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Cardiac sympathetic activity assessed by heart rate variability indicates myocardial ischemia on cold exposure in diabetes
Author(s) -
Sasaki Keita,
Matsushita Shonosuke,
Sakakibara Yuzuru
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.981.7
Subject(s) - diabetes mellitus , medicine , heart rate variability , cardiology , heart rate , propranolol , blood flow , endocrinology , anesthesia , blood pressure
Purpose Cold exposure is one of the major risk factors for cardiac events in diabetes. The aim of this study is how cardiac sympathetic nerve activity (SNA) is affected by temporal cold exposure in diabetes using heart rate variability (HRV). Methods Male Wistar Rat (n=12) were divided into two groups: Control and Diabetes. Diabetes was induced by streptozocin. Lower extremity was sprayed for cold vapor for 5 seconds. Rectal and subcutaneous tissue temperature, flow velocity of lower extremity using laser Doppler flow meter, frequency domain analysis of HRV and ST change were measured up to 15 min from initial cold exposure. Results SNA was able to define as a power between 0 and 0.2 Hz in HRV by use of propranolol (60mg/kg). SNA was enhanced in diabetes than control (p<0.05) associated with reduction of blood flow (p<0.05). SNA was decreased by cold exposure in control (p<0.005), however, diabetes did not show significant reduction. SNA was enhanced significantly in diabetes at 1, 5, 10 and 15 min after cold exposure compared with control (p<0.01, p<0.005, p<0.05, p<0.0005, p<0.01, respectively). ST change was significantly larger in diabetes than control in 1 and 5 min after cold exposure (p<0.001, p<0.005). Conclusion Cardiac SNA was decreased after cold exposure to lower extremity in control. In contrast, cardiac SNA was enhanced in diabetes than control, which may lead to cardiac ischemia in cold exposure in diabetes.