Atrium-driven Mitral Annulus Motion Velocity Reflects Global Left Ventricular Function and Pulmonary Congestion During Acute Biventricular Pacing

A novel echocardiographic parameter to identify individuals susceptible to acute mountain sickness

BACKGROUND

Acute mountain sickness (AMS) may cause life-threatening conditions. This study aimed to screen echocardiographic parameters at sea level (SL) to identify predictors of AMS development.

METHODS

Overall, 106 healthy men were recruited at SL and ascended to 4100 m within 7 days by bus. Basic characteristics, physiological data, and echocardiographic parameters were collected both at SL and 4100 m above SL. AMS was identified by 2018 Lake Louise Questionnaire Score.

RESULTS

After acute high altitude exposure (AHAE), 33 subjects were diagnosed with AMS and exhibited lower lateral mitral valve tissue motion annular displacement (MV TMAD_lateral) at SL than AMS-free subjects (13.09 vs. 13.89 mm, p = 0.022). MV TMAD_lateral at SL was significantly correlated with AMS occurrence (OR = 0.717, 95% CI: 0.534-0.964, p = 0.028). The MV TMAD_lateral<13.30-mm group showed over 4-fold risk for AMS development versus the MV TMAD_lateral≥13.30-mm group. After AHAE, the MV TMAD_lateral<13.30-mm group had increased HR (64 vs. 74 bpm, p = 0.001) and right-ventricular myocardial performance index (0.54 vs. 0.69, p = 0.009) and decreased left ventricular global longitudinal strain (-21.50 vs. -20.23%, p = 0.002), tricuspid valve E/A ratio (2.11 vs. 1.89, p = 0.019), and MV E-wave deceleration time (169.60 vs. 156.90 ms, p = 0.035).

CONCLUSION

MV TMAD_lateral at SL was a potential predictor of AMS occurrence and might be associated with differential alterations of ventricular systolic and diastolic functions in subjects with different MV TMAD_lateral levels at SL after AHAE.

Value of mitral annular plane systolic excursion in the assessment of contractile reserve in patients with ischemic cardiomyopathy before cardiac revascularization

Background

Mitral annular plane systolic excursion (MAPSE) is an M-mode derived echocardiographic marker of left ventricular longitudinal function, the aim of this study is to evaluate the value of MAPSE in assessment of contractile reserve in patients with ischemic cardiomyopathy before cardiac revascularization.

Methods

The study included 50 patients with ischemic cardiomyopathy with ejection fraction (EF) ≤35%, the patients presented to echocardiography laboratory for dobutamine stress echocardiography (DSE) to assess viability and contractile reserve before revascularization, patients with primary valvular disease, and those with significant mitral annular calcifications were excluded from the study. A low dose DSE was done to all patients using standardized incremental infusions of 5, 10, and 20 μg/kg/min and the following parameters were measured at both baseline and peak dose, (EF, wall motion score index(WMSI) and MAPSE). Contractile reserve was measured as the difference between the low dose and baseline values of the EF and WMSI.

Results

The study included 50 patients aged 55.08 ± 7.15 years, 94% were males, the DSE protocol was complete in all patients without serious side effects. A total of eight hundred segments were analyzed, at baseline 65% were dysfunctional including 31.2% hypokinetic, 28.8% were akinetic, and 5% were dyskinetic. At low dose study 70% of the dysfunctional myocardium showed viability, EF increased significantly from 30.84 ± 4.56 to 42.24 ± 8.15%, p < 0.001, the WMSI reduced significantly from 1.92 ± 0.33 to 1.47 ± 0.39, and MAPSE increased significantly from 1.02 ± 0.23 to 1.30 ± 0.30 mm. MAPSE showed a significant positive correlation with EF at both baseline and low dose study (r = 0.283, p = 0.046 & r = 0.348, p = 0.013) respectively and a significant negative correlation with WMSI at both baseline and low dose study (r = −0.3, p = 0.034 & r = −0.409, p = 0.003), respectively. By ROC curve analysis we found that Δ MAPSE ≥2 mm can predict contractile reserve at Δ EF >10% (AUC = 0.6, sensitivity 67.86, specificity 59.09), and Δ MAPSE ≥1.8 mm can predict contractile reserve at ΔWMSI ≤0.20 (AUC = 0.61, sensitivity 65.5, specificity 75.6).

Conclusions

MAPSE is a rapid simple quantitative echocardiographic method that can asses contractile reserve in patients with ischemic cardiomyopathy before cardiac revascularization.

Mitral Annular Plane Systolic Excursion-Derived Ejection Fraction: A Simple and Valid Tool in Adult Males With Left Ventricular Systolic Dysfunction

OBJECTIVES

Validation of a mitral annular plane systolic excursion (MAPSE)-derived formula to calculate the ejection fraction where EF = 4.8 × MAPSE (mm) + 5.8 in adult males with left ventricular (LV) dysfunction.

BACKGROUND

Echocardiographic assessment of LV function generally requires expert echocardiographer and is somewhat subjective and prone to reader discordance. MAPSE has been suggested as a surrogate measurement for LV function.

METHODS

Prospective analysis of 170 male patients with systolic dysfunction by two-dimensional transthoracic echocardiography was carried out. MAPSE and ejection fraction measured by qualitative visual inspection, M-mode, and biplane modified Simpson's rule were measured. MAPSE-derived EF was compared against other conventional methods to measure EF using Bland-Altman analysis and independent t-test.

RESULTS

There was a significant positive correlation between average MAPSE and EF measured by M-mode (r = 0.554, P < 0.001), Simpson's rule (r = 0.585, P < 0.001), and visual inspection (r = 0.611, P < 0.001). An average MAPSE cutoff value <= 5 provided the best balanced sensitivity (67.1%) and specificity (76.5%) to predict EF < 30%. The mean difference between MAPSE-derived EF and EF measured by visual inspection and by Simpson's method was 3.86 ± 5.24% and 3.57 ± 5.97%, respectively. The least mean difference of 0.5 ± 5.69% was present between MAPSE-derived EF and M-mode-measured EF (P value 0.2).

CONCLUSION

MAPSE-derived EF using the equation EF = 4.8 × MAPSE (mm) + 5.8 is a valid technique in adult males with severely impaired LV EF.

Rapid estimation of left ventricular function using echocardiographic speckle-tracking of mitral annular displacement

BACKGROUND

Left ventricular (LV) ejection fraction (EF) by transthoracic two-dimensional echocardiography is time-intensive and highly dependent on image quality. Mitral annular displacement (MAD) qualitatively correlates with EF and can be measured in patients with poor image quality and dropout. The authors hypothesized that speckle-tracking echocardiography (STE)-derived MAD could quantify EF accurately and tested this hypothesis using cardiac magnetic resonance (CMR) as a reference.

METHODS

One hundred eighteen patients undergoing clinical transthoracic echocardiography were screened, and 110 whose mitral annuli was sufficiently well-defined irrespective of LV endocardial visualization underwent CMR within 6 days (85 of 110 in 1 day). Reference CMR EF values were obtained using standard methodology. STE was used to track annular motion throughout the cardiac cycle in the apical 2-chamber and 4-chamber views. To establish the relationship between MAD and CMR EF and to obtain a formula to estimate EF from MAD, regression analysis was performed in a study group of 60 patients with a wide range of EFs. This formula was then used in an independent test group of 50 patients by comparing estimated MAD EF against CMR EF values using Pearson's correlation and Bland-Altman analyses.

RESULTS

In the study group, STE MAD correlated highly with CMR EF and resulted in a formula relating MAD to EF. In the test group, estimated EF correlated well with CMR EF (4-chamber, R(2) = 0.64; 2-chamber, R(2) = 0.55), with near-zero bias and acceptable limits of agreement. Intraobserver and interobserver variability were between 5.8% and 12.7%.

CONCLUSIONS

STE MAD is a clinically useful tool for quick, easy, robust, and accurate estimates of EF irrespective of LV endocardial definition.