Combined Stress Echocardiography Research Articles

Exercise limitation in hypertrophic cardiomyopathy: combined stress echocardiography and cardiopulmonary exercise test.

The study aims to investigate exercise-limiting factors in hypertrophic cardiomyopathy (HCM) using combined stress echocardiography and cardiopulmonary exercise test. A symptom-limited ramp bicycle exercise test was performed in the semi-supine position on a tilting dedicated ergometer. Echocardiographic images were obtained concurrently with gas exchange measurements along predefined stages of exercise. Oxygen extraction was calculated using the Fick equation at each activity level. Thirty-six HCM patients (mean age 67±6years, 72% men, 18 obstructive HCM) were compared with age and sex-matched 29 controls. At rest, compared with controls, E/E' ratio (6.26±2.3 vs. 14±2.5, P<0.001) and systolic pulmonary artery pressures (SPAP) (22.6±3.4 vs. 34±6.2mmHg, P=0.023) were increased. Along with the stages of exercise (unloaded; anaerobic threshold; peak), diastolic function worsened (E/e' 8.9±2.6 vs. 13.8±3.6 P=0.011; 9.4±2.3 vs. 18.6±3.3 P=0.001; 8.7±1.9 vs. 21.5±4, P<0.001), SPAP increased (23±2.7 vs. 33±4.4, P=0.013; 26±3.2 vs. 40±2.9, P<0.001; 26±3.5 vs. 45±7mmHg, P<0.001), and oxygen consumption (6.6±1.7 vs. 6.8±1.6, P=0.86; 18.1±2.2 vs. 14.6±1.5, P=0.008; 20.3±3 vs. 15.1±2.1mL/kg/min, P=0.01) was reduced. Oxygen pulse was blunted (6.3±1.8 vs. 6.2±1.9, P=0.79; 10±2.1 vs. 8.8±1.6, P=0.063; 12.2±2 vs. 8.2±2.3mL/beat, P=0.002) due to an insufficient increase in both stroke volume (92.3±17 vs. 77.3±14.5 P=0.021; 101±19.1 vs. 87.3±15.7 P=0.06; 96.5±12.2 vs. 83.6±16.1mL, P=0.034) and oxygen extraction (0.07±0.03 vs. 0.07±0.02, P=0.47; 0.13±0.02 vs. 0.10±0.03, P=0.013; 0.13±0.03 vs. 0.11±0.03, P=0.03). Diastolic dysfunction, elevated SPAP, and the presence of atrial fibrillation were associated with reduced exercise capacity. Both central and peripheral cardiovascular limitations are involved in exercise intolerance in HCM. Diastolic dysfunction seems to be the main driver for this limitation.

The Mechanism of Effort Intolerance in Patients with Peripheral Arterial Disease: A Combined Stress Echocardiography and Cardiopulmonary Exercise Test.

We used a combined stress echocardiography and cardiopulmonary exercise test (CPET) to explore effort intolerance in peripheral arterial disease (PAD) patients. Twenty-three patients who had both PAD and coronary artery disease (CAD) were compared with twenty-four sex- and age-matched CAD patients and fifteen normal controls using a symptom-limited ramp bicycle CPET on a tilting dedicated ergometer. Echocardiographic images were obtained concurrently with gas exchange measurements along predefined stages of exercise. Oxygen extraction was calculated using the Fick equation at each activity level. Along the stages of exercise (unloaded; anaerobic threshold; peak), in PAD + CAD patients compared with CAD or controls, diastolic function worsened (p = 0.051 and p = 0.013, respectively), and oxygen consumption (p < 0.001 and p < 0.001, respectively) and oxygen pulse (p = 0.0024 and p = 0.0027, respectively) were reduced. Notably, oxygen pulse was blunted due to an insufficient increase in both stroke volume (p = 0.025 and p = 0.028, respectively) and peripheral oxygen extraction (p = 0.031 and p = 0.038, respectively). Chronotropic incompetence was more prevalent in PAD patients and persisted after correction for beta-blocker use (62% vs. 42% and 11%, respectively). In PAD patients, exercise limitation is associated with diastolic dysfunction, chronotropic incompetence and peripheral factors.

Right ventricular functional recovery assessment with stress echocardiography and cardiopulmonary exercise testing after pulmonary embolism: a pilot prospective multicentre study

BackgroundData on right ventricular (RV) exercise adaptation following acute intermediate and high-risk pulmonary embolism (PE) remain limited. This study aimed to evaluate the symptom burden, RV functional recovery during exercise...

Sex differences in heart failure patients assessed by combined echocardiographic and cardiopulmonary exercise testing.

We aimed to test the differences in peak VO2 between males and females in patients diagnosed with heart failure (HF), using combined stress echocardiography (SE) and cardiopulmonary exercise testing (CPET). Patients who underwent CPET and SE for evaluation of dyspnea or exertional intolerance at our institution, between January 2013 and December 2017, were included and retrospectively assessed. Patients were divided into three groups: HF with preserved ejection fraction (HFpEF), HF with mildly reduced or reduced ejection fraction (HFmrEF/HFrEF), and patients without HF (control). These groups were further stratified by sex. One hundred seventy-eight patients underwent CPET-SE testing, of which 40% were females. Females diagnosed with HFpEF showed attenuated increases in end diastolic volume index (P = 0.040 for sex × time interaction), significantly elevated E/e' (P < 0.001), significantly decreased left ventricle (LV) end diastolic volume:E/e ratio (P = 0.040 for sex × time interaction), and lesser increases in A-VO2 difference (P = 0.003 for sex × time interaction), comparing to males with HFpEF. Females diagnosed with HFmrEF/HFrEF showed diminished increases in end diastolic volume index (P = 0.050 for sex × time interaction), mostly after anaerobic threshold was met, comparing to males with HFmrEF/HFrEF. This resulted in reduced increases in peak stroke volume index (P = 0.010 for sex × time interaction) and cardiac output (P = 0.050 for sex × time interaction). Combined CPET-SE testing allows for individualized non-invasive evaluation of exercise physiology stratified by sex. Female patients with HF have lower exercise capacity compared to men with HF. For females diagnosed with HFpEF, this was due to poorer LV compliance and attenuated peripheral oxygen extraction, while for females diagnosed with HFmrEF/HFrEF, this was due to attenuated increase in peak stroke volume and cardiac output. As past studies have shown differences in clinical outcomes between females and males, this study provides an essential understanding of the differences in exercise physiology in HF patients, which may improve patient selection for targeted therapeutics.

Low chronotropic index predicts rehospitalization in post-acute myocardial infarction patients with preserved or mildly reduced left ventricular ejection fraction

Abstract Background There are limited data about the clinical utility of combined stress echocardiography and cardiopulmonary exercise testing (CPET-ESE) in predicting prognosis in patients after acute myocardial infarction (AMI) with preserved left ventricular ejection fraction (LVEF). Aim To assess prognostic parameters using CPET-ESE in post-AMI patients with preserved or mildly reduced LVEF. Methods Eighty-seven patients after the first AMI with LVEF &amp;gt;40% were followed for 2 years (median 1.93 years IQR 1.16–2.41). The composite end-point was all-cause mortality or rehospitalization due to ischaemic heart disease (AMI, unstable angina, percutaneous coronary intervention/coronary artery bypass grafting) or heart failure exacerbation. All patients underwent symptom-limited CPET-ESE on a semi-supine cycle ergometer 3 to 5 weeks after AMI. The chronotropic index was calculated as the percent of heart rate reserve. Six patients refused to complete the survey and they were not included in the analysis. Results Follow-up was conducted in 81 consecutive patients (mean age 59±10 years, 62% males, 50% AMI with ST-segment elevation, 85% on beta-blockers). Mean LVEF was 56±9% and peak VO2 18.5±5.0 mL/kg/min. There were no deaths during follow-up. The composite end-point occurred in 13 patients. In multivariate Cox regression analysis after correction for demographic and clinical variables, only chronotropic index correlated with the composite end-point (HR 0.93, 95% CI 0.87–0.99, p=0.026). A positive predictive value of 33.3% and a negative predictive value of 91.3% (sensitivity 61.5%, specificity 76.5%, area under the curve, AUC 71%) for predicting the composite end-point was established for the chronotropic index ≤36.8% (Fig. 1). There was a statistically significant difference in the composite end-point occurrence (p&amp;lt;0.01) between subgroups with the chronotropic index above and below that threshold (Fig. 2). Conclusions In patients after the first AMI with preserved or mildly reduced left ventricular systolic function, a lower chronotropic index is a predictor of rehospitalization in 2-year follow-up. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Centre of Postgraduate Medical Education, Warsaw, Poland

Mechanisms of Exercise Capacity Improvement after Cardiac Rehabilitation Following Myocardial Infarction Assessed with Combined Stress Echocardiography and Cardiopulmonary Exercise Testing.

Cardiac rehabilitation (CR) is indicated in all patients after acute myocardial infarction (AMI) to improve prognosis and exercise capacity (EC). Previous studies reported that up to a third of patients did not improve their EC after CR (non-responders). Our aim was to assess the cardiac and peripheral mechanisms of EC improvement after CR using combined exercise echocardiography and cardiopulmonary exercise testing (CPET-SE). The responders included patients with an improved EC assessed as a rise in peak oxygen uptake (VO2) ≥ 1 mL/kg/min. Peripheral oxygen extraction was calculated as arteriovenous oxygen difference (A-VO2Diff). Out of 41 patients (67% male, mean age 57.5 ± 10 years) after AMI with left ventricular ejection fraction (LVEF) ≥ 40%, 73% improved their EC. In responders, peak VO2 improved by 27% from 17.9 ± 5.2 mL/kg/min to 22.7 ± 5.1 mL/kg/min, p < 0.001, while non-responders had a non-significant 5% decrease in peak VO2. In the responder group, the peak exercise heart rate, early diastolic myocardial velocity at peak exercise, LVEF at rest and at peak exercise, and A-VO2Diff at peak exercise increased, the minute ventilation to carbon dioxide production slope decreased, but the stroke volume and cardiac index were unchanged after CR. Non-responders had no changes in assessed parameters. EC improvement after CR of patients with preserved LVEF after AMI is associated with an increased heart rate response and better peripheral oxygen extraction during exercise.

Cardiorespiratory Abnormalities in Patients Recovering from Coronavirus Disease 2019

BackgroundA large number of patients around the world are recovering from coronavirus disease 2019 (COVID-19); many of them report persistence of symptoms. The aim of this study was to test pulmonary, cardiovascular, and peripheral responses to exercise in patients recovering from COVID-19.MethodsPatients who recovered from COVID-19 were prospectively evaluated using a combined anatomic and functional assessment. All patients underwent clinical examination, laboratory tests, and combined stress echocardiography and cardiopulmonary exercise testing. Left ventricular volumes, ejection fraction, stroke volume, heart rate, E/e′ ratio, right ventricular function, oxygen consumption (Vo2), lung volumes, ventilatory efficiency, oxygen saturation, and muscle oxygen extraction were measured in all effort stages and compared with values in historical control subjects.ResultsA total of 71 patients were assessed 90.6 ± 26 days after the onset of COVID-19 symptoms. Only 23 (33%) were asymptomatic. The most common symptoms were fatigue (34%), muscle weakness or pain (27%), and dyspnea (22%). Vo2 was lower among post-COVID-19 patients compared with control subjects (P = .03, group-by-time interaction P = .007). Reduction in peak Vo2 was due to a combination of chronotropic incompetence (75% of post-COVID-19 patients vs 8% of control subjects, P < .0001) and an insufficient increase in stroke volume during exercise (P = .0007, group-by-time interaction P = .03). Stroke volume limitation was mostly explained by diminished increase in left ventricular end-diastolic volume (P = .10, group-by-time interaction P = .03) and insufficient increase in ejection fraction (P = .01, group-by-time interaction P = .01). Post-COVID-19 patients had higher peripheral oxygen extraction (P = .004) and did not have significantly different respiratory and gas exchange parameters compared with control subjects.ConclusionsPatients recovering from COVID-19 have symptoms associated with objective reduction in peak Vo2. The mechanism of this reduction is complex and mainly involves a combination of attenuated heart rate and stroke volume reserve.

Combined use of stress echocardiography and cardiopulmonary exercise testing to assess exercise intolerance in patients treated for acute myocardial infarction.

Exercise intolerance after acute myocardial infarction (AMI) is a predictor of worse prognosis, but its causes are complex and poorly studied. This study assessed the determinants of exercise intolerance using combined stress echocardiography and cardiopulmonary exercise testing (CPET-SE) in patients treated for AMI. We prospectively enrolled patients with left ventricular ejection fraction (LV EF) ≥40% for more than 4 weeks after the first AMI. Stroke volume, heart rate, and arteriovenous oxygen difference (A-VO2Diff) were assessed during symptom-limited CPET-SE. Patients were divided into four groups according to the percentage of predicted oxygen uptake (VO2) (Group 1, <50%; Group 2, 50–74%; Group 3, 75–99%; and Group 4, ≥100%). Among 81 patients (70% male, mean age 58 ± 11 years, 47% ST-segment elevation AMI) mean peak VO2 was 19.5 ± 5.4 mL/kg/min. A better exercise capacity was related to a higher percent predicted heart rate (Group 2 vs. Group 4, p <0.01), higher peak A-VO2Diff (Group 1 vs. Group 3, p <0.01) but without differences in stroke volume. Peak VO2 and percent predicted VO2 had a significant positive correlation with percent predicted heart rate at peak exercise (r = 0.28, p = 0.01 and r = 0.46, p < 0.001) and peak A-VO2Diff (r = 0.68, p <0.001 and r = 0.36, p = 0.001) but not with peak stroke volume. Exercise capacity in patients treated for AMI with LV EF ≥40% is related to heart rate response during exercise and peak peripheral oxygen extraction. CPET-SE enables non-invasive assessment of the mechanisms of exercise intolerance.

Abstract 16032: Determinants of Exercise Capacity Assessed Using Combined Stress Echocardiography and Cardiopulmonary Exercise Testing in Patients Treated for Acute Myocardial Infarction

Introduction: Exercise capacity (EC) after acute myocardial infarction (AMI) influences prognosis, but the causes of its reduction are complex and not sufficiently studied. Methods: We prospectively enrolled consecutive patients who underwent percutaneous coronary intervention for their first AMI without residual coronary stenosis and with left ventricular ejection fraction (LVEF) &gt; 40% more than 4 weeks after the AMI. We performed combined stress echocardiography and cardiopulmonary exercise testing (CPET-SE) using a semi-supine cycle ergometer to determine predictors of EC (peak oxygen uptake [VO 2 ]). Results: Among 81 patients (70% male, mean age 58 ± 11 years), 40% suffered AMI with ST-segment elevation (STEMI), and 60% non-STEMI, LVEF was 57 ± 7%; wall motion score index, 1.18 (IQR 1.06 - 1.31); peak VO 2 , 19.5 ± 5.4 mL/kg/min. Multivariate analysis ( Table ) revealed that parameters at peak exercise: heart rate (β = 0.17, p &lt; 0.001), stroke volume (β = 0.09, p &lt; 0.001), and arteriovenous oxygen difference (β = 93.51, p &lt; 0.001) were independently positively correlated with peak VO 2 , with arteriovenous oxygen difference being its strongest contributor. At rest, left ventricular systolic and diastolic function parameters and the extent of myocardial scarring (wall motion score index) did not predict EC (p &gt; 0.05). Conclusions: In patients treated for AMI with normal/mildly reduced LVEF, EC is associated with peak peripheral oxygen extraction as well as peak heart rate and peak stroke volume. CPET-SE is a useful tool to evaluate decreased fitness in this group.

Mechanisms of Effort Intolerance in Patients With Rheumatic Mitral Stenosis: Combined Echocardiography and Cardiopulmonary Stress Protocol

ObjectivesThis study sought to evaluate mechanisms of effort intolerance in patients with rheumatic mitral stenosis (MS). BackgroundCombined stress echocardiography and cardiopulmonary testing allows assessment of cardiac function, hemodynamics, and oxygen extraction (A–Vo2 difference). MethodsUsing semirecumbent bicycle exercise, 20 patients with rheumatic MS (valve area 1.36 ± 0.4 cm2) were compared to 20 control subjects at 4 pre-defined activity stages (rest, unloaded, anaerobic threshold, and peak). Various echocardiographic parameters (left ventricular volumes, ejection fraction, stroke volume, mitral valve gradient, mitral valve area, tissue s′ and e′) and ventilatory parameters (peak oxygen consumption [Vo2] and A–Vo2 difference) were measured during 8 to 12 min of graded exercise. ResultsComparing patients with MS to control subjects, significant differences (both between groups and for group by time interaction) were seen in multiple parameters (heart rate, stroke volume, end-diastolic volume, ejection fraction, s′, e′, Vo2, and tidal volume). Exercise responses were all attenuated compared to control subjects. Comparing patients with MS and poor exercise tolerance (<80% of expected) to other subjects with MS, we found attenuated increases in tidal volume (p = 0.0003), heart rate (p = 0.0009), and mitral area (p = 0.04) in the poor exercise tolerance group. These patients also displayed different end-diastolic volume behavior over time (group by time interaction p = 0.05). In multivariable analysis, peak heart rate response (p = 0.01), tidal volume response (p = 0.0001), and peak A–Vo2 difference (p = 0.03) were the only independent predictors of exercise capacity in patients with MS; systolic pulmonary pressure, mitral valve gradient, and mitral valve area were not. ConclusionsIn patients with rheumatic MS, exercise intolerance is predominantly the result of restrictive lung function, chronotropic incompetence, limited stroke volume reserve, and peripheral factors, and not simply impaired valvular function. Combined stress echocardiography and cardiopulmonary testing can be helpful in determining mechanisms of exercise intolerance in patients with MS.

Discriminating Circulatory Problems From Deconditioning: Echocardiographic and Cardiopulmonary Exercise Test Analysis

Discriminating circulatory problems with reduced stroke volume (SV) from deconditioning, in which the muscles cannot consume oxygen normally, by gas exchange parameters is difficult. We performed combined stress echocardiography (SE) and cardiopulmonary exercise tests (CPET) in 110 patients (20 with normal effort capacity, 54 with attenuated SV response, and 36 with deconditioning) to evaluate multiple hemodynamic parameters and oxygen content difference (A-V.o2 Diff) in four predefined activity levels to assess which of the gas measures may help in the discrimination. Reduced anaerobic threshold (AT), low unchanging peak oxygen pulse, periodic breathing, shallow Δ peak oxygen consumption (V.o2)/Δwork rate (WR) ratio, and high expired volume per unit time/carbon dioxide production (V.e/V.co2) slope were all associated with abnormal SV response (P< .05 for all). The best discriminator was V.e/V.co2 slope to V.o2 ratio (≥ 2.7; area under the curve [AUC], 0.79; P< .0001). The optimal gas exchange model included ΔV.o2/ΔWR< 8.6; V.e/V.co2 slope to peak V.o2 ratio≥ 2.7, and periodic breathing (AUC of 0.84; P< .0001). The best single gas exchange parameter to discriminate between circulatory problems and deconditioning is V.e/V.co2 slope to peak V.O2 ratio. Combining it with ΔV.o2/ΔWR and periodic breathing improves the discriminative ability.

Determinants of Effort Intolerance in Patients With Heart Failure: Combined Echocardiography and Cardiopulmonary Stress Protocol

ObjectivesThe purpose of this study was to assess individual mechanisms of effort intolerance in patients with heart failure with preserved ejection fraction (HFpEF), heart failure with reduced ejection fraction (HFrEF), or normal cardiac function using combined echocardiography and cardiopulmonary stress testing. BackgroundCombined stress echocardiography and cardiopulmonary tests visualize cardiac chambers in 4 well-defined activity levels (rest, unloaded, anaerobic threshold, and peak), allowing noninvasive assessment of cardiac function, hemodynamics, and arterial venous oxygen content difference (AVo2Diff) during all stages. MethodsLeft ventricular volumes, stroke volume (SV), S', E/e', oxygen consumption (Vo2), and AVo2Diff were measured in all effort stages using ramp semirecumbent cycle prolonged (≥8 min) exercise in 45 consecutive subjects evaluated for effort intolerance (14 normal cardiac function, 16 HFpEF, and 15 HFrEF patients; age 56.5 ± 16 years; 73% male). ResultsIn HFpEF and HFrEF, the changes in Vo2 were attenuated (between group p = 0.003; group by time interaction p < 0.0001), as well as peak heart rate (p = 0.0001; p = 0.0001) and SV (p = 0.006; p = 0.0001). End-diastolic volume to E/e' ratio (measure of compliance) was superior in HFrEF and normal patients at baseline but worsened in HFpEF and HFrEF at peak exercise (8.3 ± 4 vs. 11.6 ± 5 vs. 19.1 ± 8; p = 0.004; p = 0.01). Functional mitral regurgitation worsened even during the unloaded stage, mostly in patients with HFrEF, but also in several patients with HFpEF. In multivariable analysis, heart rate response (p = 0.007), and AVo2Diff (p < 0.0001) were the most significant independent predictors of effort capacity; SV was not. ConclusionsCombined tests are feasible and allow noninvasive evaluation of effort intolerance. In HFpEF and HFrEF patients, exercise intolerance is predominantly due to chronotropic incompetence and peripheral factors. Combined stress echocardiography and cardiopulmonary tests may have potential for clinical management and selection of patients for trials.

Evaluation of graft patency after coronary artery bypass grafting by using stress echocardiography combined with strain imaging

Background: Vasodilator stress echocardiography is a non-invasive tool which allows a detailed evaluation of coronary flow reserve integrated with myocardial wall motion analysis. In the present study we aimed to evaluate the value of velocity vector imaging (VVI) –based strain imaging, combined with dipyridamole stress echocardiography for assessment of left internal mammarian artery (LIMA) graft patency in patients who underwent robotic-assisted coronary artery bypass graft (CABG) surgery. Methods: We studied 40 patients (age 59.25±9.61 years, 58% male) who had robotic-assisted CABG surgery for LIMA-left anterior descending (LAD) artery and scheduled for coronary angiography. VVI-based strain echocardiography combined with dipyridamole stress echocardiography was performed. Left ventricular (LV) myocardial motion was evaluated using global strain and strain rate measurements. Additionally, Doppler evaluation of flow reserve of each LIMA graft were assessed. Results: Echocardiographic findings were compared with angiographic data. Among 40 patients only 7 had graft stenosis, based on angiography. We observed fair agreement between VVI combined stress echocardiography results and identification of 50%-100% LIMA stenosis. Impairment in LV global strain and strain rate values at peak dose dipyridamole predicted LIMA graft patency (p=0.02 for strain and p=0.0001 for strain rate). The average coronary flow reserve (CFR) value of all the LIMA grafts was 1.28±0.55. The agreement between CFR value and graft patency did not reach statistical significance (p=0.307). Conclusions: An integrated assessment of LV wall motion and flow reserve of LIMA graft in patients who underwent robotic-assisted CABG surgery is an accurate approach for identifying graft stenosis. This combined technique provides a useful tool for the non-invasive determination of LIMA graft patency, after CABG operation.

Noninvasive Diagnostic Technique in Stenotic Coronary Atherosclerosis

Objective: to determine the sensitivity and specificity of combined stress echocardiography (EchoCG) using dipyri-damole and dobutamine in diagnosing and defining the extent of stenotic coronary lesions in coronary heart disease (CHD) in a group of critically ill patients who are unable to perform a physical exercise. Materials and methods: the study included 57 male patients with suspected acute coronary syndrome who underwent stress EchoCG using dipyridamole in high doses in combination with dobutamine, as well as coronary angiography. Results: stress EchoCG could bring up to the diagnostic criteria in all the patients, of whom 9 patients were found at coronary angiography to have no coronary lesion, 34 and 14 patients had one- and many-vessel lesions, respectively. The sensitivity and specificity of combined stress EchoCG were significantly higher than those of EchoCG used in the diagnosis of CHD. Conclusion: stress EchoCG using dipyridamole in combination with dobutamine is a highly informative safe noninvasive technique for diagnosing CHD, its helps to identify patients with atypical acute coronary syndrome and to form a group of patients to be subject to urgent coronarography and angiosurgical intervention. The pattern of segmental contractile disorders at the height of exercise during combined stress Echo-CG makes it possible to define the site of stenotic coronary atherosclerosis with 97.3% sensitivity and to diagnose many-vessel lesion with 100% sensitivity and 100%specificity.