Progressive changes to left atrial (LA) structure and function following mitral regurgitation (MR) remain incompletely understood. This study aimed to demonstrate potential underlying mechanisms ...using experimental canine models and computer simulations. A canine model of MR was created by cauterization of mitral chordae followed by radiofrequency ablation-induced left bundle-branch block (LBBB) after 4 weeks (MR-LBBB group). Animals with LBBB alone served as control. Echocardiography was performed at baseline, acutely after MR induction, and at 4 and 20 weeks, and correlated with histology and computer simulations. Acute MR augmented LA reservoir and contractile strain (40±4 to 53±6% and -11±5 to -22±9% respectively, p<0.05). LA fractional area change increased significantly (47±4 to 56±4%, p<0.05) while LA end-systolic area remained unchanged (7.2±1.1 versus 7.9±1.1 cm.sup.2 respectively, p = 0.08). LA strain 'pseudonormalized' after 4 weeks and decompensated at 20 weeks with both strains decreasing to 25±6% and -3±2% respectively (p<0.05) together with a progressive increase in LA end-systolic area (7.2±1.1 to 14.0±6.3 cm.sup.2, p<0.05). In the LBBB-group, LA remodeling was less pronounced. Histology showed a trend towards increased interstitial fibrosis in the LA of the MR-LBBB group. Computer simulations indicated that the progressive changes in LA structure and function are a combination of progressive eccentric remodeling and fibrosis. MR augmented LA strain acutely to supranormal values without significant LA dilation. However, over time, LA strain gradually decreases (pseudornormal and decompensated) with LA dilation. Histology and computer simulations indicated a correlation to a varying degree of LA eccentric remodeling and fibrosis.
Functional mitral regurgitation (FMR) can be subclassified on the basis of its proportionality relative to left ventricular (LV) volume and function, indicating potential differences in underlying ...etiology. The aim of this study was to evaluate the association of FMR proportionality with FMR reduction, heart failure hospitalization and mortality after transcatheter edge-to-edge mitral valve repair (TEER).
This multicenter registry included 241 patients with symptomatic heart failure with reduced LV ejection fraction treated with TEER for moderate to severe or greater FMR. FMR proportionality was graded on preprocedural transthoracic echocardiography using the ratio of the effective regurgitant orifice area to LV end-diastolic volume. Baseline characteristics, follow-up transthoracic echocardiography, and 2-year clinical outcomes were compared between groups.
Median LV ejection fraction, effective regurgitant orifice area and LV end-diastolic volume index were 30% (interquartile range IQR, 25%–35%), 27 mm2, and 107 mL/m2 (IQR, 90–135 mL/m2), respectively. Median effective regurgitant orifice area/LV end-diastolic volume ratio was 0.13 (IQR, 0.10–0.18). Proportionate FMR (pFMR) and disproportionate FMR (dFMR) was present in 123 and 118 patients, respectively. Compared with patients with pFMR, those with dFMR had higher baseline LV ejection fractions (median, 32% IQR, 27%–39% vs 26% IQR, 22%–33%; P < .01). Early FMR reduction with TEER was more pronounced in patients with dFMR (odds ratio, 0.45; 95% CI, 0.28–0.74; P < .01) than those with pFMR, but not at 12 months (odds ratio, 0.93; 95% CI, 0.53–1.63; P = .80). Overall, in 35% of patients with initial FMR reduction after TEER, FMR deteriorated again at 1-year follow-up. Rates of 2-year all-cause mortality and heart failure hospitalization were 30% (n = 66) and 37% (n = 76), with no differences between dFMR and pFMR.
TEER resulted in more pronounced early FMR reduction in patients with dFMR compared with those with pFMR. Yet after initial improvement, FMR deteriorated in a substantial number of patients, calling into question durable mitral regurgitation reductions with TEER in selected patients. The proportionality framework may not identify durable TEER responders.
•Transcatheter treatment of FMR is a subject of debate.•Proportionality of EROA to LV volumes could influence the outcome of TEER.•Disproportionate mitral regurgitation showed greater reduction after TEER.•A substantial part of initial FMR reduction deteriorated during follow-up.•Clinical outcomes at 2 years did not differ between different proportionality groups.
Response to cardiac resynchronization therapy varies significantly among patients, with one third of them failing to demonstrate left ventricular reverse remodeling after cardiac resynchronization ...therapy. Left atrial size and function is increasingly recognized as a marker of disease severity in the heart failure population. The aim of this study was to evaluate whether echocardiographic left atrial indices predict left ventricular reverse remodeling after cardiac resynchronization therapy.
Ninety-nine cardiac resynchronization therapy candidates were prospectively included in the study and underwent echocardiography before and 3-months after cardiac resynchronization therapy implantation. Cardiac resynchronization therapy response was defined as a 15% relative reduction in left ventricular end-systolic volume. Indexed left atrial volume, left atrial reservoir strain, left ventricular end-diastolic volume, and left ventricular ejection fraction along with other known predictors of cardiac resynchronization therapy response (gender, etiology of heart failure, presence of typical left bundle branch block pattern, QRS duration >150 ms) were included in a multivariate logistic regression model to identify predictors for cardiac resynchronization therapy response.
Cardiac resynchronization therapy response occurred in
= 63 (64%) patients. The presence of a typical left bundle branch block (OR 4.2, 95 CI: 1.4-12.1,
= 0.009), QRS duration >150 ms (OR 4.2, 95 CI: 1.4-11.0,
= 0.029), and left atrial volume index (OR: 0.6, 95 CI: 0.4-0.9,
= 0.012) remained the only significant predictors for cardiac resynchronization therapy response after three months. None of the baseline left ventricular parameters showed an independent predictive value.
Left atrial size at baseline is an independent predictor and is inversely proportional to left ventricular volumetric reverse remodeling in cardiac resynchronization therapy candidates.
CRT leads to improvement in exercise capacity, cardiac function and mortality in selected CHF patients. Exercise capacity improves even greater when combining CRT with moderate-intensity exercise ...training (ET). However, high-intensity interval training (HIT) as additional therapy to CRT has not yet been established. Given the complementary physiological effects of HIT, we hypothesized that HIT after CRT may have additional effects on exercise capacity.
24 CHF patients, NYHA class II/III and accepted for CRT underwent an echocardiogram, QoL questionnaire and CPET with cardiac output (CO) measurements before implantation, at 3 and 6 months. After 3 months, patients were randomized to usual care (UC) or HIT, consisting of 36 sessions at 85–95% of peak V̇O2.
Peak V̇O2 increased after CRT (17±5.3 to 18.7±6.2 ml/kg/min, p < 0.05); after HIT there was a non-significant increase of 1.4 ml/kg/min (p = 0.12). Peak workload increased after CRT (109±45 to 118±44 W, p = 0.001). An additional significant within- and between group increase after HIT was found in the intervention group (128±42 to 148±48 W, versus 110±50 to 110±50, respectively, p = 0.03). Peak CO did not change significantly after CRT or HIT. V̇O2 recovery kinetics speeded by 27% after CRT (p = 0.04), no further improvement after HIT was observed. LVEF increased 25% after CRT (p = 0.0001), no additional increase was seen after HIT.
This study demonstrates that HIT provides additional improvement of exercise capacity without a concomitant change in peak V̇O2 or CO suggesting that the additional effect of HIT is mainly mediated by an improvement of anaerobic performance.
•HIT after CRT improves peak workload.•Oxygen uptake recovery kinetics are faster after CRT, no further improvement after HIT.•LVEF increases after CRT, no further improvement after HIT.
The left atrium (LA) is a key player in the pathophysiology of systolic and diastolic heart failure (HF). Speckle tracking derived LA reservoir strain (LAS
) can be used as a prognostic surrogate for ...elevated left ventricular filling pressure similar to NT-proBNP. The aim of the study is to investigate the correlation between LAS
and NT-proBNP and its prognostic value with regards to the composite endpoint of HF hospitalization and all-cause mortality within 1 year.
Outpatients, sent to the echocardiography core lab because of HF, were enrolled into this study. Patients underwent a transthoracic echocardiographic examination, commercially available software was used to measure LAS
. Blood samples were collected directly after the echocardiographic examination to determine NT-proBNP.
We included 174 HF patients, 43% with reduced, 36% with mildly reduced, and 21% with preserved ejection fraction. The study population showed a strong inverse correlation between LAS
and log-transformed NT-proBNP (r = - 0.75, p < 0.01). Compared to NT-proBNP, LAS
predicts the endpoint with a comparable specificity (83% vs. 84%), however with a lower sensitivity (70% vs. 61%).
LAS
is inversely correlated with NT-proBNP and a good echocardiographic predictor for the composite endpoint of hospitalization and all-cause mortality in patients with HF.
https://www.trialregister.nl/trial/7268.
Echocardiography is essential in the evaluation of patients with cardiovascular disease. Repetitive movements, however, expose ultrasound operators to a high risk of musculoskeletal strain injuries.
...We investigated to what extent a probe stabilizer could reduce repetitive movements.
The study population consisted of 31 male patients referred for routine transthoracic echocardiography. A good apical acoustic window was prerequisite for inclusion. Standard apical views and measurements were first recorded without using the probe stabilizer. Afterwards, the same apical views and measurements were acquired with utilization of the probe stabilizer. During the entire procedure, shoulder abduction and muscle activity of right forearm flexor and extensor muscles were recorded. To this purpose, an EMG-sensor was attached to the right lower arm and a gyroscope to the right shoulder blade.
Extreme right arm abduction (>30˚) occurred in 58% of the time with use of the stabilizer and in 98% of the time without (
<0.01). Activity of right forearm extensor muscles was 42% with and 60% without stabilizer (
= 0.04). For the flexor muscles these percentages were 47% and 87%, respectively (
<0.01). Use of the stabilizer did not affect the time needed for image acquisition (308s versus 309s, respectively,
= 0.46).
This study demonstrated that the use of a stabilizer during acquisition of apical views in routine transthoracic echocardiography reduces the total time of shoulder abduction and the use of the right forearm muscles, while acquisition time was not affected.
Background and objectives: Persistent left bundle branch block (P-LBBB) has been associated with poor clinical outcomes of transcatheter aortic valve implantation (TAVI) procedures. We hypothesized ...that the distance from the aortic valve to the proximal conduction system, expressed as the effective distance between the aortic valve and conduction system (EDACS), can predict the occurrence of P-LBBB in patients undergoing a TAVI procedure. Materials and methods: In a retrospective study, data from 269 patients were analyzed. EDACS was determined using two longitudinal CT sections. Results: Sixty-four of the patients developed P-LBBB. EDACS ranged between −3 and +18 mm. EDACS was significantly smaller in P-LBBB than in non-P-LBBB patients (4.6 (2.2–7.1) vs. 8.0 (5.8–10.2) mm, median values (interquartile range); p < 0.05). Receiver operating characteristic analysis showed an area under the curve of 0.78 for predicting P-LBBB based on EDACS. In patients with EDACS of ≤3 mm and >10 mm, the chance of developing P-LBBB was ≥50% and <10%, respectively. Conclusions: A small EDACS increases the risk for the development of P-LBBB during TAVI by a factor of >25. As EDACS can be measured pre-procedurally, it may be a valuable additional factor to weigh the risks of transcatheter and surgical aortic valve replacement.
OBJECTIVES
Recently, transcatheter aortic valve implantation has been introduced, but one of its complications is left bundle branch block (LBBB), a conduction disturbance that has been associated ...with increased mortality. We investigated the incidence and fate of both right bundle branch block (RBBB) and LBBB after aortic valve replacement (AVR) using a retrospective analysis. We also studied the predictive value of both disorders for all-cause mortality.
METHODS
All patients who underwent AVR, with or without concomitant coronary artery bypass grafting surgery, between 2002 and 2010 in our centre were included. All-cause mortality was compared between patients who did and those who did not develop persistent new bundle branch block (BBB) within 7 days postoperatively. Patients were not eligible if one of their electrocardiogram (ECG) recordings prior to AVR showed a BBB or pacemaker activity. A postoperative period of 3–12 months was used to collect follow-up ECGs.
RESULTS
Of the 2279 AVR patients, 2033 patients were eligible for analysis. After excluding patients lacking baseline or follow-up ECG (n = 269), 1764 patients remained for analysis. Early LBBB and RBBB occurred in 71 (4.0%) and 92 (5.2%) patients, respectively. At follow-up, LBBB was persistent in 29 patients (1.6%) and RBBB in 74 patients (4.2%). During a median follow-up of 4.5 (2.4–6.5) years, the mortality rate was 16.3% (n = 271) in patients without BBB, 24.1% (n = 7) in patients with persistent LBBB and 18.9% (n = 14) in patients with persistent RBBB (log-rank P = 0.49). Though, in univariate analysis, the hazard ratio for mortality was 1.54 and 1.10 for LBBB and RBBB, respectively, the small numbers precluded identifying AVR-induced LBBB and RBBB as a predictor of mortality.
CONCLUSIONS
In the current practice of AVR, persistent postoperative LBBB and RBBB occur infrequently (∼5% of cases), a percentage less than half of that in current transcatheter aortic valve implantation procedures. Given the adverse effects of LBBB, the lower prevalence of procedure-induced LBBB in AVR should be taken into account while deciding which valve replacement procedure is chosen for a patient.
We aimed to evaluate whether baseline GLS (global longitudinal strain), NT-proBNP, and changes in these after cardiac resynchronization therapy (CRT) can predict long-term clinical outcomes and the ...echocardiographic-based response to CRT (defined by 15% relative reduction in left ventricular end-systolic volume).
We enrolled 143 patients with stable ischemic heart failure (HF) undergoing CRT-D implantation. NT-proBNP and echocardiography were obtained before and 6 months after. The patients were followed up (median: 58 months) for HF-related deaths and/or HF hospitalizations (primary endpoint) or HF-related deaths (secondary endpoint).
A total of 84 patients achieved the primary and 53 the secondary endpoint, while 104 patients were considered CRT responders and 39 non-responders. At baseline, event-free patients had higher absolute GLS values (
< 0.001) and lower NT-proBNP serum levels (
< 0001) than those achieving the primary endpoint. A similar pattern was observed in favor of CRT responders vs. non-responders. On Cox regression analysis, baseline absolute GLS value (HR = 0.77; 95% CI, 0.51-1.91;
= 0.002) was beneficially associated with lower primary endpoint incidence, while baseline NT-proBNP levels (HR = 1.55; 95% CI, 1.43-2.01;
= 0.002) and diabetes presence (HR = 1.27; 95% CI, 1.12-1.98;
= 0.003) were related to higher primary endpoint incidence.
In HF patients undergoing CRT-D, baseline GLS and NT-proBNP concentrations may serve as prognostic factors, while they may predict the echocardiographic-based response to CRT.
PDF
