scholarly journals Non-invasive myocardial work: characterising the normal and ischaemic response to exercise

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Borrie ◽  
C Goggin ◽  
S Ershad ◽  
W Robinson ◽  
A Sasse

Abstract Background/Introduction Myocardial work and work efficiency are new parameters for assessing left ventricular function. They have been shown to have value in a range of clinical settings but have not previously been applied to exercise stress echocardiography. Purpose We aim to characterize the normal myocardial work and work efficiency response to exercise in a mixed population and determine if myocardial work could be used to identify patients with inducible ischaemia. Methods Patients were retrospectively enrolled from an existing database of exercise stress echocardiography. Inclusion criteria were a clinical indication of possible ischemia and technical suitability to calculate myocardial work. Exclusion criteria were abnormal baseline left ventricular function or inadequate image quality. Echocardiograms positive for ischaemia were defined by independent visual assessment and compared with angiographic findings where available. Myocardial work and work efficiency were calculated using a proprietary algorithm. Results A total of 177 patients met inclusion criteria, 117 were excluded leaving 40 normal and 20 positive tests for analysis. During normal exercise global work increased 54% and efficiency remained at 96%. Segmental work showed a basal to apical gradient which became more prominent at peak exercise. In patients with inducible ischaemia during exercise there was a significant difference in response; work decreased by 1.9% and efficiency dropped to 87%. Receiver operating characteristic curve for myocardial work had an area under the curve of 0.94. Youden's J statistic suggested an optimum cut point of a 25% increase in work to define a normal test. Conclusion During normal exercise myocardial work increased and efficiency remained unchanged, however during exercise induced ischaemia both myocardial work and efficiency decreased. We have demonstrated that myocardial work can be applied to stress echocardiography to identify ischemia but the utility of this remains uncertain. Further research compared to an objective measure of functional ischemia is needed. Response to exercise Funding Acknowledgement Type of funding source: None

Author(s):  
Vidhu Anand ◽  
Garvan C Kane ◽  
Christopher G Scott ◽  
Sorin V Pislaru ◽  
Rosalyn O Adigun ◽  
...  

Abstract 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.


2021 ◽  
Vol 26 (5) ◽  
pp. 4183
Author(s):  
E. A. Karev ◽  
E. G. Malev ◽  
A. Yu. Suvorov ◽  
S. L. Verbilo ◽  
M. N. Prokudina

Aim. To compare markers of high cardiovascular risk and stress echocardiography results depending on the type of blood pressure (BP) response to exercise in patients without obstructive coronary artery disease.Material and methods. Our single-center cross-sectional study included 96 patients without hemodynamically significant coronary artery stenosis according to coronary angiography or multislice computed tomography angiography. All patients underwent physical examination, cardiovascular risk stratification, electrocardiography, extracranial cerebrovascular ultrasound, echocardiography, treadmill exercise stress echocardiography.Results. According to the test results, the patients were divided into groups with a hypertensive response (n=41) and a normal response to exercise (n=55). Patients with hypertensive response to exercise had significantly higher values of left ventricular mass index (100,0 (90,0; 107,0) g/m2 vs 76,0 (68,0; 91,0) g/m2, p<0,0000001) and left atrial volume index (36,7 (32,0; 46,0) ml/m2 vs 29,7 (26,3; 32,0) ml/m2, p=0,000003). There was also a higher level of cardiovascular SCORE risk (5,0 (2,0; 6,0) vs 2,0 (1,0; 3,0), p=0,004); patients more often had associated clinical conditions (36,6% vs 12,7%, χ2=7,57, p=0,006) and left ventricular diastolic dysfunction (39,02% vs 78,18%, χ2=15,21, p=0,0001). Pathological BP increase during stress echocardiography was associated with worse exercise tolerance (7,4 (5,6; 10,0) METs vs 10,2 (8,4; 11,95) METs, p=0,000041) and more frequent transient regional contractility impairment (46,34% vs 1,8%, p<0,00001), mainly of the lateral and inferior left ventricular walls.Conclusion. Despite the absence of coronary artery stenosis, patients with hypertensive response to exercise are significantly more likely to have markers of high cardiovascular risk and require more careful monitoring of risk factors. Also, the hypertensive response to exercise is associated with more frequent regional contractility impairment even without coronary artery stenosis.


1993 ◽  
Vol 71 (2) ◽  
pp. 136-144 ◽  
Author(s):  
Scott G. Thomas ◽  
Donald H. Paterson ◽  
David A. Cunningham ◽  
Douglas G. McLellan ◽  
William J. Kostuk

Studies of the cardiovascular response to exercise in older subjects have presented conflicting data regarding left ventricular function, the cardiac output – oxygen consumption [Formula: see text] relationship, and the pattern of change in [Formula: see text], stroke volume (SV), and arteriovenous O2 difference. We have examined the cardiovascular response to submaximal and strenuous exercise in 96 men of mean age 63 years during an incremental treadmill test with [Formula: see text] determined by CO2 rebreathing, and in 12 subjects studied during incremental supine exercise with left ventricular volumes evaluated by radionuclide angiocardiography. During treadmill exercise the [Formula: see text] was approximately 10% lower than reported for younger samples, with a lower intercept of the [Formula: see text] relationship. During near-maximal exercise [Formula: see text] was approximately 15 L∙min−1, with SV of 95 mL plateauing or showing a small decline in heavy work. Peak arteriovenous O2 difference (150+ mL∙L−1) approached values of the young. During the supine exercise SV increased from rest to exercise, with a consistent increase in ejection fraction (rest, 66%, to peak exercise, 76%). In contrast to a prior report, the end-diastolic volume was constant, with the increase of SV attributable to a reduced end-systolic volume. Also, in contrast to a number of reports in older subjects, our findings show only small losses in cardiovascular response, and in left ventricular performance during light through strenuous exercise.Key words: ejection fraction, stroke volume, arteriovenous oxygen difference, [Formula: see text]peak, age.


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