Left atrial mechanics predict the success of pulmonary vein isolation in patients with atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is a common arrhythmia with relevant impact on mortality and morbidity. Pulmonary vein isolation (PVI) is an established therapy in patients who remain symptomatic under optimal medical therapy. However, up to 70% of patients present with recurrence of AF after PVI. Therefore, identifying ideal candidates is an unmet clinical need. Left atrial (LA) fibrosis is associated with reduced LA function. Analysis of LA mechanics using 2D speckle tracking echocardiography (STE) might give more insight into LA substrates and be therefore of predictive value. METHODS: This prospective single-center pilot study included 31 patients (mean age, 62.3 ± 9.1 years; 19 males) with AF who underwent PVI and 20 matched healthy controls (mean age, 60.6 ± 6.6 years; 10 males). 2D STE strain indices of LA reservoir (RLA), conduit, and, if feasible, contractile function, were analyzed before and 6 months after PVI. Assessment of the LV diastolic function was based on standard indices. Responders to PVI were defined as being asymptomatic and free of AF in a 7-day Holter-ECG after 6 months. RESULTS: At baseline, all patients with AF had significantly lower reservoir and contractile function compared with controls. After 6 months, 17 patients (54.8%) were identified as responders. At baseline, the reservoir function was significantly higher in responders compared with nonresponders (32.7 ± 11.1 vs. 22.9 ± 10.9%; P = 0.019). Only in responders, RLA and contractile LA function improved and reached normal values whereas LA function remained unchanged in nonresponders. In a ROC analysis, a RLA value of ≥19.5% discriminated responders and nonresponders in patients with persistent AF with a sensitivity of 86% and a specificity of 100% (P = 0.012; area under the curve 0.943; CI, 0.81-1.0). CONCLUSIONS: LA reservoir function helps to predict efficacy of PVI after 6 months. Only in responders, reservoir, and contractile function normalized within 6 months after PVI indicating a lower level of atrial remodeling at baseline. No deleterious effects of ablation were detected in nonresponders.

Recovery of left ventricular and left atrial mechanics in various entities of aortic stenosis 12 months after TAVI.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) has been shown to improve prognosis of high-risk patients. Data, however, concerning the impact of TAVI on regional and global left atrial (LA) and left ventricular (LV) mechanics in varying entities of severe aortic stenosis (AS) are sparse, particularly in patients with paradoxical low-flow (PLF) AS or with reduced LV ejection fraction (LVEF). This study evaluated the effects of TAVI on LA and LV mechanics in varying entities of AS 12 months after implantation. METHODS AND RESULTS: A total of 54 consecutive patients with severe AS (24 with a normal LVEF and normal flow, 16 with PLF, and 14 with a reduced LVEF) were included. Speckle tracking echocardiography was performed before and 12 months after TAVI to determine LV global and regional longitudinal deformation as well as LA function (reservoir function, conduit phase, and active contraction). In all the three entities of AS, there was a significant improvement in global and regional LV longitudinal function (average global longitudinal strain: -14.1 ± 3.9% at baseline vs. -16.5 ± 4.0% after TAVI, P < 0.001). Interestingly, the beneficial effects were most pronounced in patients with PLF (-14.0 ± 2.9 vs. -17.0 ± 4.4%, P < 0.031). Moreover, the atrial reservoir and conduit function recovered significantly after TAVI in all patients. CONCLUSION: In conclusion, regardless of the underlying AS entity, TAVI improves global and regional LV and LA mechanics within 12 months.

Short-term effects of transcatheter aortic valve implantation on left atrial mechanics and left ventricular diastolic function.

BACKGROUND: Aortic stenosis (AS) leads to remodeling of the left heart. Strain measurements enable the assessment of left atrial (LA) mechanics. The goal of this study was to evaluate the short-term effects of transcatheter aortic valve implantation (TAVI) on LA myocardial deformation as well as left ventricular (LV) diastolic function. METHODS: Thirty-two patients with severe AS were prospectively enrolled and examined before and 8.2 ± 3.3 days after TAVI. Speckle-tracking echocardiography of the basal septal and lateral segments of the left atrium was performed to determine peak positive strain (R(LA)), strain during early diastole (E(LA)), and, if feasible, strain during atrial contraction (A(LA)). Assessment of LV diastolic function included standard indices, the atrial fraction, and LA volumes. RESULTS: Compared with baseline, the mean atrial reservoir (R(LA)) (24.0 ± 11.2% vs 32.2 ± 14.0%, P < .001) and conduit function (R(LA) - E(LA)) (13.9 ± 5.5% vs 20.8 ± 8.1%, P < .001) improved significantly after TAVI. There was a significant reduction in deceleration time (242 ± 56 vs 195 ± 65 msec, P < .001) and an improvement of pulsed-wave tissue Doppler-derived E' (5.5 ± 1.8 vs 7.3 ± 2.3 cm/sec, P = .01). Regarding LA volumes, only the minimal LA volume index changed significantly. In contrast, there was no improvement in atrial contraction, that is, contractile function (E(LA) - A(LA)) and atrial fraction. Moreover, the E/E' ratio remained unchanged. CONCLUSIONS: 8.2 ± 3.3 days after TAVI, only the reservoir and conduit function of the left atrium improved, whereas LA contraction and LA volumes, except for the systolic volume index, remained unchanged. This was accompanied by improvement of early LV diastolic function, indicating acute recovery of LV relaxation and LA function.