Echo-Doppler mitral flow monitoring: an operative tool to evaluate day-to-day tolerance to and effectiveness of beta-adrenergic blocking agent therapy in patients with chronic heart failure

Assessing Diastolic Function as an Important Tool for Clinical Decision-making in Critically Ill Patients

Diastolic dysfunction, which is increasingly seen as being influential in precipitating heart failure and determining prognosis, is often unrecognized. In elderly patients with high rates of comorbidities, determining whether symptoms are attributable to cardiac conditions or other coexisting comorbidities can be clinically challenging. Moreover, in hemodynamically unstable patients, real-time decisions regarding fluid status are critically important. With better understanding and assessment of diastolic function, physicians should be in a better position not only to diagnose diastolic dysfunction or heart failure, but also to manage it more effectively. To optimize this approach, assessing diastolic function at the time of hemodynamic compromise or symptomatic deterioration is essential. In this review, clinical implications of assessing left ventricular diastolic function and filling pressures in critically ill patients will be reviewed with case-based discussions to emphasize how information regarding left ventricular diastolic function and filling pressure can be used for correct diagnosis and proper management of these patients.

Imaging Techniques in Acute Heart Failure

In recent years, imaging techniques have revolutionized the diagnosis of heart failure. In patients with a clinical picture of acute decompensation, prognosis is largely determined by early implementation of general measures and treatment of the underlying cause. Given its diagnostic yield and portability, ultrasound has become an essential tool in the setting of acute heart failure, and is currently found in all medical departments involved in the care of the critically ill patient. Cardiac magnetic resonance and computed tomography allow detailed characterization of multiple aspects of cardiac structure and function that were previously unavailable. This helps guide and monitor many of the treatment decisions in the acute heart failure population in an entirely noninvasive way. This article aims to review the usefulness of the imaging techniques that are clinically relevant in the context of an episode of acute heart failure. We discuss the indications and limitations of these techniques in detail and describe the general principles for the appropriate interpretation of results.

The role of echocardiography in the diagnosis and prognosis of patients with heart failure

The number of patients with congestive heart failure has increased in epidemic proportions. Echocardiography plays an important role in the diagnosis and management of these patients. Recent studies have also confirmed the independent prognostic information of the echocardiographic findings.

Role of echocardiography in the contemporary management of chronic heart failure

Echocardiography is an excellent noninvasive tool for the assessment of ventricular size and both systolic and diastolic function, and it is routinely used in patients with heart failure. This review will discuss the role of echocardiography in heart failure diagnosis, prognostic assessment and in the management of heart failure patients.

Pulmonary hypertension in elderly patients with diastolic dysfunction and preserved ejection fraction

Purpose:

Patients with diastolic dysfunction may have a disproportionate degree of elevation in pulmonary pressure, particularly in the elderly. Higher pulmonary vascular resistance in the elderly patients with heart failure but preserved ejection fraction suggests that beyond the post-capillary contribution of pulmonary venous congestion, a pre-capillary component of pulmonary arterial hypertension occurs. We aim to identify if pulmonary vascular resistance in elderly patients with diastolic dysfunction is disproportionately higher than patients with systolic dysfunction independent of filling pressures.

Methods:

389 patients identified retrospectively between 2003- 2010; elderly with preserved ejection fraction, elderly with depressed ejection fraction, and primary arterial hypertension who underwent right-heart catheterization at Rush University.

Results:

No significant difference in pulmonary vascular resistance between systolic and diastolic dysfunction. The mean difference in pulmonary vascular resistance was not statistically significant at 0.40 mmHg·min/l (95% CI -3.03 to 3.83) with similar left ventricular filling pressures with mean difference of 3.38 mmHg (95% CI, -1.27 to 8.02). When adjusted for filling pressures, there remained no difference in pulmonary vascular resistance for systolic and diastolic dysfunction. The mean pulmonary vascular resistance is more elevated in systolic heart failure compared to diastolic heart failure with means 3.13 mmHg·min/l and 3.52 mmHg·min/l, respectively.

Conclusion:

There was no other association identified for secondary pulmonary hypertension other than diastolic dysfunction and chronic venous pulmonary hypertension. Our results argue against any significant arterial remodeling that would lead to disproportionate pre-capillary hypertension, and implies that treatment should focus on lowering filling pressure rather than treating the pulmonary vascular tree.

Increased mortality in patients with conflicting diastolic parameters

The aim of this study was to describe the clinical characteristics and mortality of patients with conflicting diastolic function during follow-up. Up to 30% of patients have conflicting diastolic function by echo Doppler and therefore cannot be classified into a distinct diastolic dysfunction category of stage 1, 2 or 3. Using our established echocardiography data base, we studied a cohort of 250 subjects with conflicting diastolic function. Each individual was compared to two controls with normal diastolic and systolic function. The pre-specified goal of the analysis was a 6-year follow-up. Patients with conflicting diastolic function were more likely to have diabetes, hypertension, and established coronary artery disease. The Cox proportional hazards model determined that the risk of death was significantly higher for conflicting patients compared to patients with normal diastolic parameters (HR: 1.83; 95% CI: 1.32-2.53), P < 0.001. After adjustment for covariates, the risk of death remained elevated for the conflicting group (HR: 1.56; 95% CI: 1.11-2.18), P = 0.009. Conflicting diastolic dysfunction is associated with an increased risk of death compared to individuals with normal function. In conclusion, this emphasizes the need to attain a more precise characterization and categorization for patients with diastolic dysfunction.

Doughty RN, Klein AL, Poppe KK, Gamble GD, Dini FL, Møller JE, Quintana M, Yu CM, Whalley GA. Independence of restrictive filling pattern and LV ejection fraction with mortality in heart failure: an individual patient meta-analysis

BACKGROUND

The Doppler echocardiographic restrictive mitral filling pattern (RFP) is an important prognostic indicator in patients with heart failure (HF), but the interaction between RFP, left ventricular ejection fraction (LVEF) and filling pattern remains uncertain.

AIMS

To determine whether the RFP is predictive of mortality independently of LVEF in patients with HF.

METHODS

Online databases were searched to identify studies assessing the relationship between prognosis and LV filling pattern in patients with HF. Individual patient data from 18 studies (3540 patients) were extracted and collated at the MeRGE Coordinating Centre (The University of Auckland).

RESULTS

Overall, RFP was associated with higher all-cause mortality than the non-restrictive filling pattern: hazard ratio 2.42 (95% CI 2.06, 2.83). In multivariable analysis the RFP, LVEF, NYHA class and age were independent predictors of mortality. The prevalence of the RFP was inversely related to LVEF but remained a predictor of mortality even in those patients with preserved LVEF.

CONCLUSIONS

The restrictive mitral filling pattern is a powerful predictor of mortality, independent of LVEF and age, in patients with HF. Doppler-derived LV filling patterns are an accessible marker from echocardiography that can readily be incorporated in risk stratification of all patients with HF.

Pulmonary artery pressure and diastolic dysfunction in normal left ventricular systolic function

BACKGROUND

Pulmonary arterial hypertension is a well-established sequel of LV systolic dysfunction; however its association with diastolic dysfunction in subjects with normal LV systolic function has not been thoroughly studied. The aim of this study was to evaluate the correlation between diastolic dysfunction and pulmonary arterial hypertension in patients with normal left ventricular (LV) wall motion.

METHODS

We analyzed retrospectively 477 consecutive echocardiographic studies that were performed in the Meir Medical Center echocardiography laboratory in subjects with normal LV systolic function and correlated the state of diastolic function (normal, impaired relaxation, pseudo normal and restrictive pattern) to the magnitude of pulmonary artery pressure (PAP) assessed by echocardiography. None of the subjects that were studied had any other established causes of pulmonary hypertension.

RESULTS

Mean PAP for subjects with normal diastolic function (n=110) was 31.1+/-6 mm Hg; for grade 1 diastolic dysfunction (impaired relaxation ) (n=256) 35.6+/-10.2 mm Hg; for grade 2 (pseudo normal) (n=102) 38.9=10.6 mm Hg and for grade 3 (restrictive pattern) (n=9) the pressure was 55.1+/-11.4 mm Hg (p<0.001 by one-way ANOVA, the differences were between each 2 groups of diastolic dysfunction).

CONCLUSIONS

LV diastolic dysfunction is associated with an increase in PAP in subjects with normal systolic function. PAP is significantly increased for each step-up in diastolic dysfunction grade.

Tissue Doppler imaging a new prognosticator for cardiovascular diseases

Tissue Doppler imaging (TDI) is evolving as a useful echocardiographic tool for quantitative assessment of left ventricular (LV) systolic and diastolic function. Recent studies have explored the prognostic role of TDI-derived parameters in major cardiac diseases, such as heart failure, acute myocardial infarction, and hypertension. In these conditions, myocardial mitral annular or basal segmental (Sm) systolic and early diastolic (Ea or Em) velocities have been shown to predict mortality or cardiovascular events. In particular, those with reduced Sm or Em values of <3 cm/s have a very poor prognosis. In heart failure and after myocardial infarction, noninvasive assessment of LV diastolic pressure by transmitral to mitral annular early diastolic velocity ratio (E/Ea or E/Em) is a strong prognosticator, especially when E/Ea is > or =15. In addition, systolic intraventricular dyssynchrony measured by segmental analysis of myocardial velocities is another independent predictor of adverse clinical outcome in heart failure subjects, even when the QRS duration is normal. In heart failure patients who received cardiac resynchronization therapy, the presence of systolic dyssynchrony at baseline is associated with favorable LV remodeling, which in turn predicts a favorable long-term clinical outcome. Finally, TDI and derived deformation parameters improve prognostic assessment during dobutamine stress echocardiography. A high mean Sm value in the basal segments of patients with suspected coronary artery disease is associated with lower mortality rate or myocardial infarction and is superior to the wall motion score.

Validity of Revised Doppler Echocardiographic Algorithms and Composite Clinical and Angiographic Data in Diagnosis of Diastolic Dysfunction

BACKGROUND

Commonly used echocardiographic indices for grading diastolic function predicated on mitral inflow Doppler analysis have a poor diagnostic concordance and discriminatory value. Even when combined with other indices, significant overlap prevents a single group assignment for many subjects. We tested the relative validity of echocardiographic and clinical algorithms for grading diastolic function in patients undergoing cardiac catheterization.

METHOD

Patients (n = 115), had echocardiograms immediately prior to measuring left ventricular (LV) diastolic (pre-A, mean, end-diastolic) pressures. Diastolic function was classified into the traditional four stages, and into three stages using a new classification that obviates the pseudonormal class. Summative clinical and angiographic data were used in a standardized fashion to classify each patient according to the probability for abnormal diastolic function. Measured LV diastolic pressure in each patient was compared with expected diastolic pressures based on the clinical and echocardiographic classifications.

RESULT

The group means of the diastolic pressures were identical in patients stratified by four-stage or three-stage echocardiographic classifications, indicating that both classifications schemes are interchangeable. When severe diastolic dysfunction is diagnosed by the three-stage classification, 88% and 12%, respectively, were clinically classified as high and intermediate probability, and the mean LV pre-A pressures was >12 mmHg (P < 0.005). Conversely, the mean LV pre-A pressure in the clinical low probability or echocardiographic normal groups was <11 mmHg.

CONCLUSION

Use of a standardized clinical algorithm to define the probability of diastolic function identifies patients with elevated LV filing pressure to the same extent as echocardiographic methods.

Mechanoreflex mediates the exaggerated exercise pressor reflex in heart failure

BACKGROUND

In heart failure, exercise elicits excessive increases in mean arterial pressure (MAP) and heart rate (HR). Using a novel rat model, we previously demonstrated that this exaggerated cardiovascular responsiveness is mediated by an overactive exercise pressor reflex (EPR). Although we previously determined that abnormalities in the group IV afferent neuron population (associated with the metabolic component of the reflex) initiate the development of the exaggerated EPR in heart failure, these fibers do not mediate the enhanced circulatory responses to exercise. Therefore, we hypothesized that the augmentation in EPR activity is primarily mediated by the mechanically sensitive component of the reflex (mediated predominately by activation of group III afferent fibers).

METHODS AND RESULTS

Male Sprague-Dawley rats were divided into 3 groups: sham (control), dilated cardiomyopathic (DCM), and neonatal capsaicin-treated animals (NNCAP, group IV afferent fibers ablated). Activation of the EPR by electrically induced static muscle contraction of the hindlimb resulted in larger increases in MAP and HR in DCM and NNCAP compared with sham animals. In all groups, administration of gadolinium (a selective blocker of mechanically sensitive receptors) within the hindlimb attenuated the MAP and HR responses to contraction. However, the magnitude of this reduction was greater in DCM and NNCAP compared with sham animals.

CONCLUSIONS

From these data, we conclude that the muscle mechanoreflex mediates the exaggerated EPR that develops in heart failure. Moreover, these findings suggest that mechanoreflex overactivity in heart failure may be a compensatory response to functional alterations in group IV fibers. Given these findings, the muscle mechanoreflex may serve as a novel target in the treatment of the abnormal circulatory responses to exercise in heart failure.

Echo-Doppler and clinical evaluations to define hemodynamic profile in patients with chronic heart failure: accuracy and influence on therapeutic management

BACKGROUND

Correct classification of chronic heart failure (CHF) patients by dual evidence of congestion and adequate perfusion is the primary clinical focus for management.

OBJECTIVES

To evaluate the accuracy of echo-Doppler compared with clinical evaluation in determining the hemodynamic profile of patients with CHF; and to compare therapeutic changes based on hemodynamic or echo-Doppler findings.

METHODS

Three hundred and sixty-six consecutive CHF patients (ejection fraction 25+/-7%) in sinus rhythm, undergoing evaluation for cardiac transplantation, underwent physical examination prior to right heart catheterization and echo-Doppler studies. Subsequently, patients were randomized to therapeutic optimization using either right heart catheterization or echo-Doppler data. The end-points were: identification of low cardiac output (cardiac index <2.2 l/min/m(2)); high pulmonary wedge pressure (PWP >18 mm Hg); high right atrial pressure (RAP >5 mm Hg) and analysis of therapeutic changes made in response to the right heart catheterization and echo-Doppler studies.

RESULTS

Echo-Doppler showed better accuracy in estimating abnormal hemodynamic indices than clinical variables (cardiac index <2.2 l/min/m(2): echo positive predictive accuracy (PPA) 98% vs. clinical PPA 52% p<0.00001; PWP >18 mm Hg: echo PPA 85% vs. clinical PPA 76% p=0.0011; RAP >5 mm Hg: echo PPA 82% vs. clinical PPA 57% p<0.00001). When applied to individual patients, the echo-Doppler assessment was more accurate than clinical evaluation in defining the different hemodynamic profiles: wet/cold (89% vs. 13%, p<0.0001); wet/warm (73% vs. 30%, p<0.0001); dry/cold (68% vs. 12%, p<0.0001); dry/warm (88% vs. 51%, p<0.0001). Therapeutic decision-making based on echo-Doppler findings was similar to that based on hemodynamics.

CONCLUSION

Echo-Doppler hemodynamic monitoring proved accurate in estimating hemodynamic profiles and influenced therapeutic management.

Impact of left ventricular filling properties on the benefit of exercise training in patients with advanced chronic heart failure secondary to ischemic or nonischemic cardiomyopathy

This study examined left ventricular (LV) filling properties and exercise hemodynamics noninvasively before and after an exercise training program in patients with chronic heart failure (HF). Although exercise training did not improve LV filling properties in patients with advanced HF, LV filling properties determined the hemodynamic benefit attainable from exercise in this patient group.

A practical approach to the echocardiographic evaluation of diastolic function

A number of recent community-based epidemiologic studies suggest that 40% to 50% of the cases of heart failure have preserved left ventricular systolic function. Although diastolic heart failure is often not well clinically recognized, it is associated with marked increases in morbidity and all-cause mortality. Doppler echocardiography has emerged as the principal clinical tool for the assessment of left ventricular diastolic function. Doppler mitral inflow velocity-derived variables remain the cornerstone of the evaluation of diastolic function. Pulmonary venous Doppler flow indices and mitral inflow measurements with Valsalva's maneuver are important adjuncts for differentiating normal and pseudonormal mitral inflow patterns. Unfortunately, these Doppler flow variables are significantly influenced by loading conditions and, therefore, the results from these standard techniques can be inconclusive. Recently, color M-mode and Doppler tissue imaging have emerged as new modalities that are less affected by preload and, thus, provide a strong complementary role in the assessment of diastolic function. This review will discuss the diastolic properties of the left ventricle, Doppler echocardiographic evaluation, and grading of diastolic dysfunction.

Prognostic implications of echocardiography in advanced heart failure

PURPOSE OF REVIEW

The growing epidemic of systolic congestive heart failure mandates strategies to identify accurately people with high morbidity and mortality. Echocardiography remains the most widely available noninvasive tool for the assessment of cardiac structure, function, and hemodynamics. Clinical data paired with echocardiographic analysis in patients with systolic heart failure obtained from a variety of investigations have allowed for the evaluation of this modality as a prognostic tool.

RECENT FINDINGS

Detailed appraisal of the literature has revealed five distinct, easy-to-evaluate echocardiographic parameters that may assist clinicians to segregate high-risk patients. The presence of or the inability to modify a left ventricular ejection fraction less than 25%, impaired right ventricular function (assessed by any of four methods), left ventricular end-diastolic dimension greater than 6.5 to 7 cm, a restrictive mitral inflow, or pulmonary hypertension (peak tricuspid regurgitant velocity >2.5 m/s) should alert clinicians of patients with high morbidity (recurrent congestive heart failure admission, arrhythmia, impaired functional capacity) and mortality. Particularly important among these variables is the presence of a restrictive mitral inflow pattern.

SUMMARY

Detailed analysis of two-dimensional and Doppler data routinely obtained from echocardiograms has established prognostic implications among patients with systolic heart failure. Although prospective clinical trials are lacking, the use of echocardiography to segregate risk should be incorporated into current strategies to treat congestive heart failure and influence clinical listing for cardiac transplantation.

Carvedilol: a review of its use in chronic heart failure

Carvedilol (Dilatrend) blocks beta(1)-, beta(2)- and alpha(1)-adrenoceptors, and has antioxidant and antiproliferative effects. Carvedilol improved left ventricular ejection fraction (LVEF) in patients with chronic heart failure (CHF) in numerous studies. Moreover, significantly greater increases from baseline in LVEF were seen with carvedilol than with metoprolol in a double-blind, randomised study and in a meta-analysis. Carvedilol also reversed or attenuated left ventricular remodelling in patients with CHF and in those with left ventricular dysfunction after acute myocardial infarction (MI). Combined analysis of studies in the US Carvedilol Heart Failure Trials Program (patients had varying severities of CHF; n = 1094) revealed that mortality was significantly lower in carvedilol than in placebo recipients. In addition, the risk of hospitalisation for any cardiovascular cause was significantly lower with carvedilol than with placebo. Mortality was significantly lower with carvedilol than with metoprolol in patients with mild to severe CHF in the Carvedilol Or Metoprolol European Trial (COMET) [n = 3029]. The Carvedilol Prospective Randomised Cumulative Survival (COPERNICUS) trial (n = 2289) demonstrated that compared with placebo, carvedilol was associated with significant reductions in all-cause mortality and the combined endpoint of death or hospitalisation for any reason in severe CHF. All-cause mortality was reduced in patients who received carvedilol in addition to conventional therapy compared with those who received placebo plus conventional therapy in the Carvedilol Post-Infarct Survival Control in LV Dysfunction (CAPRICORN) trial (enrolling 1959 patients with left ventricular dysfunction following acute MI). Carvedilol was generally well tolerated in patients with CHF. Adverse events associated with the alpha- and beta-blocking effects of the drug occurred more commonly with carvedilol than with placebo, whereas placebo recipients were more likely to experience worsening heart failure. In conclusion, carvedilol blocks beta(1)-, beta(2)- and alpha(1)-adrenoceptors and has a unique pharmacological profile. It is thought that additional properties of carvedilol (e.g. antioxidant and antiproliferative effects) contribute to its beneficial effects in CHF. Carvedilol improves ventricular function and reduces mortality and morbidity in patients with mild to severe CHF, and should be considered a standard treatment option in this setting. Administering carvedilol in addition to conventional therapy reduces mortality and attenuates myocardial remodelling in patients with left ventricular dysfunction following acute MI. Moreover, mortality was significantly lower with carvedilol than with metoprolol in patients with mild to severe CHF, suggesting that carvedilol may be the preferred beta-blocker.

Echocardiography and prognosis of heart failure

Echocardiography plays an important role in the diagnosis of patients with congestive heart failure (CHF). It determines the cause and readily provides a reliable noninvasive assessment of left and right ventricular function and filling pressures. This technique also has a tremendous potential in guiding therapy and tracking the clinical response. This review focuses on its prognostic power.