Peak Radial Strain Research Articles

Abnormal left ventricular torsion and cardiac autonomic dysfunction in subjects with type 1 diabetes mellitus

Left ventricular torsion is increased and cardiac energetics are reduced in uncomplicated type 1 diabetes mellitus (T1DM). Our aim was to determine the relationships of these abnormalities to cardiovascular autonomic neuropathy (CAN) in subjects with T1DM. A cross-sectional study was conducted in 20 subjects with T1DM free of known coronary heart disease attending an outpatient clinic. Cardiovascular autonomic neuropathy was assessed using heart rate variability studies and the continuous wavelet transform method. Left ventricular function was determined by speckle tracking echocardiography. Magnetic resonance spectroscopy and stress magnetic resonance imaging were used to measure cardiac energetics and myocardial perfusion reserve index, respectively. Twenty subjects (age, 35 ± 8 years; diabetes duration, 16 ± 9 years; hemoglobin A1c, 8.0% ± 1.1%) were recruited. Forty percent of the subjects exhibited definite or borderline CAN. Log peak radial strain was significantly increased in subjects with CAN compared with those without (1.56 ± 0.06 vs 1.43 ± 0.14, respectively; P = .011). Data were adjusted for log duration of diabetes, and log left ventricular torsion correlated (r = 0.593, P = .01) with log low-frequency to high-frequency ratio during the Valsalva maneuver. Log isovolumic relaxation time correlated significantly with log Valsalva ratio and log proportion of differences in consecutive RR intervals of normal beats greater than 50 milliseconds during deep breathing. However, CAN did not correlate with cardiac energetics or myocardial perfusion reserve index. Spectral analysis of low-frequency to high-frequency ratio power during the Valsalva maneuver is associated with altered left ventricular torsion in subjects with T1DM. Parasympathetic dysfunction is closely associated with diastolic deficits. Cardiovascular autonomic neuropathy is not however the principal cause of impaired cardiac energetics. The role of CAN in the development of cardiomyopathy warrants further evaluation.

121 Assessment of contractile reserve using strain delay index by speckle tracking to identify myocardial viability

In dysfunctional segment, contractility in delayed segments does not fully contribute to end-systolic function. This reserve of contraction (strain delay index) related to mechanical dyssynchrony is supposed to be greater in viable and ischemic segments than in infarct segments. Percutaneous coronary occlusion (circumflex) was performed in 13 anesthetized pigs to investigate changes in strain delay index during acute ischemia (after 3’ of occlusion) and after induced myocardial necrosis (>2 hours of occlusion). The strain delay index, which was defined as the difference between peak and end-systolic strain was computed from circumferential and radial strain curves obtained by speckle tracking analysis performed on short axis view. In related coronary occluded segments, delayed myocardial contraction and impaired regional peak strain was observed during early ischemia for circumferential and radial strain. However, despite prolonged coronary occlusion, delayed contraction and peak circumferential and radial strain remained unchanged. In contrast, regional strain delay index showed a biphasic pattern with an increased during early ischemia and a significant decrease after a prolonged coronary occlusion. Delayed myocardial contraction and reduce peak strain by speckle tracking can be similarly observed during early and prolonged coronary occlusion. In contrast, regional strain delay index used to quantify contractile reserve appears to more sensitive to identify myocardial viability.

Relative Merits of Left Ventricular Dyssynchrony, Left Ventricular Lead Position, and Myocardial Scar to Predict Long-Term Survival of Ischemic Heart Failure Patients Undergoing Cardiac Resynchronization Therapy

The relative merits of left ventricular (LV) dyssynchrony, LV lead position, and myocardial scar to predict long-term outcome after cardiac resynchronization therapy remain unknown and were evaluated in the present study. In 397 ischemic heart failure patients, 2-dimensional speckle tracking imaging was performed, with comprehensive assessment of LV radial dyssynchrony, identification of the segment with latest mechanical activation, and detection of myocardial scar in the segment where the LV lead was positioned. For LV dyssynchrony, a cutoff value of 130 milliseconds was used. Segments with <16.5% radial strain in the region of the LV pacing lead were considered to have extensive myocardial scar (>50% transmurality, validated in a subgroup with contrast-enhanced magnetic resonance imaging). The LV lead position was derived from chest x-ray. Long-term follow-up included all-cause mortality and hospitalizations for heart failure. Mean baseline LV radial dyssynchrony was 133±98 milliseconds. In 271 patients (68%), the LV lead was placed at the latest activated segment (concordant LV lead position), and the mean value of peak radial strain at the targeted segment was 18.9±12.6%. Larger LV radial dyssynchrony at baseline was an independent predictor of superior long-term survival (hazard ratio, 0.995; P=0.001), whereas a discordant LV lead position (hazard ratio, 2.086; P=0.001) and myocardial scar in the segment targeted by the LV lead (hazard ratio, 2.913; P<0.001) were independent predictors of worse outcome. Addition of these 3 parameters yielded incremental prognostic value over the combination of clinical parameters. Baseline LV radial dyssynchrony, discordant LV lead position, and myocardial scar in the region of the LV pacing lead were independent determinants of long-term prognosis in ischemic heart failure patients treated with cardiac resynchronization therapy. Larger baseline LV dyssynchrony predicted superior long-term survival, whereas discordant LV lead position and myocardial scar predicted worse outcome.

Value of velocity vector imaging and stress echocardiography in the assessment of systolic function of left ventricular in diabetic rats

Objective To investigate whether velocity vector imaging (VVI) combined with stress echocardiography could detect potential myocardial impairment of the left ventricle(LV) in diabetic rats.Methods DM rats ( n = 18,administered by STZ at 65 mg/kg) and control rats( n = 12) were performed with VVI and M-mode echocardiography both at rest and after dipyridamole stress 12 weeks later. Twodimensional echocardiographic cine loops and M-mode images of three consecutive beats were obtained from the short-axis views at the mid-LV level. The means of segmental peak systolic velocity(Vs), circumferential strain(ec) ,radial strain(er), systolic circumferential and radial strain rate (SRc, SRr) and the percent wall thickening (WT% ,derived from M-mode) were obtained. After echocardiograms were performed,the hearts were excised and prepared for HE staining and ultrastructural observations under electron microscopy.Results At rest,only SRc in the DM group was significantly lower than that in the control group( P ＜0.05), the other parameters were statistically comparable between the two groups. After dipyridamole stress,all VVI values in the DM group were significantly lower than those in the control group ( P ＜0.05).However,there was no significant difference in WT% between the two groups either at rest or after dipyridamole stress ( P ＞0.05). Conclusions The VVI parameters combined with dipyridamole stress are more effective in evaluating potential myocardial impairment of the LV walls in diabetic rats. SRc might be more sensitive indices that can be used to detect myocardial impairment at rest. Key words: Echocardiography,stress; Diabetes mellitus; Ventricular function,left; Dipyridamole; Velocity vector imaging

Regional Myocardial Function and Response to Acute Afterload Increase in Chronically Anemic Fetal Sheep: Evaluation by Two-Dimensional Strain Echocardiography

We hypothesized that in chronic fetal anemia, remodeling of the myocardium is related to abnormalities in regional wall motion and acutely increased afterload further disturbs myocardial strain. Chronic anemia was induced in one fetus of each of seven sheep twin pregnancies. The fetuses were studied by two-dimensional (2-D) strain echocardiography at baseline and during increased afterload via angiotensin II (AT II) infusion. At baseline, the peak systolic longitudinal, radial and circumferential strains in the left ventricular lateral wall in anemic fetuses were lower than those in the controls (all p < 0.05). During AT II, the circumferential strain of right ventricular free wall decreased significantly both in the control and anemic fetuses. Left ventricular free wall systolic strains were not affected by AT II. Fetal myocardial remodeling in chronic anemia decreases left ventricular systolic free wall strains. The myocardial adaptation does not change ventricular responses to acutely increased afterload. (E-mail: sahnd@ohsu.edu)

Differentiation of pseudodyskinesis of inferior left ventricular wall from inferior myocardial infarction by assessment of regional myocardial strain using two-dimensional speckle tracking echocardiography

Purpose To differentiate pseudodyskinesis (PD) of the inferior left ventricular (LV) wall from inferior myocardial infarction (IMI) noninvasively, we performed focal site evaluation using two-dimensional speckle tracking transthoracic echocardiography (TTE). Materials and methods Speckle tracking TTE was carried out in 57 patients, with 19 subjects in each of three groups (Group A, suspected PD; Group B, LV IMI; and Group C, controls). Inferior wall PD was defined as follows: compression of the inferior LV wall by the diaphragm in the LV short axis view with a normal electrocardiogram and no evidence of previous ischemic events. Results Respective values in Groups A–C for LV ejection fraction (EF) were 63.6 ± 4.2%, 52.3 ± 7.6%, and 61.5 ± 3.8%, for inferior wall speckle tracking focal site evaluation peak radial strain of 30.0 ± 14.3%, 7.5 ± 7.1%, and 42.1 ± 22.9%, for peak circumferential strain of 23.1 ± 6.0%, 16.8 ± 8.4%, and 22.7 ± 7.1%, and for longitudinal strain in the mid-inferior wall of 18.4 ± 3.4%, 11.4 ± 4.0% and 15.8 ± 5.9%. LVEF values were significantly lower in Group B than Groups A and C (P < 0.001), as were those of radial, circumferential, and longitudinal strains (P < 0.05). In receiver-operating characteristic analysis the optimal cut-off values with corresponding sensitivities and specificities for differentiation of PD from IMI were > 19% with 84.2% and 94.7% for radial, > 15% with 89.4% and 52.6% for circumferential, and > 15% with 73.6% and 100% for longitudinal strain, respectively. Conclusions Determination of regional strain from speckle tracking TTE, especially radial and longitudinal strains, can provide focal and quantitative noninvasive evaluation for distinguishing PD of the inferior wall from IMI.

Left ventricular remodeling after myocardial infarction impairs early diastolic, but not systolic, function in the radial direction in the remote normal region

It is acknowledged that expansion of the remote normal region of the left ventricle causes remodeling after myocardial infarction (MI). However, the characteristics of that region have not been fully elucidated. We studied 13 patients with atypical chest pain (controls) and 15 patients with a prior anterior MI who underwent cardiac catheterization. With Doppler strain imaging, we measured the peak radial myocardial systolic strain and peak radial early diastolic strain rate at the posterior wall of the left ventricle. None of the patients with atypical chest pain exhibited significant stenosis of the three major coronary arteries or left ventricular (LV) wall motion abnormality in cardiac catheterization. The patients with a prior anterior MI had single anterior descending artery disease without wall motion abnormality in the LV inferoposterior wall. LV ejection fraction and the LV relaxation time constant were also measured. The LV ejection fraction was significantly smaller in patients with a prior MI compared to controls. The peak radial systolic strain in the LV posterior wall was not significantly different between the patients with a prior MI and controls (125±49 vs. 122±29%). In contrast, the peak radial early diastolic strain rate in the same area was significantly lower in the patients with a prior MI than in controls (-7.4±2.7 vs. -13.2±4.0s(-1), p<0.001). Peak early diastolic radial strain rate was significantly correlated with the LV relaxation time constant in all patients (r=0.69, p<0.001). LV remodeling after an MI impairs local early diastolic myocardial function in the remote normal region and it is related to global LV diastolic dysfunction.

086 Going beyond segmental timing alone to predict response to cardiac resynchronisation therapy: evaluation of a novel radial strain dyssynchrony index

Introduction In selecting patients that may benefit from cardiac resynchronisation therapy (CRT), dyssynchrony assessment by echocardiography based only upon the timing of regional contraction is limited by being inherently independent of underlying myocardial contractility. We hypothesised that patient selection may be enhanced using a strain-based parameter based not only the timing of myocardial segmental motion, but also on the amplitude of contraction, a potential measure of contractile reserve. We assessed a combined early and late strain index (ELSI) to predict CRT response. Methods Speckle tracking radial strain was performed in 67 heart failure patients scheduled for CRT (age 69±9 years, ischaemic 56%, QRS 154±12 ms, NYHA III/IV—63/4, ejection fraction 23±7%). The ELSI was calculated as the sum for each of the 12 non apical segments of the difference in peak radial strain and strain at aortic valve closure. CRT response was defined as a >15% reduction from baseline in LV end systolic volume (LVESV) at 6 months. The predictive value of the ELSI was compared to previously reported dyssynchrony measures including the SD of time to peak myocardial longitudinal velocity of the 12 non apical segments (Ts SD12), the anteroseptal–posterior wall radial strain delay (AS-P delay) and the SD of time to peak radial strain of 12 segments (Rs-SD12). Results Response to CRT occurred in 38/67 (57%) patients. Significant differences were seen between responders and non responders in the ELSI (91±45 vs 27±14%, p Conclusion A combined early and late strain parameter based on both the timing and amplitude of segmental strain has a stronger predictive value in determining CRT response compared to widely reported dyssynchrony parameters based on segmental timing alone.

Speckle-tracking 2-dimensional strain echocardiography: A new noninvasive imaging tool to evaluate acute rejection in cardiac transplantation

There remains no reliable non-invasive method to detect cardiac transplant rejection. Recently, speckle-tracking 2-dimensional strain echocardiography (2DSE) was shown to be sensitive in the early detection of myocardial dysfunction in various models of cardiomyopathy. We aim to determine if 2DSE-derived functional indices can detect cardiac transplant rejection. Heterotopic rat cardiac transplantation was performed in histocompatible isografts or histoincompatible allografts. Histologic rejection scores were determined. Short-axis, mid-left ventricular (LV) echocardiography was performed on Day 6 after transplantation. Conventional measures of function were measured, (including LV fractional shortening and ejection fraction) as well as 2DSE parameters. Despite class IIIB rejection in allografts and no rejection in isografts, there was no difference between isografts vs allografts in fractional shortening (15% +/- 3% vs 12% +/- 3%) or ejection fraction (36% +/- 5% vs 26% +/- 6%; both not significant). In contrast, 2DSE revealed decreases between isografts and allografts in global radial strain (12.6% +/- 5.6% vs 1.1% +/- 0.2%, p < 0.05), peak radial systolic strain rate (3.10 +/- 0.74/s vs 0.54 +/- 0.13/s, p < 0.001), and peak circumferential systolic strain rate (-1.99 +/- 0.55 vs -0.43 +/- 0.11/s; p < 0.01). Systolic strain imaging using 2DSE differentiates myocardial function between experimental cardiac transplant rejection in allografts and non-rejection in isografts. Therefore, 2DSE may be useful in early non-invasive detection of transplant rejection.

Left ventricular myocardial strain and strain rates in sub-endocardial and sub-epicardial layers before and after a marathon

We assessed myocardial deformation in sub-endocardial and sub-epicardial layers of the left ventricle (LV) wall before and after running a marathon. Echocardiography scans were performed on 14 male, non-elite runners (mean +/- SD; age 32 +/- 10 years) who completed the 42.2-km London marathon. Para-sternal short axis and apical four-chamber views were recorded for off-line analysis. Peak longitudinal, radial and circumferential strains, peak systolic and early diastolic strain rates were recorded. Circumferential rotation in basal and apical LV scans was used to calculate torsion. Pre-race strain and strain rates were generally greater in the sub-endocardial layer of the LV wall. After race completion, a mixed pattern of change was observed with a reduction in sub-epicardial radial strain (32.6 +/- 12.5 to 20.3 +/- 9.6%; P < 0.01) and sub-endocardial circumferential strain (-26.9 +/- 3.6 to -23.7 +/- 4.1%; P < 0.01) at the apex. Rotation was not altered at either the apical or basal levels and thus torsion was not changed in either the sub-endocardium (6.72 +/- 3.46 degrees to 5.67 +/- 4.98 degrees) or the sub-epicardium (3.48 +/- 2.68 degrees to 3.01 +/- 3.23 degrees). Strain rates and rotation rates were only sporadically altered post-race. There are differences in deformation characteristics between the sub-endocardium and sub-epicardium at baseline, and the limited changes observed post-race were not specific to any region or depth of the LV wall.

Peak radial and circumferential strain measured by velocity vector imaging is a novel index for detecting vulnerable plaques in a rabbit model of atherosclerosis

AimsTo evaluate the reliability of velocity vector imaging (VVI) for detecting vulnerable plaques. Methods and ResultsAfter aortic balloon injury, 60 rabbits were fed a 1% cholesterol diet for 10 weeks and normal chow for another 6 weeks. Adenovirus containing p53 or lac Z was then injected into the aortic plaques and rabbits were divided into p53-treated group (n=20), lac Z-treated group (n=20) and blank control group (n=20). Peak longitudinal (LSp), radial (RSp) and circumferential (CSp) strain of plaques was measured using VVI at the end of week 18 before pharmacological triggering. Higher RSp and CSp and lower LSp were found in ruptured than those in non-ruptured plaques, and RSp, CSp and LSp correlated well with the fibrous cap thickness and plaque content of macrophages, smooth muscle cells and collagen (all p<0.01). A logistic regression model showed that both RSp (RR: 8.96, 95% CI: 5.3575–10.4857, p<0.001) and CSp (RR: 8.45, 95% CI: 5.9043–9.1043, p<0.001) were significant predictors of plaque rupture. RSp and CSp had a sensitivity of 88.0% and 88.6% and a specificity of 88.6% and 92.0% to predict plaque disruption, respectively. ConclusionVVI offers a new and noninvasive technique for measuring the peak strain of atherosclerotic plaques and RSp and CSp are a novel index with a high sensitivity and specificity for detecting plaques vulnerable to rupture.

Evaluation of Short-Axis and Long-Axis Myocardial Function with Two-Dimensional Strain Echocardiography in Patients with Different Degrees of Coronary Artery Stenosis

This study was designed to characterize the changes in the peak systolic longitudinal, circumferential and radial strains by using 2-D strain echocardiography in patients with coronary artery stenosis without segmental wall motion abnormalities on conventional 2-D echocardiography. 2D strain echocardiography was performed in 44 patients with different degrees of coronary artery stenosis. Myocardial longitudinal, circumferential and radial strain profiles were obtained and peak systolic strain values were measured. The peak systolic longitudinal strain was significantly reduced in myocardial segments subtended by coronary arteries with greater than 75% stenosis when compared with those subtended by coronary artery with less than 75% stenosis and those in control. Sensitivity and specificity were 74% and 72%, respectively, for peak systolic longitudinal strain to predict segments subtended by coronary arteries with greater than 75% stenosis (cutoff value −17.7%; area under the receiver operating characteristic curve, 0.825). There were no significant differences in circumferential and radial strains among myocardial segments subtended by coronary arteries with greater than 75% stenosis and those with less than 75% stenosis and in control. In conclusion, our study suggests that analysis of long-axis cardiac function by using the 2-D strain echocardiography may help to identify the myocardial segments subtended by coronary arteries with severe stenosis. (E-mail: youdeng@public.wh.hb.cn).

266 Transient radial myocardial dysfunction in non ischemic segment

Purpose In some patients, extensive myocardial dysfunction may be observed during acute coronary syndromes despite limited coronary lesions. Mechanism of depressed contractility during ischemia in remote segments is unclear. In the present study, we addressed the changes in myocardial deformation in remote segments during acute experimental ischemia. Methods Acute myocardial ischemia was induced in 9 anesthetized pigs by balloon coronary occlusion (left coronary descending artery, n=6). Radial and circumferential strain by speckle tracking were computed in the 6 mid short axis segment using 2D echocardiography data acquired at 5’, 15’, 30’and 60’of induced ischemia. Results Reduced in peak circumferential (−16%±2 vs. –6±2% p=0.04) and radial (45±5% vs. 17±6 p=0.002) strain occurred early after 5’of coronary occlusion and persisted during ischemia. Interestingly, reduced in peak radial strain (45±4% vs. 22±5% p=0.0005) was also observed in control segments (Figure) during the first stage of ischemia (5’). Compared to ischemic segments, impaired contraction in control segments was brief and recovered after 15’ of ischemia. Importantly only radial but not circumferential strain was affected in control segments. Conclusions A brief reduction in radial motion was observed during acute myocardial ischemia in control segments. This may explain the occurrence of transient and extensive myocardial dysfunction during acute coronary syndromes despite limited lesions. Download : Download full-size image

Characterizing Myocardial Deformation in Patients With Left Ventricular Hypertrophy of Different Etiologies Using the Strain Distribution Obtained by Magnetic Resonance Imaging

In hypertrophic cardiomyopathy (HCM), it has been suggested that regional fiber disarray produces segments that exhibit no or severely reduced deformation, and that these segments are distributed nonuniformly within the left ventricle (LV). This contrasts with observations in other types of hypertrophy, such as in athlete's heart or hypertensive left ventricular hypertrophy (HLVH), in which abnormal cardiac deformation may exist but the reduction is not so severe that some segments exhibit no deformation. Our aim was to use the strain distribution to study deformation in HCM.We used tagged magnetic resonance imaging to reconstruct LV systolic deformation in 12 controls, 10 athletes, 12 patients with HCM, and 10 patients with HLVH. Deformation was quantified using a fast nonrigid registration algorithm and peak radial and circumferential systolic strain values were determined in 16 LV segments.Patients with HCM had significantly lower average strain values than individuals in other groups. However, while the deformation observed in healthy subjects and HLVH patients clustered around the mean, in HCM patients, segments with normal contraction coexisted with segments exhibiting no or significantly reduced deformation, which resulted in a greater heterogeneity of strain values. Moreover, some nondeforming segments were observed even when fibrosis and hypertrophy were absent.The strain distribution characterized specific patterns of myocardial deformation in patients with LVH due to different etiologies. Patients with HCM had significantly lower mean strain values and a greater heterogeneity in strain values than controls, athletes and HLVH patients. In addition, they had nondeforming regions.

Assessment of left ventricular radial deformation by speckle tracking imaging

The left ventricular radial strain in the inner and outer layers was evaluated by using two-dimensional speckle tracking imaging (2DS). Twenty-five piglets were studied. The short axis views were acquired. Peak systolic radial strain was measured from 6 circumferential points related to 6 standard segments in the inner and outer layers respectively using 2DS methods. The peak positive first derivative (dp/dt) of left ventricular pressure was compared to the radial strain from 2DS. The inner band showed higher peak radial strain values as compared to the outer band at all of the segments (P<0.0001), but the differences had significance just in anteroseptal, posterior, inferior and septal segments (P<0.05). Good correlation could be found between radial strain of inner and outer layers and peak dp/dt (P<0.001). These preliminary results showed that the degree of local deformation or wall thickening of the ventricular wall in its inner layer was more obvious than its outer layer. It is suggested that the 2DS technique is useful and sensitive for better understanding the regional and global myocardial motion and its relationship to the complex architecture of myocardium.

Concentric left ventricular hypertrophy brings deterioration of systolic longitudinal, circumferential, and radial myocardial deformation in hypertensive patients with preserved left ventricular pump function

We hypothesized that deterioration of systolic left ventricular (LV) myocardial deformation exists as an early sign of "isolated" diastolic heart failure in patients with hypertension (HT) and LV hypertrophy (LVH). Two-dimensional strain echocardiography was performed in 98 patients with HT and 22 age-matched normal controls. The LV mass index and relative wall thickness were used to assign patients into 3 groups with normal geometry (N-LV, n=31), concentric hypertrophy (C-LVH, n=25), and eccentric hypertrophy (E-LVH, n=42). The LV ejection fraction was preserved (> or =50%) in the 3 HT groups. The mean peak systolic longitudinal, circumferential, and radial strains in the C-LVH group were lower compared to the control and other 2 HT groups. The mean peak systolic strain rates in the 3 directions in the C-LVH group and those in the longitudinal and radial directions in the E-LVH and N-LV groups were lower compared to the control group. In addition, the mean peak systolic circumferential strain rate was lower in the C-LVH group than in the other 2 HT groups. There were no differences in the LV torsion and torsional rate between the control and 3 HT groups. The mean peak systolic circumferential strain was an independent predictor related to LV ejection fraction in all patients. C-LVH caused deterioration of the systolic longitudinal, circumferential, and radial myocardial deformation in patients with HT. LV torsion and circumferential shortening were considered to be compensatory mechanisms for maintaining LV pump function.

Myocardial deformation in aortic valve stenosis: relation to left ventricular geometry

ObjectiveTo assess left ventricular (LV) strain and displacement and their relations to LV geometry in patients with aortic stenosis (AS).DesignCross-sectional echocardiographic study in patients with AS. Peak circumferential, radial and...

A comparison of Doppler, tissue Doppler imaging, and strain rate imaging in the assessment of postexercise left ventricular function

Left ventricular (LV) function is characterized by contraction in the longitudinal, radial, and circumferential planes. Previous studies of postexercise changes in LV function have assessed global indices of LV function. The purpose of this study was to use 2-dimensional (2D) strain analysis to examine LV function following marathon running in the circumferential, radial, and longitudinal planes, and to compare these data with other global and regional indices of function. Fifteen (mean +/- SD: age, 32 +/- 7 years; stature, 1.76 +/- 0.08 m; body mass, 77.8 +/- 8.2 kg) competitors in the London Marathon were echocardiographically assessed pre- and postrace. 2D strain (ejection fraction (EF), Doppler (early (E) and late (A) trans-mitral filling), tissue Doppler imaging (TDI) (systolic (S') and early diastolic (E') wall-motion velocities); TDI-derived longitudinal strain (epsilon(TDI)), and systolic and diastolic strain rate (SR(TDI)); and 2D-derived peak circumferential, radial, and longitudinal strain (epsilon(2D)), and systolic and diastolic strain rate (SR(2D)) were examined. Differences pre- and postrace completion were assessed using paired tau tests, with alpha set at 0.01. All participants completed the marathon in a mean time of 213 +/- 41 min. A varied response was observed for measures of LV systolic and diastolic function following completion of the marathon (mean +/- SD): EF, 63 +/- 6 vs. 63 +/- 7% (p > 0.01); E:A, 1.70 +/- 0.37 vs. 1.17 +/- 0.37; E':A', 2.36 +/- 0.79 vs. 1.60 +/- 0.57 (p < 0.01); mean longitudinal epsilon(TDI), 19.1 +/- 5.1 vs. 17.5 +/- 4.2% (p < 0.01); mean longitudinal diastolic SR(TDI), 1.81 +/- 0.54 vs. 1.58 +/- 0.51 x s(-1) (p < 0.01); mean longitudinal systolic SR(2D), 0.73 +/- 0.21 vs. 0.97 +/- 0.22 x s(-1) (p < 0.01); mean longitudinal diastolic SR(2D), 0.94 +/- 0.34 vs. 1.01 +/- 0.23 x s(-1) (p > 0.01); mean radial systolic SR(2D), 1.20 +/- 0.15 vs. 1.45 +/- 0.32 x s(-1) (p < 0.01); mean radial diastolic SR(2D), 1.19 +/- 0.25 vs. 1.29 +/- 0.41 x s(-1) (p > 0.01); mean circumferential systolic SR(2D), -1.09 +/- 0.16 vs. -1.24 +/- 0.18 x s(-1) (p < 0.01); and mean circumferential diastolic SR(2D), -1.27 +/- 0.28 vs. -1.22 +/- 0.31 x s(-1) (p > 0.01). Marathon running promotes a varied echocardiographic response, with some functional parameters showing no change, some increasing, and some decreasing postexercise. This varied response likely reflects the complexities of cardiac function and highlights the need to adopt a multimodality approach when assessing cardiac function following exercise.

Ultrasound speckle tracking imaging contributes to early diagnosis of impaired left ventricular systolic function in patients with type 2 diabetes mellitus

To investigate the value of ultrasound speckle tracking imaging (STI) in the assessment of the short-axis and long-axis systolic function of the left ventricle (LV) in patients with type 2 diabetes mellitus (DM), 100 subjects with normal ejection fraction were studied, including 41 patients with DM only (DM group), 22 patients with both DM and left ventricular hypertrophy (DH group), and 37 healthy subjects (control group). Left ventricle systolic function in the long axis defined as longitudinal strain, and that in the short axis defined as radial strain, apical and basal LV rotations, and LV twist were assessed respectively. The results showed that average peak strain in the long axis at basal, middle and apical levels, and global peak strain were significantly decreased in the patient groups when compared with the control group (P<0.001 for each). The parameters in DH group were significantly lower than those in DM group (P<0.01 for each). There were no significant differences in average radial peak strain in the short axis at different levels, and global peak strain among the three groups (P>0.05). Apical and basal LV rotations, and LV twist were greater in the patient groups than in the control group (P<0.01 for each). Basal LV rotation and LV twist were greater in DH group than those in DM group (P<0.01). It was concluded that STI may be used to identify early abnormalities in patients with type 2 DM that have normal left ventricular systolic function.

Strain Rate Imaging Detects Early Cardiac Effects of Pegylated Liposomal Doxorubicin as Adjuvant Therapy in Elderly Patients with Breast Cancer

Cardiac toxicity remains an important side effect of anthracyclines. New drug formulations (eg, pegylated liposomal doxorubicin [PL-DOX]) seem to be a successful strategy for reducing it. Changes in cardiac function induced by early chemotherapy, however, are subtle and difficult to quantitate by conventional imaging methods. Doppler myocardial imaging-based velocity, strain, and strain rate measurements have been shown to sensitively quantify abnormalities in cardiac function in other settings. We evaluated the feasibility and sensitivity of strain rate imaging compared with conventional echocardiography in detecting cardiac effects of PL-DOX therapy in elderly patients with cancer. In a pilot study, we examined 16 elderly women (age 69.8 +/- 3.1 years) with breast cancer receiving 6 cycles of PL-DOX. Conventional and Doppler myocardial imaging echocardiography were obtained at baseline and after 3 and 6 cycles of treatment. Segmental peak systolic longitudinal and radial velocity, strain, and strain rate were measured. Left ventricular dimensions, ejection fraction, and systolic myocardial velocity did not change throughout the follow-up. In contrast, a significant reduction in longitudinal and radial strain and strain rate was found after 6 cycles (longitudinal strain -18.8% +/- 2.8% vs -22.7% +/- 2.8%, P < .001 vs baseline and P = .001 vs after 3 cycles; radial strain 32.3% +/- 8.1% vs 50.1% +/- 11.6%, P < .001 vs baseline). Changes in radial function appeared earlier and were more pronounced than in longitudinal direction. In contrast with conventional echocardiography and myocardial velocity measurements, myocardial deformation parameters allowed detecting subtle changes in longitudinal and radial left ventricular function after 6 cycles of PL-DOX. We suggest that Doppler-based myocardial deformation imaging should be used for cardiac function monitoring during chemotherapy.