Echocardiographic strain imaging, also known as deformation imaging, has been developed as a means to objectively quantify regional myocardial function. First introduced as post-processing of tissue Doppler imaging velocity converted to strain and strain rate, strain imaging has more recently also been derived from digital speckle tracking analysis. Strain imaging has been used to gain greater understanding into the pathophysiology of cardiac ischemia and infarction, primary diseases of the myocardium, and the effects of valvular disease on myocardial function, and to advance our understanding of diastolic function. Strain imaging has also been used to quantify abnormalities in the timing of mechanical activation for heart failure patients undergoing cardiac resynchronization pacing therapy. Further advances, such as 3-dimensional speckle tracking strain imaging, have emerged to provide even greater insight. Strain imaging has become established as a robust research tool and has great potential to play many roles in routine clinical practice to advance the care of the cardiovascular patient. This perspective reviews the physiology of myocardial strain, the technical features of strain imaging using tissue Doppler imaging and speckle tracking, their strengths and weaknesses, and the state-of-the-art present and potential future clinical applications.

AimsThe Speckle Tracking and Resynchronization (STAR) study used a prospective multi-centre design to test the hypothesis that speckle-tracking echocardiography can predict response to cardiac resynchronization therapy (CRT).Methods and resultsWe studied 132 consecutive CRT patients with class III and IV heart failure, ejection fraction (EF) ≤35%, and QRS ≥120 ms from three international centres. Baseline dyssynchrony was evaluated by four speckle tracking strain methods; radial, circumferential, transverse, and longitudinal (≥130 ms opposing wall delay for each). Pre-specified outcome variables were EF response and three serious long-term events: death, transplant, or left ventricular assist device. Of 120 patients (91%) with baseline dyssynchrony data, both short-axis radial strain and transverse strain from apical views were associated with favourable EF response 7 ± 4 months and long-term outcome over 3.5 years (P < 0.01). Radial strain had the highest sensitivity at 86% for predicting EF response with a specificity of 67%. Serious long-term unfavourable events occurred in 20 patients after CRT, and happened three times more frequently in those who lacked baseline radial or transverse dyssynchrony than in patients with dyssynchrony (P < 0.01). Patients who lacked both radial and transverse dyssynchrony had unfavourable clinical events occur in 53%, in contrast to events occurring in 12% if baseline dyssynchrony was present (P < 0.01). Circumferential and longitudinal strains predicted response when dyssynchrony was detected, but failed to identify dyssynchrony in one-third of patients who responded to CRT.ConclusionDyssynchrony by speckle-tracking echocardiography using radial and transverse strains is associated with EF response and long-term outcome following CRT.

BackgroundThe objective of this study was to investigate the impact of sodium glucose cotransporter type 2 (SGLT2) inhibitors on left ventricular (LV) diastolic function of type 2 diabetes mellitus (T2DM) patients with heart failure (HF).MethodsThis trial was a prospective multicenter study of 58 T2DM patients with stable HF at five institutions in Japan. Patients who had been taking at least one antidiabetic drugs other than SGLT2 inhibitors started the administration of 5 mg/day of dapagliflozin. The physical examinations, blood tests, and echocardiography were performed at baseline and 6 months after administration of dapagliflozin. The primary endpoint was defined as a change in mitral inflow E and mitral e′ annular velocities (E/e′) between baseline and 6 months after the administration of dapagliflozin. The secondary end points consisted of a change in brain natriuretic peptide (BNP), LV mass index (LVMI) and left atrial volume index (LAVI).ResultsE/e′ significantly decreased from 9.3 to 8.5 cm/s (p = 0.020) 6 months after administration of dapagliflozin. LAVI and LVMI significantly decreased from 31 to 26 mL/m2 (p = 0.001), and from 75.0 to 67.0 g/m2 (p < 0.001), respectively, 6 months after administration of dapagliflozin. No significant change was observed in BNP (from 27.9 to 28.9 pg/mL; p = 0.132) 6 months after administration of dapagliflozin, except for a significant decrease from 168.8 to 114.3 pg/mL (p = 0.012) in patients with BNP ≥ 100 pg/mL.ConclusionThis prospective multicenter trial showed the beneficial effect of SGLT2 inhibitors on LV diastolic functional parameters for T2DM patients with HF. Our findings may thus offer a new insight into the management of T2DM patients.Trial registration UMIN000019789, Registered 28 September 2014, Date of registration: 11/14/2015, Date of enrolment of the first participant to the trial: 6/15/2016, Date of enrolment of the last participant to the trial: 12/9/2017

No abstract

Extensive scar burden in ICM patients unfavourably affected clinical and LV functional outcomes after CRT, regardless of baseline dyssynchrony measures. Patients with ICM and lower scar burden had significantly better outcomes, similar to NICM patients.

Previous methods to quantify dyssynchrony could not determine regional 3-dimensional (3-D)strain. We hypothesized that a novel 3-D speckle tracking strain imaging system can quantify left ventricular (LV) dyssynchrony and site of latest mechanical activation. We studied 64 subjects; 54 heart failure patients referred for cardiac resynchronization therapy (CRT) with ejection fraction 25±6% and QRS 165±29ms and 10 normal controls. The 3-D speckle tracking system determined radial strain using a 16-segment model from a pyramidal 3-D data set. Dyssynchrony was quantified as maximal opposing wall delay and standard deviation in time-to-peak strain. 3-D analysis was compared with standard 2-dimensional (2-D) strain data sets and site of 3-D latest mechanical activation, not possible by 2D was quantified. As expected, dyssynchrony in CRT patients was significantly greater than normal controls (maximal opposing wall delay 316±112* ms vs. 59±12 ms and standard deviation 124±48* ms vs. 28±11 ms, *p<0.001 vs. normal). 3-D opposing wall delay was closely correlated with 3-D 16-segment standard deviation (r = 0.95), and 2-D mid-LV strain: r=0.83 and r=0.85 for standard deviation (all p<0.001). The 3-D site of the latest mechanical activation was most commonly mid-posterior (26%), basal-posterior (22%), mid-lateral (20%), and basal-lateral (17%). Eleven patients studied after CRT demonstrated improvements in 3D synchrony (300±124 ms to 94±37 ms*) and EF (24 ± 6% to 31 ± 7%*), *p<0.05. In conclusion, 3-D speckle tracking can successfully quantify 3-D dyssynchrony and site the latest mechanical activation. This approach may play a clinical role in management of CRT patients. Keywordsechocardiography; heart failure; pacemakers Cardiac resynchronization therapy (CRT) has had a major impact on improving symptoms and survival in heart failure (HF) patients. A large body of data has demonstrated that abnormalities of left ventricular (LV) mechanical timing, known as dyssynchrony, impairs ejection efficiency and is improved with CRT. 1-3 Existing echocardiographic methods to quantify dyssynchrony, such as tissue Doppler, have been shown to have technical limitations which preclude their routine use for patient selection for CRT.4 -7. Accordingly, there is a desire for technological © 2009 Excerpta Medica, Inc. Published by Elsevier Inc. All rights reserved.Corresponding author: John Gorcsan III, MD, University of Pittsburgh, Scaife Hall 564, 200 Lothrop Street, Pittsburgh, PA 15213-2582, Phone: 412-647-6570, Fax: 412-647-0568, gorcsanj@upmc.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal ...

Background-The ability of echocardiographic dyssynchrony to predict response to cardiac resynchronization therapy (CRT) has been unclear. Methods and Results-A prospective, longitudinal study was designed with predefined dyssynchrony indexes and outcome variables to test the hypothesis that baseline dyssynchrony is associated with long-term survival after CRT. We studied 229 consecutive class III to IV heart failure patients with ejection fraction Յ35% and QRS duration Ն120 milliseconds for CRT. Dyssynchrony before CRT was defined as tissue Doppler velocity opposing-wall delay Ն65 milliseconds, 12-site SD (Yu Index) Ն32 milliseconds, speckle tracking radial strain anteroseptal-to-posterior wall delay Ն130 milliseconds, or pulsed Doppler interventricular mechanical delay Ն40 milliseconds. Outcome was defined as freedom from death, heart transplantation, or left ventricular assist device implantation. Of 210 patients (89%) with dyssynchrony data available, there were 62 events: 47 deaths, 9 transplantations, and 6 left ventricular assist device implantations over 4 years. Event-free survival was associated with Yu Index (Pϭ0.003), speckle tracking radial strain (Pϭ0.003), and interventricular mechanical delay (Pϭ0.019). When adjusted for confounding baseline variables of ischemic origin and QRS duration, Yu Index and radial strain dyssynchrony remained independently associated with outcome (PϽ0.05). Lack of radial dyssynchrony was particularly associated with unfavorable outcome in those with QRS duration of 120 to 150 milliseconds (Pϭ0.002). Conclusions-The absence of echocardiographic dyssynchrony was associated with significantly less favorable event-free survival after CRT. Patients with narrower QRS duration who lacked dyssynchrony had the least favorable long-term outcome. These observations support the relationship of dyssynchrony and CRT response.

No abstract