Practice guidance for stress echocardiography

Stress echocardiography has been one of the most promising methods for the diagnosis of ischemic heart disease, hypertrophic cardiomyopathy, and pulmonary hypertension. The Japanese Society of Echocardiography produced practical guidance for the implementation of stress echocardiography in 2018. At that time, stress echocardiography was not yet widely disseminated in Japan; therefore, the 2018 practical guidance for the implementation of stress echocardiography included a report on stress echocardiography and a specific protocol to promote its use at many institutions in Japan in the future. And now, an era of renewed interest and enthusiasm surrounding the diagnosis and treatment of valvular heart disease and heart failure with preserved ejection fraction (HFpEF) has come, which are driven by emerging trans-catheter procedures and new recommended guideline-directed medical therapy. Based on the continued evidence of stress echocardiography, the new practical guideline that describes the safe and effective methodology of stress echocardiography is now created by the Guideline Development Committee of the Japanese Society of Echocardiography and is designed to expand the use of stress echocardiography for valvular heart disease and HFpEF, as well as ischemic heart disease, hypertrophic cardiomyopathy, and pulmonary hypertension. The readers are encouraged to perform stress echocardiography which will enhance the diagnosis and management of these patients.

Left atrium reservoir function is central in patients with rheumatic mitral stenosis

We investigated the relationship between Left Atrium strain reservoir function and symptoms and its impact on modulating Left Ventricular mechanics, diastolic filling, stroke volume, mean trans-mitral gradient and pulmonary pressure in mitral stenosis (MS) patients. We examined 195 full spectrum MS patients which were divided into two groups: Group 1 (n = 109) included patients with NYHA I & II functional class and group 2 (n = 86) included patients with NYHA III & IV functional class. LA strain reservoir function and classical echocardiographic parameters were calculated. LASr was significantly higher in group 1 versus group 2 in patients with MVA ≤ 1cm2 [8.8(6.0-12.6) vs 6.8(4.1-8.9), p = 0.03) and when 1cm2 < MVA ≤ 1.5 cm2 [10.0 (5.4-13.8) vs 6.7(4.5-9.0), p = 0.02). In patients with Pulmonary Hypertension, group 1 had significantly higher LASr than group 2 [11.1(6.6-14.8) vs 5.9(4.3-9.0), p = 0.002) By multivariate analysis, diabetes (OR = 4.11, 95%CI: 1.6-10.4), stroke (OR = 2.9, 95%CI: 1.1-7.9), LASr (OR = 0.9, 95%CI: 0.80-0.99) and LV ejection fraction (LVEF)(OR = 0.9, 95%CI: 0.91-0.99) were independently associated with NYHA functional class. LASr was significantly and positively correlated to MVA (r = 0.3, p < 10-3), stroke volume (r = 0.25, p = 10-3), mitral inflow (r = 0.4, p < 10-3) and LVEF(r = 0.14, p = 0.05). It was significantly and negatively correlated to left ventricular strain (r = -0.65, p < 10-3), LA indexed volume (r = -0.40, p < 10-3), maximum tricuspid regurgitation velocity (r = -0.25, p = 0.003), MTMG (r = -0.25, p = 10-3), and heart rate (r = -0.4, p < 10-3). We demonstrated a large range of interaction between LASr and mitral valve echocardiographic parameters. This may explain the reasons we identified LASr as an independent factor for MS functional tolerance.

Updated knowledge and practical implementations of stress echocardiography in ischemic and non-ischemic cardiac diseases: an expert consensus of the Working Group of Echocardiography of the Hellenic Society of Cardiology

Stress echocardiography (SE) is a well-established and valid technique, widely-used for the diagnostic evaluation of patients with ischemic and non-ischemic cardiac diseases. This statement of the Echocardiography Working Group of the Hellenic Society of Cardiology summarizes the consensus of the writing group regarding the applications of SE, based on the expertise of their members and on a critical review of current medical literature. The main objectives of the consensus document include a comprehensive review of SE methodology and training, focusing on the preparation, the protocols used and the analysis of the SE images and an updated, evidence-based knowledge about SE applications on ischemic and non-ischemic heart diseases, such as in cardiomyopathies, heart failure and valvular heart disease.

Exercise Right Heart Catheterisation in Cardiovascular Diseases: A Guide to Interpretation and Considerations in the Management of Valvular Heart Disease

The use of exercise right heart catheterisation for the assessment of cardiovascular diseases has regained attention recently. Understanding physiologic haemodynamic exercise responses is key for the identification of abnormal haemodynamic patterns. Exercise total pulmonary resistance >3 Wood units identifies a deranged haemodynamic response and when total pulmonary resistance exceeds 3 Wood units, an exercise pulmonary artery wedge pressures/cardiac output slope >2 mmHg/l/min indicates the presence of underlying exercise-induced pulmonary hypertension related to left heart disease. In the evolving field of transcatheter interventions for valvular heart disease, exercise right heart catheterisation may objectively unmask symptoms and underlying haemodynamic abnormalities. Further studies are needed on the use of the procedure to inform the selection of patients who might receive the most benefit from transcatheter interventions for valvular heart diseases.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Pulmonary Artery Systolic Pressure Response to Exercise in Patients with Rheumatic Mitral Stenosis: Determinants and Prognostic Value

BACKGROUND

Pulmonary hypertension in response to exercise is a marker of the hemodynamic severity of mitral stenosis (MS). However, the factors related to elevated pulmonary pressure with exercise are not well defined. The aim of this study was to assess the parameters associated with the pulmonary pressure response to exercise in patients with pure rheumatic MS. An additional aim was to determine the impact of exercise-induced pulmonary hypertension on clinical outcome.

METHODS

One hundred thirty patients with MS (94% women; mean age, 45 ± 11 years) underwent exercise echocardiography. A range of echocardiographic parameters were obtained at rest and at peak exercise. Symptom-limited graded ramp bicycle exercise was performed in the supine position. The primary end point was mitral valve intervention, either percutaneous or surgical.

RESULTS

In the overall population, systolic pulmonary artery pressure (SPAP) increased from 38.3 ± 13.4 mm Hg at rest to 65.8 ± 20.7 mm Hg during exercise. Increases in mean mitral gradient, right ventricular function, left atrial volume, and net atrioventricular compliance were independently associated with SPAP at peak exercise, after adjusting for changes in heart rate. During the follow-up period (median, 17 months; range, 1-45 months), 46 adverse clinical events were observed. By multivariate Cox proportional-hazards analysis adjusted for age and sex, SPAP achieved at peak exercise was an important predictor of adverse outcome (adjusted hazard ratio, 1.025; 95% CI, 1.010-1.040; P = .001). New York Heart Association functional class (adjusted hazard ratio, 2.459; 95% CI, 1.509-4.006; P < .001) and the interaction between valve area and net atrioventricular compliance (P = .001) were also significant predictors of adverse events. Time-dependent areas under the receiver operating characteristic curve for the model with SPAP during exercise were better than for the model with SPAP at rest, with a significant improvement from 3 years onward.

CONCLUSIONS

In patients with MS, the pulmonary artery pressure response to exercise is determined by a combination of factors, including transmitral mean gradient at exercise, net atrioventricular compliance, left atrial volume, and right ventricular function. Pulmonary artery pressure at peak exercise is a predictor of clinical outcomes and adds incremental prognostic value beyond that provided by standard resting measurements, including valve area.

Prolonged pulmonary pulse transit time is associated with symptoms in patients with significant mitral stenosis and sinus rhythm

INTRODUCTION

Pulmonary pulse transit time (pPTT) is a novel noninvasive echocardiographic measure to assess pulmonary arterial hemodynamics. It has been shown to be shorter in precapillary pulmonary hypertension (PHT). Mitral stenosis (MS) is one of the causes of postcapillary PHT. We aimed to investigate pPTT in patients with MS and its relationship with symptoms.

METHODS

We included 51 patients with MS (25 were asymptomatic, NYHA I, and 26 were symptomatic, NHYA II or III), and 50 controls, and evaluated their demographic characteristics and echocardiographic variables, including pPTT.

RESULTS

Baseline characteristics, including age, sex, body mass index, and cardiovascular risk factors, were similar between the MS and the control group. The pPTT was longer in the MS group than in the control group (0.21 ± 0.08 vs 0.15 ± 0.05, P < .001). Patients with symptomatic MS had longer pPTT than asymptomatic patients (P = .005). The pPTT was positively correlated with left atrial volume index and systolic pulmonary artery pressure, and negatively with tricuspid annular plane systolic excursion (r = .432; P < .001, r = .319; P = .001, r = -.293; and P = .003, respectively).

CONCLUSION

The measurement of pPTT appears clinically relevant in patients with PHT. Further studies evaluating whether it is useful in distinguishing precapillary from postcapillary PHT are required.

Stress echocardiography in valvular heart disease

INTRODUCTION

The management of patients with heart valve disease can be complex. Patients may have symptoms disproportionate to the severity or the severity may be unclear. In addition, the optimal timing of intervention in patients with severe disease may be controversial. Areas covered: This article examines the role of stress echocardiography for assessment of patients with low-flow, low-gradient aortic stenosis, asymptomatic severe valve disease and patients where symptoms are discordant to the resting severity of valve disease. Expert commentary: Stress echocardiography helps clinicians determine the true severity of valve disease and may identify the cause of symptoms in patients with only mild/moderate disease. The data provided by stress echocardiography will help determine the appropriate management strategy and the correct timing of intervention.

Stress echocardiography in patients with native valvular heart disease

Valve stress echocardiography (VSE) can be performed as exercise stress echocardiography (ESE) or dobutamine stress echocardiography (DSE) depending on the patient’s clinical status, severity and type of valve disease. ESE combines exercise testing with two-dimensional grey scale and Doppler echocardiography during exercise. Thus, it provides objective assessment of symptomatic status (exercise test), as well as exercise-induced changes of a series of echocardiographic parameters (different depending on the valve disease type), which yield prognostic information in individual patients and help in a better treatment planning. DSE is useful in symptomatic patients with low-gradient aortic stenosis. It clarifies its severity and helps in assessing surgical risk in patients with severe disease and systolic dysfunction. It can be also used to test valve haemodynamics in asymptomatic patients with significant mitral stenosis unable to perform an exercise test or to test the left ventricle response, namely to test viability, in patients with ischaemic secondary mitral regurgitation. VSE has taught us that history taking, clinical examination and resting echocardiography give an ‘incomplete picture’ of the disease in patients presenting with a severe valve disease. Therefore, its use should be encouraged in such patients.

Decreases in left atrial compliance during early-stage exercise are related to exercise intolerance in asymptomatic significant mitral stenosis

BACKGROUND

Doppler-driven net atrioventricular compliance (C_n ), which represents left atrial (LA) compliance, is an important determinant of pulmonary hypertension in mitral stenosis (MS).

HYPOTHESIS

We hypothesized that decreases in C_n during early-stage exercise underlie exercise intolerance in patients with MS.

METHODS

Thirty-three asymptomatic patients with significant MS (valve area 1.24 ± 0.16 cm² ) underwent resting and bicycle exercise echocardiography. LA compliance and conventional parameters were assessed at each workload. The patients were classified into two groups based on whether they developed dyspnea during exercise: an exercise-intolerance group (n = 22) and an exercise-tolerance group (n = 11). Moreover, "50 W" was defined as an early exercise stage.

RESULTS

Although the groups had similar resting characteristics, there were striking differences in their echocardiographic parameters from the early stages of exercise. The relative C_n decrease at 50 W (expressed as a percentage of the resting C_n ) was significantly greater in the exercise-intolerance group (70.3 ± 15.4% vs 49.7 ± 9.7%, P < .001). The overall decrease in relative C_n was significantly greater in the exercise-intolerance group (P = .0005). Furthermore, differences in the trends in this parameter were observed between the two groups (P < .0001 for interaction). Multivariate analysis revealed that the relative C_n decrease at 50 W was an independent predictor of exercise intolerance (adjusted OR 1.105, 95% CI 1.030-1.184) after adjustment for other conventional parameters.

CONCLUSIONS

Decreases in C_n during early-stage exercise are an important mechanism underlying exercise intolerance in MS.

Stress echocardiography: what is new and how does it compare with myocardial perfusion imaging and other modalities?

Cardiovascular disease is a leading cause of morbidity and mortality, and noninvasive strategies to diagnose and risk stratify patients remain paramount in the evaluative process. Stress echocardiography is a well-established, versatile, real-time imaging modality with advantages including lack of radiation exposure, portability, and affordability. Innovative techniques in stress echocardiography include myocardial contrast echocardiography, deformation imaging, three-dimensional (3D) echocardiography, and assessment of coronary flow reserve. Myocardial perfusion imaging with single-photon emission computed tomography (SPECT) or positron emission tomography (PET) are imaging alternatives, and stress cardiac magnetic resonance imaging and coronary computed tomography (CT) angiography, including CT perfusion imaging, are emerging as newer approaches. This review will discuss recent and upcoming developments in the field of stress testing, with an emphasis on stress echocardiography while highlighting comparisons with other modalities.

Risk factors for midterm cardiac function deterioration after valve replacement surgery in patients with rheumatic mitral stenosis

BACKGROUND

A symptomatic reduction in left ventricular ejection fraction (LVEF) is the main reason for postoperative heart failure after valve replacement surgery. However, postoperative heart failure occurs in patients with normal preoperative LVEF. Therefore, we examined clinical and echocardiographic data of patients with rheumatic heart disease to determine additional risk factors for low LVEF in the postoperative period.

METHODS AND RESULTS

Ninety-seven patients with rheumatic heart disease (RHD) who underwent mitral valve replacement for severe mitral valve stenosis were included retrospectively in this study. All patients had normal LVEF before surgery. Patients were divided into 2 groups based on postoperative LVEF 6 months after surgery. Groups A had normal postoperative LVEF (82 cases, 84.5%), and group B had low postoperative LVEF (15 cases, 15.5%). Clinical and electrocardiographic data were collected to determine risk factors for deterioration in cardiac function. Multivariate analysis revealed that preoperative low systolic peak velocities at the lateral tricuspid annulus (St) and no or mild aortic stenosis were independent risk factors for cardiac deterioration in patients with normal preoperative LVEF. Individuals with preoperative St ≤ 4.8 cm/s were more likely to develop lower LVEF at follow-up (χ(2) = 7.54; P = .006; odds ratio 5.03, 95% confidence interval 1.31-20.82). All 15 patients who had normal preoperative LVEF but abnormal postoperative LVEF had no or only mild aortic valve stenosis.

CONCLUSIONS

Decreased right ventricular function and no or mild aortic stenosis were independent risk factors for low LVEF at follow-up in patients with RHD who had normal preoperative LVEF. The velocity of the tricuspid valve ring should be included in preoperative evaluations to improve the accuracy of postsurgical prognosis and clinical decision making.

The year 2012 in the European Heart Journal-Cardiovascular Imaging. Part II

The part II of the best of the European Heart Journal - Cardiovascular Imaging in 2012 specifically focuses on studies of valvular heart diseases, heart failure, cardiomyopathies, and congenital heart diseases.

The most important publications of the past year in echocardiography

We review the published literature on clinical echocardiography of the past year. Key topics were valvular heart disease, in particular aortic stenosis, and the imaging requirements for transcatheter aortic valve implantation. Three-dimensional echocardiography and deformation imaging have yielded important new insights in valvular heart disease. Other key fields have been assessment of heart failure, in particular heart failure with preserved ejection fraction, and the relationship of this condition with diastolic dysfunction and left atrial function. Functional imaging of cardiomyopathies was also an important topic.

Effect of electrical stimulus parameters on the development and propagation of action potentials in short excitable fibres

Intracellular action potentials (IAPs) produced by short fibres in response to their electrical stimulation were analysed. IAPs were calculated on the basis of the Hodgkin-Huxley (1952) model by the method described by Joyner et al. (1978). Principal differences were found in processes of activation of short (semilength L less than 5 lambda) and long fibres under near-threshold stimulation. The shorter the fibre, the lower was the threshold value (Ithr). Dependence of the latency on the stimulus strength (Ist) was substantially non-linear and was affected by the fibre length. Both fibre length and stimulus strength influenced the IAP amplitude, the instantaneous propagation velocity (IPV) and the site of the first origin of the IAP (and, consequently, excitability of the short fibre membrane). With L less than or equal to 2 lambda and Ithr less than or equal to Ist less than or equal to 1.1Ithr, IPV could reach either very high values (so that all the fibre membrane fired practically simultaneously) or even negative values. The latter corresponded to the first origin of the propagated IAP, not at the site of stimulation but at the fibre termination or at a midpoint. The characters of all the above dependencies were unchanged irrespective of the manner of approaching threshold (variation of stimulus duration or its strength). Reasons for differences in processes of activation of short and long fibres are discussed in terms of electrical load and latency. Applications of the results to explain an increased jitter, velocity recovery function and velocity-diameter relationship are also discussed.