Mechanisms of cold intolerance in patients with angina
B Marchant,
G Donaldson,
K Mridha,
M Scarborough,
and
AD Timmis
Department of Cardiology, London Chest Hospital, England, United Kingdom.
OBJECTIVES. Patients with angina often report that symptoms are worse in cold weather. This study was designed to determine differences between cold-tolerant and cold-intolerant patients in the hemodynamic and ischemic response to exercise at cold temperatures and to assess the role of catecholamines and baroreceptor function. BACKGROUND. Studies have suggested that the heart rate response may differ at cold temperatures, but the mechanism and role of this variation have not been examined. METHODS. Seven cold-intolerant and seven cold-tolerant patients with angina underwent exercise treadmill testing at 6 and 25 degrees C with measurement of catecholamines. Baroreceptor function was assessed by the decrease in systolic blood pressure after patients stood up from the supine position. RESULTS. Norepinephrine levels increased by 139% in the cold environment, but there were no differences between cold-intolerant and cold-tolerant patients. Consequently, blood pressure was higher in the cold environment in all patients, but the heart rate response was similar. However, cold-intolerant patients had a steeper heart rate response in the cold and developed ischemia (mean [+/- SEM] 201 +/- 58 vs. 242 +/- 50 s, p = 0.05) and angina (348 +/- 87 vs. 449 +/- 60 s, p = 0.04) earlier in the cold environment, a difference not seen in the cold-tolerant patients. Baroreceptor function was impaired in cold-intolerant patients (decrease in systolic blood pressure after patients stood up from the supine position 19 +/- 7 vs. 0 +/- 4 mm Hg, p = 0.04). CONCLUSIONS. Exposure to cold causes an increase in blood pressure with an associated increase in myocardial oxygen demand in all patients. In cold-tolerant patients, this increase may be offset by a reduction in heart rate if baroreceptor function is normal. If baroreceptor function is abnormal, heart rate may not decrease in response to a cold-induced increase in blood pressure. This mechanism may account for some of the variability in tolerance to cold exposure that affects patients with exertional angina.
This article has been cited by other articles:
|
|
|
|
 
I. K. Carlsson, J. A. Nilsson, and L. B. Dahlin
Cut-off value for self-reported abnormal cold sensitivity and predictors for abnormality and severity in hand injuries
J Hand Surg Eur Vol.,
June 1, 2010;
35(5):
409 - 416.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Y. Gerber, S. J. Jacobsen, J. M. Killian, S. A. Weston, and V. L. Roger
Seasonality and Daily Weather Conditions in Relation to Myocardial Infarction and Sudden Cardiac Death in Olmsted County, Minnesota, 1979 to 2002
J. Am. Coll. Cardiol.,
July 18, 2006;
48(2):
287 - 292.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
F. De Lorenzo, Z. Kadziola, M. Mukherjee, N. Saba, and V.V. Kakkar
Haemodynamic responses and changes of haemostatic risk factors in cold-adapted humans
QJM,
September 1, 1999;
92(9):
509 - 513.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Danet, F. Richard, M. Montaye, S. Beauchant, B. Lemaire, C. Graux, D. Cottel, N. Marecaux, and P. Amouyel
Unhealthy Effects of Atmospheric Temperature and Pressure on the Occurrence of Myocardial Infarction and Coronary Deaths : A 10-Year Survey: The Lille-World Health Organization MONICA Project (Monitoring Trends and Determinants in Cardiovascular Disease)
Circulation,
July 6, 1999;
100(1):
e1 - e7.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
