The relationship between post-operative time and cardiac autonomic modulation in breast cancer survivors.
OBJECTIVE
Breast cancer survivors present autonomic dysfunction when evaluated by their heart rate variability (HRV). The purpose of this study is to investigate the relationship between post-operative time and cardiac autonomic modulation in breast cancer survivors and compare these values to those of women without cancer.


METHODS
This is a cross-sectional study consisting of 45 women from 35 to 70years old. These women were divided into two after breast cancer groups (BCG1 and BCG2) and a control group (CG). Group BCG1 consisted of women who had undergone breast cancer surgery within the last 18months and BCG2 those whose postoperative periods were more than 18months. The control group was formed by cancer-free women. HRV indices were used in the time and the frequency domain and geometric indexes.


RESULTS
The indices in millisecond, RMSSD (BCG1=19.83; BCG2=14.99; CG=31.46), SD1 (BCG1=14.03; BCG2=10.61; CG=22.27), SD2 (BCG1=39.17; BCG2=35.28; CG=61.16), SDNN (BCG1=29.58; BCG2=26.12; CG=46.36) and HF in milliseconds squared (BCG1=194.2; BCG2=91.07; CG=449.4) showed statistically significant reductions in the breast cancer groups compared to the CG (p≤0.0001). Lower SD1 index values were observed when comparing BCG2 to BCG1.


CONCLUSIONS
Breast cancer survivors regardless of their postoperative period exhibited a decrease in overall variability and both sympathetic and parasympathetic activity when compared to women without the disease. The group with the longer postoperative period manifested more pronounced autonomic modulation changes.
Faculty of Science and Technology FCT/UNESP, Presidente Prudente, SP, Brazil. Electronic address: marianaromanholi@hotmail.com.
Mariana Romanholi
MR
Palma
Department of Physical Therapy and Graduate Program in Physical Therapy, Faculty of Science and Technology FCT/UNESP, Presidente Prudente, SP, Brazil.
Luiz Carlos Marques
LC
Vanderlei
Faculty of Science and Technology FCT/UNESP, Presidente Prudente, SP, Brazil.
Fernanda Elisa
FE
Ribeiro
Biosciences Institute UNESP, Rio Claro, SP, Brazil.
Alessandra Madia
AM
Mantovani
Department of Physical Therapy and Graduate Program in Physical Therapy, Faculty of Science and Technology FCT/UNESP, Presidente Prudente, SP, Brazil.
Diego Giulliano Destro
DG
Christofaro
Department of Physical Therapy and Graduate Program in Physical Therapy, Faculty of Science and Technology FCT/UNESP, Presidente Prudente, SP, Brazil.
Cristina Elena Prado Teles
CE
Fregonesi
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects*; D001341:Autonomic Nervous System / Q000187:drug effects / Q000503:physiopathology; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis / Q000503:physiopathology; D001938:Brazil / Q000453:epidemiology; D001943:Breast Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D003430:Cross-Sectional Studies; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008408:Mastectomy / Q000009:adverse effects / Q000379:methods; D008875:Middle Aged; D009367:Neoplasm Staging; D011184:Postoperative Period; D013223:Statistics as Topic; D013997:Time Factors
D000970:Antineoplastic Agents
Autonomic nervous system; Breast neoplasms; Heart rate variability