Relationship between QRS measurements and left ventricular morphology and function in asymptomatic individuals

The Neonatal QRS Complex and Its Association with Left Ventricular Mass

To evaluate QRS complex features during the first month of life and the association with echocardiographic measurements of left ventricular mass in neonates. Prospective cohort study of neonates with electrocardiography (ECG) and echocardiography performed during the first month of life. Left ventricular mass index (LVMI) was determined by echocardiography and the correlation with electrocardiographic markers of LVMI outliers (≥ 98th percentile) were analyzed. We included 17,450 neonates (52% boys; median age at examination 11 days) and found an increase in median QRS duration and LVMI during the first month of life (54 vs. 56 ms and 24.7 vs. 28.6 g/m2 at days 0-4 and 25-30, respectively; both p < 0.001). All investigated ECG features (QRS duration, QRS area in V1/V6, maximum amplitudes of S-V1/R-V6, and the Sokolow-Lyon voltage product) showed no to low correlation with LVMI, resulting in low sensitivities (0-9.0%), but high specificities (97.2-98.1%), and area under the curve values close to the identity line (0.49-0.61) for identifying LVMI outliers. Adjustment of outlier definition for LVMI and threshold for QRS features had no significant effect on sensitivity. We present reference values for QRS complex features and their association with LVMI in neonates from a large, unselected, population-based cohort. The QRS complex gradually evolved during the first month of life but had a low correlation with LVMI. Our results indicate a poor diagnostic value of using ECG features to identify LVMI outliers in neonates.Trial Registry Copenhagen Baby Heart, NCT02753348, https://clinicaltri-als.gov/ct2/show/NCT02753348?cond=Copenhagen+Baby+Heart&draw=2&rank=1 , deidentified individual participant data will not be made available.

Transcatheter mitral valve repair in proportionate and disproportionate functional mitral regurgitation-insights from a small cohort study

Background

Functional mitral regurgitation (FMR) can be subclassified based on its proportionality relative to left ventricular function and end-diastolic volume. FMR proportionality could help identify responders to transcatheter edge-to-edge mitral valve repair (MitraClip) in terms of residual FMR and/or clinical improvement.

Methods

This single-centre retrospective cohort study evaluated the feasibility of determining FMR proportionality in symptomatic heart failure patients with reduced left ventricular function who were treated with MitraClip for ≥ moderate-to-severe FMR. Baseline proportionate (pFMR) and disproportionate FMR (dFMR) were distinguished. Patient characteristics and MitraClip procedural outcomes were described.

Results

From an overall cohort of 81 eligible FMR patients, 23/81 (28%) had to be excluded due to missing transthoracic echocardiogram parameters, 22/81 were excluded based on FMR severity. The remaining cohort, of 36/81 patients (44%), could be classified into dFMR (n = 26) or pFMR (n = 10). Conduction disorders were numerically increased in dFMR. All cases requiring > 2 clips were in the dFMR group and absence of FMR reduction occurred more frequently with dFMR.

Point of view/Conclusion

Important limitations in terms of imaging acquisition affect the translation of the FMR proportionality concept to a real-world data set. We did observe different demographic and FMR response patterns in patients with proportionate and disproportionate FMR that warrant further investigation.

Supplementary Information

The online version of this article (10.1007/s12471-021-01583-6) contains supplementary material, which is available to authorized users.

The impact of age on cardiac electromechanical function in asymptomatic individuals

BACKGROUND AND AIM

Whether aging affects left ventricular (LV) filling and ejection and the LV electric function is not well established. We investigated the effect of normal aging on echocardiographic measurements of LV morphology and function, LV electric function and the relationship between LV electric and mechanical function in asymptomatic individuals.

METHODS

As part of a cross-sectional survey for the prevalence of coronary risk factors in the general population in Caltanissetta, Italy, individuals without signs or symptoms of coronary artery disease or heart failure were randomly selected and underwent electrocardiographic and echocardiographic examination. QRS duration and amplitude, PR, QT and QTc intervals, were automatically measured. Echocardiographic examination included the measurement of LV systolic and diastolic dimensions, volumes and ejection fraction (EF). From the spectral Doppler flow LV early diastolic (E wave) and atrial systolic (A wave) velocities, isovolumic relaxation time (IVRT) and isovolumic contraction time (IVCT) were measured. Global LV dyssynchrony was assessed using the total isovolumic time (T-IVT) and the Tei index.

RESULTS

Aging reduced LV long-axis function, LV filling time and E wave velocity and prolonged T-IVT, IVRT and Tei index. It did not affect LV dimensions, ejection fraction, IVCT or QRS amplitude and duration. QRS duration correlated with LV dimensions, wall thickness and left atrial area. QRS amplitude and QTc interval correlated with the markers of LV dyssynchrony T-IVT and Tei index.

CONCLUSIONS

Overall, systolic and electric LV function are not affected by age, whereas subendocardial function, diastolic and synchronous function are significantly influenced.