Poorer Exercise Accommodation of Regional Systolic Myocardial Motion after Spironolactone Treatment in Heart Failure Patients with Preserved Ejection Fraction and Ventricular Dyssynchrony

Patients with heart failure and preserved ejection fraction (HFpEF) are known to have reduced systolic myocardial velocity (Sm) with impaired accommodation to exercise. We tested the impact of an aldosterone antagonist on Sm at rest and post-exercise. Forty-nine HFpEF patients (65 ± 11 years, 24 male) with HF signs/symptoms, mitral E/Ea (annular early diastolic velocity) > 8, and left ventricular (LV) EF > 50% were randomized to spironolactone (25 mg/day, 25 patients) or the Control. At baseline and 6 months, we analyzed Sm of basal LV segments at rest and after a 6 min treadmill exercise. At 6 months, post-exercise mean Sm in the spironolactone group became greater than that in the Control (9.2 ± 1.6 vs. 8.3 ± 1.0 cm/s, p = 0.021), mainly due to the increment of post-exercise % increase of lateral Sm (44 ± 30 vs. 30 ± 19% at baseline, p = 0.045). Further analyses showed the presence of systolic dyssynchrony (standard deviation of electromechanical delay of 6-basal LV segments > 35 ms) was independently associated with a poorer response to spironolactone, defined as a post-exercise % increase of lateral Sm < 50% (OR = 2.7, 95% CI = 1.8–4.2) and the increment of Ea < 1.5 cm/s (OR = 1.5, 95% CI = 1.1–2.3). Spironolactone could improve exercise accommodation of regional systolic myocardial velocity for HFpEF patients. However, its benefits could be decreased in those with ventricular dyssynchrony. This suggested possible therapeutic impacts from underlying heterogeneity within HFpEF patients.

Early detection of myocardial dysfunction in a cat that gradually progressed to endomyocardial form of restrictive cardiomyopathy

Background Restrictive cardiomyopathy (RCM) is a common myocardial disease in cats, characterized by diastolic dysfunction and atrial enlargement without myocardial hypertrophy. Especially, endomyocardial form of RCM, one of the subtypes in RCM, is characterized by endocardial fibrosis, endocardial scar bridging the interventricular septum and left ventricular (LV) free wall, and deformation and distortion of the LV. However, it is unclear how the myocardial dysfunction and the endocardial scar contribute to the pathophysiology of RCM disease progression. Case presentation A 3 years and 2 months old, intact male, Domestic shorthaired cat was presented for consultation of cardiac murmur. At the first visit (day 0), the notable abnormal finding was echocardiography-derived chordae tendineae-like structure bridging the interventricular septum and the LV free wall, resulting high-speed blood flow in the left ventricle. Electrocardiography, thoracic radiography and noninvasive blood pressure measurements were normal. No left atrial enlargement was observed, and LV inflow velocity showed an abnormal relaxation pattern. Although there was no abnormality in tissue Doppler imaging-derived myocardial velocity, two-dimensional speckle tracking echocardiography (2D-STE) revealed a decrease in the LV longitudinal strain and an increase in endocardial to epicardial ratio of the LV circumferential strain on day 0. On day 468, obvious left atrium enlargement and smoke like echo in the left atrium were observed. The LV inflow velocity was fused, and the tissue Doppler imaging-derived early-diastolic myocardial velocity of the septal mitral annulus decreased. Regarding 2D-STE, LV circumferential strain was further decreased, and right ventricular strain was additionally decreased. Although the general condition was good, we made a clinical diagnosis of endomyocardial RCM based on the above findings. On day 503, the cat showed the radiographic evidence of pulmonary edema and congestive heart failure signs. Conclusions Cats with abnormal LV structure and associated myocardial dysfunction like this case needs careful observation. Additionally, 2D-STE indices may be useful for early detection of myocardial dysfunction in feline RCM.

Fast and Automated Segmentation for the Three-Directional Multi-Slice Cine Myocardial Velocity Mapping

Three-directional cine multi-slice left ventricular myocardial velocity mapping (3Dir MVM) is a cardiac magnetic resonance (CMR) technique that allows the assessment of cardiac motion in three orthogonal directions. Accurate and reproducible delineation of the myocardium is crucial for accurate analysis of peak systolic and diastolic myocardial velocities. In addition to the conventionally available magnitude CMR data, 3Dir MVM also provides three orthogonal phase velocity mapping datasets, which are used to generate velocity maps. These velocity maps may also be used to facilitate and improve the myocardial delineation. Based on the success of deep learning in medical image processing, we propose a novel fast and automated framework that improves the standard U-Net-based methods on these CMR multi-channel data (magnitude and phase velocity mapping) by cross-channel fusion with an attention module and the shape information-based post-processing to achieve accurate delineation of both epicardial and endocardial contours. To evaluate the results, we employ the widely used Dice Scores and the quantification of myocardial longitudinal peak velocities. Our proposed network trained with multi-channel data shows superior performance compared to standard U-Net-based networks trained on single-channel data. The obtained results are promising and provide compelling evidence for the design and application of our multi-channel image analysis of the 3Dir MVM CMR data.

Common Doppler artefacts and pitfalls

Artefacts are spurious signals that do not represent true signals or physical structures. It is important to differentiate artefacts from genuine signals in ultrasound studies as this may help avoid misinterpretations and measurement errors. The nature of many Doppler ultrasound artefacts is similar to 2D echocardiography artefacts, including inappropriate gain settings, mirror artefacts, and reverberation artefacts. However, as Doppler ultrasound is used to detect blood flow and myocardial velocity, it is susceptible to insonation (Doppler) angle error, aliasing, and other velocity-related artefacts. These will be presented in this chapter as two main types of artefacts: one that is related to spectral Doppler, and the other related to colour-flow Doppler ultrasound.

P3467Tricuspid annular isovolumic acceleration is more useful for the assessment of right ventricular systolic function in patients after repair of tetralogy of Fallot with pulmonary regurgitation

Introduction The detrimental impact of pulmonary regurgitation (PR) on right ventricular (RV) function of patients after repair of tetralogy of Fallot (TOF) is recognized. Although tricuspid annular isovolumic acceleration (IVA) is useful for the evaluation of RV function, it requires complicated measurement. Tricuspid annular plane systolic excursion (TAPSE) is measured easily and has also been validated as a marker of RV systolic function. Hypothesis We assessed the hypothesis that IVA has advantage to the stratification of the detrimental impact of PR on RV systolic function after TOF repair compared with TAPSE. Methods We prospectively examined patients after TOF repair. Patients <1 year after the repair, those with the history of sustained arrhythmia and those who required concomitant tricuspid and/or pulmonary valve surgery were excluded from the study. IVA was measured by dividing the myocardial velocity during isovolumic contraction by the time interval from the onset of the myocardial velocity during the isovolumic contraction to the time at the peak velocity of this wave. TAPSE was measured using M-mode echocardiography with the M-line passing through the lateral annulus of tricuspid valve in the apical 4-chamber plane. PR jets were evaluated in the parasternal short-axis plane. PR degree was assessed by the number of correspondence to the following conditions; 1) diastolic flow reversal in the main pulmonary artery, 2) diastolic flow reversal in the branch pulmonary arteries, 3) pressure half-time of PR signal <100 msec and 4) the ratio of the duration of the PR signal to the total duration of diastole <0.77. PR degree was graded from 0 to 4. Results Twenty-two patients were enrolled to the study. Age, female, period after the TOF repair and body height of the patients were 11±6 years, 55%, 9±5 years and 137±28 cm, respectively. In all the patients, IVA and TAPSE were 160±27 cm/sec2 and 12±2 mm, respectively. PR degrees were graded as 2, 3 and 4 in 4, 14 and 4 patients, respectively. By the Kruskal-Wallis test, only IVA showed a significant difference among the 3 PR degrees. Conclusion In conclusion, IVA can be a useful index for the stratification of RV function in patients after TOF repair with various degrees of PR.