Long-axis Shortening Research Articles

PRELIMINARY CLINICAL STUDY OF LEFT VENTRICULAR GLOBAL SYSTOLIC FUNCTION IN PATIENTS WITH CORONARY ARTERY HEART DISEASE BY AUTOMATED MOTION TRACKING OF MITRAL ANNULAR DISPLACEMENT

ObjectivesTo assess the left ventricular global systolic function in patients with coronary artery heart disease by automated motion tracking of mitral annular displacement (TMAD).Methods30 patients (20 males and 10 females,...

Significance of force transfer in mitral valve–left ventricular interaction: In vivo assessment

The objective of this study was to assess the combined force transfer from the papillary muscle tips to the mitral valve through the chordae tendineae invivo, and thereby quantify the force transmitted through the papillary-chordal complex to augment left ventricular ejection. In an acute porcine model (n=8), force transfer between papillary muscles and the mitral valve was recorded on the anterior and posterior papillary muscle tip using dedicated force transducers. Ultrasound sonomicrometry was utilized to record and calculate left ventricular long-axis shortening and mitral annular geometry. The closing force acting on the mitral valve leaflets was calculated as mitral annular area multiplied by the transmitral pressure difference throughout systole. Mitral valve competence was verified before measurements with color Doppler ultrasound. Peak force in the anterior and posterior papillary muscle was 5.9 ± 0.6 N and 5.8 ± 0.7 N (mean ± standard error of the mean), respectively, and peak closing force was 6.8 ± 0.3 N all at a transmitral pressure of 90 mm Hg. Peak rate of left ventricular contraction coincided with peak papillary muscle force. This study is the first to assess the magnitude and time course of the longitudinal force transmitted through the papillary-chordal complex to the left ventricular wall during ejection. The study also demonstrates a significant force transfer to the closing force acting on the mitral valve leaflets that constitutes an essential component of valvular-ventricular interaction to enhance left ventricular systolic pump performance. The magnitude of the combined papillary muscle force component emphasizes the crucial role of preserving mitral valve-left ventricular continuity in mitral valve surgery.

Study of quantitative assessment of left ventricular systolic function by tissue motion annular displacement in heart failure patients

ObjectiveTo evaluate the ability of tissue motion annular displacement (TMAD) for assessment of global left ventricular systolic function in heart failure patients.MethodsThe HF group and the control group were composed...

Left and right ventricular systolic long-axis function and diastolic function in patients with takotsubo cardiomyopathy

Takotsubo cardiomyopathy is characterized by apical wall motion abnormalities without coronary stenosis. Limited information is available on the genesis of the underlying reversible contractile disorder. Our objective in this prospective study was to investigate biventricular changes in systolic long-axis function and diastolic parameters in the acute phase and after recovery. Thirteen consecutive patients were examined by echocardiography and coronary angiography at admission and again by echocardiography after 3 months. Amplitudes, systolic and diastolic velocities of the mitral and tricuspid annuli and conventional diastolic parameters were measured. Systolic long-axis shortening of the left ventricle (LV) and right ventricle (RV) improved from 9.6 ± 2.2 mm to 11.2 ± 1.9 mm (P = 0.02) and from 21.3 ± 3.6 mm to 24.1 ± 2.8 mm (P = 0·02), respectively. LV systolic, early and late diastolic velocities measured by pulsed-wave tissue Doppler also improved, while additional conventional diastolic parameters of the LV and RV diastolic function were unchanged. Takotsubo cardiomyopathy temporarily affects systolic LV and RV function, while most diastolic parameters remain unchanged.

Randomised trial of ramipril in repaired tetralogy of Fallot and pulmonary regurgitation: The APPROPRIATE study ( Ace inhibitors for Potential PRevention Of the deleterious effects of Pulmonary Regurgitation In Adults with repaired TEtralogy of Fallot)

Background Optimal treatment for stable repaired tetralogy of Fallot (rTOF) patients with pulmonary regurgitation (PR) and related right ventricular (RV) dilatation, including timing of valve implantation, remains uncertain. We sought to study tolerability of the angiotensin-converting-enzyme (ACE) inhibitor ramipril and its effects on cardiovascular function in these patients. Methods Clinically stable rTOF patients with moderate/severe PR were included. A double-blinded, placebo-controlled study of 6 months of ramipril vs placebo was performed. All patients underwent cardiovascular magnetic resonance (CMR), echocardiography, neurohormonal analysis, and objective cardiopulmonary exercise testing at baseline and follow-up. Primary endpoint The main aim was to detect changes in RV function (primary endpoint CMR-derived RV ejection fraction). Results Seventy-two patients were enrolled and 64 qualified for the final analysis. There was no difference in the primary endpoint RV ejection fraction. RV long-axis shortening significantly improved in the ramipril group compared to placebo (RV: 2.3 ± 3.8 vs 0.02 ± 2.7 mm; P = 0.017) as did LV long-axis shortening (1.9 ± 4.5 vs −0.2 ± 3.7 mm respectively; P = 0.030). No clear differences were detected between ramipril and placebo for other measures. In a subgroup of patients with restrictive RV physiology, ramipril resulted in decrease in LV end-systolic volume index and increase in LVEF (−2.4 ± 5.0 vs 2.7 ± 3.6 mL/m 2; P = 0.005, 2.5 ± 5.0 vs −1.3 ± 3.5%; P = 0.03). Ramipril did not cause adverse events and was well tolerated. Conclusions Ramipril is a well tolerated therapy, improves biventricular function in patients with rTOF and may have a particular role in patients with restrictive RV physiology. Larger, longer-term studies are needed to determine if ACE inhibitors can improve both ventricular remodelling and clinical outcomes. (ISRCTN: 97515585)

Diastolic and systolic heart failure: Different stages or distinct phenotypes of the heart failure syndrome?

It remains uncertain if diastolic heart failure (DHF) is a distinct HF phenotype or a precursor stage of systolic HF (SHF). The unimodal distribution of left ventricular ejection fraction (LVEF) in HF, depressed LV long-axis shortening in DHF, and progression to eccentric LV remodeling in hypertension favor DHF and SHF as successive stages. These arguments are countered by the bimodal distribution of LVEF after correction for gender, by the preserved LV twist in DHF and by the low incidence of eccentric LV remodeling in hypertension. Clinical features, LV anatomy and histology, cardiomyocyte stiffness, myocardial effects of diabetes, and the response to HF therapy support DHF and SHF as distinct phenotypes. Comparison of the myocardial signal transduction cascades that drive LV remodeling in DHF and SHF may solve the controversy. This review analyzes arguments supporting DHF and SHF as successive stages or distinct phenotypes of the HF syndrome.

Is remodeling the dominant compensatory mechanism in both chronic heart failure with preserved and reduced left ventricular ejection fraction?

The mechanisms of heart failure are ill understood with multiple, heterogeneous hypotheses proposed to describe the condition. This study examines the individual effects of left ventricular hypertrophy, long-axis shortening and the effect of left ventricular remodeling on ejection fraction, end-diastolic volume and stroke volume using a mathematical model of left ventricular contraction. Reducing long-axis shortening caused a decline in stroke volume independently of hypertrophy. Increasing concentric left ventricular hypertrophy resulted in an increase in ejection fraction secondary to augmented wall thickening. A decline in stroke volume occurred despite a preserved ejection fraction when concentric hypertrophy was present. Normalization of stroke volume by remodeling resulted in a marked increase in end-diastolic volume in the absence of hypertrophy and an end-diastolic volume similar to normal in the presence of concentric hypertrophy. The model predicts that the dominant compensatory mechanism in chronic heart failure is remodeling with normalization of stroke volume. Observational data cited supports this conclusion.

Echocardiographic epidemiology--an emerging tool for early diagnosis, studying pathophysiology, predicting prognosis, and testing treatments

Advances in echocardiography mean that it is now possible to measure myocardial function accurately and non-invasively. Paradoxically, objective quantification of myocardial motion, contraction, and relaxation in each segment of the left ventricle actually makes it more difficult to define normality and disease in the individual patient, but the technique raises intriguing possibilities in population studies for diagnosing early heart muscle disease and testing new approaches to treatment. The catalyst to this approach was the development of tissue Doppler echocardiography to measure the velocity of myocardial motion, and then the processing of digitally stored velocity data to obtain measurements of regional myocardial deformation (strain and strain rate). Machines do not apply the Doppler equation when processing these signals, and so an alternative and more accurate term that encompasses all available methods is myocardial velocity imaging. Mogelvang et al. have reported their findings from performing echocardiography in >1000 subjects in the Copenhagen City Heart Study.1 These subjects comprised 17% of the total sample which had been drawn randomly from population registers, who attended when echocardiography with myocardial velocity imaging could be performed. They were aged between 20 and 93 years, and included substantial numbers of subjects with hypertension (>140/90 mmHg), diabetes [plasma glucose >11.1 mmol/L, or glycosylated haemoglobin (HbA1c) >7%, or on treatment], and/or ischaemic heart disease (IHD, diagnosed from history or abnormal ECG). Compared with ‘control’ subjects with none of these conditions, the subjects with hypertension, diabetes, or IHD had lower systolic velocities of long-axis shortening of the left ventricle (on average, –13%), less systolic mitral annular excursion (also –13%), and lower velocities of long-axis lengthening in early diastole (by an average of –33%). Overall, only 2% of the subjects with disease had a low ejection fraction (<50%) and only 8% had any degree of … *Corresponding author. Tel: + 44 29 2074 3489, Fax: + 44 29 2074 3500, Email: fraserag{at}cf.ac.uk

Abstract 2486: Early Diastolic Mitral Annulus Lengthening Velocity Reflects Coupling between Systolic and Diastolic Function

Background: Peak early-diastolic mitral annulus velocity (E’) by tissue Doppler imaging (TDI) has been introduced as a marker of diastolic function. This study investigates mechanisms of E’. Methods: In 7 anesthetized dogs we measured E’ and systolic long-axis shortening (SS) by sonomicrometry and TDI, and the time constant ( tau ) of LV relaxation by micromanometer. In 8 healthy subjects (HS) we measured E’ by TDI and SS by M-mode echo at baseline and during lower body negative pressure (LBNP). We studied 6 patients with myocardial infarction, acutely and after 6 –12 months. Results: In dogs there was a strong correlation between E’ and SS (Fig 1 ), suggesting that E’ is determined primarily by systolic function. However, during ischemia which increased tau (p&lt;&lt;med&gt;0.01) , the relationship between E’ and LV end-diastolic pressure (LVEDP), shifted markedly downwards (Fig 2 ). During volume loading which increased LVEDP (p&lt;0.01), the relationship between E’ and tau shifted markedly upwards (Fig 3 ). Consistent with findings in dogs, healthy subjects demonstrated a strong correlation between E’ and SS during LBNP (Fig 4 ). However, in patients with chronic myocardial infarction the relationship between E’ and systolic shortening was shifted downwards (Fig 4 ). Conclusions: During a wide range of hemodynamic conditions there were strong correlations between E’ and SS. The shifts in the relationships between E’ and LVEDP during ischemia and between E’ and tau during volume loading, indicates that diastolic function modulates E’. These observations indicate a tight coupling between systolic and diastolic function, and challenge the concept that E’ is a specific marker of LV relaxation. Fig 1 Experimental study Fig 2 Experimental study Fig 3 Experimental study Fig 4 Clinical study

Right Ventricular Mechanics and QRS Duration in Patients With Repaired Tetralogy of Fallot

Patients after repair of tetralogy of Fallot (ToF) frequently have right ventricular (RV) dysfunction and prolonged QRS duration (QRSd) and thus could be candidates for cardiac resynchronization therapy. We aimed to assess the relationship between QRSd and the timing of RV wall motion, including the RV outflow tract (RVOT), in these patients. Sixty-seven repaired ToF patients (median age, 34 years; interquartile range, 24 to 43 years) and 35 age-matched control subjects were studied by echocardiography and cardiovascular magnetic resonance (n=55 of 67 ToF patients). Time intervals of the RV cardiac cycle were measured from Doppler recordings. Long-axis M-mode recordings were acquired from the right ventricular (RV) free wall and RV outflow tract (RVOT), and the delay in onset of long-axis shortening was measured. ToF patients showed minor abnormalities of the RV cardiac cycle unrelated to QRSd. RV ejection time was prolonged and correspondingly filling time was reduced compared with control subjects (22.3+/-2.6 versus 20.0+/-2.9 s/min, P<0.0001; 29.0+/-3.8 versus 32.7+/-3.5 s/min, P<0.0001). Total isovolumic time was normal in ToF patients (8.7+/-4.0 versus 7.4+/-2.9 s/min; P=NS). QRSd correlated with the delay in RV free wall motion (r=0.55, P<0.0001) and more so with the delay in RVOT shortening (r=0.82, P<0.0001). QRSd also correlated with measures of RVOT abnormality such as long-axis RVOT excursion and akinetic area length (r=-0.46, P=0.004; r=0.33, P=0.01). QRSd in postoperative ToF patients reflects mainly abnormalities of the RVOT rather than the RV body itself. Thus, prevention and treatment of mechanical asynchrony and malignant arrhythmia should focus on the RV infundibulum. Indications for cardiac resynchronization therapy after ToF repair warrant further investigation.

What is the actual contribution of atrioventricular plane displacement to left ventricular stroke volume?

to the editor: In the recent article by Carlsson et al. ([4][1]), the authors found that left atrioventricular plane displacement (AVPD) accounted for 60% of left ventricular (LV) stroke volume. The discrepancy with earlier reports suggesting lower values ([3][2]) mostly depends on the use of

A novel mechanism of heart failure with normal ejection fraction

Background:Patients with heart failure and a normal left ventricular ejection fraction have significantly reduced left ventricular long-axis function. This paper proposes an explanation for this apparent paradox and suggests a...

Maternal left ventricular diastolic and systolic long-axis function during normal pregnancy

The aim of this study was to evaluate left ventricular (LV) function during normal pregnancy and investigate the effect of maternal factors. Little information about LV diastolic and long-axis systolic function in normal pregnancy exists. Two hundred and twenty eight Doppler echocardiography and DTI studies of the mitral annulus were performed in 63 normal pregnant women longitudinally at 11-14, 20-24, 26-32, 33-38weeks and 8-12weeks postpartum. Cardiac output, stroke volume and heart rate increased during pregnancy and total vascular resistance decreased. Long-axis shortening decreased, transmitral A velocity increased (p=0.003) and the ratio of transmitral E to A velocity decreased (p=0.001). DTI early diastolic velocity (E') decreased and late diastolic velocity (A') remained unaltered. DTI systolic velocity (S') and the E/E' ratio did not change significantly during pregnancy. Tei index increased throughout pregnancy (p=0.03). Maternal age was related to E velocity (p=0.001) and E/A ratio (p=0.001) while ethnicity was related to cardiac output (p<0.001), stroke volume (p<0.02) and heart rate (p<0.0001). This study gives normal ranges for Doppler tissue imaging measurements, but demonstrates that maternal characteristics may affect these and all measures of systolic and diastolic function.

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Maternal cardiac function in fetal growth restriction

To assess the maternal central haemodynamics in normotensive women with pregnancies complicated by severe fetal growth restriction (FGR). Cross-sectional study. A tertiary referral fetal medicine unit. The study groups comprised 107 women with normal singleton pregnancies and 20 with singleton pregnancies complicated by FGR at 25-37 weeks. In the latter group, assessment was carried out within 10 days prior to their delivery. All the women were normotensive, without any medical problems. Two-dimensional and M-mode echocardiography of the left ventricle. Maternal left ventricular systolic and diastolic function. In the FGR group, compared with the normal group, there was increased total vascular resistance (TVR), reduced systolic function characterised by lower cardiac output, stroke volume, heart rate, ejection time and septal and lateral long-axis shortening. Mean arterial pressure (MAP) was not significantly different between the groups. Severe FGR is associated with reduced maternal systolic function and increased TVR but no change in MAP. TVR may be a useful tool in the classification and management of FGR. The findings suggest that in FGR, there is increased blood viscosity due to lack of intravascular space expansion.

Misinterpretation About the Contribution of the Left Ventricular Long-Axis Shortening to the Stroke Volume

Misinterpretation about the contribution of the left ventricular long-axis shortening to the stroke volume

“Pure” diastolic dysfunction is associated with long‐axis systolic dysfunction. Implications for the diagnosis and classification of heart failure

To investigate regional systolic function of the left ventricle, to test the hypothesis that "pure" diastolic dysfunction (impaired global diastolic filling, with a preserved ejection fraction > or = 50%) is associated with longitudinal systolic dysfunction. One hundred thirty subjects (31 patients with asymptomatic diastolic dysfunction, 30 with diastolic heart failure, 30 with systolic heart failure; and 39 age-matched normal volunteers) were studied by conventional and tissue Doppler echocardiography. Global diastolic function was assessed using the flow propagation velocity, and by estimating left ventricular filling pressure from the ratio of transmitral E and mitral annular E(TDE) velocities (E/E(TDE)); and global systolic function by measurement of ejection fraction. Radial and longitudinal functions were assessed separately from posterior wall and mitral annular velocities. Global and radial systolic function were similar in patients with "pure" diastolic dysfunction and normal subjects, but patients with either asymptomatic diastolic dysfunction or diastolic heart failure had impaired longitudinal systolic function (mean velocities: 8.0+/-1.2 and 7.7+/-1.5 cm/s, respectively, versus 10.1+/-1.5 cm/s in controls; p<0.001). In subjects with normal ejection fraction, global diastolic function correlated with longitudinal systolic function (r=0.56 for flow propagation velocity, and r=-0.53 for E/E(TDE) ratio, both p<0.001), but not with global systolic function. Worsening global diastolic dysfunction of the left ventricle is associated with a progressive decline in longitudinal systolic function. Diastolic heart failure as conventionally diagnosed is associated with regional, subendocardial systolic dysfunction that can be revealed by tissue Doppler of long-axis shortening. Diagnostic algorithms and definitions of heart failure need to be revised.

Longitudinal myocardial dysfunction in healthy older subjects as a manifestation of cardiac ageing

Abnormalities of longitudinal left ventricular (LV) contraction and relaxation may be early markers of cardiac disease. This study was designed to assess the relationship between long-axis LV function and age in healthy subjects. 118 healthy individuals aged 57 +/-19 years (range 20-90 years) with no evidence of cardiovascular disease under-went echocardiography with Doppler examination of transmitral flow. To assess longitudinal LV function, systolic (S(m)), early diastolic (E(m)) and late diastolic (A(m)) mitral annular velocities were measured using colour-coded tissue Doppler imaging. The left atrium was enlarged (P<0.001) in subjects >/=60 years of age compared to those <60 years, but there were no differences in LV volumetric indices and ejection fraction. Peak E velocity was lower (P<0.001) and peak A velocity of transmitral flow was higher in older subjects (P<0.001) with a higher E/A ratio (P<0.001) and longer isovolumic relaxation time (P= 0.001) indicative of impaired ventricular relaxation. S m and E m mitral annular velocities decreased (P<0.001) and A m velocity increased (P=0.002) in the older group. E m velocity and E m /A m ratio showed a strong negative correlation with age (r= -0.80, P<0.001 and r=-0.78, P<0.001, respectively). Global LV systolic function is preserved but the velocity of long-axis systolic shortening is depressed in older individuals, indicating selective impairment of the longitudinal component of systolic contraction. The decline in the velocity of early diastolic long-axis LV lengthening and the changes in the pattern of transmitral flow suggest impaired ventricular relaxation. These measures of cardiac function may be a useful index of normal cardiac ageing.

Tissue Doppler imaging for the evaluation of patients with hypertrophic cardiomyopathy.

To discuss the role of tissue Doppler imaging for assessing regional myocardial function in patients with proven or suspected hypertrophic cardiomyopathy and review its application in clinical practice for diagnosis, estimation of filling pressures, and monitoring of treatment. Patients with hypertrophic cardiomyopathy have very abnormal systolic and diastolic myocardial function, even if global systolic function of the left ventricle appears normal. Regional function is most abnormal in walls that are markedly hypertrophied, but it is also abnormal in segments that are not affected by hypertrophy, and it is depressed in patients who have a mutation for hypertrophic cardiomyopathy but have not yet developed clear phenotypic changes. Genetic diagnosis remains difficult especially in sporadic cases, due to the very large number of mutations that have been identified; the hypertrophy may represent a nonspecific compensatory response to any mutation that impairs myofibrillar function. Subclinical changes especially affect long-axis ventricular function, and tissue Doppler imaging is the most sensitive test to identify reduced velocities of long-axis shortening and early diastolic lengthening of the left ventricle, prolonged contraction and relaxation times, and reduced strain in affected segments, both in patients with hypertrophy and in asymptomatic subjects with mutations. It can also discriminate well between hypertrophic cardiomyopathy and athlete's heart, and can be used with standard echocardiographic measurements to estimate left ventricular filling pressure or to monitor treatment. Tissue Doppler imaging can now be usefully incorporated into the routine echocardiographic study of patients with proven or suspected hypertrophic cardiomyopathy.

Fixed-apex mitral annular descent correlates better with left ventricular systolic function than does free-apex left ventricular long-axis shortening

Echocardiographic measures of mitral annular descent (MAD) assume a fixed left ventricular (LV) apex throughout the cardiac cycle, ignoring the apical component of LV long-axis shortening (LAS). We tested whether apical motion contributes significantly to LAS, making LAS a better surrogate of LV systolic function than MAD. Three-dimensional LV systolic MAD, LAS, and apical motion were measured in sheep using implanted radiopaque markers and biplane videofluoroscopy. End-diastolic volume-stroke work relationship (preload recruitable stroke work) was computed as a load-independent index of LV systolic function. Apical motion was 1.4 ± 0.8 mm, representing 22% of LAS ( P < .05). Linear regression demonstrated that MAD correlated slightly better with preload recruitable stroke work ( r = 0.808) than LAS ( r = 0.792, both P < .001). Receiver operating characteristic curves demonstrated MAD was more accurate in predicting depressed LV function than LAS (93% vs 84%, respectively). Although LV apical motion contributed significantly to LAS, MAD measured with a fixed-apex assumption, as currently done echocardiographically, correlated more closely with LV preload recruitable stroke work.