Cardiovascular Autonomic Dysfunction in Patients with Cancer

Prognostic relevance of ventricular arrhythmias in surgical patients with gastrointestinal tumors

BACKGROUND

Individuals diagnosed with gastrointestinal tumors are at an increased risk of developing cardiovascular diseases. Among which, ventricular arrhythmia is a prevalent clinical concern. This suggests that ventricular arrhythmias may have predictive value in the prognosis of patients with gastrointestinal tumors.

AIM

To explore the prognostic value of ventricular arrhythmias in patients with gastrointestinal tumors receiving surgery.

METHODS

We retrospectively analyzed data from 130 patients undergoing gastrointestinal tumor resection. These patients were evaluated by a 24-h ambulatory electrocardiogram (ECG) at the Sixth Affiliated Hospital of Sun Yat-sen University from January 2018 to June 2020. Additionally, 41 general healthy age-matched and sex-matched controls were included. Patients were categorized into survival and non-survival groups. The primary endpoint was all-cause mortality, and secondary endpoints included major adverse cardiovascular events (MACEs).

RESULTS

Colorectal tumors comprised 90% of cases. Preoperative ambulatory ECG monitoring revealed that among the 130 patients with gastrointestinal tumors, 100 (76.92%) exhibited varying degrees of premature ventricular contractions (PVCs). Ten patients (7.69%) manifested non-sustained ventricular tachycardia (NSVT). The patients with gastrointestinal tumors exhibited higher PVCs compared to the healthy controls on both conventional ECG [27 (21.3) vs 1 (2.5), P = 0.012] and 24-h ambulatory ECG [14 (1.0, 405) vs 1 (0, 6.5), P < 0.001]. Non-survivors had a higher PVC count than survivors [150.50 (7.25, 1690.50) vs 9 (0, 229.25), P = 0.020]. During the follow-up period, 24 patients died and 11 patients experienced MACEs. Univariate analysis linked PVC > 35/24 h to all-cause mortality, and NSVT was associated with MACE. However, neither PVC burden nor NSVT independently predicted outcomes according to multivariate analysis.

CONCLUSION

Patients with gastrointestinal tumors exhibited elevated PVCs. PVCs > 35/24 h and NSVT detected by 24-h ambulatory ECG were prognostically significant but were not found to be independent predictors.

Effects of Traditional Chinese Medicine "Fuzheng Qingdu Decoction" on Autonomic Function and Cancer-Related Symptoms in Patients with Advanced Gastric Cancer undergoing Chemotherapy: A Controlled Trial

OBJECTIVE

To evaluate the effects of Fuzheng Qingdu Decoction (FZQDD) on the autonomic function and cancer-related symptoms of patients with advanced gastric cancer undergoing chemotherapy to verify its clinical efficacy.

METHODS

Sixty-two patients with stage III or IV gastric cancer were included in this study. The patients were divided into 2 groups: the chemotherapy (33 patients) and chemotherapy with FZQDD (29 patients) groups. The primary outcome was the autonomic function of the patients before and after the interventions. The parameters that were used to assess autonomic function were deceleration capacity (DC) and acceleration capacity (AC) of heart rate and heart rate variability (HRV), which comprised standard deviation of the normal-normal interval (SDNN), root mean square of successive interval differences (RMSSD), low-frequency power (LF), high-frequency power (HF), total power (TP), and LF-HF ratio. The secondary outcomes were cancer-related symptoms and the quality of life.

RESULTS

DC and HRV parameters (ie, SDNN, RMSSD, LF, HF, and TP) were significantly decreased in the chemotherapy group; however, AC significantly increased after the interventions. No significant differences were observed in the DC, AC, and HRV parameters before and after the interventions in the chemotherapy with FZQDD group. Nevertheless, the changes in DC, AC, and HRV parameters (SDNN, RMSSD, HF, and TP) before and after the interventions were statistically significant between both the groups. FZQDD significantly improved the cancer-related symptoms and the quality of life of the patients.

CONCLUSIONS

Oxaliplatin combined with S-1 (tegafur, gimeracil, and oteracil potassium) can impair autonomic modulation in patients with advanced gastric cancer. FZQDD can alleviate autonomic dysfunction by increasing the parasympathetic activity and decreasing the sympathetic tone, helping patients restore the dynamic sympathovagal balance, and significantly improving the cancer-related symptoms and the quality of life of patients.

Profile of Cardiovascular Autonomic Dysfunctions in Breast Cancer Patients

Background Patients on breast cancer chemotherapy frequently present with signs and symptoms of autonomic dysfunction. Cardiac autonomic dysfunction (CAD) is a significant cause of morbidity and mortality, affecting the quality of life with progressive advancing disease. It is associated with the short survival of breast cancer patients. Therefore, thoroughly assessing cardiovascular autonomic functions is crucial to monitor these patients' disease prognosis and chemotherapy side effects. The present study evaluated baseline heart rate variability (HRV) and Ewing's battery of cardiac autonomic reactivity tests in breast cancer patients on chemotherapy to evaluate CAD. Methodology This is a case-control study. Autonomic reactivity tests were performed in the autonomic function laboratory, Department of Physiology, All India Institute of Medical Sciences, Raipur. HRV was recorded using a lead II electrocardiogram (ECG) in two groups, namely, controls (n = 25 healthy female volunteers) and cases (n = 25 histologically proven stage I-III breast cancer patients, age 30-65 years, received three cycles of chemotherapy). Results Patients on chemotherapy had significantly lower reactivity for the time domain (all parameters) and frequency domain (absolute total power) of HRV compared to age-matched healthy controls. Autonomic reactivity showed significant loss in the patient group. Conclusions The sympathetic and parasympathetic parameters showed a significant loss of autonomic functions in the patient group compared to the healthy controls. This may be because of the chemotherapeutic drugs taken by the patients or cancer as the disease per se. As autonomic dysfunction is highly prevalent in patients with cancer and is associated with multiple symptoms, it is essential to study it in the cancer population.

An online home-based exercise program improves autonomic dysfunction in breast cancer survivors

Introduction: Exercise interventions for breast cancer survivors have proved their potential to improve clinical, physical, and psychosocial outcomes. However, limited studies have explored exercise effects on autonomic dysfunction and the measurement of exercise tolerance and progression through daily heart rate variability (HRV). Purpose: To analyze the effects of a 16-wk exercise intervention on the autonomic modulation of breast cancer survivors, as well as to examine the evolution of daily measured HRV and its interaction with exercise sessions in this population. Methods: A total of 29 patients who had undergone chemotherapy and radiotherapy were randomly assigned to the exercise group or to the control group. The exercise intervention was delivered remotely through online meetings and consisted of supervised training resistance and cardiovascular exercise 3 times per week. During the intervention all patients measured their HRV daily obtaining the napierian logarithm of the root mean square of successive differences between normal heartbeats (lnrMSSD) and the napierian logarithm of the standard deviation of the interbeat interval of normal sinus beats (lnSDNN) values at four moments: day 0 (the morning of the training sessions), 24, 48, and 72 h after exercise. Results: The results revealed a significant interaction between group and months during the intervention period for lnrMSSD and lnSDNN (p < 0.001). Additionally, there were significant differences in lnSDNN recovery time between months (p < 0.05), while differences in lnrMSSD become apparent only 24 h after exercise (p = 0.019). The control group experienced a significant decrease in both variables monthly (p < 0.05) while exercise group experienced a significant increment (p < 0.05). Conclusion: HRV is daily affected by exercise training sessions in cancer patients. Although results strongly support the role of exercise as a post-chemotherapy and radiotherapy rehabilitation strategy for breast cancer survivors to improve autonomic imbalance, further research is necessary to validate these initial findings.

Assessment of short-term effects of thoracic radiotherapy on the cardiovascular parasympathetic and sympathetic nervous systems

Background

Prior research suggests that cardiovascular autonomic dysfunction might be an early marker of cardiotoxicity induced by antitumor treatment and act as an early predictor of cardiovascular disease-related morbidity and mortality. The impact of thoracic radiotherapy on the parasympathetic and sympathetic nervous systems, however, remains unclear. Therefore, this study aimed to evaluate the short-term effects of thoracic radiotherapy on the autonomic nervous system, using deceleration capacity (DC), acceleration capacity (AC) of heart rate, and heart rate variability (HRV) as assessment tools.

Methods

A 5 min electrocardiogram was collected from 58 thoracic cancer patients before and after thoracic radiotherapy for DC, AC, and HRV analysis. HRV parameters employed included the standard deviation of the normal-normal interval (SDNN), root mean square of successive interval differences (RMSSD), low frequency power (LF), high frequency power (HF), total power (TP), and the LF to HF ratio. Some patients also received systemic therapies alongside radiotherapy; thus, patients were subdivided into a radiotherapy-only group (28 cases) and a combined radiotherapy and systemic therapies group (30 cases) for additional subgroup analysis.

Results

Thoracic radiotherapy resulted in a significant reduction in DC (8.5 [5.0, 14.2] vs. 5.3 [3.5, 9.4], p = 0.002) and HRV parameters SDNN (9.9 [7.03, 16.0] vs. 8.2 [6.0, 12.4], p = 0.003), RMSSD (9.9 [6.9, 17.5] vs. 7.7 [4.8, 14.3], p = 0.009), LF (29 [10, 135] vs. 24 [15, 50], p = 0.005), HF (35 [12, 101] vs. 16 [9, 46], p = 0.002), TP (74 [41, 273] vs. 50 [33, 118], p < 0.001), and a significant increase in AC (-8.2 [-14.8, -4.9] vs. -5.8 [-10.1, -3.3], p = 0.003) and mean heart rate (79.8 ± 12.6 vs. 83.9 ± 13.6, p = 0.010). Subgroup analysis indicated similar trends in mean heart rate, DC, AC, and HRV parameters (SDNN, RMSSD, LF, HF, TP) in both the radiotherapy group and the combined treatment group post-radiotherapy. No statistically significant difference was noted in the changes observed in DC, AC, and HRV between the two groups pre- and post-radiotherapy.

Conclusion

Thoracic radiotherapy may induce cardiovascular autonomic dysfunction by reducing parasympathetic activity and enhancing sympathetic activity. Importantly, the study found that the concurrent use of systemic therapies did not significantly amplify or contribute to the alterations in autonomic function in the short-term following thoracic radiotherapy. DC, AC and HRV are promising and feasible biomarkers for evaluating autonomic dysfunction caused by thoracic radiotherapy.

Exploring autonomic modulation: day-to-day recovery after exercise sessions in breast cancer survivors

Purpose

The current study aimed to analyze the changes in heart rate variability (HRV) 24h, 48h and 72h after exercise sessions in breast cancer survivors.

Methods

Sixteen survivors who had undergone chemotherapy and radiotherapy were included. Participants trained resistance and cardiovascular components 3 times per week. The intervention was supervised and delivered online for 4 weeks. In this period, patients measured their HRV daily obtaining the lnrMSSD and lnSDNN values of: day 0 (the morning of the training sessions), 24h, 48h and 72h after exercise.

Results

Significant changes in lnrMSSD (p=0.015) and lnSDNN (p=0.031) during recovery times and lnSDNN during the weeks were found (p=0.015). The most prominent differences were identified between the baseline measurement taken on day 0 and 24h after exercise (p=0.007 and p=0.048, respectively) and between measurements obtained 24h and 48h after the training session (p=0.019 and p=0.026, respectively).

Conclusion

Our study suggests that patients may decrease their lnrMSSD and lnSDNN values 24h after exercise and they were close to recover 48h after the sessions. In this regard, HRV may be an useful tool to monitor their recovery and exercise tolerance.

Effect of transcutaneous auricular vagal nerve stimulation on the fatigue syndrome in patients with gastrointestinal cancers - FATIVA: a randomized, placebo-controlled pilot study protocol

BACKGROUND

Cancer-related fatigue (CRF) is defined as a "distressing, persistent, subjective sense of physical, emotional, and/or cognitive tiredness or exhaustion related to cancer or cancer treatment that is not proportional to recent activity and interferes with usual functioning." CRF is frequently observed in cancer patients even before the initiation of tumor therapy. Its cause is not clear, but in addition to primary effects of therapy, a tumor-induced elevated level of inflammatory cytokines may play a role. Transcutaneous auricular vagal nerve stimulation (taVNS) is a noninvasive way to activate central nervous pathways and modulate pain perception and the immune system. It has positive effects on autoimmune conditions and can also improve fatigue associated with Sjogren's syndrome. It is the main purpose of this feasibility study to investigate the feasibility of daily taVNS against CRF. Therefore, the stimulation protocol of the newly introduced smartphone app of the manufacturer is evaluated. Additionally, the effect taVNS on CRF and quality of life (QoL) shall be evaluated.

METHODS

Thirty adult patients with gastrointestinal tumors during or after treatment, relevant CRF (Hornheide questionnaire) and life expectancy > 1 year, are enrolled. Patients are randomized to treatment or sham arm and be informed that they will either feel the stimulation or not. Treatment group will receive left-sided tragus above-threshold stimulation with 25 Hz, 250 µs pulse width, and 28-s/32-s on/off paradigm for 4 h throughout the day for 4 weeks. Sham group will receive no stimulation via a nonfunctional electrode. A daily stimulation protocol with time and average intensity is automatically created by a smartphone app connected to the stimulator via Bluetooth®. Multidimensional Fatigue Inventory-20, Short-Form 36 and Beck Depression Inventory questionnaires will be filled out before and after 4 weeks of stimulation.

DISCUSSION

Primarily, the patients' daily stimulation time and intensity will be evaluated through the electronic protocol after 4 weeks. Secondarily, the effect of taVNS on cancer-related fatigue and QoL will be measured through the questionnaires. As taVNS seems to modulate inflammatory cytokines, this noninvasive method may - if accepted by the patients - be a promising adjunct in the treatment of cancer-related fatigue.

TRIAL REGISTRATION

The study was approved by local ethics committee (21-7395) and registered at the DRKS database (DRKS00027481).

High-intensity exercise prescription guided by heart rate variability in breast cancer patients: a study protocol for a randomized controlled trial

BACKGROUND

Breast cancer is a chronic disease with a large growth in its treatments, prognosis, improvements, side effects and rehabilitation therapies research. These advances have also highlighted the need to use physical exercise as a countermeasure to reduce the cardiotoxicity of pharmacological treatments, increase patients' strength and quality of life and improve body composition, physical condition and mental health. However, new investigations show the need for a closed exercise individualisation to produce higher physiological, physical and psychological benefits in remote exercise programs. To this end, the present study will use, in a novel way in this population, heart rate variability (HRV) as a measure for prescribing high-intensity training. Thus, the primary objective of this randomised clinical trial is to analyse the effects of a high-intensity exercise program daily guided by HRV, a preplanned moderate to high-intensity exercise intervention and a usual care group, in breast cancer patients after chemotherapy and radiotherapy treatments.

METHODS

For this purpose, a 16-week intervention will be carried out with 90 breast cancer patients distributed in 3 groups (a control group, a moderate to high-intensity preplanned exercise group and a high-intensity exercise group guided by HRV). Both physical exercise interventions will be developed remotely and supervised including strength and cardiovascular exercises. Physiological variables, such as cardiotoxicity, biomarkers, lipid profile, glucose, heart rate and blood pressure; physical measures like cardiorespiratory capacity, strength, flexibility, agility, balance and body composition; and psychosocial variables, as health-related quality of life, fatigue, functionality, self-esteem, movement fear, physical exercise level, anxiety and depression will be measure before, after the intervention and 3 and 6 months follow up.

DISCUSSION

Personalized high-intensity exercise could be a promising exercise intervention in contrast to moderate-intensity or usual care in breast cancer patients to reach higher clinical, physical and mental effects. In addition, the novelty of controlling HRV measures daily may reflect exercise effects and patients' adaptation in the preplanned exercise group and a new opportunity to adjust intensity. Moreover, findings may support the effectiveness and security of physical exercise remotely supervised, although with high-intensity exercise, to reach cardiotoxicity improvements and increase physical and psychosocial variables after breast cancer treatments. Trial registration ClinicalTrials.gov nº NCT05040867 ( https://clinicaltrials.gov/ct2/show/record/NCT05040867 ).

Effect of neoadjuvant chemotherapy on intraoperative core temperature in patients with breast cancer: a retrospective cohort study

Background

Clinical evidence suggests that chemotherapeutic agents are associated with neuropathy and peripheral autonomic dysfunction. However, the possible effects of neoadjuvant chemotherapy on intraoperative temperature remain poorly characterised.

Methods

We evaluated patients who underwent a mastectomy for breast cancer between April 2016 and July 2020. Propensity scores were used to match patients who received neoadjuvant chemotherapy with those who did not, and intraoperative core temperature patterns were analysed in the matched cohort. The independent associations between vasopressor use and heart rate during general anaesthesia in the matched cohort were also analysed.

Results

Data from 1764 patients were analysed (882 patients in each group). Both groups presented a similar pattern of heat redistribution and subsequent rewarming; however, the neoadjuvant chemotherapy group did not reach the same intraoperative plateau temperature as the group that did not receive prior chemotherapy, with differences of up to 0.4°C (95% confidence interval: 0.11-0.63°C; P=0.005). In a subgroup analysis, neuropathy in patients who received neoadjuvant chemotherapy was associated with increased use of vasopressors and higher heart rate.

Conclusions

In patients with breast cancer, neoadjuvant chemotherapy is associated with lower plateau core temperatures, increased vasopressor use, and higher heart rates during general anaesthesia, which is more severe in the presence of neuropathy.

Unusual vasovagal-type autonomic dysfunction secondary to immune checkpoint inhibitor therapy

We present the case of a patient with oral squamous cell carcinoma treated with the programmed death ligand inhibitor, pembrolizumab, an immune checkpoint inhibitor. She subsequently developed vasovagal-type autonomic dysfunction thought to be secondary to the pembrolizumab. The patient's vasovagal symptoms resolved with the initiation of oral glucocorticoids.

Off-Target Effects of Cancer Therapy on Development of Therapy-Induced Arrhythmia: A Review

BACKGROUND

Advances in cancer therapeutics have improved overall survival and prognosis in this patient population; however, this has come at the expense of cardiotoxicity including arrhythmia.

SUMMARY

Cancer and its therapies are associated with cardiotoxicity via several mechanisms including inflammation, cardiomyopathy, and off-target effects. Among cancer therapies, anthracyclines and tyrosine kinase inhibitors (TKIs) are particularly known for their pro-arrhythmia effects. In addition to cardiomyopathy, anthracyclines may be pro-arrhythmogenic via reactive oxygen species (ROS) generation and altered calcium handling. TKIs may mediate their cardiotoxicity via inhibition of off-target tyrosine kinases. Ibrutinib-mediated inhibition of CSK may be responsible for the increased prevalence of atrial fibrillation. Further investigation is warranted to further elucidate the mechanisms behind arrhythmias in cancer therapies.

KEY MESSAGES

Arrhythmias are a common cardiotoxicity of cancer therapies. Cancer therapies may induce arrhythmias via off-target effects. Understanding the mechanisms underlying arrhythmogenesis associated with cancer therapies may help design cancer therapies that can avoid these toxicities.

Management and treatment of cardiotoxicity due to anticancer drugs: 10 questions and answers

Since the introduction of anthracyclines into clinical practice in the 1960s, chemotherapy has always been associated with cardiotoxicity. Patients on cardiotoxic drugs can develop a wide range of cardiovascular diseases, including left ventricular (LV) systolic dysfunction and heart failure (HF), arrhythmias, hypertension, and coronary artery disease (CAD). The rising number of cancer patients, population ageing, and the frequent overlap of cardiovascular and oncological diseases have highlighted the importance of close collaboration between cardiologists and oncologists. As a result, in 1995, cardiologists at the IEO (European Institute of Oncology) coined the term cardioncology, a new discipline focused on the dynamics of cardiovascular disease in cancer patients. Given the complex scenario characterized by a constant dialogue between the oncological condition and cardiovascular comorbidity, it is essential for the clinician to get the knowledge to properly fulfill the needs of the oncological patient under cardiotoxic treatment. Through the answer to 10 questions, we aim to describe the complex issue of cardiotoxicity by addressing the main critical points and current evidence related to the assessment, management, treatment, and surveillance of cancer patients under chemotherapy.

Cardiovascular Dysautonomia in Patients with Breast Cancer

Breast cancer is the most frequent malignant disease among women, being responsible for a considerable percentage of fatalities and comorbidities every year. Despite advances in early detection and therapy, evidence shows that breast cancer survivors are at increased risk of developing other chronic conditions, such as cardiovascular diseases.

Autonomic dysfunction is an emerging, but poorly understood topic that has been suggested as a risk factor for cardiovascular disease in breast cancer patients. It clinically manifests through persistently elevated heart rates and abnormal heart rate variability, even before any signs of cardiovascular dysfunction appear. Since changes in the left ventricular ejection fraction only manifest when myocardial injury has already occurred, it has been hypothesized that autonomic dysfunction can constitute an early biomarker of cardiovascular impairment in breast cancer patients.

This review focuses on the direct and indirect effects of cancer and its treatment on the autonomic nervous system in breast cancer patients. We highlight the mechanisms potentially involved in cancer and antineoplastic therapy-related autonomic imbalance and review the potential strategies to prevent and/or attenuate autonomic dysfunction.

There are gaps in the current knowledge; more research in this area is needed to identify the relevance of autonomic dysfunction and define beneficial interventions to prevent cardiovascular disease in breast cancer patients.

Cancer treatment-related cardiac dysfunction

OBJECTIVES

This paper describes cardiotoxicity and cancer treatment-related cardiac dysfunction (CTRCD). Long-term sequelae of treatment are important, and changing, and may manifest when a patient is under the care of a supportive care service.

METHODS

Key messages for supportive and palliative care clinicians are outlined to facilitate identification and management of CTRCD.

RESULTS

Not all cardiotoxicity is alike. Types of cardiotoxicity, cardiac complications of immunotherapy, the challenge of autonomic nervous system dysfunction in cancer and management of cardiotoxicity are highlighted.

CONCLUSIONS

The key strategies are early detection of cardiotoxicity, monitoring for development of CTRCD during treatment and surveillance in survivorship.

Arrhythmic Complications Associated with Cancer Therapies

Over the last several decades, advancements in cancer screening and treatment have significantly improved cancer mortality and overall quality of life. Unfortunately, non-cancer-related side effects, including cardiovascular toxicities can impact the continued delivery of these treatments. Arrhythmias are an increasingly recognized class of cardiotoxicity that can occur as a direct consequence of the treatment or secondary to another type of toxicity such as heart failure, myocarditis, or ischemia. Atrial arrhythmias, particularly atrial fibrillation (AF) are most commonly encountered, however, ventricular- and bradyarrhythmias can also occur, albeit at lower rates. Treatment strategies tailored to patients with cancer are essential to allow for the safe delivery of the cancer treatment without affecting short- or long-term oncologic or cardiovascular outcomes.

Randomized Pilot Trial Using External Yarrow Liver Compress Applications With Metastatic Cancer Patients Suffering From Fatigue: Evaluation of Sympathetic Modulation by Heart Rate Variability Analysis

Background:

Liver compresses are commonly applied in complementary medicine during cancer treatment and are believed to have an energizing effect. We conducted a pilot study to investigate the influence of external application of yarrow liver compresses on the autonomous nervous system by analyzing the heart rate variability (HRV) in metastatic cancer patients undergoing radiation therapy and suffering from cancer-related fatigue (CRF).

Methods:

A randomized pilot trial was undertaken with patients suffering from CRF receiving palliative radiation therapy for bone or brain metastasis over 2 weeks. CRF patients were randomized into an intervention group receiving yarrow liver compresses and a control group receiving no external application. HRV was analyzed at the beginning (T1) and end (T2) period of the study during daytime (d) and nighttime (n) in both groups and quantified using time-, frequency-, and nonlinear dynamics domains.

Results:

A total of 39 patients were randomized between September 2017 and August 2019 and a total of 20 patients (10 per group) were available for analysis. For both groups, significant differences in HRV analyses were found in the comparison over the timeline between the first and second measurement (T1d→T2d) during daytime. Specifically, the intervention group showed decreased HRV and complexity of heart rate regulation, indicating increased sympathetic activity at time T2d, whereas the control group showed increased HRV and complexity of heart rate regulation, indicating increased vagal activity at time T2d. Furthermore, the observed HRV analyses showed almost no significant differences between the 2 groups in a direct comparison at the beginning and the end of the study (exception: T2d).

Conclusions:

Yarrow liver compresses led to increased sympathetic activity during daytime in the intervention group, whereas in the control group, which did not receive any external application, increased parasympathetic activity was observed.

The prevalence, distribution and impact of peripheral neuropathy among Danish patients with cancer - a population-based cross-sectional study

BACKGROUND

Prevalence of peripheral neuropathy (PN) has been studied in patients undergoing treatment with taxanes, platinums and vinca alkaloids. The prevalence is unknown in the general oncological cancer population, characterized by advanced age, comorbidities and heterogeneous treatments.

MATERIAL AND METHODS

A cross-sectional survey was administered to all adult patients, attending outpatient services at three Danish departments of oncology. The survey contained the EORTC-CIPN20, the EORTC-QLQ-C30, the GAD7 and PHQ9 questionnaires. A high PN symptom score was defined as a summary score ≥30 points on the CIPN20. P-values were adjusted for multiple testing.

RESULTS

With an overall response rate of 83% (2839 patients), prevalence of PN was 17% overall, varying from 6 to 33% between diagnosis groups.A high score was more common among females (19 vs. 14%, p = .008), smokers (21 vs. 15%, p = .04), patients living alone (21 vs. 15%, p = .002) and patients using cannabis (29 vs. 15%, p < .001), as well as patients suffering from diabetes (26 vs. 16%, p < .001), cardiac heart disease (27 vs. 16%, p < .001), arthritis (32 vs. 15%, p < .001) or chronic obstructive pulmonary disease (25 vs. 16%, p = .01). High score patients were also older (69ys vs 67ys, p = .048) and more likely experiencing polypharmacy (OR = 3.38 [95% CI, 2.64;4.35]).Patients with a high CIPN20 symptom score scored worse on all EORTC QLQ-C30 function and symptom scales. The mean adjusted C30 SumScore difference was -18.66 ([95% CI, -20.31; -17.02], p < .001).

CONCLUSION

Symptoms of PN are experienced widely across cancer groups in the oncology setting. PN symptoms were associated with clinically relevant worse health-related quality of life and with patient-related factors as living alone, various comorbidities, polypharmacy, and cannabis use.

Cancer classification using machine learning and HRV analysis: preliminary evidence from a pilot study

Most cancer patients exhibit autonomic dysfunction with attenuated heart rate variability (HRV) levels compared to healthy controls. This research aimed to create and evaluate a machine learning (ML) model enabling discrimination between cancer patients and healthy controls based on 5-min-ECG recordings. We selected 12 HRV features based on previous research and compared the results between cancer patients and healthy individuals using Wilcoxon sum-rank test. Recursive Feature Elimination (RFE) identified the top five features, averaged over 5 min and employed them as input to three different ML. Next, we created an ensemble model based on a stacking method that aggregated the predictions from all three base classifiers. All HRV features were significantly different between the two groups. SDNN, RMSSD, pNN50%, HRV triangular index, and SD1 were selected by RFE and used as an input to three different ML. All three base-classifiers performed above chance level, RF being the most efficient with a testing accuracy of 83%. The ensemble model showed a classification accuracy of 86% and an AUC of 0.95. The results obtained by ML algorithms suggest HRV parameters could be a reliable input for differentiating between cancer patients and healthy controls. Results should be interpreted in light of some limitations that call for replication studies with larger sample sizes.

Rehabilitation program combining physical exercise and heart rate variability biofeedback in hematologic patients: a feasibility study

Purpose

Hematologic patients have a poorer health-related quality of life due to the disease and its treatments. Non-pharmacological interventions represent an opportunity in tertiary cancer prevention to manage persistent symptoms and support patients in their return to active daily living. This interventional study aimed to evaluate the feasibility of a program combining physical exercise (PE) and heart rate variability biofeedback (HRVB) in hematologic patients.

Method

Hematologic patients in remission within 6 months participated in a 12-week rehabilitation program including 24 supervised sessions of PE associated with 10 supervised sessions of HRVB and daily home-based practice of paced breathing. We assessed patient adherence, fatigue, physical function, and heart rate variability.

Results

Twenty patients were included, 17 completed the protocol and 3 dropped out due to disease progression or time constraints; no adverse events or incidents were reported. Participation rates were 85% for PE and 98% for HRVB-supervised sessions. Significant improvements of physical capacity (6-min walk test, p < 0.001; 50-foot walk test, p < 0.001), muscle strength (grip force test, p < 0.01), and flexibility (toe-touch test, p < 0.001; back scratch test, p < 0.05) were measured. Coherence ratio (p < 0.001) and low-frequency spectral density of HRV signal (p < 0.003) increased significantly, suggesting improved autonomic function. Fatigue, static balance, and other time and frequency indicators of HRV were not improved (all p > 0.05).

Conclusion

A rehabilitation program combining PE and HRVB is feasible in hematologic patients and effective on physical function. Further research with a larger sample size is needed to investigate effectiveness on patients’ autonomic functions and their impacts on symptomatology.

Can Exercise Reduce the Autonomic Dysfunction of Patients With Cancer and Its Survivors? A Systematic Review and Meta-Analysis

Background: Cancer therapies have increased patient survival rates, but side effects such as cardiotoxicity and neurotoxicity can lead to autonomic nervous and cardiovascular system dysfunction. This would result in a decrease in parasympathetic activity and the enhancement of sympathetic activity. Heart rate variability (HRV), which reflects autonomic modulation, is a valuable physiological tool since it correlates with cancer-related fatigue, stress, depression, and mortality in patients with cancer.

Objective: This study aimed to analyze the effects of exercise programs on the autonomic modulation, measured by the HRV of patients with cancer and its survivors.

Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the quality of the articles was assessed with the Physiotherapy Evidence Database (PEDro) scale. The meta-analysis statistic procedure was performed by using RevMan software version 5.3.

Results: From the 252 articles found, six studies were included in the review involving 272 participants aged 30–75 years. Exercise programs had a mean length of 10.4 ± 4.6 weeks, a frequency of 3 ± 1.4 days/week, and a mean duration of 78 ± 23.9 min. In time-domain HRV measures, exercise may increase in the SD of normal-to-normal intervals [p < 0.00001, with a mean difference (MD) of 12.79 ms from 9.03 to 16.55] and a decreased root mean square of successive R–R interval differences (p = 0.002, with an MD of 13.08 ms from 4.90 to 21.27) in comparison with control groups (CG). The frequency-domain data reveal that the exercise group (EG) improve significantly more than the CGs in low frequency [absolute power: p < 0.0001, with a standardized mean difference (SMD) of 0.97 from 0.61 to 1.34; relative power: p = 0.04, with an MD = −7.70 from −15.4 to −0.36], high-frequency [absolute power: p = 0.001, with a SMD of 1.49 from 0.32 to 2.66; relative power: p = 0.04, with an MD of 8.00 normalized units (n.u.) from 0.20 to 15.80], and low-to-high frequency ratio (p = 0.007 with an MD of −0.32 from −0.55 to −0.09).

Conclusion: Exercise programs could lead to positive effects on the autonomic modulation of patients with cancer and its survivors. More beneficial changes may occur with resistance and endurance workouts. However, due to the low number of interventions performed, further research is needed to substantiate the findings and to provide additional insights regarding the exercise intensity required to increase the autonomic modulation of the patient.

Stress Echo 2030: The Novel ABCDE-(FGLPR) Protocol to Define the Future of Imaging

With stress echo (SE) 2020 study, a new standard of practice in stress imaging was developed and disseminated: the ABCDE protocol for functional testing within and beyond CAD. ABCDE protocol was the fruit of SE 2020, and is the seed of SE 2030, which is articulated in 12 projects: 1-SE in coronary artery disease (SECAD); 2-SE in diastolic heart failure (SEDIA); 3-SE in hypertrophic cardiomyopathy (SEHCA); 4-SE post-chest radiotherapy and chemotherapy (SERA); 5-Artificial intelligence SE evaluation (AI-SEE); 6-Environmental stress echocardiography and air pollution (ESTER); 7-SE in repaired Tetralogy of Fallot (SETOF); 8-SE in post-COVID-19 (SECOV); 9: Recovery by stress echo of conventionally unfit donor good hearts (RESURGE); 10-SE for mitral ischemic regurgitation (SEMIR); 11-SE in valvular heart disease (SEVA); 12-SE for coronary vasospasm (SESPASM). The study aims to recruit in the next 5 years (2021–2025) ≥10,000 patients followed for ≥5 years (up to 2030) from ≥20 quality-controlled laboratories from ≥10 countries. In this COVID-19 era of sustainable health care delivery, SE2030 will provide the evidence to finally recommend SE as the optimal and versatile imaging modality for functional testing anywhere, any time, and in any patient.

Subclinical cardiac damage in cancer patients before chemotherapy

Cancer and cardiovascular diseases, including heart failure (HF), are the main causes of death in Western countries. Several anticancer drugs and radiotherapy have adverse effects on the cardiovascular system, promoting left ventricular dysfunction and ultimately HF. Nonetheless, the relationship between cancer and HF is likely not unidirectional. Indeed, cancer and HF share common risk factors, and both have a bidirectional relationship with systemic inflammation, metabolic disturbances, and neurohormonal and immune activation. Few studies have assessed the impact of untreated cancer on the heart. The presence of an active cancer has been associated with elevated cardiac biomarkers, an initial impairment of left ventricular structure and function, autonomic dysfunction, and reduced exercise tolerance. In turn, these conditions might increase the risk of cardiac damage from chemotherapy and radiotherapy. HF drugs such as beta-blockers or inhibitors of the renin–angiotensin–aldosterone system might exert a protective effect on the heart even before the start of cancer therapies. In this review, we recapitulate the evidence of cardiac involvement in cancer patients naïve from chemotherapy and radiotherapy and no history of cardiac disease. We also focus on the perspectives for an early diagnosis and treatment to prevent the progression to cardiac dysfunction and clinical HF, and the potential benefits of cardioactive drugs on cancer progression.

Vibration Perception Threshold and Heart Rate Variability as methods to assess chemotherapy-induced neuropathy in women with breast cancer - a pilot study

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a recognized adverse effect of standard (neo)adjuvant chemotherapy in breast cancer (BC) treatment. However, there is no consensus on a validated method for assessing CIPN. Heart rate variability (HRV) and vibration perception threshold (VPT) could be used as objective measures to describe CIPN. The aim of this pilot study was to investigate whether subjectively reported CIPN was associated with altered HRV and VPT in BC patients.

METHODS

We performed a cross-sectional pilot study evaluating 30 BCE patients previously treated with chemotherapy, 26 BCE patients who did not receive chemotherapy, and 22 controls without breast cancer. Self-reported CIPN was registered for the BC patients. All participants were subjected to multi-frequency vibration analyses to determine VPT along with short ECG measurements to determine HRV measures.

RESULTS

Self-reported CIPN was registered in 14 (46.6%) BC patients treated with chemotherapy. The VPT at 64 Hz (P = 0.022) and mean HR (P = 0.022) were significantly higher and the HRV measures SDNN (P = 0.023), RMSSD (P = 0.007), LF (P = 0.050) and HF (P = 0.045) were significantly lower in BC patients reporting CIPN compared to controls when adjusted for age. VPT at 64 Hz and 125 Hz were significantly higher in BC patients not reporting CIPN compared to controls when adjusted for age.

CONCLUSION

We found elevated VPT and mean HR along with decreased HRV parameters in 14 BCE patients reporting CIPN. These findings support the need for further investigation into whether HRV and vibration analysis could contribute to an objective assessment of CIPN.

Recognition, Prevention, and Management of Arrhythmias and Autonomic Disorders in Cardio-Oncology: A Scientific Statement From the American Heart Association

With the advent of novel cancer therapeutics and improved screening, more patients are surviving a cancer diagnosis or living longer with advanced disease. Many of these treatments have associated cardiovascular toxicities that can manifest in both an acute and a delayed fashion. Arrhythmias are an increasingly identified complication with unique management challenges in the cancer population. The purpose of this scientific statement is to summarize the current state of knowledge regarding arrhythmia identification and treatment in patients with cancer. Atrial tachyarrhythmias, particularly atrial fibrillation, are most common, but ventricular arrhythmias, including those related to treatment-induced QT prolongation, and bradyarrhythmias can also occur. Despite increased recognition, dedicated prospective studies evaluating true incidence are lacking. Moreover, few studies have addressed appropriate prevention and treatment strategies. As such, this scientific statement serves to mobilize the cardio-oncology, electrophysiology, and oncology communities to develop clinical and scientific collaborations that will improve the care of patients with cancer who have arrhythmias.

Cardiotoxicity of Radiation Therapy: Mechanisms, Management, and Mitigation

OPINION STATEMENT

Radiation therapy is a key component of modern-day cancer therapy and can reduce the rates of recurrence and death from cancer. However, it can increase risk of cardiovascular (CV) events, and our understanding of the timeline associated with that risk is shorter than previously thought. Risk mitigation strategies, such as different positioning techniques, and breath hold acquisitions as well as baseline cardiovascular risk stratification that can be undertaken at the time of radiotherapy planning should be implemented, particularly for patients receiving chest radiation therapy. Primary and secondary prevention of cardiovascular disease (CVD), as appropriate, should be used before, during, and after radiation treatment in order to minimize the risks. Opportunistic screening for subclinical coronary disease provides an attractive possibility for primary/secondary CVD prevention and thus mitigation of long-term CV risk. More data on long-term clinical usefulness of this strategy and development of appropriate management pathways would further strengthen the evidence for the implementation of such screening. Clear guidelines in initial cardiovascular screening and cardiac aftercare following radiotherapy need to be formulated in order to integrate these measures into everyday clinical practice and policy and subsequently improve post-treatment morbidity and mortality for these patients.

Exercise and pyridostigmine prevents gastric emptying delay and increase blood pressure and cisplatin-induced baroreflex sensitivity in rats

Cisplatin treatment induces an autonomic dysfunction and gastrointestinal and cardiovascular disorders. Physical exercise as well as pyridostigmine treatment induces improves in the autonomic nervous system. In the current study, we investigated the effect of physical exercise and pyridostigmine treatment on gastrointestinal and cardiovascular changes in cisplatin-treated rats. Rats were divided into groups: Saline (S), Cisplatin (Cis), Exercise (Ex), Cisplatin+Exercise (Cis+Ex), Pyridostigmine (Pyr), and Cisplatin+Pyridostigmine (Cis+Pyr). We induced gastrointestinal dysmotility by administering 3 mg kg-1 of cisplatin once week for 5 weeks. The Ex was swimming (1 h per day/5 days per week for 5 weeks with 5% b.w.). GE was evaluated through the colorimetric method of fractional red phenol recovery 10 min after feeding. Pyr groups received 1.5 mg kg-1, p.o. or concomitant Cis treatment. Moreover, gastric contraction in vitro and hemodynamic parameters such as MAP, HR, and evoked baroreflex sensitivity were assessed, as well as sympathetic and parasympathetic tone and intrinsic heart rate (IHR). Cis decrease GE vs. saline (p<0.05). Cis+Ex or Cis+Pyr prevented (p<0.05) decrease in GE vs. Cis rats. Cis decreased (p<0.05) gastric responsiveness in vitro vs. saline. Cis+Ex or Cis+Pyr prevented this phenomenon. Cis treatment increase MAP and decrease in HR (p<0.05) vs saline. Cis+Ex or Cis+Pyr attenuated (p<0.05) both alterations. Cis increased sympathetic tone and decreased vagal tone and IHR (p<0.05) vs. the saline. Cis+Ex or Cis+Pyr prevented those effects vs. the Cis group. In conclusion, physical exercise and pyridostigmine treatment improves autonomic dysfunction and prevented GE delay and changes in hemodynamic parameters, baroreflex sensitivity, and cardiac autonomic control in cisplatin-treated rats.

Working cancer survivors' physical and mental characteristics compared to cancer-free workers in Japan: a nationwide general population-based study

PURPOSE

This study compared working cancer survivors' self-rated health status (SRHS), physical functional capacity, depressive symptoms, and happiness to those of cancer-free workers.

METHODS

A nationwide general population-based cross-sectional study on a sample of Japanese was conducted. Prevalence of deteriorated SRHS, restricted physical functional capacity, depressive symptoms, and perceived happiness were compared between working cancer survivors and cancer-free workers with multivariable logistic regression analysis adjusted for age and sociodemographic and health-related backgrounds.

RESULTS

Of the 28,311 male and 26,068 female workers, 977 (3.5%) and 1267 (4.9%) were cancer survivors, respectively. Working cancer survivors reported deteriorated SRHS more frequently than cancer-free workers: 21.3% vs. 13.8%, multivariable-adjusted odds ratio (95% confidence interval), 1.64 (1.39-1.95) for men, 23.8% vs. 17.5%, 1.34 (1.16-1.54) for women. Restricted physical functional capacity was reported more frequently in working cancer survivors than cancer-free workers: 6.8% vs. 2.6%, 1.76 (1.34-2.32) for men, 4.9% vs. 2.0%, 2.06 (1.56-2.71) for women. No significant difference was found for depressive symptoms: 21.6% vs. 22.9% in men, 30.0% vs. 28.5% in women. Working cancer survivors felt happiness more frequently than cancer-free survivors in men (77.3% vs. 71.7%, 1.21 (1.01-1.45)) but not in women (76.1% vs. 74.9%).

CONCLUSIONS

Working cancer survivors had worse SRHS and more restricted physical functional capacity than cancer-free workers. In men, working cancer survivors felt happiness more frequently than cancer-free workers.

IMPLICATIONS FOR CANCER SURVIVORS

Continuous support to improve cancer survivors' SRHS and physical functional capacity would be necessary even while they are working.

Chemotherapy and Radiation-Associated Cardiac Autonomic Dysfunction

PURPOSE OF REVIEW

Cardiovascular autonomic dysfunction (AD) among cancer survivors is increasingly being recognized. However, the mechanisms and incidence are poorly understood. In this review, the clinical features, diagnostic modalities, proposed mechanisms, and currently available treatments of cardiovascular AD in cancer survivors are described.

RECENT FINDINGS

Much of our current understanding of cardiovascular AD is based on disease states such as diabetes, multisystem atrophy, and Parkinson's disease. Several non-invasive tests, measurements, and scoring systems have been developed as surrogates for autonomic function, with some even demonstrating associations with all-cause mortality. The mechanism of cardiovascular AD specifically in the cancer population, however, has not been directly studied. The etiology of cardiovascular AD in cancer survivors is likely multifactorial, and proposed mechanisms include direct nerve damage by chemoradiation, the pro-inflammatory state associated with malignancy, and paraneoplastic syndromes. It may also be that cardiovascular AD is an early marker of global cardiomyopathy rather than its own condition. Current pharmacologic options for cardiovascular AD are extrapolated from how it has been treated in other disease processes, and these agents have not been studied in the cancer population or compared head-to-head. Cardiovascular AD in cancer survivors can cause significant debilitation and may be associated with all-cause mortality. Current diagnostic modalities have several limitations, such as standardization and validity. However, given the nonspecific nature of cardiovascular AD, these tools provide an objective marker for diagnosis and tracking treatment response. While the mechanism of cardiovascular AD in cancer survivors has not been directly studied, it may be useful to evoke mechanisms of cardiovascular AD in other disease states such as diabetes, Parkinson's disease, and multisystem atrophy in addition to identifying unique conditions associated with malignancy like a pro-inflammatory state. Until further studies are performed, management of cardiovascular AD as seen in other disease states may serve as a guide for symptom management in cancer survivors.

Impact of respiratory physical therapy on heart rate autonomic control in children with leukemia

INTRODUCTION

Considering that heart rate (HR) autonomic control is impaired in cancer and subsequent respiratory effort may overload the heart, we aimed to evaluate the effect of a respiratory physical therapy session on HR autonomic regulation in children with leukemia so as to confirm its safety.

METHODS

We selected children with leukemia (n = 10) and healthy children (n = 11), which were submitted to a session of respiratory physical therapy. We used Spiron Kids (NCS, Brazil), Children's Voldyne (HUDSON RCI, USA), and Shaker (NCS, Brazil) as respiratory devices. The respiratory exercise protocols were founded on three standardized protocols. HR variability (HRV) was analyzed before, in the first minute and 5 to 10 min after intervention.

RESULTS

We recognized no change between rest and recovery from intervention in HRV (rMSSD-square root mean square of the differences between adjacent normal R-R intervals)-Control: p = 0.8111, Leukemia: p = 0.1197, among groups: p = 0.6574; SD1-standard deviation from instantaneous beat-to-beat variability-Control: p = 0.8111, Leukemia: p = 0.131, among groups: p = 0.6556; 0V-with no variation (3 equal symbols, for example (2,2,2)-Control: p = 0.3679, Leukemia: p = 0.3553, among groups: p = 0.7421); 2UV-with two variations to the contrary (the three symbols form a peak or a valley, for instance (3,5,3)-Control: p = 0.3679, Leukemia: p = 0.2359, among groups: p = 0.4007). HF-high frequency component, range 0.15 to 0.4 Hz-decreased 0 to 1 min after intervention in the leukemia group (p = 0.0303) and no change was observed in the control group between rest versus recovery from intervention (p = 0.9761). No significant change was reported in HF between groups (p = 0.8700). Two leukemia subjects treated with vincristine presented different HRV responses to the intervention group.

CONCLUSION

A respiratory physical therapy session did not significantly change autonomic control of HR in children with leukemia. Yet, clinicians should be mindful of subjects undergoing treatment with vincristine.

Quantitative assessment of cardiovascular autonomic impairment in cancer survivors: a single center case series

BACKGROUND

Cardiovascular autonomic dysfunction in cancer survivors is poorly understood.

OBJECTIVES

To better characterize the clinical characteristics and types of autonomic dysfunction in this population.

METHODS

A retrospective analysis of cancer survivors within an academic cardio-oncology program referred for suspected autonomic dysfunction was performed. Autonomic reflex testing of adrenergic, cardiovagal, and sudomotor function was done. Autonomic impairment was graded on severity based on the Composite Autonomic Severity Score system. Patients with pre-existing autonomic dysfunction prior to their cancer diagnosis were excluded.

RESULTS

Of approximately 282 total patients in the UCLA Cardio-Oncology program, 24 were referred for suspected autonomic dysfunction and met the inclusion criteria. 22 had autonomic impairment on autonomic reflex testing. Eight patients were female, and the mean age at time of autonomic testing was 51.3 years. The average duration from cancer diagnosis to autonomic testing was 10.3 years. The reasons for referral included dizziness, tachycardia, palpitations, and syncope. The majority of patients (75%) had hematologic disorders. The most common chemotherapies administered were vinca alkaloids (54.2%), alkylating agents (66.7%), and anthracyclines (54.2%). Most patients received radiation to the thorax (66.7%) and neck (53.3%). Eleven patients had mild autonomic impairment, 7 had moderate, and 4 had severe autonomic impairment. Dysfunction was commonly present in the sympathetic and parasympathetic branches, but most pronounced in the sympathetic system. The majority of patients were diagnosed with orthostatic hypotension (50%), inappropriate sinus tachycardia (20.8%), and postural orthostatic tachycardia syndrome (12.5%) and had subjective improvement with treatment.

CONCLUSION

Cardiovascular autonomic dysfunction occurs in cancer survivors, and commonly affects both the sympathetic and parasympathetic systems. Symptom recognition in patients should prompt autonomic testing and treatment where appropriate.

Late side effects of radiation treatment for head and neck cancer

Patients undergoing radiation therapy for head and neck cancer (HNC) experience significant early and long-term side effects. The likelihood and severity of complications depends on a number of factors, including the total dose of radiation delivered, over what time it was delivered and what parts of the head and neck received radiation. Late side effects include: permanent loss of saliva; osteoradionecrosis; radiation recall myositis, pharyngoesophageal stenosis; dental caries; oral cavity necrosis; fibrosis; impaired wound healing; skin changes and skin cancer; lymphedema; hypothyroidism, hyperparathyroidism, lightheadedness, dizziness and headaches; secondary cancer; and eye, ear, neurological and neck structures damage. Patients who undergo radiotherapy for nasopharyngeal carcinoma tend to suffer from chronic sinusitis. These side effects present difficult challenges to the patients and their caregivers and require life-long strategies to alleviate their deleterious effect on basic life functions and on the quality of life. This review presents these side effects and their management.

Is heart rate variability a valuable method to investigate cardiac autonomic dysfunction in subjects with leukemia? A systematic review to evaluate its importance in clinical practice

Impaired cardiovascular and autonomic function during treatment and during recovery from leukemia has been indicated. In this context, heart rate variability (HRV) is a non-invasive measure that describes the oscillations of the intervals between consecutive heart beats (RR intervals), influenced by the autonomic nervous system. We intend to review literature showing HRV changes in leukemia subjects. The articles selected in the current review were attained up to March 2018, and the search was limited to articles in English language, published in peer-reviewed journals, with both adult and child age samples. The articles were investigated in the five electronic databases: PubMed, Physiotherapy Evidence Database (PEDro), Cochrane Clinical Trials, Scientific Electronic Library Online (SciELO), and Excerpta Medica dataBASE (EMBASE). Towards the end of the research, 9 studies were included. Subjects undergoing treatment for leukemia have reduced HRV, signifying decreased vagal control of heart rate. The subjects that undertook leukemia treatment and their survivors experienced a reduction in HRV with subsequent recovery, but the recovery time is ill defined. HRV is reduced in leukemia subjects who progress to neuropathy secondary to chemotherapy, accompanied by cardiac dysfunction. We advocate the use of HRV to evaluate autonomic function and decide the treatment to prevent autonomic impairment in leukemia subjects.