Left Ventricular Elastic Recoil Research Articles

Correlation Between Longitudinal Strain in the Apical Segments of the Left Ventricle at End-Systole Obtained by 2-Dimensional Speckle-Tracking Echocardiography and Left Ventricular Relaxation.

It is well acknowledged that left ventricular (LV) contractile performance affects LV relaxation via LV elastic recoil. Accordingly, we aimed to investigate whether global longitudinal strain (GLS), particularly longitudinal strain at LV apical segments at end-systole (ALS), obtained by 2-dimensional speckle-tracking echocardiography could be used to assess LV relaxation. We enrolled 121 patients with suspected or definite coronary artery disease in whom echocardiography and diagnostic cardiac catheterization were performed on the same day. We obtained conventional echo-Doppler parameters and GLS, as well as ALS prior to catheterization. LV functional parameters were obtained from the LV pressure recorded using a catheter-tipped micromanometer. In all patients, GLS and ALS were significantly correlated with the time constant τ of LV pressure decay during isovolumetric relaxation (r=0.63 [P<0.001] and r=0.66 [P<0.001], respectively). Receiver operating characteristic curve analysis for identifying impaired LV relaxation (τ ≥48 ms) revealed that ALS greater than -22.3% was an optimal cut-off value, with 81.7% sensitivity and 82.4% specificity. Even in patients with preserved LV ejection fraction, the same ALS cut-off value enabled the identification of impaired LV relaxation with 70% sensitivity and 87.5% specificity. The findings indicate that contractile dysfunction at LV apical segments slows LV relaxation via loss of LV elastic recoil, even in patients with preserved LVEF.

Patients with left ventricular ejection fraction greater than 58% have fewer incidences of future acute decompensated heart failure admission and all-cause mortality.

Based on our previous observation, inertia stress (IS) of late systolic aortic flow was often observed in left ventricles with relatively higher left ventricular (LV) ejection fraction (EF). Most left ventricles with relatively lower LVEF did not have IS. Accordingly, lack of IS may correlate with LV diastolic dysfunction through the loss of LV elastic recoil and may contribute to the pathogenesis of heart failure (HF) and reduced survival. We enrolled 144 consecutive patients that underwent cardiac catheterization for the diagnosis of coronary artery disease. Left ventricular ejection fraction (LVEF) was obtained from left ventriculography. The IS was calculated from the LV pressure (P)−dP/dt relation. The study endpoint of this retrospective outcome-observational study was combined subsequent acute decompensated heart failure (ADHF) and all-cause mortality. During the follow-up period (median 6.1 years), seven unscheduled hospitalizations for ADHF and nine all-cause deaths were observed. The event-free survival rate was significantly higher among patients with IS than among patients without IS (log-rank, p = 0.001). On a multivariate Cox regression analysis, lack of IS was a prime predictor of the endpoint during follow-up (hazard ratio: 6.98; 95 % confidence interval: 1.48–33.03; p = 0.01). An LVEF ≥ 58 % was a surrogate indicator for the presence of IS, and patients with LVEF ≥ 58 % had fewer incidences of the endpoint than patients with LVEF < 58 %. In conclusion, lack of IS or LVEF < 58 % should be a predictor of future ADHF and all-cause mortality.Electronic supplementary materialThe online version of this article (doi:10.1007/s00380-015-0657-1) contains supplementary material, which is available to authorized users.

Plasma N-Terminal Pro-Brain Natriuretic Peptide Levels Identifying Left Ventricular Diastolic Dysfunction in Patients With Preserved Ejection Fraction

Diagnosis of left ventricular (LV) diastolic dysfunction by blood testing is expedient in the clinical setting. In 98 patients with LV ejection fraction ≥50% who underwent cardiac catheterization for evaluation of coronary artery disease, LV pressure (LVP) was measured using a catheter-tipped micromanometer. A time constant, τ, of LV relaxation was computed from LVP decay; the inertia force (IF) of late systolic aortic flow, a surrogate index of LV elastic recoil, was also computed from the LVP-dP/dt relation (phase loop). Patients were classified into 2 groups: those with impaired LV relaxation (τ ≥48 ms) and those with preserved LV relaxation (τ <48 ms). Patients were also classified into another 2 groups: those with IF (≥0.5 mmHg) and those without (<0.5 mmHg). Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) ≥56.5 pg/ml had a sensitivity of 100%, specificity of 52.5%, and negative predictive value of 100% for identifying impaired LV relaxation. NT-proBNP ≥244.5 pg/ml had a sensitivity of 62.5% and specificity of 93.9% for detecting lack of IF. NT-proBNP level <56.5 pg/ml could be used as a value to sensitively identify patients with preserved LV systolic and diastolic function among those with coronary artery disease. NT-proBNP level ≥244.5 pg/ml is able to specifically detect a lack of IF and has potential for specifically diagnosing LV isolated diastolic dysfunction.

Biventricular Pacing Improves Left Ventricular Isovolumetric Relaxation and Compliance More Excellently Than LV Pacing Alone

Introduction: There are few reports that evaluated the effectiveness of cardiac resynchronization therapy (CRT) for left ventricular (LV) diastolic function by an invasive method. We aimed to clarify the hemodynamic improvement brought by CRT, especially throughout diastole. Methods: Twenty-seven patients who underwent CRT were enrolled. We measured 4 LV hemodynamic parameters; +dP/dtmax, −dP/dtmax, tau and LV end-diastolic pressure (LVEDP), using a manometer-tipped catheter. During the measurements, each patient was paced at the same heart rate in 4 different pacing modes; AAI (atrial pacing), DDDRV (right ventricular pacing), DDDLV (LV pacing), DDDBV (biventricular pacing). We compared the parameters in DDDBV with those in the other pacing modes, using repeated measures ANOVA. Results: In DDDBV, both +dP/dtmax and −dP/dtmax were significantly higher, and both tau and LVEDP were prominently lower than those in AAI. The systolic improvement (+dP/dtmax) in DDDLV (1132±275 mmHg/s) was similar to that in DDDBV (1142±270 mmHg/s). Surprisingly, the improvement of LV relaxation (−dP/dtmax, tau) and LV compliance (LVEDP) in DDDBV was superior to those in DDDLV (1117±290 mmHg/s vs 1036±282 mmHg/s; p=0.0189, 51.4±12.8 ms vs 57.0±16.3 ms; p=0.0014, 11.5±8.4 mmHg vs 13.7±8.9 mmHg; p=0.0027, respectively). Conclusions: Biventricular pacing improved both LV relaxation and compliance better than single-LV pacing, probably due to favorable interaction of biventricular contraction and LV elastic recoil.

Peak Mitral Annular Velocity During Early Diastole and Propagation Velocity of Early Diastolic Filling Flow Are Not Interchangeable as the Parameters of Left Ventricular Early Diastolic Function

The difference between peak mitral annular velocity during early diastole (Ea) and the propagation velocity of left ventricular (LV) early diastolic filling flow (Vp) obtained using Doppler imaging as LV relaxation parameters was not fully elucidated. Thus, this issue was investigated in 117 patients with suspected coronary artery disease. During cardiac catheterization, LV volumes, the LV relaxation time constant Tp, and inertia force of late systolic aortic flow were obtained. Ea significantly and closely correlated with Tp (r = -0.70, p <0.0001) and significantly but weakly correlated with LV ejection fraction (r = 0.37, p <0.0001) and inertia force (r = 0.34, p = 0.0002). Conversely, Vp significantly and closely correlated with both LV ejection fraction (r = 0.66, p <0.0001) and inertia force (r = 0.72, p <0.0001) and significantly but weakly correlated with Tp (r = - 0.35, p = 0.0001). In conclusion, Ea and Vp reflect different aspects of LV behavior from end-systole to early diastole. Ea can be used to index LV relaxation, whereas Vp might not be a proper parameter of LV intrinsic relaxation because it is significantly dependent on LV systolic function and LV chamber size at end-systole. Both parameters are not interchangeable as those of LV early diastolic function. Vp may be a noninvasive parameter of LV elastic recoil.

The mechanism of emergence and clinical significance of apically directed intraventricular flow during isovolumic relaxation

The mechanism of emergence and the clinical significance of apically directed intraventricular flow during isovolumic relaxation were investigated. The relation between the spatial distribution of the flow and left ventricular (LV) apical wall motion abnormality, as well as LV performance, was studied in 97 patients who underwent cardiac catheterization for evaluation of chest pain. According to the distribution of the flow, the patients were classified into the following 3 groups: flow observed in the whole area between the tip of the papillary muscle and the apex (spread flow) (n = 38), flow observed in the same area that did not fill the whole area (localized flow) (n = 15), and no apparent flow observed in the area (without flow) (n = 44). An absence of flow disclosed apical asynergy with a sensitivity of 97% and specificity of 87%. The time constant of LV relaxation was significantly shorter in patients with spread flow than in those without flow. A significant difference was also observed in end-systolic volume index (18.8 ± 6.8 vs 30.9 ± 7.7 vs 42.3 ± 20.2 mL/m2, spread flow < localized flow < without flow, P <.05) among the 3 groups. The propagation velocity of LV early diastolic filling flow was significantly greater in patients with spread flow (47.0 ± 8.3 cm/s) than in those with localized flow (30.7 ± 7.8 cm/s) or without flow (28.6 ± 7.8 cm/s) (P <.001). These findings indicate that the greater magnitude of LV elastic recoil and the faster LV relaxation in patients without LV apical asynergy produce apically directed intraventricular flow during isovolumic relaxation, enhancing the speed of LV early diastolic filling. Apically directed intraventricular flow during isovolumic relaxation may play an important role as a mediator of better LV systolic performance and LV relaxation to LV early diastolic filling. Absence of apically directed intraventricular flow during isovolumic relaxation is a manifestation of LV apical asynergy and global LV dysfunction from end systole to early diastole. (J Am Soc Echocardiogr 2002;15:715-22.)

Evaluation of left ventricular early diastolic performance by color tissue Doppler imaging of the mitral annulus

A noninvasive assessment of left ventricular (LV) diastolic performance by tissue Doppler imaging was performed in 56 patients (8 patients with atypical chest pain, 42 with coronary artery disease with a previous myocardial infarction, and 6 without a previous myocardial infarction) who underwent cardiac catheterization. Mitral annular velocity (MAV) during early ventricular diastole was obtained by M-mode color tissue Doppler imaging at the posterior corner of the mitral annulus. In each patient, the negative peak of the first derivative of LV pressure decay (peak −dP/dt) and a time constant of LV relaxation (τ) were calculated from the LV pressure waves obtained by a catheter-tip micromanometer. LV end-systolic volume index was measured from contrast left ventriculography. MAV during early diastole was significantly correlated with τ (r = −0.73, p <0.001), peak −dP/dt (r = 0.58, p <0.001), and LV end-systolic volume index (r = −0.63, p <0.001). On multivariate regression analysis with MAV during early diastole, τ and LV end-systolic volume index were selected as prime determinants (r = 0.80, p <0.001). These findings suggest that MAV during early diastole has a direct relation to LV elastic recoil as well as to LV relaxation. MAV during early diastole gives important information regarding LV behavior in late systole to early diastole where LV early diastolic performance is determined.