Exercise Pulmonary Hypertension in Heart Valve Disease.

The optimal management of heart valve disease (HVD) is still debated and many studies are underway to identify the best time to refer patients for the most appropriate treatment strategy (either conservative, surgical or transcatheter interventions). Exercise pulmonary hypertension (PH) can be detected during exercise stress echocardiography (ESE) and has been demonstrated to have an important prognostic role in HVD, by predicting symptoms and mortality. This review article aims to provide an overview on the prognostic role of exercise PH in valvulopathies, and its possible role in the diagnostic-therapeutic algorithm for the management of HVD.

Usefulness of cardiopulmonary exercise test combined with exercise stress echocardiography in mild chronic thromboembolic pulmonary disease.

PURPOSE: Chronic thromboembolic pulmonary disease (CTEPD) can lead to exercise limitations even without right ventricular (RV) dysfunction or pulmonary hypertension at rest. Combining exercise stress echocardiography with cardiopulmonary exercise testing (ESE-CPET) for RV function and pressure changes combined measuring overall function may be useful for CTEPD evaluation. This study aims to investigate CPET and ESE results to elucidate the mechanisms of exercise limitation in mild CTEPD cases. METHODS: Among our CTEPD registry, 50 patients who performed both right heart catheterization data of mild disease (less than 30 mm Hg of mean pulmonary arterial pressure (mPAP)) and ESE-CPET were enrolled. Echocardiography and CPET-derived parameters were compared with hemodynamic parameters measured through right heart catheterization. RESULTS: Peak VO2 (maximal oxygen consumption) was decreased in overall population (71.3 ± 16.3% of predictive value). Peak VO2 during exercise was negatively correlate with mPAP and pulmonary vascular resistance at rest. A substantial increase in RV systolic pressure (RVSP) was observed during exercise (RVSP: pre-exercise 37.2 ± 11.8 mm Hg, postexercise 64.3 ± 24.9 mm Hg, p-value < .001). Furthermore, RV function deteriorated during exercise when compared to the baseline (RV fractional area change: 31.5 ± 10.0% to 37.8 ± 7.0%, p-value < .001; RV global longitudinal strain: -17.1 ± 4.2% to -17.7 ± 3.3%, p-value < .001) even though basal RV function was normal. While an excessive increase in RVSP during exercise was noticed in both groups, dilated RV and RV dysfunction during exercise were demonstrated only in the impaired exercise capacity group. CONCLUSION: CTEPD patients with mild PH or without PH exhibited limited exercise capacity alongside an excessive increase in RVSP during exercise. Importantly, RV dysfunction during exercise was significantly associated with exercise capacity. ESE-CPET could aid in comprehending the primary cause of exercise limitation in these patients.

Exercise in Hypertrophic Cardiomyopathy: Recent Conceptual Changes and Recommendations for Pre-Exercise Tests.

Traditionally, individuals with hypertrophic cardiomyopathy (HCM) have been advised not to participate in more than low-intensity exercises. HCM was originally described in the context of sudden death, and early literature from the registry showed that HCM was the most common cause of sudden cardiac death in young athletes. Therefore, there has long been a concern that exercise could trigger ventricular arrhythmia and sudden cardiac death. Although a few patients with HCM may progress along deteriorating disease pathways, many have no clinically significant symptoms or adverse events, no need for major treatment, and a normal life expectancy. Therefore, the routine restriction of any exercise intensity in this large group deprives them of the multiple benefits of exercise and may have detrimental effects on long-term clinical outcomes. However, it has been reported that light to moderate exercise is acceptable for many patients with HCM, and recent evidence suggests that vigorous exercise does not increase the risk of sudden death in this population. Thus, we reviewed previous literature regarding the effects of exercise in patients with HCM and provided cutting-edge information on the safety and concerns of exercise. In addition, based on our experience and previous research, we reviewed the conditions that should be met before starting exercise and the tests required to confirm them.

Assessment of left ventricular energy loss in patients with mild coronary artery stenosis by using vector flow mapping combined with exercise stress echocardiography.

OBJECTIVES: To evaluate the left ventricular energy loss (EL), energy loss reserve (EL-r), and energy loss reserve rate in patients with mild coronary artery stenosis by using vector flow mapping (VFM) combined with exercise stress echocardiography. METHODS: A total of 34 patients (case group) with mild coronary artery stenosis and 36 sex and age matched patients (control group) without coronary artery stenosis according to coronary angiogram were prospectively enrolled. The total energy loss (ELt), basal segment energy loss (ELb), middle segment energy loss (ELm), apical segment energy loss (ELa), energy loss reserve (EL-r), and energy loss reserve rate were recorded in the isovolumic systolic period (S1), rapid ejection period (S2), slow ejection period (S3), isovolumic diastolic period (D1), rapid filling period (D2), slow filling period (D3), and atrial contraction period (D4). RESULTS: Compared with the control group, some of the EL in the resting case group were higher; some of the EL in the case group were lower after exercise, and those during D1 ELb and D3 ELb were higher. Compared with the resting state, the total EL and the EL within the time segment in the control group were higher after exercise, except during D2 ELb. In the case group, except for during D1 ELt, ELb and D2 ELb, the total and segmental EL of each phase was mostly higher after exercise (p < .05). Compared with the control group, most of the EL-r and EL reserve rates in the case group were lower (p < .05). CONCLUSION: The EL, EL-r, and energy loss reserve rate have a certain value in the evaluation of cardiac function in patients with mild coronary artery stenosis.

Assessing the future risks of subsequent pregnancies in peripartum cardiomyopathy.

Peripartum cardiomyopathy is a myocardial disease process which occurs in young women either in late pregnancy or the early postpartum period. Due to the young age of women effected by this disease, many of these patients elect to pursue a subsequent pregnancy after their initial diagnosis. Currently, echocardiography is used to better elucidate the cardiovascular risks these young patients face when undergoing a subsequent pregnancy; however, the most accurate modality to determine these risks is debatable. In this review, we explore the current literature regarding the use and accuracy of resting transthoracic echocardiography, exercise stress echocardiography, and dobutamine stress echocardiography in risk stratification of a subsequent pregnancy in a patient with peripartum cardiomyopathy.

Exercise Stress Echocardiography for Stable Coronary Artery Disease: Succumbed to the Modern Conceptual Revolution or Still Alive and Kicking?

The modern conceptual revolution in managing patients with stable coronary artery disease (CAD), based on improvement in preventive and pharmacological therapy, advocates coronary artery revascularization only for smaller group of patients with refractory angina, poor left ventricular systolic function, or high-risk coronary anatomy. Therefore, our conventional wisdom about stress testing must be questioned within this new and revolutionary paradigm. Exercise stress echocardiography (ESE) is still a well-known technique for assessing known or suspected stable CAD, it is safe, accessible, and well-tolerated, and there is an widespread evidence base. ESE has been remarkably resilient throughout years of innovation in noninvasive cardiology. Its value is not to be determined over the short portion of diagnostic accuracy but mainly through its prognostic value evident in a wide range of patient subsets. It is coming very close to the modern profile of a leading test that should include, in addition to an essential accettable diagnostic and prognostic accuracy, qualities of low cost, no radiation exposure, and minor environmental traces. In this review, we will discuss advantages, diagnostic accuracy, prognostic value in general and special populations, cost-effectiveness, and changes in referral patterns of ESE in the modern era.

Prognostic value of peak stress cardiac power in patients with normal ejection fraction undergoing exercise stress echocardiography.

AIMS: Cardiac power is a measure of cardiac performance that incorporates both pressure and flow components. Prior studies have shown that cardiac power predicts outcomes in patients with reduced left ventricular (LV) ejection fraction (EF). We sought to evaluate the prognostic significance of peak exercise cardiac power and power reserve in patients with normal EF. METHODS AND RESULTS: We performed a retrospective analysis in 24 885 patients (age 59 ± 13 years, 45% females) with EF ≥50% and no significant valve disease or right ventricular dysfunction, undergoing exercise stress echocardiography between 2004 and 2018. Cardiac power and power reserve (developed power with stress) were normalized to LV mass and expressed in W/100 g of LV myocardium. Endpoints at follow-up were all-cause mortality and diagnosis of heart failure (HF). Patients in the higher quartiles of power/mass (rest, peak stress, and power reserve) were younger and had higher peak blood pressure and heart rate, lower LV mass, and lower prevalence of comorbidities. During follow-up [median 3.9 (0.6-8.3) years], 929 patients died. After adjusting for age, sex, metabolic equivalents (METs) achieved, ischaemia/infarction on stress test results, medication, and comorbidities, peak stress power/mass was independently associated with mortality [adjusted hazard ratio (HR), highest vs. lowest quartile, 0.5, 95% confidence interval (CI) 0.4-0.6, P < 0.001] and HF at follow-up [adjusted HR, highest vs. lowest quartile, 0.4, 95% CI (0.3, 0.5), P < 0.001]. Power reserve showed similar results. CONCLUSION: The assessment of cardiac power during exercise stress echocardiography in patients with normal EF provides valuable prognostic information, in addition to stress test findings on inducible myocardial ischaemia and exercise capacity.

The feasibility, reliability, and incremental value of two-dimensional speckle-tracking for the detection of significant coronary stenosis after treadmill stress echocardiography.

BACKGROUND: Two-dimensional speckle-tracking echocardiography (STE) may help detect coronary artery disease (CAD) when combined with dobutamine stress echocardiography. However, few studies have explored STE with exercise stress echocardiography (ESE). We aimed to evaluate the feasibility, reliability, and incremental value of STE combined with treadmill ESE compared to treadmill ESE alone to detect CAD. METHODS: We conducted a case-control study of all consecutive patients with abnormal ESE in 2018-2020 who subsequently underwent coronary angiography within a six-month interval. We 1:1 propensity score-matched these patients to those with a normal ESE. Two blinded operators generated a 17-segment bull's-eye map of longitudinal strain (LS). We utilized the mean differences between stress and baseline LS values in segments 13-17, segment 17, and segments 15-16 to create receiver operator curves for the overall examination, the left anterior descending artery (LAD), and the non-LAD territories, respectively. RESULTS: We excluded 61 STEs from 201 (30.3%) eligible ESEs; 47 (23.4%) because of suboptimal image quality and 14 (7.0%) because of excessive heart rate variability precluding the calculation of a bull's-eye map. After matching, a total of 102 patients were included (51 patients in each group). In the group with abnormal ESE patients (mean age 66.4 years, 39.2% female), 64.7% had significant CAD (> 70% stenosis) at coronary angiogram. In the group with normal ESE patients (mean age 65.1 years, 35.3% female), 3.9% were diagnosed with a new significant coronary stenosis within one year. The intra-class correlation for global LS was 0.87 at rest and 0.92 at stress, and 0.84 at rest, and 0.89 at stress for the apical segments. The diagnostic accuracy of combining ESE and STE was superior to visual assessment alone for the overall examination (area under the curve (AUC) = 0.89 vs. 0.84, p = 0.025), the non-LAD territory (AUC = 0.83 vs. 0.70, p = 0.006), but not the LAD territory (AUC = 0.79 vs. 0.73, p = 0.11). CONCLUSIONS: Two-dimensional speckle-tracking combined with treadmill ESE is relatively feasible, reliable, and may provide incremental diagnostic value for the detection and localization of significant CAD.

Characterisation of LV myocardial exercise function by 2-D strain deformation imaging in elite adolescent footballers.

PURPOSE: Few data exist on the descriptions of LV myocardial mechanics and reserve during dynamic exercise of adolescent athletes. The aim of this study was to describe the LV myocardial and cardiopulmonary changes during exercise using 2-D strain deformation imaging. METHODS: Elite adolescent male football players (n = 42) completed simultaneous cardiopulmonary exercise testing (CPET) and exercise echocardiography measurement of LV myocardial deformation by 2-D strain imaging. LV longitudinal and circumferential 2-D strain and strain rates were analyzed at each stage during incremental exercise to a work rate of 150 W. Additionally, exercise LV myocardial deformation and its relation to metabolic exercise parameters were evaluated at each exercise stage and in recovery using repeated measures ANOVA, linear regression and paired t tests. RESULTS: LV peak systolic baseline 2-D strain (longitudinal: - 15.4 ± 2.5%, circumferential: - 22.5 ± 3.1%) increased with each exercise stage, but longitudinal strain plateaued at 50 W (mean strain reserve - 7.8 ± 3.0) and did not significantly increase compared to subsequent exercise stages (P > 0.05), whilst circumferential strain (mean strain reserve - 11.6 ± 3.3) significantly increased (P < 0.05) throughout exercise up to 150 W as the dominant mechanism of exercise LV contractility increase. Regression analyses showed LV myocardial strain increased linearly relative to HR, VO2 and O2 pulse (P < 0.05) for circumferential deformation, but showed attenuation for longitudinal deformation. CONCLUSION: This study describes LV myocardial deformation dynamics by 2-D strain and provides reference values for LV myocardial strain and strain rate during exercise in adolescent footballers. It found important differences between LV longitudinal and circumferential myocardial mechanics during exercise and introduces a methodology that can be used to quantify LV function and cardiac reserve during exercise in adolescent athletes.

Prognostic significance of right ventricular function during exercise in asymptomatic/minimally symptomatic patients with nonobstructive hypertrophic cardiomyopathy.

BACKGROUND: The risk stratification of hypertrophic cardiomyopathy (HCM) without left ventricular outflow tract (LVOT) obstruction and the utility of exercise stress echocardiography (ESE) remains unclear. We investigated the value of right ventricular (RV) function and RV-pulmonary artery (PA) coupling during exercise in asymptomatic/minimally symptomatic patients with nonobstructive HCM (nHCM). METHOD AND RESULTS: This retrospective study evaluated 74 HCM patients (age 63 ± 13 years, 65% men) without LVOT obstruction (≥30 mmHg) who underwent​ ESE. Eight patients (11%) suffered from HCM-related cardiac events during a median 2.5 years follow-up. During exercise, tricuspid annular plane systolic excursion (Ex-TAPSE) and Ex-TAPSE/systolic pulmonary artery pressure [SPAP] ratio were more impaired in patients with than in those without events (22 ± 4 vs 26 ± 4 mm, P = .005; and 0.45 [0.41, 0.47] vs 0.56 [0.47, 0.82] mm/mmHg, P = .002). In Cox regression analysis, Ex-TAPSE (HR: 1.397, P = .002) and the Ex-TAPSE/SPAP ratio (HR: 2.737, P = .006) were associated with cardiac events. In Kaplan-Meier analysis, patients with a low Ex-TAPSE (<24 mm) and Ex-TAPSE/SPAP ratio (<0.50 mm/mmHg) had a higher incidence of adverse outcomes than those with high Ex-TAPSE (Log rank, P < .001 and =.001, respectively). CONCLUSIONS: A low Ex-TAPSE and Ex-TAPSE/SPAP ratio were associated with adverse outcomes in nHCM. Evaluation of RV functional performance during exercise may play a crucial role in the risk stratification of nHCM.

Noninvasive Testing for Diagnosis of Stable Coronary Artery Disease in the Elderly.

Efficient diagnostic approaches to detect coronary artery disease (CAD) in elderly patients are necessary to ensure optimal and timely treatment. The population of suspected CAD patients older than 70 years is especially vulnerable and constantly growing. Finding the optimal diagnostic approach is challenging due to certain features of this population, such as high prevalence of comorbidities, existing contraindications to exercise tests or cognitive decline, which hinders correct assessment of the patient's situation. Moreover, some symptoms of CAD can have variable significance in the elderly compared to younger adult groups. In this review, we present current recommendations of the United States (US) and European cardiologists' associations and discuss their applicability for diagnostics in the elderly population. Exercise electrocardiogram (ECG) and exercise stress echocardiography (SE) tests are not feasible for a substantial proportion of elderly patients. Coronary computed tomography angiography (CTA) appears to be an attractive alternative for such patients, but is not universally applicable; for instance, it is problematic in patients with significant calcification of the vessels. Moreover, more studies are needed to compare the results delivered by CTA to those of other diagnostic methods. Future efforts should be focused on comparative studies to better understand the limits and advantages of different diagnostic methods and their combinations. It is possible that some of the currently used diagnostic criteria could be improved to better accommodate the needs of the elderly population.

Diastolic Intra-Left Ventricular Pressure Difference During Exercise: Strong Determinant and Predictor of Exercise Capacity in Patients With Heart Failure.

BACKGROUND: Although the enhancement of early-diastolic intra-left ventricular pressure difference (IVPD) during exercise is considered to maintain exercise capacity, little is known about their relationship in heart failure (HF). METHODS AND RESULTS: Cardiopulmonary exercise testing and exercise-stress echocardiography were performed in 50 HF patients (left ventricular [LV] ejection fraction 39 ± 15%). Echocardiographic images were obtained at rest and submaximal and peak exercise. Color M-mode Doppler images of LV inflow were used to determine IVPD. Thirty-five patients had preserved exercise capacity (peak oxygen consumption [VO2] ≥14 mL·kg-1·min-1; group 1) and 15 patients had reduced exercise capacity (group 2). During exercise, IVPD increased only in group 1 (group 1: 1.9 ± 0.9 mm Hg at rest, 4.1 ± 2.0 mm Hg at submaximum, 4.7 ± 2.1 mm Hg at peak; group 2: 1.9 ± 0.8 mm Hg at rest, 2.1 ± 0.9 mm Hg at submaximum, 2.1 ± 0.9 mm Hg at peak). Submaximal IVPD (r = 0.54) and peak IVPD (r = 0.69) were significantly correlated with peak VO2. Peak IVPD determined peak VO2 independently of LV ejection fraction. Moreover, submaximal IVPD could well predict the reduced exercise capacity. CONCLUSION: Early-diastolic IVPD during exercise was closely associated with exercise capacity in HF. In addition, submaximal IVPD could be a useful predictor of exercise capacity without peak exercise in HF patients.

Regional layer-specific longitudinal peak systolic strain using exercise stress two-dimensional speckle-tracking echocardiography for the detection of functionally significant coronary artery disease.

The present study aimed to investigate whether layer-specific regional peak-systolic longitudinal strain (LS) measurement on transthoracic echocardiogram (TTE) with exercise stress can be useful for the detection of functionally significant coronary artery disease as confirmed by invasive fractional flow reserve (FFR) in stable patients. This is a prospective analysis of 88 coronary arteries in 30 stable patients undergoing invasive FFR measurement and ergometer exercise stress TTE. Regional LS in the mid, endocardial and epicardial layers was calculated at rest, peak stress and early and late recovery phases after the exercise stress test. The endocardial-to-epicardial LS ratio was calculated as an indicator of endocardial-layer dependency of the left ventricular myocardium. Ischemic FFR defined as FFR ≤ 0.80 was observed in 33 of 88 coronary arteries. The mid-, endocardial- and epicardial-layer LS at early recovery (- 15.4 ± 5.2 vs. - 13.0 ± 4.4%, P = 0.040; - 15.7 ± 5.1 vs. - 13.2 ± 4.5%, P = 0.029; - 14.6 ± 5.1 vs. - 12.4 ± 4.0%, P = 0.038, respectively) and the percent change in the endocardial-to-epicardial LS ratio from baseline to peak stress, early recovery, and late recovery phases (1.5 ± 11.2% vs. 6.6 ± 10.5%, P = 0.009; 2.8 ± 8.9% vs. 7.1 ± 12.6%, P = 0.002; 5.2 ± 8.8% vs. 8.5 ± 13.7%, P = 0.026; respectively) were significantly more impaired in the ischemic territories (FFR ≤ 0.80) compared with the non-ischemic territories (FFR > 0.80). According to the receiver operating characteristic curve analysis, a combination of endocardial LS and percent change in the endocardial-to-epicardial LS ratio at early recovery phase plus visual evaluation of LV wall motion had incremental diagnostic value for the detection of the ischemic territory compared with visual evaluation alone (area under the curve = 0.752 and 0.618, P = 0.006). The results of this study suggested that assessing layer-specific LS and the endocardial-to-epicardial LS ratio after exercise stress on speckle-tracking TTE may have potential for objective and quantitative evaluation in the assessment of myocardial ischemia. Further studies in a larger population are needed to confirm these findings.

Influence of impaired right ventricular contractile reserve on exercise capacity in patients with precapillary pulmonary hypertension: A study with exercise stress echocardiography.

OBJECTIVES: Right ventricular (RV) contractile reserve reflects the ability of RV to accommodate the increased afterload and may play an essential role in the evaluation of precapillary pulmonary hypertension (PH). This study aimed to assess RV contractile reserve based on exercise stress echocardiography (ESE) and to determine the echocardiographic determinants of exercise capacity in patients with precapillary PH. METHODS: A total of 31 patients with precapillary PH and 15 age- and sex-matched healthy control subjects were prospectively recruited. All subjects underwent ESE to assess RV function at rest and under peak exercise. Changes in these parameters during exercise were calculated to quantify the RV contractile reserve. Patients with precapillary PH also underwent cardiopulmonary exercise test (CPET), and data pertaining to peak oxygen uptake (peak VO2 ) and minute ventilation/carbon dioxide production (VE/VCO2 ) were collected. RESULTS: Right ventricular contractile reserve including change in tricuspid annular plane systolic excursion (∆TAPSE), change in RV fractional area change (∆RVFAC), and change in Doppler-derived tricuspid lateral annular peak systolic velocity (∆S') was significantly depressed in precapillary PH patients compared with control subjects (P < 0.05). Parameters of RV function and RV contractile reserve were markedly associated with maximal exercise capacity (P < 0.05). ∆RVFAC was an independent predictor of peak VO2 (r2  = 0.601, P < 0.05). CONCLUSIONS: Assessment of RV contractile reserve facilitates identification of subclinical dysfunction and evaluation of clinical status and severity of precapillary PH. ESE as a noninvasive method may provide a comprehensive clinical assessment and facilitate therapeutic decision-making for these patients.

Impaired left ventricular mechanics and functional reserve are associated with reduced exercise capacity in patients with hypertrophic cardiomyopathy.

BACKGROUND: Reduced metabolic equivalents (METs) are an indicator of exercise intolerance, which predicts poor prognosis in hypertrophic cardiomyopathy (HCM) patients. We sought to evaluate the changes in left ventricular (LV) mechanics and functional reserves, as well as their association with functional capacity in HCM patients. METHODS: Seventy HCM patients and thirty controls were included in this study. LV mechanics were evaluated at rest and during exercise by echocardiography and two-dimensional speckle-tracking imaging to obtain parameters of functional reserve, LV global longitudinal strain (LVGLS), strain rate (SR), and circumferential strain. RESULTS: Hypertrophic cardiomyopathy (HCM) patients had lower LVGLS, systolic SR, early and late diastolic SR at rest and during exercise, and reduced absolute and relative systolic and diastolic reserve compared to controls. LV circumferential strain was significantly higher at rest but lower during exercise in HCM patients. Exercise capacity was markedly reduced in HCM patients, and peak exercise LVGLS (LVGLS-exe) significantly correlated with exercise capacity. Multivariate regression analyses showed that LVGLS-exe, LV filling pressure during exercise (E/e'-exe), and LV mass index (LVMI) were independent predictors of exercise capacity. Moreover, LVGLS-exe displayed incremental predictive value over E/e'-exe and LVMI for exercise intolerance. Receiver operating characteristic curve analysis showed LVGLS-exe had optimal accuracy for predicting exercise intolerance in HCM patients. CONCLUSIONS: Hypertrophic cardiomyopathy (HCM) patients have reduced LV mechanics at rest and during exercise and impaired mechanical reserve. LVGLS-exe is associated with exercise capacity and is an optimal predictive value for reduced exercise capacity in HCM patients.

Speckle Tracking Imaging in Normal Stress Echocardiography.

OBJECTIVES: Exercise stress echocardiography is a widely used modality for the diagnosis and follow-up of patients with coronary artery disease. During the last decade, speckle tracking imaging has been used increasingly for accurate evaluation of cardiac function. This work aimed to assess speckle-tracking imaging parameters during nonischemic exercise stress echocardiography. METHODS: During 2011 to 2014 we studied 46 patients without history of coronary artery disease, who completed exercise stress echocardiography protocol, had normal left ventricular function, a nonischemic response, and satisfactory image quality. These exams were analyzed with speckle-tracking imaging software at rest and at peak exercise. Peak strain and time-to-peak strain were measured at rest and after exercise. Clinical follow-up included a telephone contact 1 to 3 years after stress echo exam, confirming freedom from coronary events during this time. RESULTS: Global and regional peak strain increased following exercise. Time-to-peak global and regional strain and time-to-peak strain adjusted to the heart rate were significantly shorter in all segments after exercise. Rest-to-stress ratio of time-to-peak strain adjusted to the heart rate was 2.0 to 2.8. CONCLUSIONS: Global and regional peak strain rise during normal exercise echocardiography. Peak global and regional strain occur before or shortly after aortic valve closure at rest and after exercise, and the delay is more apparent at the basal segments. Time-to-peak strain normally shortens significantly during exercise; after adjustment to heart rate it shortens by a ratio of 2.0 to 2.8. These data may be useful for interpretation of future exercise stress speckle-tracking echocardiography studies.

Tissue Doppler imaging during exercise stress echocardiography demonstrates a mechanism for impaired exercise performance in children with hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is associated with decreased exercise tolerance in children, presumably due to diastolic dysfunction. Modern imaging techniques to assess myocardial function during active exercise have not been applied to this population. We hypothesized that impaired contractile reserve, as assessed by tissue Doppler imaging (TDI) and strain, contributes to reduced exercise capacity in affected individuals. METHODS: Children (<18 years) with HCM and healthy age- and sex-matched controls were prospectively enrolled. Resting echocardiograms and staged upright cycle ergometry with simultaneous echocardiograms were performed. During exercise, left ventricular outflow tract (LVOT) gradients and color Doppler maps of apical four-chamber and parasternal short-axis views were obtained. Post processing of images was performed to obtain TDI velocities, and measurements of strain were attempted. Exercise parameters and staged TDI values were compared. RESULTS: The study population consisted of 58 subjects (22 with HCM and 36 controls). Patients with HCM had significantly higher peak LVOT gradients compared to controls at baseline and at each exercise stage. TDI revealed that diastolic function, as assessed by E' velocities at septal and lateral mitral annuli, normalized with exercise in HCM patients. Further, systolic function (S' velocity) of HCM patients at rest was normal but failed to augment normally at peak exercise. CONCLUSIONS: Children with HCM have decreased TDI velocities at rest. With exercise, they may increase their E' velocities but fail to augment S' velocities, demonstrating decreased contractile reserve. In the patient with suspected HCM but equivocal findings, exercise TDI assessment may complement the diagnostic evaluation.

Clinical Application of Exercise Stress Echocardiography in an Outpatient Pediatric Population.

Background: Exercise stress echocardiography (ESE) is commonly employed in adults, but its applicability in pediatric populations remains to be clarified. Methods: A total of 309 consecutive children (C), with a mean age of 14.1 ± 2.6 years (range 6-17 years), underwent treadmill ESE starting in 2002. They were divided into two groups: Group I comprised 258 children, including 237 with symptoms related to exercise (such as chest pain, fatigue, lipothymia/syncope, or one aborted sudden death), 15 with electrocardiogram (ECG) abnormalities, and 6 with a positive ECG stress test showing ST changes. Group II consisted of 10 asymptomatic children whose parents requested routine screening, 11 with symptoms unrelated to exercise, 12 with a family history of sudden death, and 17 with known pathologies (including 10 with hypertrophic cardiomyopathy, 2 with aortic coarctation, and the remainder with various conditions, such as Cortriatriatum sinister, pulmonary stenosis, subaortic stenosis, bicuspid aortic valve, left ventricular hypertrophy related to arterial hypertension, and aortic switch operation). Regional wall motion abnormalities (RWMAs) and transvalvular or intraventricular (IVG) gradients were assessed using 2D and continuous-wave Doppler, respectively, in all cases. Results: The success rate was 100% (309/309). Stress-induced RWMAs were observed in two children. A significant IVG (>30 mmHg) was detected in 101 out of the 258 children (39%) in Group I, who presented with exercise-related symptoms, ECG abnormalities, or positive stress ECG. In Group I, the odds ratio (OR) of ESE reproducing the symptoms in children with IVG compared to those without IVG was 8.22 (95% CI: 4.84-13.99, p < 0.001). Conclusions: Treadmill ESE is both feasible and safe for pediatric populations. RWMAs demonstrated limited utility in our cohort of children, while IVG induced by exercise was frequently observed in symptomatic children.

Prediction of symptom development and aortic valve replacement in patients with low-gradient severe aortic stenosis.

Aims: Current evidence on the prognostic value of exercise stress echocardiography (ESE) in asymptomatic patients with low-gradient severe aortic stenosis (AS) is limited. Therefore, this study aimed to elucidate its prognostic implications for patients with low-gradient severe AS and determine the added value of ESE in risk stratification for this population. Methods and results: This retrospective observational study included 122 consecutive asymptomatic patients with either moderate [mean pressure gradient (MPG) < 40 mmHg and aortic valve area (AVA) 1.0-1.5 cm2] or low-gradient severe (MPG < 40 mmHg and AVA < 1.0 cm2) AS and preserved left ventricular ejection fraction (≥50%) who underwent ESE. All patients were followed up for AS-related events. Of 143 patients, 21 who met any exclusion criteria, including early interventions, were excluded, and 122 conservatively managed patients [76.5 (71.0-80.3) years; 48.3% male] were included in this study. During a median follow-up period of 989 (578-1571) days, 64 patients experienced AS-related events. Patients with low-gradient severe AS had significantly lower event-free survival rates than those with moderate AS (log-rank test, P < 0.001). Multivariable Cox regression analysis showed that the mitral E/e' ratio during exercise was independently associated with AS-related events (hazard ratio = 1.075, P < 0.001) in patients with low-gradient severe AS. Conclusion: This study suggests that asymptomatic patients with low-gradient severe AS have worse prognoses than those with moderate AS. Additionally, the mitral E/e' ratio during exercise is a useful parameter for risk stratification in patients with low-gradient severe AS.

A case of syncope after exertion due to sigmoid septum evaluated by exercise stress echocardiography.

A sigmoid septum is associated with sharp angulation and aging of the aortic root; however, it does not affect the pressure gradient in the left ventricular outflow tract and is generally asymptomatic. This report describes a 73-year-old woman who presented with syncope after exertion. Echocardiography revealed that the cause was left ventricular outflow tract stenosis associated with a sigmoid septum; her symptoms improved with beta-blocker therapy. Exercise stress echocardiography was performed to determine treatment efficacy. Sigmoid septum causes syncope on exertion; however, drug therapy is effective. Exercise stress echocardiography is effective in determining treatment efficacy. If syncope is present, a sigmoid septum should be considered as a cause. Learning objectives: 1.A sigmoid septum is part of or resembles hypertrophic cardiomyopathy, resulting in left ventricular outflow tract (LVOT) stenosis that is exacerbated by exertion and may cause syncope.2.A sigmoid septum is a differential diagnosis for the cause of syncope and is diagnosed using cardiac echocardiography.3.LVOT stenosis due to a sigmoid septum can be improved with drug therapy such as beta-blockers.4.The effects of beta-blocker therapy can be determined by exercise stress echocardiography.