Speckle Tracking Echocardiographic Assessment of Left Ventricular Function by Myocardial Strain Before and After Aortic Valve Replacement

Background & objectivesIn patients of aortic stenosis and regurgitation, pressure and volume effects on left ventricular function are occult and missed by routine echocardiography markers like ejection fraction (EF). Speckle tracking analysis by measuring global longitudinal strain and global circumferential strain seems to ascertain this occult LV function parameters at an early phase in a more comprehensive manner. Limited studies have examined these parameters pre/post aortic valve replacement (AVR).Methods94 consecutive patients with symptomatic severe aortic stenosis (AS) or aortic regurgitation (AR), planned for AVR were included (as per set inclusion criteria) along with 15 normal controls-15 months prospective study. Routine echocardiography and speckle tracking imaging was done at baseline (pre AVR) and post AVR at 1st week, 1st month and 3rd month of follow up.Results90 patients completed study (70 in AS and 20 in AR group). In AS group mean values (± 2 standard deviations) of global longitudinal strain (GLS) improved from a baseline −10.9% (± 3.9) to −19.4% (±3.8) at 3rd month (p value < 0.0001). Mean values of global circumferential strain (GCS) too improved from −17.3% (±4.5) to −21.4% (±3.6) respectively (p value < 0.0001). In AR group too mean values of global longitudinal strain progressed from a baseline −12.6% (±3.9) to −19.4% (±3.4) at three months of follow (p value < 0.0001) and mean values of global circumferential strain also progressed from −15.3% (±3.4) at baseline to −21.7% (±3.1) respectively (p value < 0.0001).ConclusionMagnitude of recovery of GLS and GCS after AVR was more as compared to recovery in EF. Poor GLS/GCS values at baseline were associated with lesser recovery pressing need for an earlier intervention.     

Left Ventricular Relative Wall Thickness Versus Left Ventricular Mass Index in Non-Cardioembolic Stroke Patients

In non-cardioembolic stroke patients, the cardiac manifestations of high blood pressure are of particular interest. Emerging data suggest that echocardiographically determined left ventricular hypertrophy is independently associated with risk of ischemic stroke.The primary objective of this study was to evaluate the frequency of different patterns of left ventricular (LV) remodeling and hypertrophy in a group of consecutive patients admitted with non-cardioembolic stroke or transient ischemic attack (TIA). In particular, we were interested in how often the relative wall thickness (RWT) was abnormal in patients with normal LV mass index (LVMI). As both abnormal RWT and LVMI indicate altered LV remodeling, the secondary objective of this research was to study whether a significant number of patients would be missing the diagnosis of LV remodeling if the RWT is not measured.All patients were referred within 48 hours after a stroke or a TIA for a clinically indicated transthoracic echocardiogram. The echocardiographic findings of consecutive patients with non-cardioembolic stroke or TIA were analyzed.All necessary measurements were performed in 368 patients, who were enrolled in the study. Mean age was 63.7 ± 12.5 years, 64.4% men. Concentric remodeling carried the highest frequency, 49.2%, followed by concentric hypertrophy, 30.7%, normal pattern, 15.5%, and eccentric hypertrophy, 4.1%. The frequency of abnormal left ventricular RWT (80.4%) was significantly higher than that of abnormal LVMI (35.3%), (McNemar P < 0.05).In this group of non-cardioembolic stroke patients, abnormal LV remodeling as assessed by relative wall thickness is very frequent. As RWT was often found without increased LV mass, the abnormal left ventricular geometry may be missed if RWT is not measured or reported.     

Correlation between Left Ventricular Global and Regional Longitudinal Systolic Strain and Impaired Microcirculation in Patients with Acute Myocardial Infarction

Objectives: We investigated the correlation between left ventricular global and regional longitudinal systolic strain (GLS and LRS) and coronary flow reserve (CFR) assessed by transthoracic echocardiography (TTE) in patients with a recent acute myocardial infarction (AMI). Furthermore, we investigated if LRS and GLS imaging is superior to conventional measures of left ventricle (LV) function. Methods: In a consecutive population of first time AMI patients, who underwent successful revascularization, we performed comprehensive TTE. GLS and LRS were obtained from the three standard apical views. Assessment of CFR by TTE was performed in a modified apical view using color Doppler guidance. Results: The study population consisted of 183 patients (51 females) with a median age of 63 [54;70] years. Eighty‐nine (49%) patients had a non‐ST elevation myocardial infarction and 94 (51%) patients had a ST elevation myocardial infarction. The GLS was ?15.2 [?19.3;?10.1]% in the total population of 183 patients. Total wall motion score index (WMSI) in the population was 1.19 [1;1.5]. Eighty‐five patients suffered from culprit lesion in left anterior descending artery (LAD). The CFR in these patients was 1.86 [1.36;2.35] and the GLS was ?14.3 [?18.9; ?9.8]%. A significant difference was observed in the LRS in LAD territory in culprit LAD infarction patients with a CFR ≤ 2 (?9.6 [?13.77;?6.44]) compared with the LRS in LAD territory in culprit LAD infarction patients with a CFR > 2 (?19.33 [?21.1;?16.5]), P < 0.0001. We found no significant difference between WMSI in LAD territory in culprit LAD infarction patients with a CFR ≤ 2 (1.56 [1.06;2.23]) compared with WMSI in LAD territory in culprit LAD infarction patients with a CFR > 2 (1.37 [1.03;2.11]); P = 0.18. The same pattern was observed in both circumflex coronary artery (CX) and right coronary artery (RCA) territories. In the total population, we found a strong correlation between CFR and GLS (r = ?0.85, P < 0.0001). This was also seen in the multivariate regression model adjusting for possible confounders including WMSI (P < 0.001). Conclusion: In this study, we have shown a close association between myocardial deformation in patients with a recent AMI and the degree of diminished microcirculation. We found that both GLS and LRS correlated with CFR. We conclude that GLS and LRS are significantly better tools to assess impaired CFR and LV function after a recent AMI, than conventional echocardiographic measurements.     

Echocardiographic Findings in a Patient with Left Ventricular Pseudoaneurysm

ABSTRACT A 57-year-old woman, treated for a large anterior transmural myocardial infarction, was readmitted after 8 weeks because of progressive cardiac failure. Chest X-ray showed cardiomegaly with an atypical cardiac silhouette. Two-dimensional echocardiography disclosed a large left ventricular pseudoaneurysm. The patient underwent resection of the false aneurysm with repair of the left ventricular wall and recovered gradually. Different methods for diagnosing pseudoaneurysm are discussed.     

Instantaneous Decrease in Left Ventricular Afterload during Transcatheter Aortic Valve Implantation Results in Immediate Changes in Left Ventricular Strain

Severe aortic stenosis causes chronic increased afterload on the left ventricle (LV) resulting in myocardial hypertrophy and ultimately dysfunction if left untreated. Transcatheter aortic valve implantation (TAVI) immediately decreases the afterload on the LV by reducing the pressure gradient through the aortic valve. In our study, we aim to evaluate immediate changes in LV mechanics using intra‐procedural transesophageal echocardiography (TEE) to assess circumferential and radial strain via speckle tracking. Intra‐operative TEE was performed during TAVI for 53 patients (mean age 84 ± 8 years). Two‐dimensional images in the transgastric view were acquired at the level of the papillary muscle. Circumferential and radial strain was calculated using speckle tracking with Philips Qlab software. Global LV afterload was measured by calculating valvulo‐arterial impedance (Zva). Immediately post‐TAVI, there was a change in both radial strain rate (Pre: 0.73 ± 0.04 vs. Post: 0.88 ± 0.04 per second, P < 0.001) and circumferential strain rate (?0.53 ± 0.04 (pre) vs. ?0.74 ± 0.04 (post) per second, P < 0.001). There was also an immediate improvement in circumferential global strain parameters (?14.5 ± 5% (pre) vs. ?16.0 ± 4.7% (post), P < 0.05), whereas there was no significant change seen in global radial strain (15.6 ± 0.8% (pre) vs. 15.2 ± 0.9% (post), P = 0.69). No significant change was seen in LV ejection fraction (51.5 ± 14.2% (pre) vs. 52.1 ± 14.0% (post), P = 0.77). Speckle tracking using TEE images is feasible and identifies significant improvements in LV strain and strain rate immediately following TAVI that is not detected by conventional measure of LV function.     

Acute Myocarditis and Left Ventricular Hypertrophy

Echocardiographic abnormalities of myocarditis are polymorphous and nonspecific. The presence of increased ventricular wall thickness, typically transient, is an infrequent finding in myocarditis that can correspond to an improvement in the clinical status of the patient and the ejection fraction. We report the case of a patient with acute myocarditis and the echocardiographic abnormalities observed during the course of his myocarditis: transient left ventricular hypertrophy associated with improvement of the left ventricular function.     

Longitudinal Tissue Velocity and Deformation Imaging in Inferobasal Left Ventricular Aneurysm

Background: Longitudinal myocardial tissue velocity imaging (TVI) and strain rate imaging (SRI) quantify regional myocardial function. We aimed to measure TVI and SRI indices for inferobasal aneurysmal segments by echocardiography at rest. Method: Sixteen patients with inferobasal left ventricular (LV) aneurysm, LV ejection fraction (EF) ≤50%, and 14 normal coronaries with normal echocardiography (control group) were studied. In SRI, peak systolic strain (ST), strain rate (SR), and pattern of strain curves and in TVI, peak systolic inward motion (Sm) were evaluated all at rest. Ascending curve means systolic expansion and descending means shortening. Results: LVEF was significantly lower in the patient group. Mean ST, SR, and Sm of inferobasal segment showed significant difference between patient and control groups; for ST: 1.45 ± 7.18% versus ?17.64 ± 7.45%, P < 0.0001; SR: ?0.25 ± 0.26 versus ?1.44 ± 0.64 sec^?1, P < 0.0001; and Sm: 3.85 ± 1.26 versus 5.56 ± 1.28 cm/sec, P = 0.006, respectively. All inferobasal aneurysmal segments had ascending curve while normal segments showed a descending curve. In patient group, aneurysmal segments had significantly reduced ST and SR compared to normal segments. Normal functioning segments of patients showed significant reduction of ST and SR compared to normal LV segments in control subjects. The range of SR and ST for inferobasal aneurysmal segments did not overlap with that of the normal segments (?0.60, 0.19 and ?3.00, ?0.80 sec^?1 for SR, and ?8.30, 23.30 and ?35.30, ?10.00% for ST, respectively). Conclusion: SRI indices were significantly reduced in inferobasal aneurysmal segment in comparison with either the same segment in normal subjects or normal functioning segments in the same patients. SR and ST may be superior to Sm in the evaluation of inferobasal aneurysmal segments. (Echocardiography 2010;27:803‐808)