repeated ablations were required in 35 (31.2%) patients. After ablation, antiarrhythmic drugs continued to be taken in 75 (66.9%) patients. During follow-up, NYHA class improved at least one class more often among patients in stable sinus rhythm than patients with recurrences (77.5% vs 51.2%, p=0.003). LV EF improved in patients maintaining sinus rhythm (36.6% vs 19.4%; P=0.016), and the degree of mitral regurgitation was significantly reduced (P<0.001) only in these patients. On multivariate analysis, maintenance of sinus rhythm was an independent predictor (odds ratio 4.56, 95% CI 1.69–9.94, P=0.002) of long-term clinical improvement (reduction in NYHA class ≥1 and relative improvement in LVEF ≥10%).
Conclusions
In patients with reduced LV EF, maintenance of sinus rhythm after ablation is associated with more significant clinical improvement. In the long-term period, the effectiveness of AF ablation in patients with reduced LVEF, as an improvement in the NYHA class and an increase in LVEF, is affected by a high rate of long-term recurrences.
Funding Acknowledgement
Type of funding sources: None.
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