The Functional Role of Longitudinal, Circumferential, and Radial Myocardial Deformation for Regulating the Early Impairment of Left Ventricular Contraction and Relaxation in Patients With Cardiovascular Risk Factors: A Study With Two-Dimensional Strain Imaging

https://doi.org/10.1016/j.echo.2008.07.016Get rights and content

Background

Two-dimensional strain imaging allows rapid and accurate analysis of regional left ventricular (LV) systolic and diastolic mechanics in the longitudinal, radial, and circumferential directions. The aim of this study was to assess precisely the differences in early impairment of LV myocardial contraction and relaxation among the 3 directions in 70 patients with cardiovascular risk factors and preserved LV pump function.

Methods

The patients were classified into 2 groups according to the ratio of early diastolic to atrial systolic velocity (E/A) of transmitral flow: E/A ≥ 1 (n = 35, 57 ± 6.8 years) or E/A < 1 (n = 35, 60 ± 4.9 years). The longitudinal strain and strain rate curves were determined in apical 2- and 4-chamber views, and radial and circumferential strain and strain rate curves and LV torsion curve were determined in the parasternal short-axis views.

Results

The mean peak systolic longitudinal strain and strain rate were lower, whereas the mean peak systolic circumferential strain and strain rate were greater in the E/A < 1 group. There were no significant differences in the mean peak systolic radial strain and strain rate between the 2 groups. The mean peak early diastolic longitudinal strain rate was markedly lower in the E/A < 1 group. The mean peak LV strain rates during atrial systole in all 3 directions were greater in the E/A < 1 group. The mean peak LV systolic longitudinal strain and longitudinal strain rate during atrial systole were independent predictors related to E/A in all patients. There were no significant differences in torsion and torsional and untwisting rates between the 2 groups.

Conclusion

LV myocardial contraction and relaxation were first impaired in the longitudinal direction among the 3 directions in subclinical patients with cardiovascular risk factors. However, LV pump function and LV filling were compensated by circumferential shortening at ventricular systole and 3 directional lengthenings at atrial systole, respectively.

Section snippets

Study Population

The study population included 2 groups: 1) patients with cardiovascular risk factors but no overt cardiac disease, and 2) age-matched subjects with no risk factors, who served as controls. A total of 70 patients with risk factors were selected because they had adequate acoustic windows and 1 or more of the following criteria: 1) current smoker; 2) body mass index ≥ 25 kg/m2; 3) hypertension with systolic or diastolic blood pressure > 140 mm Hg or 90 mm Hg, respectively; 4) hyperlipidemia with

Clinical Characteristics

There were no significant differences in all clinical parameters but low-density lipoprotein cholesterol between the control and E/A ≥ 1 groups (Table 1). There were no significant differences in body mass index, heart rate, blood pressure, or hemoglobin A1c between the E/A ≥ 1 and E/A < 1 groups.

In the 2 patient groups, risk factors were observed as follows: >20 cigarettes for 10 or more years in 4 patients of the E/A ≥ 1 group and 10 patients of the E/A < 1 group, body mass index ≥ 25 kg/m2

Discussion

The present study indicates that LV myocardial contraction and relaxation were first impaired in the longitudinal direction in subclinical patients with cardiovascular risk factors. However, LV pump function and LV filling were compensated by circumferential shortening at ventricular systole and 3 directional lengthening at atrial systole, respectively.

The 3-dimensional dynamic geometry and myofiber architecture of the LV should be considered to accurately understand LV deformation.3, 4, 5 The

Conclusions

Both longitudinal LV diastolic and systolic function were first impaired in subclinical patients with cardiovascular risk factors and preserved LV pump function. In systole, radial thickening was preserved, with an increase in circumferential shortening accompanying the decrease in longitudinal shortening, resulting in maintenance of LV ejection fraction. In diastole, the early diastolic strain rate decreased in longitudinal and radial directions, particularly in the former direction. However,

References (43)

  • S.S. Ahmed et al.

    Preclinical abnormality of left ventricular function in diabetes mellitus

    Am Heart J

    (1975)
  • F.M. Fouad et al.

    Left ventricular diastolic function in hypertension: relation to left ventricular mass and systolic function

    J Am Coll Cardiol

    (1984)
  • L.R. Peterson et al.

    Alterations in left ventricular structure and function in young healthy obese women: assessment by echocardiography and tissue Doppler imaging

    J Am Coll Cardiol

    (2004)
  • M. Alam et al.

    Acute effects of smoking on diastolic function in healthy participants: studies by conventional Doppler echocardiography and Doppler tissue imaging

    J Am Soc Echocardiogr

    (2002)
  • Y. Mishiro et al.

    Use of angiotensin II stress pulsed tissue Doppler imaging to evaluate regional left ventricular contractility in patients with hypertrophic cardiomyopathy

    J Am Sco Echocardiogr

    (2000)
  • M. Takeuchi et al.

    Age-related changes in left ventricular twist assessed by two-dimensional speckle-tracking imaging

    J Am Soc Echocardiogr

    (2006)
  • P.P. Sengupta et al.

    Disparate patterns of left ventricular mechanics differentiate constrictive pericarditis from restrictive cardiomyopathy

    J Am Coll Cardiol Img

    (2008)
  • H.K. Kim et al.

    Assessment of left ventricular rotation and torsion with two-dimensional speckle tracking echocardiography

    J Am Soc Echocardiogr

    (2007)
  • H. Tanaka et al.

    Contribution of the pericardium to left ventricular torsion and regional myocardial function in patients with total absence of the left pericardium

    J Am Soc Echocardiogr

    (2008)
  • U.N. Khot et al.

    Prevalence of conventional risk factors in patients with coronary heart disease

    JAMA

    (2003)
  • P. Greenland et al.

    Major risk factors as antecedents of fatal and nonfatal coronary heart disease events

    JAMA

    (2003)
  • Cited by (0)

    View full text