Impaired Left Ventricular Systolic Synchronicity in Hypertensive Patients with Ventricular Arrhythmias

Strain/strain rate imaging of impaired left atrial function in patients with metabolic syndrome

Left ventricular (LV) dysfunction has been demonstrated in patients with metabolic syndrome (MetS). However, alterations in left atrial (LA) function in MetS are unknown. We aimed to use strain/strain rate (SR) imaging to investigate the effect of MetS on LA function. A total of 177 MetS patients and 156 normal subjects underwent echocardiography. Strain and SR tissue Doppler imaging values were used to evaluate LA function. Partial correlation and multiple stepwise regression analyses were used to determine the risk factors for impaired LA function. Compared with the controls, the MetS patients showed significantly lower levels of mean strain, mean peak systolic SR and mean peak early diastolic SR (P<0.001 for all), with no difference in the mean peak late diastolic SR. Central obesity, hypertension, dyslipidemia and LV diastolic abnormality were independent risk factors for impaired LA function. LA function was impaired in patients with MetS as a result of metabolic disturbance and LV diastolic abnormality. SR imaging is reliable in assessing LA function in MetS patients.

Correlation between systolic deformation and dyssynchrony indices and the grade of left ventricular hypertrophy in hypertensive patients with a preserved systolic ejection fraction undergoing coronary angiography, based on tissue Doppler imaging

OBJECTIVES

The purpose of this study was to investigate whether systolic mechanical dyssynchrony occurs in hypertensive patients with a normal coronary artery and a normal ejection fraction and its relationship with different degrees of left ventricular (LV) hypertrophy.

METHODS

A total of 125 angiographically normal coronary patients (42.4% male; mean age ± SD, 57.16 ± 8.26 years) with an ejection fraction greater than 50% were included, of which 84 were hypertensive and 41 normotensive. The hypertensive patients were categorized into 3 groups: no, mild, and moderate LV hypertrophy. Tissue Doppler and deformation imaging parameters were measured in the 6 LV basal segments at peak systole.

RESULTS

The frequency of dyssynchrony was 40.5% in the hypertensive patients compared to 19.5% in the control patients (P = .020). Among the hypertensive patients, LV dyssynchrony was found in 5 patients (20%) with no hypertrophy, 20 (42.6%) with mild hypertrophy, and 9 (75%) with moderate hypertrophy. There was a moderate correlation between the grade of hypertrophy and septal-lateral wall delay (r = 0.497), 6-basal segment delay (r = 0.454), overall strain (r = 0.453), overall peak systolic velocity (r = -0.430), and standard deviation of the time to peak systolic velocity in the basal segments (r = 0.429). After adjustment for the LV end-systolic diameter and body surface area, overall strain was the best correlate of the hypertrophy grade (odds ratio, 7.043; 95% confidence interval, 1.839-26.980; P = .0044).

CONCLUSIONS

Among tissue Doppler and deformation indices, overall peak systolic strain was the strongest correlate of the LV hypertrophy grade. Therefore, in hypertensive patients with normal cardiac systolic function, a reduction in overall strain in the 6 basal LV segments may be a good indicator of progression of the LV hypertrophy grade and systolic dysfunction.

Left ventricular geometry, global function, and dyssynchrony in infants and children with pompe cardiomyopathy undergoing enzyme replacement therapy

BACKGROUND

Enzyme replacement therapy (ERT) for infantile-onset Pompe disease effectively reduces the left ventricular (LV) mass. This study sought to explore detailed process of LV reverse remodeling after ERT with the use of tissue Doppler and stain rate imaging.

METHODS AND RESULTS

Nine infants and children with Pompe cardiomyopathy undergoing ERT for ≥1 year, as well as 36 healthy control subjects, were studied. Global systolic and diastolic function was evaluated by peak systolic and early-diastolic velocity at mitral annulus. Temporal systolic and diastolic dyssynchrony was evaluated by the coefficient of variation of the time from the QRS complex to peak systolic and early-diastolic strain rate among 12 LV segments. All pre-ERT patients had impaired global systolic and diastolic function as well as increased regional dyssynchrony (P < .001 for each of all). During the regression of LV hypertrophy, all of these functional indices improved (P for trend <.001), with temporal diastolic dyssynchrony being a significant factor linking to LV mass index in multivariate analysis (P < .001).

CONCLUSIONS

ERT improved global LV function and dyssynchrony in Pompe patients. The relationship between LV mass and temporal diastolic dyssynchrony during reverse remodeling suggested a pathophysiologic role of dyssynchrony in Pompe cardiomyopathy.

Evaluation of left ventricular synchronicity in hypertensive patients with overweight or obesity

The left ventricular synchronicity in hypertensive patients with overweight or obesity has not been well elucidated. This study was designed to evaluate the left ventricular synchronicity in these patients. Tissue Doppler imaging was performed in 126 hypertensive patients and 25 control subjects. The hypertensive patients were divided into three groups according to BMI: normal weight group (BMI <25 kg/m(2), n = 32, H-NW group), overweight group (BMI 25-29.9 kg/m(2), n = 64, H-OW group), and obese group (BMI >or=30 kg/m(2), n = 30, H-OB group). Left ventricular systolic and diastolic synchronicity were determined by measuring the maximal differences in time to peak myocardial systolic contraction (T(s)-diff) and early diastolic relaxation (T(e)-diff) between any two of the left ventricular segments and the standard deviation of time to peak myocardial systolic contraction (T(s)-SD) and early diastolic relaxation (T(e)-SD) of all 12 segments. Compared with the control group, the indexes of synchronicity including T(s)-diff, T(s)-SD, T(e)-diff, and T(e)-SD were significantly prolonged in the hypertensive patients. Furthermore, although the indexes of blood pressure had no difference among the hypertensive groups, the impaired systolic and diastolic synchronicity including T(s)-diff, T(s)-SD, and T(e)-SD was obviously aggravated with the increasing BMI. Stepwise multivariate analysis revealed BMI as an independent predictor of T(s)-SD and T(e)-SD. Therefore, the impairment of left ventricular synchronicity was aggravated with increasing BMI in hypertensive patients. Overweight and obesity may be important factors to impact the left ventricular synchronicity.

Impaired left ventricular systolic and diastolic function in patients with metabolic syndrome as assessed by strain and strain rate imaging

The present study aimed to investigate cardiac structural and functional alterations in patients with metabolic syndrome (MS) and to compare those with control subjects. Strain and strain rate (SR) imaging were preformed in 200 patients with MS and 197 normal subjects. The patients were further divided into Group 1 (with three metabolic disorders) and Group 2 (with four metabolic disorders) to elucidate the influence of different metabolic components on left ventricular (LV) functions. LV diastolic and systolic functions were determined by the mean systolic strain, SR-LVs and SR-LVe. There were no differences in LVEF among the three groups. However, the mean systolic strain, SR-LVs and SR-LVe, were significantly decreased in Group 1 and Group2 when compared with control subjects (all P<0.001). The mean systolic strain and SR-LVe were lower in Group 2 than Group 1 (all P<0.05). Stepwise multiple regression analyses revealed that the W-H ratio was an independent predictor of the LV systolic function, whereas W-H ratio, HDL cholesterol and SBP were independent predictors of LV diastolic function. In summary, our results demonstrated that LV systolic and diastolic functions were impaired in patients with metabolic syndrome even if they have normal LVEF. Strain and SR imaging would be a sensitive and feasible method to detect subclinical abnormalities in those populations.