Contribution of asynchrony and nonuniformity to  mechanical interaction in normal and stunned myocardium

Fan, Dongsheng; Soei, Loe Kie; Stubenitsky, René; Boersma, Eric; Duncker, Dirk J.; Verdouw, Pieter D.; Krams, Rob

doi:10.1152/ajpheart.1997.273.5.h2146

Cited by 17 publications

(12 citation statements)

References 31 publications

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“…However, it should be stressed that these authors used an anesthetized open-chest model and a pericardial cradle which might have altered myocardial contraction [7].…”

Section: Aynchrony and Postsystolic Wall Thickeningmentioning

confidence: 99%

Regional and temporal heterogeneity of postsystolic wall thickening is associated with left ventricular asynchrony in normal and experimental stunned myocardium

et al. 2008

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“…However, it should be stressed that these authors used an anesthetized open-chest model and a pericardial cradle which might have altered myocardial contraction [7].…”

Section: Aynchrony and Postsystolic Wall Thickeningmentioning

confidence: 99%

Regional and temporal heterogeneity of postsystolic wall thickening is associated with left ventricular asynchrony in normal and experimental stunned myocardium

et al. 2008

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“…20 Previous studies have reported that both LV hypertrophy and increased afterload of LV are related to LV asynchrony. 2,7,19,20 In the present study, despite the elevation of systolic blood pressure during dobutamine infusion, asynchrony improved in both groups, so we hypothesized that LV asynchrony in mild LV hypertrophy caused by hypertension is more closely related to LV hypertrophy itself than to increased afterload.…”

Section: Possible Mechanism Of LV Asynchronymentioning

confidence: 56%

“…7,15 Prior studies have shown that prolongation of decay time with increasing end-systolic pressure is exacerbated as contractility falls. [17][18][19] Another study showed that the LV time constant correlated well with the amount of the nonuniformity, which is responsible for the systolic loading dependent relaxation. 20 Previous studies have reported that both LV hypertrophy and increased afterload of LV are related to LV asynchrony.…”

Section: Possible Mechanism Of LV Asynchronymentioning

confidence: 99%

Effect of Dobutamine on Regional Diastolic Left Ventricular Asynchrony in Patients With Left Ventricular Hypertrophy. On-Line Quantification Using Automated Segmental Motion Analysis System.

Liu¹,

Murata²,

Fujino³

et al. 2003

Circ J

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eft ventricular (LV) diastolic function is impaired in many patients with coronary heart disease and in the hypertrophied heart in which LV systolic performance is normal. 1-4 LV nonuniformity, in addition to altered LV loading and myocardial ischemia, is one of the important determinants of diastolic function. [5][6][7] It is well recognized that dobutamine, a -adrenergic receptor stimulator, improves not only LV systolic performance (inotropic effect), but also diastolic performance (lusitropic effect); 8 however, its effect on LV regional nonuniformity is not clear.We have developed a new on-line automated segmental motion analysis (A-SMA) system, which is based on an automatic border detection technique of 2-dimensional (D) echocardiography. 9 Using this system, the changes in the LV regional area can be displayed on-line as a time -area curve and its first derivative curve, and an analysis of the timing of these curves provides an evaluation of LV nonuniformity.The present study compared LV regional nonuniformityCirculation Journal Vol.67, February 2003 in hypertensive patients with that in healthy subjects using the A-SMA system and evaluated the effects of dobutamine on regional LV nonuniformity and global LV function. Methods Study SubjectsThe subjects were 20 patients with left ventricular hypertrophy (LVH) caused by essential hypertension and 16 age-matched healthy subjects. Five patients and 1 healthy subject were excluded from the study because of inadequate A-SMA images, so 15 patients (10 male (M), 5 female (F); mean age, 64±8 years, range 49-75) with LVH were recruited into the study and 15 age-matched healthy subjects (10 M, 5 F; mean age, 61±12 years, range 38-78) served as controls. The diagnosis of LVH was based on septal and LV posterior wall thickness on conventional echocardiography (end-diastolic thickness of septal and LV posterior wall ≥12 mm). Patients were being treated with a variety of antihypertensive drugs, mainly angiotensin-converting enzyme inhibitors and calcium antagonists. No subject had ischemic or valvular heart disease, or pulmonary disease. All subjects were in sinus rhythm without intraventricular conduction disturbances. Echocardiography showed normal ventricular diameters and regional wall motion at rest. The Institutional Review Board of Yamaguchi University Hospital approved the study. unknown. An on-line automated segmental motion analysis (A-SMA) system was developed, based on an automatic border detection technique, to evaluate the effect of dobutamine on LV asynchrony in patients with LV hypertrophy (LVH). Low dose (5 g·kg -1 ·min -1 ) dobutamine stress echocardiography was performed in 15 patients with LVH and in 15 healthy subjects. Short-axis LV views were obtained and divided into 4 wedge-shaped segments using A-SMA. The time -area curve and its first derivative curve in each segment were displayed. Total normalized peak filling rates (nPFR) were obtained. Systolic and diastolic asynchronies were assessed from the coefficient of variation (CV) of the regio...

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“…Another porcine heart study found that mechanical dyssynchrony was affected by regionally stunned myocardium. 20 In addition, clinical studies showed that mechanical dyssynchrony was also associated with coronary stenosis but without a RWMA on resting echocardiography. 2, 21 Mechanical dyssynchrony, as defined by the standard deviation of time to peak systolic velocity by tissue Doppler imaging, reflects both electrical activation and/or the result of heterogeneity of contractile properties in the wall.…”

Section: Discussionmentioning

confidence: 99%

Left Ventricular Mechanical Dyssynchrony Impairs Exercise Capacity in Patients With Coronary Artery Disease With Preserved Left Ventricular Systolic Function and a QRS Duration ≤120ms

Wang

Yan

Yue

et al. 2012

Circ J

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Background: Left ventricular (LV) mechanical dyssynchrony can lead to impairment of LV function and is associated with adverse clinical outcomes in coronary artery disease (CAD) patients. The impact of LV dyssynchrony on exercise capacity (EC) in patients with CAD was investigated. Methods and Results:An echocardiographic examination with tissue Doppler imaging and exercise treadmill testing in 151 CAD patients with normal LV ejection fraction was performed. LV intra- and inter-ventricular dyssynchrony were defined by the standard deviation of time interval between LV 6 basal segments (Ts-SD), and the time interval from the right ventricular (RV) free wall to LV lateral wall (Ts-RV) respectively, and EC was measured as metabolic equivalents (METs) on the treadmill. Patients with impaired EC (defined by a METs ≤8, which is the mean MET of the study population) were older (71±7 vs. 62±2 years, P<0.01), however, there were no differences in gender and clinical status such as prevalence of prior myocardial infarction (MI), regional wall motion abnormality (RWMA), and coronary revascularization between patients with (n=90) or without (n=61) impaired EC. Univariate analysis showed that age, body mass index, LV systolic and diastolic volume, mitral inflow A velocity, and Ts-SD were all significantly associated with METs (all P<0.05). However, multivariate regression analysis revealed that old age (odd ratio [OR]: 1.136, 95% confidence interval [CI]: 1.080-1.196, P<0.001), and Ts-SD (OR: 1.026, 95%CI: 1.003-1.049, P=0.027) only were independent predictors for impaired EC. Conclusions:In patients with CAD, LV systolic dyssynchrony predicts impaired EC independently of history of previous MI or RWMA. (Circ J 2012; 76: 682 - 688)

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Contribution of asynchrony and nonuniformity to mechanical interaction in normal and stunned myocardium

Cited by 17 publications

References 31 publications

Regional and temporal heterogeneity of postsystolic wall thickening is associated with left ventricular asynchrony in normal and experimental stunned myocardium

Regional and temporal heterogeneity of postsystolic wall thickening is associated with left ventricular asynchrony in normal and experimental stunned myocardium

Effect of Dobutamine on Regional Diastolic Left Ventricular Asynchrony in Patients With Left Ventricular Hypertrophy. On-Line Quantification Using Automated Segmental Motion Analysis System.

Left Ventricular Mechanical Dyssynchrony Impairs Exercise Capacity in Patients With Coronary Artery Disease With Preserved Left Ventricular Systolic Function and a QRS Duration ≤120ms

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