Dysautonomia in Childhood Cancer Survivors: A Widely Underestimated Risk

Cardiorespiratory Fitness and Cardiac Magnetic Resonance Imaging in Childhood Acute Lymphoblastic Leukemia Survivors

BACKGROUND

Childhood acute lymphoblastic leukemia survivors' anthracycline-induced cardiotoxicity could be prevented with good cardiorespiratory fitness levels and regular physical activity. This cross-sectional study aimed to assess the association between cardiorespiratory fitness and physical activity with cardiac magnetic resonance parameters.

METHODS

A total of 96 childhood acute lymphoblastic leukemia survivors underwent a maximal cardiopulmonary exercise test and answered physical activity questionnaires. We calculated the odds ratio of the preventive fraction of regular physical activity (≥150 min/wk) and adequate cardiorespiratory fitness levels (above the median ≥31.4 mL·kg-1·min-1) on cardiac magnetic resonance parameters (left ventricular [LV] and right ventricular [RV] morphological and functional parameters).

RESULTS

An adequate cardiorespiratory fitness was associated with a significant preventive fraction for LV (up to 84% for LV end-diastolic volume) and RV volumes (up to 88% for RV end-systolic volume). The adjusted analyses highlighted a preventive fraction of 36% to 91% between an adequate cardiorespiratory fitness and LV and RV parameters, late gadolinium enhancement fibrosis, and cardiac magnetic resonance relaxation times. No associations were reported with regular physical activity.

CONCLUSIONS

This study provides additional evidence regarding the benefits of an adequate cardiorespiratory fitness level for childhood cancer survivors' cardiac health.

Intensive chemotherapy perturbs heart rate variability in children with cancer

OBJECTIVES

In children, cancer chemotherapy may impair the functioning of the cardiac autonomic nervous system. Moreover, it is not known whether there are any differences between intensive and maintenance phases of chemotherapy. Therefore, the aim of the current study was to assess autonomic nervous system activity using heart rate variability, in children receiving intensive or maintenance cancer chemotherapy.

METHODS

For that purpose, children who were healthy (healthy control, n = 30), receiving intensive chemotherapy (chemotherapy, n = 30), and receiving maintenance chemotherapy (maintenance, n = 25) were included in the study. Autonomic nervous system activity was measured by means of heart rate variability. Electrocardiogram recordings were used to calculate time- and frequency-domain heart rate variability parameters.

RESULTS

Time-domain parameters such as standard deviation of NN intervals and frequency-domain parameters such as total power were lower during the intensive chemotherapy but not during maintenance phase (standard deviation of NN intervals: 50±5, 33±3, and 48±3 ms, and total power: 2613±504, 1379±296 and 2295±264 ms², respectively for healthy control, chemotherapy and maintenance groups, P<0.001 for both standard deviation of NN intervals and total power).

DISCUSSION

The present results indicate that intensive chemotherapy perturbs the function of heart rate variability in children, with recovery during the maintenance phase. This suggests that intensive chemotherapy is likely to affect the autonomic nervous system but this effect does not appear to be permanent.

Orthostatic intolerance syndromes after hematopoietic cell transplantation: clinical characteristics and therapeutic interventions in a single-center experience

Background

Hematopoietic cell transplantation (HCT) is an established and potentially curative therapeutic option for hematologic cancers. HCT survivors are at risk of developing long-term complications impacting on morbidity and mortality. Orthostatic hypotension (OH) and postural tachycardia syndrome (POTS) have been anecdotally described after HCT. However, the incidence and clinical characteristics of patients with OH and POTS after HCT has not been well defined.

Methods

This retrospective study included 132 patients who had HCT between March 2011 and July 2018 and were referred to Cardio-oncology clinic. Patients were screened for OH and POTS. Using logistic regression analysis we evaluated the association between clinical factors and the incidence of OH and POTS.

Results

Median age was 58 (47–63) years, 87 (66%) patients were male, 95 (72%) were Caucasian. OH was diagnosed in 30 (23%) subjects and POTS in 12 (9%) after the HCT. No significant differences in demographic characteristics were found when comparing patients with and without OH or POTS. The two groups did not differ for cardiovascular diseases prevalence nor for the prior use of antihypertensive drugs. Previous radiotherapy and treatment with specific chemotherapy drugs were found to be associated with the incidence of OH or POTS, but none of the factors maintained the significance in the multivariate model. Pharmacological therapy was required in 38 (91%) cases, including a b-adrenergic blocker (n = 24, 57%), midodrine (n = 24, 57%) and fludrocortisone (n = 7, 18%).

Conclusion

Orthostatic intolerance syndromes are commonly diagnosed in patients referred to the cardiologist after HCT, involving approximately 1/3 of patients and requiring pharmacological therapy to cope with symptoms in the majority of cases. Risk factors specific to this population are identified but cannot fully explain the incidence of POTS and OH after HCT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40959-021-00126-7.

Heart rate variability and psychosocial symptoms in adolescents and young adults with cancer

Background

Heart Rate Variability (HRV) is a valid, scalable biomarker of stress. We aimed to examine associations between HRV and psychosocial outcomes in adolescents and young adults (AYAs) with cancer.

Methods

This was a secondary analysis of baseline data from a randomized trial testing a resilience intervention in AYAs with cancer. Two widely used HRV metrics, the standard deviation of normal to normal beats (SDNN) and root mean square of successive differences (RMSSD), were derived from electrocardiograms. Patient-reported outcome (PRO) survey measures included quality of life, anxiety, depression, distress, and resilience. Linear regression models were used to test associations between HRV and PRO scores. The Wilcoxon rank sum test was used to test differences in median HRV values among participant subgroups.

Results

Among the n = 76 patients with available electrocardiograms, the mean age was 16 years (SD 3y), 63% were white, and leukemia/lymphoma was the most common diagnosis. Compared to healthy adolescents, AYAs with cancer had lower median HRV (SDNN [Females: 31.9 (12.8–50.7) vs 66.4 (46.0–86.8), p<0.01; Males: 29.9 (11.5–47.9) vs 63.2 (48.4–84.6), p<0.01]; RMSSD [Females: 28.2 (11.1–45.5) vs 69.0 (49.1–99.6), p<0.01; Males: 27.9 (8.6–48.6) vs 58.7 (44.8–88.2), p<0.01]). There was no statistically significant association between PRO measures and SDNN or RMSSD in either an unadjusted or adjusted linear regression models.

Conclusion

In this secondary analysis, we did not find an association between HRV and psychosocial PROs among AYAs with cancer. HRV measures were lower than for healthy adolescents. Larger prospective studies in AYA biopsychosocial research are needed.

Childhood Cancer Survivorship: Daily Challenges

Survivors of childhood cancer are at risk of experiencing fatigue, pain, lower levels of physical activity, increased engagement in risky health behavior, and poor social adjustment, after finishing treatment. Risks are more pronounced for survivors of specific diagnoses or receiving specific treatment protocols. Interventions to address these outcomes are in their infancy. Future research should focus on exploring the antecedents and consequences of these outcomes. In the meantime, researchers and cancer centers should attempt to provide high-quality and accessible health information to survivors through various media outlets to encourage healthy behaviors.

Measuring Heart Rate Variability Using Commercially Available Devices in Healthy Children: A Validity and Reliability Study

Heart rate variability (HRV) is an accepted method for determining autonomic nervous system activity and cardiovascular risk in various populations. This study assessed the validity and reliability of a commercially available finger photoplethysmography (PPG) system for measuring pediatric HRV in a real-world setting. Sixteen healthy children (4.06 ± 0.58 years) were recruited. The PPG system was compared to the Polar H10 heart rate (HR) sensor validated against ECG (gold standard) for HRV measurement. Seated short-term resting R-R intervals were recorded simultaneously using both systems. Recordings were performed on 3 days at the participants’ school. Paired t-tests, effect sizes and Bland–Altman analyses determined the validity of the PPG system. The relative and absolute reliability of both systems were calculated. No HRV parameters were valid for the PPG system. Polar H10 yielded moderate (0.50–0.75) to good (0.75–0.90) relative reliability with R-R intervals and the standard deviation of instantaneous and continuous R-R variability ratio showing the best results (ICCs = 0.84). Polar H10 displayed better absolute reliability with the root mean square of successive differences, R-R intervals and HR showing the lowest values (TEM% < 12%). The use of the Polar H10 and not the PPG system is encouraged for HRV measurement of young children in an educational real-world setting.