Pathophysiology of exercise intolerance in breast cancer survivors with preserved left ventricular ejection fraction

2016 ◽  
Vol 130 (24) ◽  
pp. 2239-2244 ◽  
Author(s):  
Mark J. Haykowsky ◽  
Rhys Beaudry ◽  
R. Matthew Brothers ◽  
Michael D. Nelson ◽  
Satyam Sarma ◽  
...  

Breast cancer (BC) survival rates have improved during the past two decades and as a result older BC survivors are at increased risk of developing heart failure (HF). Although the HF phenotype common to BC survivors has received little attention, BC survivors have a number of risk factors associated with HF and preserved ejection fraction (HFPEF) including older age, hypertension, obesity, metabolic syndrome and sedentary lifestyle. Moreover, not unlike HFPEF, BC survivors with preserved left ventricular ejection fraction (BCPEF) have reduced exercise tolerance measured objectively as decreased peak oxygen uptake (peak VO2). This review summarizes the literature regarding the mechanisms of exercise intolerance and the role of exercise training to improve peak VO2 in BCPEF.

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Kelvin C Chua ◽  
Carmen Teodorescu ◽  
Audrey Uy-Evanado ◽  
Kyndaron Reinier ◽  
Kumar Narayanan ◽  
...  

Introduction: If we are to improve risk stratification for sudden cardiac death (SCD) we should extend beyond the LV ejection fraction (LVEF). The frontal QRS-T angle has been shown to predict risk of SCD but its value independent of LVEF has not been investigated. Hypothesis: We hypothesize that a wide frontal QRS-T angle predicts SCD independent of LVEF. Methods: Cases of adult sudden cardiac arrest with an available electrocardiogram before the event were identified from a large ongoing population based study of SCD in the Northwest US (population approx. one million). Subjects with a computable frontal QRS-T angle were included. A total of 686 SCD cases (mean age 67.4 years; 95% CI, 52.5 to 82.3 years; 68.2% males; 83.5% whites) met criteria, and were compared to 871 controls with and without coronary artery disease (mean age 66.8 years, 55.3 to 78.3 years; 67.7% males; 90.6% whites) from the same geographical region. Results: The mean frontal QRS-T angle was higher in SCD cases (73.9 degrees; 95% CI, 17.5 to 130.3 degrees, p<0.0001) compared to controls (51.1 degrees; 95% CI 5.0 to 97.2 degrees). Using a cut-off of more than 90 degrees, the frontal QRS-T angle was predictive of SCD, and remained predictive, after adjusting for age, sex, left ventricular ejection fraction (LVEF), prolonged QTc, prolonged QRS duration and baseline comorbidities (OR 1.80; 95% CI, 1.27 to 2.55, p=0.001). On the receiver operating characteristic (ROC) curve, the QRS-T angle demonstrated an area-under-curve (AUC) value of 0.614. Compared to the lowest quartile of QRS-T angle, the highest quartile had nearly a triple increase in the risk of SCD (OR 2.71; 95% CI; 2.03 to 3.60; p<0.0001). Conclusion: A wide QRS-T angle greater than 90 degrees is associated with increased risk of sudden cardiac death independent of left ventricular ejection fraction.


2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
A Ovchinnikov ◽  
A V Potekhina ◽  
A A Borisov ◽  
N M Ibragimova ◽  
E N Yushchyuk ◽  
...  

Abstract Background Diagnosis of early heart failure with preserved ejection fraction (HFpEF) may be challenging because exertional dyspnea is not specific for heart failure, and biomarkers and indicators of volume overload may be absent at rest. We aimed to characterize the contribution of abnormal left atrial (LA) mechanical properties to exercise intolerance in early HFpEF (normal left ventricular filling pressures at rest but elevated during exercise). Methods Diastolic stress testing (DST) was performed in 104 patients with left ventricular ejection fraction ≥50%, in sinus rhythm, and no more than LV diastolic dysfunction grade I, referred for assessment of exertional dyspnoea. Patients exercised supine cycle ergometry at 60 rpm starting with a 3-min period of low-level 25-W workload followed by 25-W increments in 3-minute stages to maximum tolerated levels. According to DST, 43 patients were diagnosed with HFpEF (average mitral E-to-annular e′ ratio [E/e′] &gt; 14, and peak TR velocity &gt;2.8 m/sec at maximal exertion) and 61 as non-cardiac dyspnea (NCD). During the test, two-dimensional images, mitral E/e′, peak tricuspid regurgitation (TR) velociry, and two-dimensional LA mechanical parameters (longitudinal LA strain [LASR] and strain rate [LASRR] during reservoir phase and LA stiffness assessed as a ratio of mitral E/e′ ratio to LASR) were analysed at baseline, and at peak. Results HFpEF and NCD patients were similar in regard to the LA volume index (34.4 [30.2;39.4] vs. 33.6 [28.4;37.1] ml/m2), and NT-proBNP level (132 [80;238] vs. 129 [80;197] pg/ml). As compared with NCD patients, HFpEF patients displayed reduced LA reservoir function assessed by LASR (22.3 [18.9;25.6] vs. 24.2 [21.2;29.8] % at rest, and 25.3 [21.4;30.2] vs. 29.0 [24.2;33.3] % with exercise) and LASRR (0.78 [0.58;0.96] vs. 0.90 [0.68;1.12] /s at rest, and 1.10 [0.79;1.31] vs. 1.24 [1.03;1.56] s–1 with exercise) with increased LA stiffness (0.57 [0.44;0.70] vs. 0.42 [0.30;0.49] mmHg/% at rest, and 0.61 [0.46;0.74] vs. 0.40 [0.32;0.51] mmHg/% with exercise, all P &lt; 0.05). Additionally, HFpEF patients showed smaller exercise elevation in LASRR (+31 [-5;77] vs. +47 [12;85] % as compared with resting values, P &lt; 0.05). Exercised LA stiffness and reservoir strain correlated with exercise LV filling pressures estimated by mitral E/e′ ratio (r = 0.72 and r =–0.35, P &lt; 0.001). LA stiffness showed a good diagnostic accuracy (area under the curve 0.75), and LA stiffness &gt; 0.46 mmHg/% demonstrated reasonable sensitivity (79%) and specificity (71%) to diagnose HFpEF. Neither LV global longitudinal strain and ejection fraction at rest nor their exercise-induced elevation differed between HFpEF and NCD. Conclusion Impaired LA reservoir function and increased stiffness are associated with exercise intolerance in patients with early HFpEF, while LV systolic function seems preserved in this stage of the disease. LA stiffness provides HFpEF diagnostic potential in ambulatory patients with dyspnea


2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
D Di Lisi ◽  
G Manno ◽  
FA Immordino ◽  
R Intravaia ◽  
D Calcullo ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Background The aim of our study was to assess subclinical cardiac effects of anthracyclines (ANTs) in women treated for breast cancer (BC). Methods We enrolled 46 female patients with BC undergoing adjuvant treatment with anthracycline-containing chemotherapy (CT) followed by taxane (paclitaxel/docetaxel).  Patients underwent physical examination, electrocardiogram (ECG) and standard transthoracic echocardiography (TTE) including evaluation of diastolic and systolic function, measured as left ventricular ejection fraction (LVEF), left ventricular global longitudinal strain (GLS) and myocardial work (MW) expressed as global work index (GWI), global constructive work (GCW), global work waste (GWW), and global work efficiency (GWE). The parameters were measured at baseline (T0) and at 3 months (T1) and 6 months (T2) follow up. Results All patients completed the chemotherapy cycles. No significant cardiovascular adverse events were observed during treatment. Neither 2D left ventricular ejection fraction (LVEF) nor E/e’ ratio evaluation at TDI were significantly changed after treatment. Conversely, GLS was significantly reduced at T1 and T2 since baseline  (GLS - 19,99 % IQR -20,6 -19,3 % at T0 vs -17,88 % IQR -18,8 -16,9 % at T1, p&lt; 0,00 1 and -16,71 % IQR 17,6 -15,7 % at T2, p&lt; 0,001). Consensually, a significant reduction in myocardial work was also measured (GWI 2115 mmHg% IQR 1888 – 2342 mmHg%  at T0 vs 1714 mmHg% IQR 1557 – 1870 mmHg% at T1, p&lt; 0,0001 and 1694 mmHg% IQR 1482 – 1907 mmHg% at T2, p&lt; 0,0001). Conclusion Our study demonstrates that evaluation of myocardial work allows very early detection of subclinical cardiac damage induced by chemotherapy, consensually to the reduction of the GLS. A multiparametric assessment of the myocardial function, including myocardial work and GLS, could improve the accuracy of risk stratification of cardiotoxicity in patients undergoing ANTs treatment.


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