Effects of cold on ST amplitudes and blood pressure during exercise in angina pectoris.
ABSTRACT To investigate the mechanisms of cold susceptibility in angina pectoris nine male angina patients were studied. All were cold susceptible by history and had developed ischaemic ST changes during a previous exercise test. The patients underwent two additional bicycle exercise tests, one in a cold chamber with an average temperature of -8 degrees C, and the other at room temperature. The ECG was computer analysed and the intra-arterial blood pressure was measured. No significant decrease in work capacity was found during exercise in the cold chamber. In the cold, systolic blood pressure was consistently higher throughout the test and in seven of nine subjects ST depression was more pronounced at corresponding workloads. ST depression was also analysed versus heart work which was assessed as rate pressure product. In the cold, 1 mm ST depression appeared at a somewhat higher rate pressure product when compared to room temperature. It was concluded, therefore, that an augmented heart work, secondary to substantial increases in blood pressure, appears to account for the cold-induced increase in ST depression found in the angina patients in this study.
SourceAvailable from: Jayne Wilson
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ABSTRACT: Cold temperature is known to commonly precipitate angina pectoris in patients with symptomatic coronary artery disease (CAD). It was previously shown that the ischemic threshold was lower during exercise testing at -8 degrees C than at +20 degrees C in patients with a history of cold-induced angina, whereas it was unchanged in patients without cold-induced angina. Few data exist on the impact of more severe cold exposure on myocardial ischemia. To determine the effect of extreme cold exposure (-20 degrees C) on the ischemic threshold among CAD patients. Thirteen men with CAD and documented exercise-induced ischemia performed two treadmill exercise tests, one at +20 degrees C and one at -20 degrees C, in random order. Electrocardiograms were recorded every 30 s and analyzed separately in random order by two experienced readers blinded to temperature. The mean (+/- SD) time to ischemic electrical threshold was 53+/-60 s lower at -20 degrees C than at +20 degrees C (P=0.008), corresponding to a relative change of -8.0+/-10.5%. All other exercise parameters, including total exercise time and rate-pressure product, were unchanged during exposure to extreme cold. Exposure to extreme cold (-20 degrees C) lowers the ischemic threshold during exercise testing in patients with CAD, even if asymptomatic or without a history of cold-induced angina. Patients with CAD and evidence of exertional angina or myocardial ischemia wishing to perform exercise at extremely low temperatures should discuss this matter with their physicians.The Canadian journal of cardiology 02/2010; 26(2):e50-3. DOI:10.1016/S0828-282X(10)70007-6 · 3.94 Impact Factor
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ABSTRACT: The climatic stress was anticipated to increase direct and indirect risks to human health via different pathways and mechanisms. Extremely high air temperature might trigger the onset of cardiovascular events in the vulnerable. Cold-related mortality was much less understood than heat-related one, and was considered another climatic example of the effects on the human health. Increases in mortality with cardiovascular diseases in extreme heat and cold weather had been studied in many regions. These results suggested that people died rapidly from climate-change related cardiovascular diseases before they were sent to hospital. Obviously, these findings reminded us that climatic stress can be considered as a new potential risk factor of sudden cardiovascular events in human health, and there was an urgent need for large-scale, prospective, community-based and international study of sudden cardiovascular events to explore deeply the risk factors to schedule preventive strategies.European Journal of Internal Medicine 06/2010; 21(3):164-7. DOI:10.1016/j.ejim.2010.03.001 · 2.30 Impact Factor