Peak systolic velocity of mitral annular longitudinal movement measured by pulsed tissue Doppler imaging as an index of global left ventricular contractility

Insulin resistance may accelerate typical changes in heart function among type 1 diabetes patients, particularly in overweight patients: a preliminary study

Introduction

Type 1 diabetes (T1D) is a metabolic disease characterized by insulin deficiency and subsequent hyperglycemia. Cardiovascular diseases are the prime cause of mortality and morbidity among patients with T1D. Accumulating metabolic disturbances and accelerated cardiac fibrosis fuel the development of heart dysfunction. As insulin resistance (IR) is a risk factor for the development and worsened course of heart failure, this study aimed to assess its impact on heart function in patients with T1D.

Methods

Adult participants were recruited prospectively. The inclusion criteria included a diagnosis of T1D. The exclusion criteria were other types of diabetes, symptoms/treatment of heart failure, AST and/or ALT exceeding the upper reference limit by ≥2x, hepatitis, alcoholism, metformin treatment, and pregnancy. The participants underwent a medical interview, physical examination, biochemical test, and echocardiography.

Results

The mean age in the study group was 38 ± 9.6 years, and the mean diabetes duration was 21.8 ± 11.3 years. The median BMI in the study cohort was 23.39 kg/m2. Patients with IR had significantly lower mitral E/A ratio and left ventricular and left atrial volume ratio (LVLAVR), higher LV mass index, and presented with altered mitral annular velocities.

Conclusions

IR seems to accelerate the pattern of typical changes in heart function among patients with T1D, especially in the overweight subgroup.

Mitral annular dynamics are influenced by left ventricular load and contractility in an acute animal model

The purpose of this study was to investigate the effects of loading conditions and left ventricular (LV) contractility on mitral annular dynamics. In 10 anesthetized pigs, eight piezoelectric transducers were implanted equidistantly around the mitral annulus. High-fidelity catheters measured left ventricular pressures and the slope of the end-systolic pressure-volume relationship (Ees ) determined LV contractility. Adjustments of pre- and afterload were done by constriction of the inferior caval vein and occlusion of the descending aorta. Mitral annulus area indexed to body surface area (MAAi ), annular circularity index (ACI), and non-planarity angle (NPA) were calculated by computational analysis. MAAi was more dynamic in response to loading interventions than ACI and NPA. However, MAAi maximal cyclical reduction (-Δr) and average deformational velocity (-v ¯ $$ \overline{v} $$ ) did not change accordingly (p = 0.31 and p = 0.22). Reduced Ees was associated to attenuation in MAAi -Δr and MAAi -v ¯ $$ \overline{v} $$ (r2  = 0.744; p = 0.001 and r2  = 0.467; p = 0.029). In conclusion, increased cardiac load and reduced LV contractility may cause deterioration of mitral annular dynamics, likely impairing coaptation and increasing susceptibility to valvular incompetence.

Cardiac and vascular effects of low-dose steroids during the early phase of septic shock: An echocardiographic study

Background

Low-dose steroids are known to increase arterial pressure during septic shock through restoration of vasopressor response to norepinephrine. However, their effects on cardiac performance and ventriculo-arterial coupling (VAC) have never been scrutinized during human septic shock. The aim of this study was to perform a comprehensive description of the cardiovascular effects of low-dose steroids using modern echocardiographic tools (including speckle tracking imaging).

Methods

This prospective study was conducted in the intensive care unit (ICU) of a university hospital in France. Consecutive adult patients admitted for septic shock and requiring low-dose steroid therapy were prospectively enrolled within 24 h of septic shock onset. We recorded hemodynamic and echocardiographic data to explore left ventricle (LV) contractility, loading conditions and VAC just before the initiation of low-dose steroids (50 mg intravenous hydrocortisone plus 50 μg enteral fludrocortisone) and 2–4 h after.

Results

Fifty patients [65 (55–73) years; 33 men] were enrolled. Arterial pressure, heart rate, almost all LV afterload parameters, and most cardiac contractility parameters significantly improved after steroids. VAC improved with steroid therapy and less patients had uncoupled VAC (> 1.36) after (24%) than before (44%) treatment.

Conclusion

In this comprehensive echocardiographic study, we confirmed an improvement of LV afterload after initiation of low-dose steroids. We also observed an increase in LV contractility with improved cardiovascular efficiency (less uncoupling with decreased VAC).

Acute Kidney Injury in Critically-Ill COVID-19 Patients

Purpose: Acute kidney injury (AKI) is common in patients with COVID-19, however, its mechanism is still controversial, particularly in ICU settings. Urinary proteinuria profile could be a non-invasive tool of interest to scrutinize the pathophysiological process underlying AKI in COVID-19 patients. Material and Methods: We conducted a retrospective study between March 2020 and April 2020. All patients with laboratory-confirmed COVID-19 and without end-stage kidney disease requiring renal replacement therapy before ICU admission were included. Our objectives were to assess the incidence and risk factors for AKI and to describe its clinical and biological characteristics, particularly its urinary protein profile. Results: Seventy patients were included; 87% needed mechanical ventilation and 61% needed vasopressor during their ICU stay; 64.3% of patients developed AKI and half of them needed dialysis. Total and tubular proteinuria on day 1 were higher in patients with AKI, whereas glomerular proteinuria was similar in both groups. The main risk factor for AKI was shock at admission (OR = 5.47 (1.74−17.2), p < 0.01). Mortality on day 28 was higher in AKI (23/45, 51.1%) than in no-AKI patients (1/25, 4%), p < 0.001. Risk factors for 28-days mortality were AKI with need for renal replacement therapy, non-renal SOFA score and history of congestive heart failure. Conclusions: AKI is common in COVID-19 patients hospitalized in ICU; it seems to be related to tubular lesions rather than glomerular injury and is related to shock at ICU admission.

Tissue motion annular displacement to assess the left ventricular systolic function in healthy cats

The tissue motion annular displacement (TMAD) measures the longitudinal displacement of the mitral annulus during systole, using speckle-tracking echocardiography (STE). The main objective was to determine the TMAD means in healthy cats, exploring the correlations with systolic surrogates. The influence of age, body surface area (BSA), heart rate, and systemic blood pressure on the indices was also analyzed. One hundred ninety-three healthy, client-owned cats participated in this prospective, cross-sectional observational study undergoing conventional and STE. Apical four-chamber (AP4) and two-chamber (AP2) images were recorded for offline calculations. Mean TMAD values were similar to mitral annulus plane systolic excursion (MAPSE), varying between 4 to 4.8 mm depending on the annulus and image used. No significant differences between age and BSA categories were detected, except for AP4 MP%, reduced in the heavier group. TMAD variables showed moderate correlation with longitudinal strain (LSt) and MAPSE, but not with fraction shortening (FS) and ejection fraction (EF). The median time required for the offline calculation was 12.2 s for AP4 and 11.8 s for AP2. The technique showed moderate inter and intraobserver variation, proving a reliable tool for assessing left ventricular longitudinal systolic function in cats.

Cardiovascular Responses During Sepsis

Sepsis is the life-threatening organ dysfunction arising from a dysregulated host response to infection. Although the specific mechanisms leading to organ dysfunction are still debated, impaired tissue oxygenation appears to play a major role, and concomitant hemodynamic alterations are invariably present. The hemodynamic phenotype of affected individuals is highly variable for reasons that have been partially elucidated. Indeed, each patient's circulatory condition is shaped by the complex interplay between the medical history, the volemic status, the interval from disease onset, the pathogen, the site of infection, and the attempted resuscitation. Moreover, the same hemodynamic pattern can be generated by different combinations of various pathophysiological processes, so the presence of a given hemodynamic pattern cannot be directly related to a unique cluster of alterations. Research based on endotoxin administration to healthy volunteers and animal models compensate, to an extent, for the scarcity of clinical studies on the evolution of sepsis hemodynamics. Their results, however, cannot be directly extrapolated to the clinical setting, due to fundamental differences between the septic patient, the healthy volunteer, and the experimental model. Numerous microcirculatory derangements might exist in the septic host, even in the presence of a preserved macrocirculation. This dissociation between the macro- and the microcirculation might account for the limited success of therapeutic interventions targeting typical hemodynamic parameters, such as arterial and cardiac filling pressures, and cardiac output. Finally, physiological studies point to an early contribution of cardiac dysfunction to the septic phenotype, however, our defective diagnostic tools preclude its clinical recognition. © 2021 American Physiological Society. Compr Physiol 11:1605-1652, 2021.

Sex, racial differences and healthy aging in normative reference ranges on diastolic function in Ethnic Asians: 2016 ASE guideline revisited

BACKGROUND

Diastolic dysfunction (DD) has shown to be a hallmark pathological intermediate in the development of heart failure with preserved ejection fraction (HFpEF). We aim to establish age- and sex-stratified normal reference values of diastolic indices and to explore racial-differences.

METHODS

We explored age- and sex-related structural/functional alterations from 6023 healthy ethnic Asians (47.1 ± 10.9 years, 61.3% men) according to 2016 American Society of Echocardiography (ASE) diastolic dysfunction (DD) criteria. Racial comparisons were made using data from London Life Sciences Prospective Population (LOLIPOP) study.

RESULTS

Age- and sex-based normative ranges (including mean, median, 10% and 90% lower and upper reference values) were extracted from our large healthy population. In fully adjusted models, advanced age was independently associated with cardiac structural remodeling and worsened diastolic parameters including larger indexed LA volume (LAVi), lower e', higher E/e', and higher TR velocity; all p < 0.001), which were more prominent in women (P interaction: <0.05). Broadly, markedly lower e', higher E/e' and smaller LAVi were observed in ethnic Asians compared to Whites. DD defined by 2016 ASE criteria, despite at low prevalence (0.42%) in current healthy population, increased drastically with advanced age and performed perfectly in excluding abnormal NT-proBNP (≥125 pg/mL) (Specificity: 99.8%, NPV: 97.6%).

CONCLUSION

This is to date the largest cohort exploring the normative reference values using guideline-centered diastolic parameters from healthy Asians, with aging played as central role in diastolic dysfunction. Our observed sex and ethnic differences in defining healthy diastolic cut-offs likely impact future clinical definition for DD in Asians.

Retinoid X receptor agonists attenuates cardiomyopathy in streptozotocin-induced type 1 diabetes through LKB1-dependent anti-fibrosis effects

Diabetic cardiac fibrosis increases ventricular stiffness and facilitates the occurrence of diastolic dysfunction. Retinoid X receptor (RXR) plays an important role in cardiac development and has been implicated in cardiovascular diseases. In the present study, we investigated the effects of RXR agonist treatment on streptozotocin (STZ)-induced diabetic cardiomyopathy (DCM) and the underlying mechanism. Sprague-Dawley (SD) rats induced by STZ injection were treated with either RXR agonist bexarotene (Bex) or vehicle alone. Echocardiography was performed to determine cardiac structure and function. Cardiac fibroblasts (CFs) were treated with high glucose (HG) with or without the indicated concentration of Bex or the RXR ligand 9-cis-retinoic acid (9-cis-RA). The protein abundance levels were measured along with collagen, body weight (BW), blood biochemical indexes and transforming growth factor-β (TGF-β) levels. The effects of RXRα down-regulation by RXRα small interfering RNA (siRNA) were examined. The results showed that bexarotene treatment resulted in amelioration of left ventricular dysfunction by inhibiting cardiomyocyte apoptosis and myocardial fibrosis. Immunoblot with heart tissue homogenates from diabetic rats revealed that bexarotene activated liver kinase B1 (LKB1) signaling and inhibited p70 ribosomal protein S6 kinase (p70S6K). The increased collagen levels in the heart tissues of DCM rats were reduced by bexarotene treatment. Treatment of CFs with HG resulted in significantly reduced LKB1 activity and increased p70S6K activity. RXRα mediated the antagonism of 9-cis-RA on HG-induced LKB1/p70S6K activation changes in vitro. Our findings suggest that RXR agonist ameliorates STZ-induced DCM by inhibiting myocardial fibrosis via modulation of the LKB1/p70S6K signaling pathway. RXR agonists may serve as novel therapeutic agents for the treatment of DCM.

Understanding cardiac systolic performance beyond left ventricular ejection fraction

Left ventricular ejection fraction is the critical parameter used for heart failure classification, decision making and assessing prognosis. It is defined as a volumetric ratio and is essentially a composite of arterial and ventricular elastances, but not intrinsic contractility. The clinician should be aware of its numerous limitations when measuring and reporting it. And make a step toward more insightful understanding of hemodynamics.

[Why not integrate the spectral tissue Doppler E/(e'xs') in the multiparametric assessment of cardiovascular diseases by transthoracic Doppler echocardiography?]

Assessment of left ventricular diastolic function by transthoracic Doppler echocardiography is based on a multiparametric approach which includes the spectral tissue Doppler-derived E/e'. Recently, a new Doppler index, E/(e'xs'), which combines E/e' with a spectral tissue Doppler-derived marker of systolic function, s', has been proposed in noninvasive assessment of left ventricular myocardial dysfunction. Current literature provides evidence that E/(e'xs') has good correlation with NT proBNP levels and invasive left ventricular end-diastolic pressure, both used as markers of left ventricular myocardial dysfunction, irrespective of left ventricular ejection fraction and wall motion abnormalities. More specifically, E/(e'xs') has good diagnostic accuracy in patients with intermediate values for E/e' (8 to 15). Average E/(e'xs')>1.6 is reported to predict invasive left ventricular end-diastolic pressure>15mmHg with a sensitivity of 86% and a specificity of 85%. Current literature provides evidence that E/(e'xs') could offer better prognostic information than E/e' in patients with systolic heart failure and heart failure with normal ejection fraction, as well as in patients with asymptomatic heart disease. A few clinical studies also suggest that E/(e'xs') could predict recurrence of atrial fibrillation after cardioversion and left ventricular remodeling after acute myocardial infarction. Further experimental and clinical investigation is critically needed to determine the role of this under-recognized tissue Doppler index in noninvasive assessment of cardiovascular diseases, in particular heart failure with normal ejection fraction.

Quantitative Analysis of an Intraoperative Digitalized Esophageal Heart Sound Signal to Speculate on Perturbed Cardiovascular Function

Although visualization of heart sounds, known as phonocardiography, provides valuable information on cardiovascular hemodynamics, its use has not been widely encouraged due to the scarcity of information on its interpretation. In the present study, using the intraoperative phonocardiogram recorded by an esophageal stethoscope, we quantitatively evaluated the time and frequency domains of modulation of the heart sounds components and their association with left ventricular contractility and systemic vascular resistance under the effects of various cardiovascular drugs. We analyzed 29 pairs of intraoperative digitalized phonocardiographic signals and their corresponding hemodynamic data before and after cardiovascular drug administration (ephedrine, esmolol, phenylephrine, and/or nicardipine) in 17 patients who underwent liver transplantation. The S1 and S2 components of the heart sounds (the first and second heart sounds, respectively) were identified and their modulation in time and frequency domains was analyzed. As an index of cardiovascular function, systolic tissue Doppler wave velocity (TDI S'), maximal dP/dt from the arterial waveform, and systemic vascular resistance were simultaneously evaluated. Ephedrine/esmolol and phenylephrine/nicardipine primarily affected the S1 and S2 components of the heart sounds, respectively. This result implies that the intraoperative phonocardiogram may have the potential to be useful in detecting the changes in contractility and afterload that commonly occur in patients receiving anesthesia. In an era of constant need for noninvasive hemodynamic assessment, phonocardiography has the potential for use as a novel and informative tool for monitoring of hemodynamic function.

Cardiovascular organ damage in type 2 diabetes mellitus: the role of lipids and inflammation

Background

The relationship between dyslipidemia, inflammation and CV organ damage in type 2 diabetes mellitus (T2DM) is complex. Insulin resistance and inflammatory cytokines interleukins (ILs) increase plasma triglycerides (TG). ILs also up-regulate expression of matrix-metalloproteinases (MMPs) that, together with TG, decrease high density lipoprotein cholesterol (HDL) levels. High TG, low HDL, increased ILs and MMPs trigger structural and functional changes in different parts of cardiovascular (CV) system. To understand better the role of lipids and inflammation in CV organ damage, the present study investigated the inter-relationships between lipids, ILs and MMPs, as well as the associations of lipids, ILs and MMPs with various CV measures, both in diabetic and non-diabetic population (nonT2DM).

Methods

In T2DM patients (N = 191) and nonT2DM subjects (N = 94) were assessed carotid intima-media thickness (cIMT) and inter-adventitial diameter (IADiam), carotid wave speed (ccaWS), carotid-femoral pulse wave velocity (cfPWV), left ventricular (LV) mass, LV systolic (s′) and early diastolic (e′) longitudinal velocities of mitral annulus, together with glycemic control, lipid profile, IL-6, IL-18 and MMP-12.

Results

T2DM patients, as compared to nonT2DM subjects, had significantly higher plasma levels of IL-6, IL-18, MMP-12 and lower HDL (P < 0.05–0.0001). They had also higher cIMT, IADiam, ccaWS, cfPWV and LV mass, and lower e′ velocity (P < 0.005–0.0001). Both in T2DM patients and nonT2DM subjects, MMP-12 increased with IL-6 (r = 0.43 and 0.39; P < 0.0001) and IL-18 (r = 0.32 and 0.42; P < 0.0001), and HDL decreased with MMP-12 (r = − 0.29 and − 0.42; P < 0.0001). In both populations, MMP-12 was directly associated with IADiam, ccaWS, cfPWV and LV mass (r = 0.42, 0.32, 0.26 and 0.29; P < 0.0001 in T2DM patients, and r = 0.39, 0.28, 0.32 and 0.27; P < 0.01–0.0001 in nonT2DM subjects). In multivariate analysis, MMP-12 remained independently related to IADiam, ccaWS, cfPWV and LV mass in T2DM patients, and to IADiam only in nonT2DM subjects.

Conclusions

This cross-sectional study demonstrated a direct association between ILs and MMP-12, as well as an inverse association between MMP-12 and HDL, both in T2DM patients and in nonT2DM subjects. In T2DM patients, who had higher levels of ILs and MMP-12, the latter was independently related to several structural and functional markers of preclinical CV organ damage.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0865-6) contains supplementary material, which is available to authorized users.

Clinical Usefulness of an Echo-Doppler Model in Predicting Elevated Pulmonary Capillary Wedge Pressure in Patients With Heart Failure

Although several tissue-Doppler imaging (TDI) models for pulmonary capillary wedge pressure (PCWP) estimation have been reported, their reliability remains uncertain. Our previous theoretical and experimental analyses suggest that right atrial pressure (RAP) corrected by tissue-Doppler imaging tricuspid/mitral annular peak systolic velocities (S_T/S_M) (RAP × S_T/S_M) reliably predicts elevated PCWP. We sought to investigate its clinical usefulness for predicting elevated PCWP in heart failure (HF) patients. Ninety-eight patients admitted with HF who underwent right heart catheterization were prospectively studied. RAP and PCWP were measured by right heart catheterization. Simultaneously, S_T/S_M, early diastolic transmitral flow velocity to mitral annular velocity ratio (E/Ea), and diameter of inferior vena cava at inspiration (IVCDi), a noninvasive surrogate for RAP, were measured by echocardiography. RAP correlated with IVCDi (R² = 0.57). A significantly stronger correlation was observed between IVCDi corrected by S_T/S_M (IVCDi × S_T/S_M) and PCWP than between E/Ea and PCWP (R² = 0.47 vs 0.18). Receiver-operating characteristic analyses indicated that IVCDi × S_T/S_M >16 mm predicted PCWP >18 mm Hg with 90% sensitivity and 77% specificity, and the area under the curve was 0.86, which was significantly larger than that of E/Ea (area under the curve=0.72). In conclusions, IVCDi × S_T/S_M is a new useful noninvasive model to predict elevated PCWP in HF patients.

Pharmacodynamic Analysis of the Influence of Propofol on Left Ventricular Long-Axis Systolic Performance in Cardiac Surgical Patients

BACKGROUND

Propofol induced a decline in the left ventricular (LV) systolic performance in non-cardiac surgery. We tested the hypothesis that propofol decreased the LV contractile function by dose dependent manner in cardiac surgery patients.

METHODS

Anesthesia was maintained with target-controlled infusions of propofol and remifentanil in cardiac surgery patients. With a fixed effect-site concentration (Ce) of remifentanil (20 ng/mL) after sternotomy, the Ce of propofol was adjusted to maintain a Bispectral index of 40-60 (Ce1). Mitral annular Doppler tissue image tracings and other echocardiographic variables, including end-diastolic and end-systolic volumes, stroke volume, and mitral inflow pulse wave Doppler profile at Ce1, were recorded using transesophageal echocardiography. Echocardiographic recordings were repeated after the Ce-values of propofol were doubled and tripled at 10-minute intervals (defined as Ce2 and Ce3, respectively). Serial changes in echocardiographic variables for each Ce of propofol were assessed using generalized linear mixed effect modeling. The pharmacodynamic relationship between the Ce of propofol and peak systolic mitral annular velocity (Sm) was analyzed by logistic regression using non-linear mixed effect modeling (NONMEM).

RESULTS

Means of Ce1, Ce2, and Ce3 were 0.8, 1.6, and 2.4 μg/mL, respectively, and their means of Sm (95% confidence interval) were 9.7 (9.3-10.2), 8.7 (8.2-9.1), and 7.5 cm/sec (7.0-8.0), respectively (P < 0.01). Ce values of propofol and Sm showed a significant inter-correlation and predictability (intercept, 10.8; slope-1.0 in generalized mixed linear modeling; P < 0.01). Ce values producing 10% and 20% decline of Sm with 50%-probability were 1.4 and 2.1 μ/mL, respectively.

CONCLUSION

Propofol reduces LV systolic long-axis performance in a dose-dependent manner.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01826149.

Cardiac function during weaning failure: the role of diastolic dysfunction

Background

Cardiac dysfunction is a common cause of weaning failure. Weaning shares some similarities with a cardiac stress test and may challenge active phases of the cardiac cycle-like ventricular contractility and relaxation. This study aimed at assessing systolic and diastolic function during the weaning process and scrutinizing their dynamics during weaning trials.

Methods

Echocardiography was performed during baseline ventilator settings to assess cardiac function at the initiation of the weaning process and at the start and the end of consecutive weaning trials (performed at day-1, day-2, and before extubation if applicable) to explore the evolution of left ventricle contractility and relaxation in a subset of patients.

Results

Among 67 patients included, weaning was prolonged (≥ 7 days) in 18 (27%) patients and short (< 7 days) in 49 (73%). Prevalence of systolic dysfunction and isolated diastolic dysfunction before the initiation of weaning process were 37 and 17%, respectively. Isolated diastolic dysfunction was more frequent in patients with prolonged weaning as compared to their counterparts. Thirty-one patients were explored by echocardiography during consecutive weaning trials. An increase in filling pressures with an alteration of ventricular relaxation (as assessed by a decrease in tissue Doppler early mitral diastolic wave velocity) was found during failed weaning trials.

Conclusions

Isolated diastolic dysfunction was associated with a prolongation of weaning. Increased filling pressures with left ventricle relaxation impairment may be a key mechanism of weaning trial failure.

Electronic supplementary material

The online version of this article (10.1186/s13613-017-0348-4) contains supplementary material, which is available to authorized users.

Association between subclinical left ventricular systolic dysfunction and glycemic control in asymptomatic type 2 diabetic patients with preserved left ventricular function

BACKGROUND

Type 2 diabetes is strongly associated with the occurrence of cardiovascular diseases, especially heart failure. Some studies have suggested that subclinical systolic dysfunction as assessed by tissue Doppler imaging (TDI) is already present in uncomplicated diabetic patients with normal left ventricular ejection fraction (LVEF). Considering the importance of this aspect, the aim of this cross-sectional study was to examine the relationship between glycated hemoglobin and mean s' wave velocity (a reliable measure of early LV systolic dysfunction) in a cohort of type 2 diabetic outpatients with preserved LVEF and without ischemic heart disease.

METHODS

Forty-four male patients with newly diagnosed and 172 male patients with established type 2 diabetes were recruited for this cross-sectional study. All patients were evaluated with a transthoracic echocardiographic Doppler. The statistical analysis was conducted by a linear multivariate regression analysis, including several potential confounders.

RESULTS

The mean values of mean s' wave velocity were lower in patients with a worse glycemic control and progressively decreased across the quartiles of glycated hemoglobin. The multivariate linear regression analysis showed that mean s' wave velocity was inversely and independently associated with glycated hemoglobin (standardized beta coefficient -0.178; p = 0.043) after adjustment for age, duration of diabetes, body mass index, pulse pressure, estimated glomerular filtration rate, microvascular complication status, and indexed cardiac mass.

CONCLUSIONS

These results suggest that s' wave velocity, as evaluated by TDI echocardiography, was an early marker of systolic dysfunction in type 2 diabetic patients with preserved LVEF and without prior ischemic heart disease. Moreover, early systolic dysfunction was independently associated with poor glycemic control in these patients. Future studies are needed to elucidate the pathogenic role of chronic hyperglycemia in the development of early LV systolic dysfunction.

Systolic mitral annulus velocity is a sensitive index for changes in left ventricular systolic function during inotropic therapy in patients with acute heart failure

BACKGROUND

Echocardiography is recommended for assessment of left ventricular systolic function in patients with acute heart failure but few randomised trials have validated techniques like tissue Doppler (TDI) and speckle tracking (STE) in patients with acute heart failure following ST-elevation myocardial infarction.

METHODS

This was a substudy from the LEAF (LEvosimendan in Acute heart Failure following myocardial infarction) trial (NCT00324766 ), which randomised 61 patients developing acute heart failure, including cardiogenic shock, within 48 hours after ST-elevation myocardial infarction, double-blind to a 25-hour infusion of levosimendan or placebo. TDI-derived systolic mitral annulus velocity (S'), STE-derived global longitudinal strain (S_l) and strain rate (SR_l) were measured at baseline, day 1, day 5 and after 42 days.

RESULTS

Datasets rejected for analyses were 2% (TDI) and 17% (STE). S' increased by 23% in the levosimendan group versus 8% in the placebo group from baseline to day 1 ( p= 0.011) and by 30% vs. 3% from baseline to day 5 ( p <0.0005). Significant, but less pronounced, improvements in global S_l ( p = 0.025 and p = 0.032) and in global SR_l ( p = 0.046 and p = 0.001) in favour of levosimendan were also present.

CONCLUSION

S' by TDI and STE-derived S_l and SR_l were sensitive indices for changes in left ventricular systolic function related to treatment with levosimendan. However, S' by TDI was more feasible and sensitive and might be preferred for assessment of changes in left ventricular systolic function in critically ill patients with acute heart failure receiving inotropic therapy.

Association of left ventricular structure and function with peripheral blood mitochondrial DNA content in a general population

BACKGROUND/OBJECTIVES

mtDNA content might be an important biomarker in heart disease prediction and to date no population studies are available on the association of mtDNA content with cardiac structure and function. We, therefore, investigated in a general population in cross-sectional and longitudinal studies whether echocardiographic indexes of LV structure and function are associated with mtDNA content measured in peripheral blood cells.

METHODS

At baseline we performed echocardiography in 701 randomly selected individuals (50.9% women, mean age, 53.2years) from a Flemish population. Relative mtDNA copy number compared to nuclear DNA was measured by quantitative real-time PCR in peripheral blood cells.

RESULTS

With adjustments applied, we observed significant inverse association of LV diastolic and systolic diameters (P≤0.028) and volumes (P=0.013) with mtDNA content. Moreover, for a 1-SD increment in mtDNA (0.37), we found an increase in Tissue Doppler s' velocity by 0.093cm/s (P=0.019) and a decrease in E/e' ratio by 0.18 (P=0.008). In 223 subjects with available echocardiography and mtDNA content at baseline and follow-up, we observed that higher baseline mtDNA content was associated with less increase in 2D LV diastolic volume (P=0.0003), M-mode LV diameter (P=0.046) and LV mass (P=0.003) during the follow-up period.

CONCLUSIONS

In the general population, higher mtDNA content was associated with smaller LV diastolic and systolic diameters and volumes and better LV systolic and diastolic function. Moreover, we observed that baseline mtDNA content was a significant predictor of longitudinal changes of LV diastolic volume and dimension, and LV mass.

Reduced Longitudinal Function in Chronic Aortic Regurgitation

Background

Chronic aortic regurgitation (AR) patients demonstrate left ventricular (LV) remodeling with increased LV mass and volume but may have a preserved LV ejection fraction (EF). We hypothesize that in chronic AR, global longitudinal systolic and diastolic function will be reduced despite a preserved LV EF.

Methods

We studied with Doppler echocardiography 27 normal subjects, 87 patients with chronic AR with a LV EF > 50% (AR + PEF), 66 patients with an EF < 50% [AR + reduced LV ejection fraction (REF)] and 82 patients with hypertensive heart disease. LV volume, transmitral spectral and tissue Doppler were obtained. Myocardial velocities and their timing and longitudinal strain of the proximal and mid wall of each of the 3 apical views were obtained.

Results

As compared to normals, global longitudinal strain was reduced in AR + PEF (13.8 ± 4.0%) and AR + REF (11.4 ± 4.7%) vs. normals (18.4 ± 3.6%, both p < 0.001). As an additional comparison group for AR + PEF, global longitudinal strain was reduced as compared to patients with hypertensive heart disease (p = 0.032). The average peak diastolic annular velocity (e') was decreased in AR + PEF (6.9 ± 3.3 cm/s vs. 13.4 ± 2.6 cm/s, p < 0.001) and AR + REF (4.8 ± 2.1 cm/s, p < 0.001). Peak rapid filling velocity/e' (E/e') was increased in both AR + PEF (14.4 ± 6.2 vs. 6.2 ± 1.3, p < 0.001) and AR + REF (18.8 ± 6.4, p < 0.001 vs. normals). Independent correlates of global longitudinal strain (r = 0.6416, p < 0.001) included EF (p < 0.0001), E/e' (p < 0.0001), and tricuspid regurgitation velocity (p = 0.0176).

Conclusion

With chronic AR, there is impaired longitudinal function despite preserved EF. Moreover, global longitudinal strain was well correlated with noninvasive estimated LV filling pressures and pulmonary systolic arterial pressures.

Automated quantitative assessment of cardiovascular magnetic resonance-derived atrioventricular junction velocities

The assessment of atrioventricular junction (AVJ) deformation plays an important role in evaluating left ventricular systolic and diastolic function in clinical practice. This study aims to demonstrate the effectiveness and consistency of cardiovascular magnetic resonance (CMR) for quantitative assessment of AVJ velocity compared with tissue Doppler echocardiography (TDE). A group of 145 human subjects comprising 21 healthy volunteers, 8 patients with heart failure, 17 patients with hypertrophic cardiomyopathy, 52 patients with myocardial infarction, and 47 patients with repaired Tetralogy of Fallot were prospectively enrolled and underwent TDE and CMR scan. Six AVJ points were tracked with three CMR views. The peak systolic velocity (Sm1), diastolic velocity during early diastolic filling (Em), and late diastolic velocity during atrial contraction (Am) were extracted and analyzed. All CMR-derived septal and lateral AVJ velocities correlated well with TDE measurements (Sm1: r = 0.736; Em: r = 0.835; Am: r = 0.701; Em/Am: r = 0.691; all p < 0.001) and demonstrated excellent reproducibility [intrastudy: r = 0.921-0.991, intraclass correlation coefficient (ICC): 0.918-0.991; interstudy: r = 0.900-0.970, ICC: 0.887-0.957; all p < 0.001]. The evaluation of three-dimensional AVJ motion incorporating measurements from all views better differentiated normal and diseased states [area under the curve (AUC) = 0.918] and provided further insights into mechanical dyssynchrony diagnosis in HF patients (AUC = 0.987). These findings suggest that the CMR-based method is feasible, accurate, and consistent in quantifying the AVJ deformation, and subsequently in diagnosing systolic and diastolic cardiac dysfunction.

Phosphoregulation of Cardiac Inotropy via Myosin Binding Protein-C During Increased Pacing Frequency or β1-Adrenergic Stimulation

BACKGROUND

Mammalian hearts exhibit positive inotropic responses to β-adrenergic stimulation as a consequence of protein kinase A-mediated phosphorylation or as a result of increased beat frequency (the Bowditch effect). Several membrane and myofibrillar proteins are phosphorylated under these conditions, but the relative contributions of these to increased contractility are not known. Phosphorylation of cardiac myosin-binding protein-C (cMyBP-C) by protein kinase A accelerates the kinetics of force development in permeabilized heart muscle, but its role in vivo is unknown. Such understanding is important because adrenergic responsiveness of the heart and the Bowditch effect are both depressed in heart failure.

METHODS AND RESULTS

The roles of cMyBP-C phosphorylation were studied using mice in which either WT or nonphosphorylatable forms of cMyBP-C [ser273ala, ser282ala, ser302ala: cMyBP-C(t3SA)] were expressed at similar levels on a cMyBP-C null background. Force and [Ca(2+)]in measurements in isolated papillary muscles showed that the increased force and twitch kinetics because increased pacing or β1-adrenergic stimulation were nearly absent in cMyBP-C(t3SA) myocardium, even though [Ca(2+)]in transients under each condition were similar to WT. Biochemical measurements confirmed that protein kinase A phosphorylated ser273, ser282, and ser302 in WT cMyBP-C. In contrast, CaMKIIδ, which is activated by increased pacing, phosphorylated ser302 principally, ser282 to a lesser degree, and ser273 not at all.

CONCLUSIONS

Phosphorylation of cMyBP-C increases the force and kinetics of twitches in living cardiac muscle. Further, cMyBP-C is a principal mediator of increased contractility observed with β-adrenergic stimulation or increased pacing because of protein kinase A and CaMKIIδ phosphorylations of cMyB-C.

Phosphorylation of cardiac Myosin-binding protein-C is a critical mediator of diastolic function

BACKGROUND

Heart failure (HF) with preserved ejection fraction (HFpEF) accounts for ≈50% of all cases of HF and currently has no effective treatment. Diastolic dysfunction underlies HFpEF; therefore, elucidation of the mechanisms that mediate relaxation can provide new potential targets for treatment. Cardiac myosin-binding protein-C (cMyBP-C) is a thick filament protein that modulates cross-bridge cycling rates via alterations in its phosphorylation status. Thus, we hypothesize that phosphorylated cMyBP-C accelerates the rate of cross-bridge detachment, thereby enhancing relaxation to mediate diastolic function.

METHODS AND RESULTS

We compared mouse models expressing phosphorylation-deficient cMyBP-C(S273A/S282A/S302A)-cMyBP-C(t3SA), phosphomimetic cMyBP-C(S273D/S282D/S302D)-cMyBP-C(t3SD), and wild-type-control cMyBP-C(tWT) to elucidate the functional effects of cMyBP-C phosphorylation. Decreased voluntary running distances, increased lung/body weight ratios, and increased brain natriuretic peptide levels in cMyBP-C(t3SA) mice demonstrate that phosphorylation deficiency is associated with signs of HF. Echocardiography (ejection fraction and myocardial relaxation velocity) and pressure/volume measurements (-dP/dtmin, pressure decay time constant τ-Glantz, and passive filling stiffness) show that cMyBP-C phosphorylation enhances myocardial relaxation in cMyBP-C(t3SD) mice, whereas deficient cMyBP-C phosphorylation causes diastolic dysfunction with HFpEF in cMyBP-C(t3SA) mice. Simultaneous force and [Ca(2+)]i measurements on intact papillary muscles show that enhancement of relaxation in cMyBP-C(t3SD) mice and impairment of relaxation in cMyBP-C(t3SA) mice are not because of altered [Ca(2+)]i handling, implicating that altered cross-bridge detachment rates mediate these changes in relaxation rates.

CONCLUSIONS

cMyBP-C phosphorylation enhances relaxation, whereas deficient phosphorylation causes diastolic dysfunction and phenotypes resembling HFpEF. Thus, cMyBP-C is a potential target for treatment of HFpEF.

Mitral annulus displacement measured by two-dimensional speckle tracking imaging to assess the left ventricular longitudinal systolic function in coronary heart disease

AIM

To assess the clinical utility of measuring mitral annulus displacement (MAD) by two-dimensional speckle tracking for the rapid evaluation of left ventricular longitudinal systolic function in patients with coronary heart disease (CHD).

METHODS

Left ventricular longitudinal systolic function was evaluated by MAD using speckle tracking echocardiography in 30 healthy volunteers (controls) as well as in 30 patients with mild, 30 patients with moderate, and 30 patients with severe CHD. All participants had their apical four-chamber and two-chamber view echocardiographic images recorded. Left ventricular end-diastolic volume, left ventricular end-systolic volume, and left ventricular ejection fraction were calculated by the biplane Simpson method. MAD of interventricular septum (MADsep), left ventricular lateral wall (MADlat), and the middle point of the mitral annulus (MADmid) were measured offline with speckle-tracking echocardiography. MADmid% was defined as MADmid divided by left ventricular end-diastolic diameter.

RESULTS

MADmid% was 16.9 ± 1.9, 11.8 ± 3.2, 11.8 ± 2.9, and 10.3 ± 3.6, respectively, in controls and in patients with mild, moderate, and severe CHD. All MAD indexes were lower in patients with moderate or severe CHD than in controls or patients with mild CHD.

CONCLUSIONS

MAD is an early and rapid index for the assessment of left ventricular longitudinal systolic function in patients with different degrees of coronary artery disease.

Depressed systolic function after a prolonged and strenuous exercise

INTRODUCTION

Prolonged and strenuous exercise (PSE) induces transient left ventricular (LV) dysfunction. Although a consensus exists regarding the decrease in diastolic function, the existence of a decrease in systolic function by a PSE remains controversial, probably due to the transient tachycardia and changes in loading conditions observed upon the completion of exercise. Therefore, the objective was to evaluate LV systolic function before and after a PSE using two-dimensional speckle tracking echocardiography not only at rest but also during incremental tests to adjust heart rates (HR).

METHODS AND RESULTS

Sixteen healthy young men (23 ± 3 yr old) performed a 3-h period of intensity-controlled upright cycling. LV strain (S), systolic strain rate (SR), rotation, and systolic rotational rate were evaluated by two-dimensional speckle tracking echocardiography before and after a 3-h period of PSE at rest and during incremental tests. Posttest evaluation was performed once the HR had returned to the pretest value. Under resting conditions, parameters of systolic function were either unchanged or increased after the PSE. However, during the incremental test, all LV systolic SR and apical rotational rates were decreased after PSE (radial SR at workload 3 (W3): 2.21 ± 0.12.s(-1) vs 1.87 ± 0.10.s(-1), P < 0.01 and apical rotational rate at W3: 128 ± 28 deg.s(-1) vs 105 ± 26 deg.s(-1), P < 0.05). Regression analyses between LV systolic SR and HR showed lower y-intercepts without differences in slopes, suggesting a decrease of both global and regional systolic functions irrespective of HR after the PSE.

CONCLUSION

Our findings based on LV S and SR data during incremental tests demonstrate that the 3-h period of PSE induces LV systolic dysfunction.

Relationship between fragmented QRS complex and left ventricular systolic and diastolic function in kidney transplant patients

BACKGROUND

Kidney transplant is a most important replacement therapy. It reduces cardiovascular mortality and morbidity but does not fully correct impairments in cardiac function. Fragmented QRS (fQRS) complex includes various RSR' patterns with different QRS complex morphologies on electrocardiograms.

OBJECTIVE

To analyze fQRS frequency and the relationship between fQRS and left ventricular function in kidney transplant patients.

METHOD

-After demographic data on 39 kidney transplant patients were recorded and biochemical parameters were investigated, electrocardiograms were evaluated for the presence of fQRS. Left ventricular ejection fraction, mitral annular plane systolic excursion, peak early diastolic mitral annular velocities, late diastolic mitral annular velocities, and systolic mitral annular velocity were analyzed.

RESULTS

Fragmented QRS was detected in 16 patients. A history of hypertension was associated with the presence of fQRS. Patients with fQRS had significantly lower systolic and peak early diastolic mitral annular velocities, mitral annular plane systolic excursion, and left ventricular ejection fraction than did patients without fQRS (P= .03, .01, <.001, and .03, respectively).

CONCLUSION

Detection of fQRS on electrocardiograms may be useful in predicting systolic and diastolic dysfunction of the left ventricle in kidney transplant patients.

A novel technique to predict pulmonary capillary wedge pressure utilizing central venous pressure and tissue Doppler tricuspid/mitral annular velocities

Assessing left ventricular (LV) filling pressure (pulmonary capillary wedge pressure, PCWP) is an important aspect in the care of patients with heart failure (HF). Physicians rely on right ventricular (RV) filling pressures such as central venous pressure (CVP) to predict PCWP, assuming concordance between CVP and PCWP. However, the use of this method is limited because discordance between CVP and PCWP is observed. We hypothesized that PCWP can be reliably predicted by CVP corrected by the relationship between RV and LV function, provided by the ratio of tissue Doppler peak systolic velocity of tricuspid annulus (S(T)) to that of mitral annulus (S(M)) (corrected CVP:CVP·S(T)/S(M)). In 16 anesthetized closed-chest dogs, S T and S M were measured by transthoracic tissue Doppler echocardiography. PCWP was varied over a wide range (1.8-40.0 mmHg) under normal condition and various types of acute and chronic HF. A significantly stronger linear correlation was observed between CVP·S(T)/S(M) and PCWP (R2 = 0.78) than between CVP and PCWP (R2 = 0.22) (P < 0.01). Receiver-operating characteristic (ROC) analysis indicated that CVP·S(T)/S(M) >10.5 mmHg predicted PCWP >18 mmHg with 85% sensitivity and 88% specificity. Area under ROC curve for CVP·S T/S M to predict PCWP >18 mmHg was 0.93, which was significantly larger than that for CVP (0.66) (P < 0.01). Peripheral venous pressure (PVP) corrected by S T/S M (PVP·S(T)/S(M) also predicted PCWP reasonably well, suggesting that PVP·S(T)/S (M) may be a minimally invasive alternative to CVP·S(T)/S(M) In conclusion, our technique is potentially useful for the reliable prediction of PCWP in HF patients.

Reference values of the mitral annular peak systolic velocity (Sm) in 690 healthy pediatric patients, calculation of Z-score values, and comparison to the mitral annular Plane systolic excursion (MAPSE)

BACKGROUND

The mitral annular peak systolic velocity (Sm) is an echocardiographic measurement using tissue Doppler imaging to assess longitudinal left ventricular (LV) systolic function in children and adults. We determined growth-related changes in Sm to establish reference values for the entire pediatric age group.

METHODS AND RESULTS

A prospective study was conducted in a group of 690 healthy pediatric patients (age: 1 day-18 years). We determined the effects of age, sex, and body surface area (BSA) on the Sm values. Regression analysis was used to estimate Sm from age, BSA, and sex. In addition, a correlation of normal Sm with normal age-matched values of the M-mode parameter mitral annular plane systolic excursion (MAPSE) was measured. The Sm ranged from a mean of 5.8 cm/sec (Z-score ±2: 3.6-8.0 cm/sec) in the newborn to 11.8 cm/sec (Z-score ±2: 8.5-15.1 cm/sec) in the 18-year-old adolescent. The Sm values showed a positive correlation with age and BSA with a nonlinear course. There was no significant difference in Sm values between females and males. A significant correlation was found between Sm and MAPSE values.

CONCLUSION

Z-scores of Sm values were calculated and percentile charts were established to serve as reference data in patients with congenital heart diseases.

Cardiac myosin-binding protein-C is a critical mediator of diastolic function

Diastolic dysfunction prominently contributes to heart failure with preserved ejection fraction (HFpEF). Owing partly to inadequate understanding, HFpEF does not have any effective treatments. Cardiac myosin-binding protein-C (cMyBP-C), a component of the thick filament of heart muscle that can modulate cross-bridge attachment/detachment cycling process by its phosphorylation status, appears to be involved in the diastolic dysfunction associated with HFpEF. In patients, cMyBP-C mutations are associated with diastolic dysfunction even in the absence of hypertrophy. cMyBP-C deletion mouse models recapitulate diastolic dysfunction despite in vitro evidence of uninhibited cross-bridge cycling. Reduced phosphorylation of cMyBP-C is also associated with diastolic dysfunction in patients. Mouse models of reduced cMyBP-C phosphorylation exhibit diastolic dysfunction while cMyBP-C phosphorylation mimetic mouse models show enhanced diastolic function. Thus, cMyBP-C phosphorylation mediates diastolic function. Experimental results of both cMyBP-C deletion and reduced cMyBP-C phosphorylation causing diastolic dysfunction suggest that cMyBP-C phosphorylation level modulates cross-bridge detachment rate in relation to ongoing attachment rate to mediate relaxation. Consequently, alteration in cMyBP-C regulation of cross-bridge detachment is a key mechanism that causes diastolic dysfunction. Regardless of the exact molecular mechanism, ample clinical and experimental data show that cMyBP-C is a critical mediator of diastolic function. Furthermore, targeting cMyBP-C phosphorylation holds potential as a future treatment for diastolic dysfunction.

Does left ventricular tissue Doppler peak systolic velocity (Sm) reflect cardiac output in the critically ill?

Cardiac output (CO) is dependent on a number of factors, in particular, the systolic function of the heart. Tissue Doppler (TD) is a modality in echocardiography that measures myocardial velocity and is related to contractility. TD can therefore be used to measure the systolic function of the heart. This study sought to establish whether the systolic component of TD can be used to estimate CO in critically ill patients. Retrospective data was obtained from a total of 80 patients: 29 patients with a normal echocardiogram, and 51 intensive care unit patients; 28 septic and 23 with heart failure. The mean TD peak systolic velocity (Sm) was significantly lower in the heart failure patients (P <0.05) compared to both normal and septic group. The mean CO was significantly higher in septic patients when compared to heart failure patients. A mild to moderate positive correlation was found between Sm and CO in the heart failure group and with all patients combined (r2=0.19, P <0.001). Subsequent analysis of Sm versus stroke volume again showed a mild positive correlation in the heart failure group and combined results (r2=0.18, P <0.001). Sm was weakly correlated to heart rate only in the normal group but not in the combined cohort. Our data confirms a weak to moderate correlation between Sm and CO, probably resulting from a positive correlation of Sm and stroke volume. This correlation is not strong enough to support the use of an individual's Sm to estimate CO in intensive care patients.

Enhanced characterization of ventricular performance after coarctation repair in neonates and young children

BACKGROUND

Within the group of patients undergoing coarctectomy today, two subgroups can be identified: neonates with a critical coarctation and nonneonatal patients. We hypothesize that patients who have to undergo repair in the neonatal period will have more persistent impairment of ventricular performance postoperatively. Accordingly, we aimed to characterize biventricular performance after coarctectomy in neonatal and nonneonatal patients.

METHODS

Children (aged 0 to 17 years) undergoing a coarctectomy were prospectively included and classified as neonatal (<1 month old) or nonneonatal patients. Age-matched controls were included for each measurement occasion. To evaluate left (LV) and right ventricular (RV) performance, fractional shortening, peak systolic (S') and early diastolic (E') tissue Doppler imaging velocities, and E/E' were assessed preoperatively, at discharge, and 1 year postoperatively (11.4 ± 8.3 months).

RESULTS

In neonatal (n = 18) and nonneonatal (n = 19) patients LV performance significantly improved within the first postoperative year. Yet 1 year postoperatively, LV S' was still lower in neonatal patients vs controls (4.8 ± 1.1 vs 6.1 ± 1.6 cm/s; p = 0.036), whereas comparable results were observed in nonneonatal patients and controls. One year postoperatively, LV diastolic performance was impaired in neonatal (LV E' 8.7 ± 3.1 vs 13.2 ± 3.9 cm/s, p = 0.005) and nonneonatal patients (LV E' 12.1 ± 3.5 vs 15.1 ± 2.4 cm/s, p = 0.008) vs controls. In RV performance variables, no differences were observed 1 year postoperatively between neonatal and nonneonatal patients and controls.

CONCLUSIONS

In both subgroups, LV diastolic performance does not recover to normal values within the first postoperative year. However, LV systolic performance remains more persistently impaired in patients who have to undergo repair in the neonatal period vs nonneonatal repair.

Tissue Doppler imaging detects impaired biventricular performance shortly after congenital heart defect surgery

Cardiac surgery with cardiopulmonary bypass is associated with the development of a systemic inflammatory response, which can lead to myocardial damage. However, knowledge concerning the time course of ventricular performance deterioration and restoration after correction of a congenital heart defect (CHD) in pediatric patients is sparse. Therefore, the authors perioperatively quantified left ventricular (LV) and right ventricular (RV) performance using echocardiography. Their study included 141 patients (ages 0-18 years) undergoing CHD correction and 40 control subjects. The study assessed LV systolic performance (fractional shortening) and diastolic performance (mitral Doppler flow) in combination with RV systolic performance [tricuspid annular plane systolic excursion (TAPSE)] and diastolic performance (tricuspid Doppler flow). Additionally, systolic (S') and diastolic (E', A', E/E') tissue Doppler imaging (TDI) measurements were obtained at the LV lateral wall, the interventricular septum, and the RV free wall. Echocardiographic studies were performed preoperatively, 1 day postoperatively, and at hospital discharge after 9 ± 5 days. Although all LV echocardiographic measurements showed a deterioration 1 day after surgery, only LV TDI measurements were impaired in patients at discharge versus control subjects (S': 5.7 ± 2.0 vs 7.1 ± 2.7 cm/s; E': 9.8 ± 3.9 vs 13.7 ± 5.1 cm/s; E/E': 12.2 ± 6.4 vs 8.8 ± 4.3; p < 0.05). In the RV, TAPSE and RV TDI velocities also were impaired in patients at discharge versus control subjects (TAPSE: 9 ± 3 vs 17 ± 5 mm; S': 5.2 ± 1.7 vs 11.4 ± 3.4 cm/s; E': 7.3 ± 2.5 vs 16.3 ± 5.2 cm/s; E/E': 12.5 ± 6.8 vs 4.8 ± 1.9; p < 0.05). Furthermore, longer aortic cross-clamp times were associated with more impaired postoperative LV and RV performance (p < 0.05). In conclusion, both systolic and diastolic biventricular performances were impaired shortly after CHD correction. This impairment was detected only by TDI parameters and TAPSE. Furthermore, a longer-lasting negative influence of cardiopulmonary bypass on myocardial performance was suggested.

Determinants of left ventricular vortex flow parameters assessed by contrast echocardiography in an in vivo animal model

BACKGROUND

Various left ventricular (LV) vortex parameters obtained during contrast echocardiography (CE) have been recently described. The aim of this study was to investigate their determinants and associations with conventional hemodynamic variables.

METHODS

CE was performed and LV pressure was simultaneously measured during pharmacologic inotropic modulation in 8 mongrel dogs. Customized software was used to assess both vortex geometric parameters (vortex depth [VD], length [VL], width [VW], transverse position, and sphericity index [SI]) and pulsatility parameters (relative strength [RS], vortex relative strength [VRS], and vortex pulsation correlation [VPC]). The associations between each of these parameters and conventional indices representing LV systolic and diastolic function were analyzed.

RESULTS

VD and VW did not change significantly during pharmacologic modulation, whereas VL (P = 0.0034) and SI (P = 0.001) showed significant and progressive linear decreases from baseline during dobutamine infusion. Significant linear changes during positive and negative inotropic modulation were observed in all pulsatiliy parameters (P < 0.01 each). Geometric parameters were critically dependent on LV volume, with pulsatility parameters showing significant positive correlations with heart rate, systolic and diastolic blood pressure (DBP), dp/dtmax , early and late mitral inflow velocities, and peak systolic and diastolic annular velocities. In multivariate analysis, LV end-diastolic volume was a main determinant for VL (r = 0.29, P < 0.001) and VW (r = 0.65, P < 0.001), whereas dp/dtmax for pulsatility parameters (RS [r = 0.61, P < 0.001], VRS [r = 0.46, P < 0.001] and VPC [r = 0.62, P < 0.001]).

CONCLUSION

Geometric and pulsatility parameters differed in their association with LV geometry and conventional physiologic indices representing LV function. These differences should be considered in interpreting these variables.

Assessing left ventricular systolic dysfunction after myocardial infarction: are ejection fraction and dP/dt(max) complementary or redundant?

Among the various cardiac contractility parameters, left ventricular (LV) ejection fraction (EF) and maximum dP/dt (dP/dt(max)) are the simplest and most used. However, these parameters are often reported together, and it is not clear if they are complementary or redundant. We sought to compare the discriminative value of EF and dP/dt(max) in assessing systolic dysfunction after myocardial infarction (MI) in swine. A total of 220 measurements were obtained. All measurements included LV volumes and EF analysis by left ventriculography, invasive ventricular pressure tracings, and echocardiography. Baseline measurements were performed in 132 pigs, and 88 measurements were obtained at different time points after MI creation. Receiver operator characteristic (ROC) curves to distinguish the presence or absence of an MI revealed a good predictive value for EF [area under the curve (AUC): 0.998] but not by dP/dt(max) (AUC: 0.69, P < 0.001 vs. EF). Dividing dP/dt(max) by LV end-diastolic pressure and heart rate (HR) significantly increased the AUC to 0.87 (P < 0.001 vs. dP/dt(max) and P < 0.001 vs. EF). In naïve pigs, the coefficient of variation of dP/dt(max) was twice than that of EF (22.5% vs. 9.5%, respectively). Furthermore, in n = 19 pigs, dP/dt(max) increased after MI. However, echocardiographic strain analysis of 23 pigs with EF ranging only from 36% to 40% after MI revealed significant correlations between dP/dt(max) and strain parameters in the noninfarcted area (circumferential strain: r = 0.42, P = 0.05; radial strain: r = 0.71, P < 0.001). In conclusion, EF is a more accurate measure of systolic dysfunction than dP/dt(max) in a swine model of MI. Despite the variability of dP/dt(max) both in naïve pigs and after MI, it may sensitively reflect the small changes of myocardial contractility.

Peak systolic mitral annulus velocity reflects the status of ventricular-arterial coupling-theoretical and experimental analyses

BACKGROUND

Peak systolic mitral annular velocity (S(m)) measured by tissue Doppler echocardiography has been recognized as an independent predictor of mortality in patients with heart failure and in the general population. However, the mechanical determinants of S(m) remain poorly defined.

METHODS

A theoretical model of S(m) was derived, which indicates that S(m) is affected positively by left ventricular (LV) contractility and preload and inversely by LV afterload and ejection time (EJT). In 16 anesthetized dogs, S(m), LV volume, and LV pressure were measured using sonomicrometry and catheter-tip micromanometry. LV contractility, preload, and afterload were indexed by the end-systolic pressure/volume ratio (E(es)'), end-diastolic volume (V(ed)), and effective arterial elastance (E(a)), respectively. LV contractility, loading conditions, and heart rate were varied over wide ranges, and a total of 76 data sets were obtained for S(m) (1.2-9.1 cm/sec), E(es)' (1.5-17.6 mm Hg/mL), V(ed) (11-99 mL), E(a) (3.6-58.4 mm Hg/mL), EJT (100-246 msec), heart rate (66-192 beats/min), and the ventricular-arterial coupling ratio (E(es)'/E(a); 0.2-3.0).

RESULTS

The theoretical model accurately predicted S(m) (R(2) = 0.79, P < .0001). By univariate analysis, S(m) was correlated significantly with E(es)' (R(2) = 0.64, P < .0001) and with the reciprocal of E(a) (R(2) = 0.49, P < .01). V(ed) and EJT did not affect S(m). E(es)'/E(a) was correlated strongly with S(m) (R(2) = 0.73, P < .0001). E(es)' and the reciprocal of E(a) were not correlated with each other.

CONCLUSIONS

LV contractility and afterload independently determine S(m). The effects of LV preload and EJT on S(m) might be small, even though they are theoretically associated with S(m). S(m) strongly reflects the status of ventricular-arterial coupling.