Increased left ventricular stiffness assessed by diastolic wall strain causes symptoms in patients with premature ventricular contraction

Background Premature ventricular contraction (PVC) is one of common arrhythmias and only some patients complain of PVC-related symptoms, however the mechanisms which cause the symptoms remain unclear in patients with PVCs. Purpose We investigated whether the left ventricular (LV) stiffness assessed by diastolic wall strain (DWS) relate symptoms or not in patients with PVC. Methods We studied 109 patients (48 males, age 60±19) with frequent monomorphic PVCs who underwent 12-leads electrocardiogram (ECG), signal-averaged electrocardiogram (SAECG), 24h-Holter ECG recording, and transthoracic echocardiography (TTE). Patients with structural heart disease or other arrhythmias such as atrial fibrillation were excluded. Clinical factors, blood samples for atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), and filtered QRS duration (f-QRS) and root mean square voltage of the terminal 40ms of the QRS complex (RMS40) obtained by SAECG were evaluated. We assessed PVC-SV (stroke volume during PVC), PVC-CI (CI between the previous sinus beat and VPC), and left ventricular (LV) stiffness assessed by diastolic wall strain (DWS). DWS was calculated from the M-mode echocardiographic measurement of the LV posterior wall thickness at end-systole (PWs) and end-diastole (PWd) during sinus rhythm, and DWS was defined as (PWs − PWd)/PWs. Results 31patients (28%) had PVC-related symptoms (18 palpitation and 13 pulse deficit). Patients with PVC-related symptoms showed shorter PVC coupling interval index (52±10 vs. 58±11%, p=0.0140), reduced PVC-SV (21±12 vs. 29±17ml, p=0.0103) and decreased DWS (0.38±0.06 vs. 0.42±0.06, p=0.0011). Meanwhile, the level of BNP and ANP, f-QRS, RMS40, QRS morphology of PVC and the total number of PVC per day were not associated with PVC-related symptoms. On multivariate analysis, decreased DWS was only independently associated with PVC-related symptoms (p=0.0357, OR 2.3629 for each 0.1 decrease in DWS 95% CI 1.0583–5.5815). Conclusion The reduced diastolic wall strain relates with PVC-related symptoms. The increased left ventricular stiffness might cause symptoms in patients with PVC. Funding Acknowledgement Type of funding source: None

Left ventricular stiffness assessed by diastolic wall strain predicts asymptomatic atrial high rate episodes in patients with pacemaker implantation

Background Asymptomatic atrial fibrillation has been reported to be associated with an increased risk of embolism. Purpose We investigated whether the left ventricular (LV) stiffness assessed by diastolic wall strain (DWS) predicts atrial high rate episodes (AHREs) in patients with pacemaker implantation (PMI). Methods One hundred forty seven patients (76 males, 75.2±8.9 years, 62 with sick sinus syndrome; SSS and 85 with atrioventricular block) who did not show atrial tachyarrhythmia before PMI were studied. DWS and other measurements were assessed using transthoracic echocardiography before DDD-pacemaker implantation. DWS was calculated from the M-mode echocardiographic measurement of the LV posterior wall thickness at end-systole (PWs) and end-diastole (PWd), and DWS was defined as (PWs-PWd)/PWs. Results AHREs (>5 min and >180 beats/min) were detected in 50/147 patients during follow-up periods (38.3±13.8 months). Patients with AHREs showed reduced DWS (0.29±0.07 vs. 0.39±0.06, p<0.0001), larger left atrial volume index, elevated E/e' ratio, thicker LV PWd, higher prevalence of SSS, and left bundle branch block pattern during ventricular pacing. On multivariate analysis, DWS was only independently associated with AHREs (p<0.0001, HR 1.987 for each 0.1 decrease in DWS, 95% CI 1.553–2.650). Patients with reduced DWS (<0.33) had a higher risk of incidences of AHREs (Figure 1). Conclusions LV stiffness assessed by DWS predicts AHREs in patients with PMI. Figure 1 Funding Acknowledgement Type of funding source: None

P303Prognostic value of diastolic wall strain in patients with asymptomatic severe aortic stenosis

Background Diastolic wall strain (DWS) has been reported to be associated with left ventricular (LV) stiffness and worse clinical outcomes. We sought to assess the utility of this new index for prediction of prognosis in asymptomatic patients with severe aortic stenosis (AS). Methods Asymptomatic severe AS patients [peak flow velocity (PFV) ≥4.0m/s, mean pressure gradient (mPG) ≥40mmHg, aortic valve area (AVA) ≤1.0cm2, or indexed AVA ≤0.6cm2/m2)] diagnosed between July 2007 and April 2016 were included in this study. Patients with significant mitral valve disease, posterior wall motion abnormality, prior cardiac surgery, hypertrophic cardiomyopathy, and LV ejection fraction <50% were excluded. DWS was calculated with a validated formula [DWS = (posterior wall thickness at end-systole − posterior wall thickness at end-diastole)/posterior wall thickness at end-systole]. All study patients were prospectively followed up to last visit or death until November 2017, and predictive value of all-cause death was assessed using Cox-proportional hazards modeling. Patients who underwent aortic valve replacement (AVR) during the study period were censored on the date of surgery. Results A total of 184 asymptomatic severe AS, 138 (age 76±9year-old, men 41%, PFV 3.9±1.0m/s, mPG 38±19mmHg, AVA 0.83±0.18cm2, indexed AVA 0.56±0.13cm2/m2) met all study criteria. Of whom, 43 (31%) underwent AVR and 28 (20%) died during a mean follow-up of 25±28months. In a multivariable model after adjusting for clinical and echocardiographic variables, advancing age (per10yrs; HR=2.19, 95% CI=1.19–4.03, P<0.05), history of hemodialysis (HR=4.31, 95% CI=1.30–14.35, P<0.05), and low-DWS (DWS <0.30) (HR=2.83, 95% CI=1.25–6.40, P<0.05) were independent predictors of all-cause death. In the Kaplan-Meier estimates of cumulative survival stratified by DWS status were shown (Figure). The Kaplan-Meier estimates of survival Conclusion Low-DWS provides prognostic information in patients with asymptomatic severe AS.

P3790Left ventricular stiffness assessed by diastolic wall strain predicts infrequent atrial fibrillation

Background Left ventricular (LV) stiffness as the passive LV filling property in the LV diastolic function has been reported to be related with the prevalence of atrial fibrillation (AF). On the other hand, a novel insertable monitoring (ICM) system is a powerful tool to detect AF with rare appearance in patients with embolic stroke of undetermined source (ESUS). We investigated whether the LV stiffness assessed by diastolic wall strain (DWS) predicts infrequent atrial fibrillation. Methods Fifty-five patients (41 males, 68±14 years) who underwent ICM implantation for ESUS (n=19) or unexplained syncope (n=36) were studied. DWS, left atrial (LA) stiffness and other measurements were assessed using transthoracic echocardiography before the ICM implantation. DWS was calculated from the M-mode echocardiographic measurement of the LV posterior wall thickness at end-systole (PWs) and end-diastole (PWd) during sinus rhythm, and DWS was defined as PWd/PWs. LA stiffness index was defined as the ratio of E/e' to LA peak strain. Results AF was detected in 20 patients (36%) during the follow-up periods (280±243 days). Patients with AF showed reduced DWS (0.30±0.07 vs. 0.41±0.08, p<0.0001), larger LA volume index (39.0±10.9 vs. 32.3±9.0, p=0.0174), and higher age (74.6±10.4 vs. 64.6±14.9, p=0.0105). On the other hand, LA stiffness index, LA function (reservoir, booster, and conduit function estimated by LA volume), and LV relaxation function (E wave, E/A ratio, deceleration time) were not associated with detection of AF. There was no difference on AF detection rate between ESUS and unexplained syncope (26% vs. 42%, p=0.2604). On multivariate analysis, DWS was only independently associated with detection of AF (p<0.0001, OR 5.647 for each 0.1 decrease in DWS, 95% CI 1.084–1.338). Moreover, patients with reduced DWS (<0.38) had a higher risk of incidences of AF than patients with preserved DWS (figure). Figure 1 Conclusions LV stiffness assessed by DWS predicts infrequent AF. Reduced LV stiffness rather than LA dysfunction or LV relaxation dysfunction may be the main cause of AF in the early stages.