Pui-Wai Lee

Tissue Doppler velocity is superior to displacement and strain mapping in predicting left ventricular reverse remodelling response after cardiac resynchronisation therapy

Objective: To compare the values of three different forms of tissue Doppler imaging (TDI) processing in predicting left ventricular (LV) reverse remodelling—namely, tissue velocity, displacement and strain mapping. Design: Standard echocardiography with TDI was performed before and 3 months after cardiac resynchronisation therapy (CRT). Setting: University teaching hospital. Patients: 55 patients with heart failure who received CRT and were followed up for at least 3 months were recruited. Interventions: During off-line analysis, the time to peak systolic velocity in the ejection phase, time to peak positive displacement and time to peak negative strain were measured in the six basal, six mid-segmental model. Parameters of systolic asynchrony derived by velocity, displacement and strain mapping were correlated with percentage reduction in LV end systolic volume (LVESV) and absolute gain in ejection fraction (EF). Results: Among the three TDI processing technologies, all parameters of tissue velocity correlated with LV reverse remodelling (r  = −0.49 to r  =  −0.76, all p < 0.001), but the predictive value was strongest in models with 12 LV segments. For displacement mapping, only the two parameters that included 12 LV segments correlated modestly with reduction in LVESV (r  =  −0.36, p < 0.05) and gain in EF. However, none of the strain mapping parameters predicted a favourable echocardiographic response. The receiver operating characteristic (ROC) curve areas were higher for parameters of tissue velocity based on 12 LV segments (ROC areas 0.88 and 0.94) than the corresponding areas derived from displacement mapping (ROC areas 0.72 and 0.71). Conclusion: Tissue velocity parameters of systolic asynchrony are superior to those of displacement and strain mapping in predicting LV reverse remodelling response after CRT.

Impact of Cardiac Contractility Modulation on Left Ventricular Global and Regional Function and Remodeling

OBJECTIVES This study aimed to evaluate the impact of cardiac contractility modulation (CCM) on left ventricular (LV) size and myocardial function. BACKGROUND CCM is a device-based therapy for patients with advanced heart failure. Previous studies showed that CCM improved symptoms and exercise capacity; however, comprehensive assessment of LV structure, function, and reverse remodeling is not available. METHODS Thirty patients (60 + or - 11 years, 80% male) with New York Heart Association (NYHA) functional class III heart failure, ejection fraction <35%, and QRS <120 ms were assessed at baseline and 3 months. LV reverse remodeling was measured by real-time 3-dimensional echocardiography. Using tissue Doppler imaging, the peak systolic velocity (Sm) and peak early diastolic velocity (Em) were calculated for LV function, while the standard deviation of the time to peak systolic velocity (Ts-SD) and the time to peak early diastolic velocity (Te-SD) were calculated for mechanical dyssynchrony. RESULTS LV reverse remodeling was evident, with a reduction in LV end-systolic volume by -11.5 + or - 10.5% and a gain in ejection fraction by 4.8 + or - 3.6% (both p < 0.001). Myocardial contraction was improved in all LV walls, including sites remote from CCM delivery (all p < 0.05); hence, the mean Sm of 12 (2.2 + or - 0.6 cm/s vs. 2.5 + or - 0.7 cm/s) or 6 basal LV segments (2.5 + or - 0.6 cm/s vs. 3.0 + or - 0.7 cm/s) were increased significantly (both p < 0.001). In contrast, CCM had no impact on regional or global Em (2.9 + or - 1.3 cm/s vs. 2.9 + or - 1.1 cm/s), whereas Ts-SD (28.2 + or - 11.2 ms vs. 27.9 + or - 12.7 ms) and Te-SD (30.0 + or - 18.3 ms vs. 30.1 + or - 20.7 ms) remained unchanged (all p = NS). Mitral regurgitation was reduced (22 + or - 14% vs. 17 + or - 15%, p = 0.02). Clinically, there was improvement of NYHA functional class (p < 0.001) and 6-min hall walk distance (p = 0.015). A 24-h Holter monitor showed that premature ventricular contractions were not increased during CCM. CONCLUSIONS CCM improves both global and regional LV contractility, including regions remote from the impulse delivery, and may contribute to LV reverse remodeling and gain in systolic function. Such improvement is unrelated to diastolic function or mechanical dyssynchrony.

Left ventricular systolic and diastolic dyssynchrony in coronary artery disease with preserved ejection fraction

The present study aims to evaluate LV (left ventricular) mechanical dyssynchrony in CAD (coronary artery disease) with preserved and depressed EF (ejection fraction). Echocardiography with TDI (tissue Doppler imaging) was performed in 311 consecutive CAD patients (94 had preserved EF > or =50% and 217 had depressed EF <50%) and 117 healthy subjects to determine LV systolic and diastolic dyssynchrony by measuring Ts-SD (S.D. of time to peak myocardial systolic velocity during the ejection period) and Te-SD (S.D. of time to peak myocardial early diastolic velocity during the filling period) respectively, using a six-basal/six-mid-segmental model. In CAD patients with preserved EF, both Ts-SD (32.2+/-17.3 compared with 17.7+/-8.6 ms; P<0.05) and Te-SD (26.2+/-13.6 compared with 20.3+/-8.1 ms; P<0.05) were significantly prolonged when compared with controls, although they were less prolonged than CAD patients with depressed EF (Ts-SD, 37.8+/-16.5 ms; and Te-SD, 36.0+/-23.9 ms; both P<0.005). Patients with preserved EF who had no prior MI (myocardial infarction) had Ts-SD (32.9+/-17.5 ms) and Te-SD (28.6+/-14.8 ms) prolonged to a similar extent (P=not significant) to those with prior MI (Ts-SD, 28.4+/-16.8 ms; and Te-SD, 25.5+/-15.0 ms). Patients with class III/IV angina or multi-vessel disease were associated with more severe mechanical dyssynchrony (P<0.05). Furthermore, the majority of patients with mechanical dyssynchrony had narrow QRS complexes in those with preserved EF. This is in contrast with patients with depressed EF in whom systolic and diastolic dyssynchrony were more commonly associated with wide QRS complexes. In conclusion, LV mechanical dyssynchrony is evident in CAD patients with preserved EF, although it was less prevalent than those with depressed EF. In addition, mechanical dyssynchrony occurred in CAD patients without prior MI and narrow QRS complexes.

Relation of Left Ventricular Systolic Dyssynchrony in Patients With Heart Failure to Left Ventricular Ejection Fraction and to QRS Duration

Left ventricular (LV) systolic dyssynchrony is an important pathologic mechanism in patients with heart failure (HF). However, the prevalence of intraventricular dyssynchrony in patients with different LV ejection fractions (EFs) is unknown. This study evaluated 402 consecutive patients with HF (mean age 64.99 +/- 13.15 years, 72.4% men) and 120 healthy controls. Dyssynchrony indexes included the SD of the time to peak systolic velocity (Ts) in ejection phase in the 12-segmental model (Ts-SD) and the difference in Ts between basal septal and basal lateral segments (Ts-Septal-Lateral) using tissue Doppler imaging. Patients were divided into 3 groups according to LVEF (LVEF <20%, >20% to 35%, and >35% to 50%) and compared with healthy controls. Both indexes were significantly higher in all 3 LVEF groups compared with controls (p <0.0001). Based on the established cut-off values, systolic dyssynchrony was equally prevalent in all 3 LVEF groups and was 67%, 62%, and 55% using Ts-SD and 38%, 36%, and 35% using Ts-Septal-Lateral, respectively. However, the prevalence of systolic dyssynchrony was higher using Ts-SD than Ts-Septal-Lateral (chi-square = 94.43, p <0.001). Conversely, the prevalence of electrical dyssynchrony, defined as a >120-ms QRS duration, decreased significantly with increasing LVEF (44%, 35%, and 16%; chi-square 5.60, p <0.001). In conclusion, the prevalence of mechanical systolic dyssynchrony was independent of severity of LV systolic dysfunction. This may implicate the potential role of cardiac resynchronization therapy for those with LVEF of 35% to 50%, in particular when systolic dyssynchrony is present.

Diffuse Infiltration of Lymphoma of the Myocardium Mimicking Clinical Hypertrophic Cardiomyopathy

A 51-year-old man with good health previously presented with a 1-month history of shortness of breath on exertion. Transthoracic echocardiography revealed marked biventricular hypertrophy, mild mitral regurgitation, and moderate tricuspid regurgitation, suggestive of hypertrophic cardiomyopathy (Figure 1A and 1B; Movie I and Movie II). In the parasternal short-axis view, thickening of the left atrial wall and para-aortic tissue were evident, which is unusual in typical hypertrophic cardiomyopathy, a disease that primarily affects the ventricular myocardium (Figure 1C and Movie III). Computerized tomographic arteriography revealed no coronary artery disease. His heart failure symptoms worsened, and atrial fibrillation developed. At the same time, maculopapular skin rash developed on the upper trunk and the head and neck region. Hypercalcemia with an adjusted serum calcium level greater than 4 mmol/L was recorded. Other blood chemistry and hematologic examinations were unremarkable. His conditions deteriorated rapidly and, despite maximal supportive measures, he died 1 week after hospitalization. Limited clinical postmortem examination revealed a well-built gentleman with a heart weighing 790 g (Figure 2A). The walls of all 4 chambers of the heart were diffusely thickened by tan-colored infiltrative growth. The left and right ventricular …

Impact of a Dedicated Training Program on the Reproducibility of Systolic Dyssynchrony Measures Using Tissue Doppler Imaging

BACKGROUND The reproducibility of the measurement of mechanical dyssynchrony by echocardiography including Doppler tissue imaging has recently been questioned. The aim of this study was to ascertain the role of a dedicated training program to improve skills and the reproducibility of dyssynchrony assessment. METHODS In 70 patients with heart failure, color Doppler tissue images were acquired, and the time to peak systolic velocity of each segment and several dyssynchrony indices, including the standard deviation of time to peak systolic velocity, were measured by an expert to constitute a reference standard. The same images were then assessed by two beginners, who had only basic knowledge of dyssynchrony analysis after a 1-hour lecture, and two graduates, who had received a structured hands-on training program. Both sets of results were compared with the standard. RESULTS For the standard deviation of time to peak systolic velocity, the linear correlations between the standard and beginner 1 (r = 0.643) and beginner 2 (r = 0.532) were only modest (P < .001 for both). When referenced to the standard, interobserver variability was 18% for beginner 1 and 19% for beginner 2. Measurements with differences of ≥10 msec were found in 24% and 22% of cases by beginners 1 and 2, respectively. In contrast, the assessments made by graduates 1 and 2 were significantly improved. The correlation coefficients were 0.935 and 0.929 (P < .001 for both), and interobserver variability values were 8% and 7%. The prevalence rates of measurements with differences ≥ 10 msec were 1.5% and 3%, respectively. CONCLUSIONS There is a learning curve for the measurement of systolic dyssynchrony using Doppler tissue imaging, but good reproducibility can be achieved by the use of a dedicated training program.

Changes of ventricular and peripheral performance in patients with heart failure and normal ejection fraction: insights from ergometry stress echocardiography

We assessed the left ventricular (LV) and peripheral performance at rest and during exercise in healthy and heart failure subjects with normal ejection fraction (HFNEF) or with reduced ejection fraction (HFREF).

Investigational devices for mitral regurgitation: state of the art

The incidence of mitral regurgitation (MR) is rising as a result of an aging population worldwide. Surgical repair or replacement of the mitral valve remains the standard of care for patients with severe MR as the only approach to achieve sustained relief of symptoms or heart failure. However, the majority of patients with severe MR do not undergo surgery because of high perceived perioperative risk. Recently, there has been great enthusiasm in the pursuit of a less invasive percutaneous approach to the treatment of MR to avoid thoracotomy or cardiopulmonary bypass, even if less efficacious. This article reviews the latest developments of various percutaneous options in the treatment of MR.