Effects of Cardiac Resynchronization Therapy on Incidence of Atrial Fibrillation in Patients With Poor Left Ventricular Systolic Function

Abstract Background In approximately 30-40% of cases, the left ventricular systolic function does not improve following cardiac resynchronization therapy (CRT; non-responders). Currently, the role of right ventricular (RV) systolic function is not yet completely clear in the background. Our aim was to assess the RV systolic function with 3D echocardiography in CRT patients. Methods We selected 19 patients who received CRT in our department between May and June 2017, and whose 1-year follow-up data were available. We characterized several 2D parameters of RV systolic function, such as RV free wall strain (RV GLSFW), annular s’ wave velocity (TDI s), tricuspid annulus plane systolic excursion (TAPSE), RV fractional area change (RV FAC). A number of 3D parameters were also assessed, such as RV ejection fraction (EF), end-diastolic (EDV) and end-systolic (ESV) volumes, using a dedicated RV analysis software. Moreover, we measured the LV EF and considered the patients "responder", when the LV EF improved with at least 10% after CRT implantation. Results From 19 patients, 12 was identified as responders (R) and 7 as non-responders (NR). No significant difference was seen in the mean age of patients in the two groups (NR: 68 ± 6 year; R: 67 ± 9 year, p = 0.76), however, the proportion of male individuals was higher in the NR group (8/12 vs. 1/7). The RV EF was higher in the R group (41 ± 8% vs.29 ± 10%; p = 0.012), while the EDV or ESV did not differ between the two groups. The RV GLSFW (–21.2 ± 7% vs.–13.9 ± 7%, p = 0.045) and the TAPSE (16.8 ± 5 mm vs.11.4 ± 3 mm, P = 0.03) values were significantly different between the two groups. Based on logistic regression analysis, the RV EF was an independent predictor of non-respondence. Conclusions The lower RV EF indicates non-respondence to CRT, however, it is not associated with RV dilation, i.e.adverse remodelling. These results suggest mechanical abnormality of RV function in the background of impaired EF.

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Abstract 12650: Unexpected Response to Atrial Fibrillation Reduction in Patients With Cardiac Resynchronization Therapy

Circulation ◽

10.1161/circ.130.suppl_2.12650 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Hamid Assadi ◽

Hossein Shenasa ◽

Shahriar Heidary ◽

Mohammad Shenasa

Keyword(s):

Atrial Fibrillation ◽

Cardiac Resynchronization Therapy ◽

Systolic Function ◽

Systolic Heart Failure ◽

Left Ventricular ◽

Cardiac Resynchronization ◽

P Value ◽

Resynchronization Therapy ◽

Group I ◽

Before And After

Background: Cardiac resynchronization therapy (CRT) is known to improve left ventricular (LV) systolic function and symptoms of systolic heart failure. The effect of CRT on atrial fibrillation (AF) burden is less clarified. Methods: 18 patients mean age of 77 ± 11 (72% male) underwent CRT implantations. There were no changes to concomitant anti-arrhythmic medication and permanent AF patients were excluded. Echocardiograms were obtained six month before and after device implantation. LV ejection fraction (LVEF), LV end diastolic dimension (LVEDd), left atrial (LA) dimension, and magnitude of mitral regurgitation (MR) were measured by echocardiogram before and after CRT. The burden of AF was evaluated by 24-hour Holter monitoring before and by device arrhythmic log after implantation. There were no concomitant medication changes. The results were later divided into presence (Group I) and absence (Group II) of paroxysmal or persistent AF. No patient was in permanent AF at the time of CRT implantation. Results: LVEF improved after CRT in both groups. Patients with AF showed the most beneficial effects of LVEF with average improvement of 41% (P-value=0.004) in comparison to 13% improvement in patients without AF (P-value=0.044). The LVEDd was improved by 11.9% in patients with AF (P-value=0.01) while it was improved by only 5.6% in patients without AF (P-value=0.08). LA Dimension was decreased by 4.4% in patients with AF (P-value=0.038). MR was reduced on average from moderate to mild for both groups. The number of AF episodes and duration of the AF were also decreased in all of our AF patients. The pre and post effect of CRT in patients with and without AF is shown in the table below: Conclusions: The AF burden in patients who received CRT was significantly reduced. There were excellent correlations between improvement of LVEF, LVEDd, LA dimension, and AF burden. This may be due to LV and LA remodeling. Further studies need to elaborate the mechanisms of this finding.

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