Autonomic function and specific right atrial functions - Is there a relationship? Correlations from the three-dimensional speckle-tracking echocardiographic MAGYAR-Healthy Study

INTRODUCTION

Similarly to the ventricles, the atria are under sympathetic/parasympathetic neural regulation. Accordingly, correlations were investigated between Ewing's standard cardiovascular reflex tests (SCRTs) and three-dimensional speckle-tracking echocardiography (3DSTE)-derived right atrial (RA) volumes and strains in healthy subjects.

MATERIALS AND METHODS

The study comprised 45 healthy adults, but 5 subjects were excluded due to inferior image quality for 3DSTE-derived RA assessments. The remaining 40 individuals being in sinus rhythm had a mean age of 35.1 ± 3.5 years (20 men). Two-dimensional, Doppler, 3DSTE and SCRTs were performed in all cases.

RESULTS

RA maximum volume and total and passive RA stroke volumes correlated with the Valsalva ratio. Active RA stroke volume and emptying fraction showed correlations with 30/15 ratio. Peak global and mean segmental RA circumferential (CS) and longitudinal strains (LS) showed correlation with the Valsalva ratio. At atrial contraction, global RA-LS and mean segmental RA-CS showed correlations with the Valsalva ratio. Moreover, mean segmental RA-CS correlated with 30/15 ratio and mean segmental RA radial strain showed correlations with systolic blood pressure in response to standing. Autonomic neuropathy score correlated with peak global RA-LS.

CONCLUSIONS

Autonomic function parameters have significant associations with specific RA functions in healthy adults, making the latter possible indicators of autonomic dysregulation.

Relationship Between Image Quality and Bias in 3D Echocardiographic Measures: Data From the SABRE (Southall and Brent Revisited) Study

Background

Image‐quality (IQ) compromises left ventricle assessment by 3‐dimensional echocardiography (3DE). Sicker/frailer patients often have suboptimal IQ, and therefore observed associations may be biased by IQ. We investigated its effect in an observational study of older people and when IQ was modified experimentally in healthy volunteers.

Methods and Results

3DE feasibility by IQ was assessed in 1294 individuals who attended the second wave of the Southall and Brent Revisited study and was compared with 2‐dimensional (2D)‐echocardiography feasibility in 147 individuals. Upon successful analysis, means of ejection fraction (3D‐EF) and global longitudinal strain (3D‐GLS) (plus 2D‐EF) were compared in individuals with poor versus good IQ. In 2 studies of healthy participants, 3DE‐IQ was impaired by (1) intentionally poor echocardiographic technique, and (2) use of a sheet of ultrasound‐attenuating material (neoprene rubber; 2–4 mm). The feasibility was 41% (529/1294) for 3DE versus 61% (89/147) for 2D‐EF, P<0.0001. Among acceptable images (n=529), good IQ by the 2015 American Society of Echocardiography/European Association of Cardiovascular Imaging criteria was 33.6% (178/529) and 71.3% (377/529) for 3D‐EF and 3D‐GLS, respectively. Individuals with poor IQ had lower 3D‐EF and 3D‐GLS (absolute) than those with good IQ (3D‐EF: 52.8±6.0% versus 55.7±5.7%, Mean‐Δ −2.9 [−3.9, 1.8]; 3D‐GLS: 18.6±3.2% versus 19.2±2.9%, Mean‐Δ −0.6 [−1.1, 0.0]). In 2 experimental models of poor IQ (n=36 for both), mean differences were (−2.6 to −3.2) for 3D‐EF and (−1.2 to −2.0) for 3D‐GLS. Similar findings were found for other 3DE left ventricle volumes and strain parameters.

Conclusions

3DE parameters have low feasibility and values are systematically lower in individuals with poor IQ. Although 3D‐EF and 3D‐GLS have potential advantages over conventional echocardiography, further technical improvements are required to improve the utility of 3DE in clinical practice.

Advantage and validation of vendor-independent software for myocardial strain analysis compared to vendor-specific software

Introduction

One of the main limitations incorporating strain imaging into widespread clinical practice is inter-vendor incompatibility. This poses a problem when serial strain measurements are required in a multi-vendor echocardiography laboratory.

Methods

This study sought to compare the variability of two-dimensional speckle-tracking global and regional longitudinal strain using vendor-specific software and vendor-independent software from images acquired by two different commercially available ultrasound systems. Forty subjects underwent two sequential echocardiographic acquisitions using different ultrasound systems (GE Vivid E9 and Philips iE33). Global longitudinal strain and regional peak longitudinal strain were derived using vendor-specific software (EchoPAC BT 13 v201 and QLAB version 10.3) and vendor-independent software (TomTec Image Arena version 4.6). Agreement and reproducibility of global and regional strain between vendor-specific and vendor-independent software were assessed by independent blinded observers.

Results

Global longitudinal strain derived from vendor-independent software was comparable to global longitudinal strain derived from vendor-specific software, whilst regional strain was lower in agreement compared to global longitudinal strain. There was good overall agreement and high inter- and intra-observer reproducibility using vendor-independent software for global longitudinal strain and regional strain.

Conclusions

Vendor-independent software provides good agreement with vendor-specific software for global longitudinal strain. However, minor variability exists for regional strain measurements between vendor-independent and vendor-specific software. Good agreement of strain measurements derived by vendor-independent software suggests vendor-independent software could potentially be useful for serial follow-up of global longitudinal strain.

Regenerative Therapy Prevents Heart Failure Progression in Dyssynchronous Nonischemic Narrow QRS Cardiomyopathy

Background

Cardiac resynchronization therapy using bi-ventricular pacing is proven effective in the management of heart failure (HF) with a wide QRS-complex. In the absence of QRS prolongation, however, device-based resynchronization is reported unsuitable. As an alternative, the present study tests a regenerative cell-based approach in the setting of narrow QRS-complex HF.

Methods and Results

Progressive cardiac dyssynchrony was provoked in a chronic transgenic model of stress-triggered dilated cardiomyopathy. In contrast to rampant end-stage disease afflicting untreated cohorts, stem cell intervention early in disease, characterized by mechanical dyssynchrony and a narrow QRS-complex, aborted progressive dyssynchronous HF and prevented QRS widening. Stem cell-treated hearts acquired coordinated ventricular contraction and relaxation supporting systolic and diastolic performance. Rescue of contractile dynamics was underpinned by a halted left ventricular dilatation, limited hypertrophy, and reduced fibrosis. Reverse remodeling reflected a restored cardiomyopathic proteome, enforced at systems level through correction of the pathological molecular landscape and nullified adverse cardiac outcomes. Cell therapy of a dyssynchrony-prone cardiomyopathic cohort translated prospectively into improved exercise capacity and prolonged survivorship.

Conclusions

In narrow QRS HF, a regenerative approach demonstrated functional and structural benefit, introducing the prospect of device-autonomous resynchronization therapy for refractory disease.

Mechanical dyssynchrony precedes QRS widening in ATP-sensitive K⁺ channel-deficient dilated cardiomyopathy

Background

Contractile discordance exacerbates cardiac dysfunction, aggravating heart failure outcome. Dissecting the genesis of mechanical dyssynchrony would enable an early diagnosis before advanced disease.

Methods and Results

High‐resolution speckle‐tracking echocardiography was applied in a knockout murine surrogate of adult‐onset human cardiomyopathy caused by mutations in cardioprotective ATP‐sensitive K⁺ (K_ATP) channels. Preceding the established criteria of cardiac dyssynchrony, multiparametric speckle‐based strain resolved nascent erosion of dysfunctional regions within cardiomyopathic ventricles of the K_ATP channel–null mutant exposed to hemodynamic stress. Not observed in wild‐type counterparts, intraventricular disparity in wall motion, validated by the degree, direction, and delay of myocardial speckle patterns, unmasked the disease substrate from asymptomatic to overt heart failure. Mechanical dyssynchrony preceded widening of the QRS complex and exercise intolerance and progressed into global myocardial discoordination and decompensated cardiac pump function, precipitating a low output syndrome.

Conclusions

The present study, with the use of high‐resolution imaging, prospectively resolved the origin and extent of intraventricular motion disparity in a K_ATP channel–knockout model of dilated cardiomyopathy. Mechanical dyssynchrony established as an early marker of cardiomyopathic disease offers novel insight into the pathodynamics of dyssynchronous heart failure.