The Use of Electrocardiographic Changes Caused by Induced Anoxemia as a Test for Coronary Insufficiency

Levy, Robert L.; Bruenn, Howard G.; Russell, Nelson G.

doi:10.1097/00000441-193902000-00012

Cited by 65 publications

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“…This, in addition to the respiratory alkalosis that occurs, may further predispose to palpitations, arrhythmias and ischaemia [5], especially in those with pre-existing cardiac disease. It is interesting to note that the effect of high altitude as a cardiac stressor was utilised in the Levy test of the 1940s, which simulated the hypoxic environment of 5,500 m as a diagnostic tool for coronary artery disease [6]. …”

Section: Introductionmentioning

confidence: 99%

High Altitude Arrhythmias

Woods¹,

Allen

Betts

et al. 2008

Cardiology

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Objective: To investigate the cause and nature of palpitations occurring at high altitude. Methods: Implantable loop recorders were inserted subcutaneously in the left pectoral region of 9 healthy male volunteers. Subjects flew to Kathmandu (1,250 m) and then Lukla (2,800 m) before immediately commencing an identical ascent and descent profile to high altitude. The loop recorders were activated with any episode of palpitations and during exercise, rest and sleep. Arterial oxygen saturation was assessed concomitant with device activation. Results: Above 5,000 m all subjects reported palpitations during exercise. All subjects demonstrated sinus tachycardia and marked sinus arrhythmia; one subject demonstrated atrial flutter; one subject had non-conducted p waves, and a further subject had marked ST segment depression. Conclusions: Significant arrhythmias occur at high altitude. In view of the increased risk of sudden cardiac death at high altitude, and considering that the elderly account for 15% of the 100 million visitors to altitude annually, further investigation is required.

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Section: Introductionmentioning

confidence: 99%

High Altitude Arrhythmias

Woods¹,

Allen

Betts

et al. 2008

Cardiology

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“…4) (Levy et al 1939). The combination of intense sympathetic activation and coronary vasoconstriction may provide the conditions for takotsubo or ''stress'' cardiomyopathy (Vaccaro et al, 2014).…”

Section: Provocable Ischemiamentioning

confidence: 99%

Going High with Heart Disease: The Effect of High Altitude Exposure in Older Individuals and Patients with Coronary Artery Disease

Levine

2015

High Altitude Medicine & Biology

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Levine, Benjamin D. Going high with heart disease: The effect of high altitude exposure in older individuals and patients with coronary artery disease. High Alt Med Biol 16:89-96, 2015.--Ischemic heart disease is the largest cause of death in older men and women in the western world (Lozano et al., 2012 ; Roth et al., 2015). Atherosclerosis progresses with age, and thus age is the dominant risk factor for coronary heart disease in any algorithm used to assess risk for cardiovascular events. Subclinical atherosclerosis also increases with age, providing the substrate for precipitation of acute coronary syndromes. Thus the risk of high altitude exposure in older individuals is linked closely with both subclinical and manifest coronary heart disease (CHD). There are several considerations associated with taking patients with CHD to high altitude: a) The reduced oxygen availability may cause or exacerbate symptoms; b) The hypoxia and other associated environmental conditions (exercise, dehydration, change in diet, thermal stress, emotional stress from personal danger or conflict) may precipitate acute coronary events; c) If an event occurs and the patient is far from advanced medical care, then the outcome of an acute coronary event may be poor; and d) Sudden death may occur. Physicians caring for older patients who want to sojourn to high altitude should keep in mind the following four key points: 1). Altitude may exacerbate ischemic heart disease because of both reduced O2 delivery and paradoxical vasoconstriction; 2). Adverse events, including acute coronary syndromes and sudden cardiac death, are most common in older unfit men, within the first few days of altitude exposure; 3). Ensuring optimal fitness, allowing for sufficient acclimatization (at least 5 days), and optimizing medical therapy (especially statins and aspirin) are prudent recommendations that may reduce the risk of adverse events; 4). A graded exercise test at sea level is probably sufficient for most clinical decision making and will allow for assessment of exercise capacity, and provocable ischemia. Given these considerations, most older individuals with CHD should be able to tolerate exposure to high altitude safely, and with minimal increased risk.

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“…Using a vertical ballistocardiograph, Starr and McAichael'5 studied the circulatory changes occurring in 21 normal persons subjected to simulated altitudes of 16,000 to 18,000 ft. in a low pressure chamber. It was found that the mean fall in arterial oxygen saturation of 21 per cent resulted in an average increase in cardiac output of 39 per cent.…”

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confidence: 99%

“…It was found that the mean fall in arterial oxygen saturation of 21 per cent resulted in an average increase in cardiac output of 39 per cent. A similar increase in cardiac output has recently been reported by Steele and Galdston'4 using the ballistocardiograph and by Keys and co-workers '3 using an x-ray cardiac output technic.…”

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confidence: 99%

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The Cardiovascular Effect of Induced Controlled Anoxemia

et al. 1951

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with the technical assistance of Jacob Beser, B.M.E., Salle A. Lore and Grace Saltzer Cardiovascular responses were studied by means of the ballistocardiograph and electrocardiograph in 16 normal subjects and 11 patients with suspected coronary artery disease before, during and after the induction of oximetiicallv controlled anoxemia. Progressive and significant increases occurred in cardiac output, pulse rate, left ventricular work, maximum cardiac force and pulse pressure during anoxemia in all of the normal subjects and in the 5 patients whose ballistocardiograms allowed the calculation of these variables. The increase in carliac output resulte(l almost entirely from an acceleration of cardiac rate. In the normal subjects control ballistocardiograms were normal in form and remained normal throughout anoxemia. Of the patients, 1 with normal, 2 with borderline and 1 with abnormal ballistocardiograms became abnormal or more abnormal. Two of the patients had a positive electrocardiographic test for coronary insufficiency while the test was negative in all of the normal subjects.The linear relationship between left ventricular work and arterial oxygen saturation suggests that when cardiovascular function is tested by means of anoxemic stress the level of arterial desaturation should be controllable. This is made possible by the use of a variable oxygen-nitrogen mixture and an oximeter. SINCE THE Pike's Peak expedition by Douglas, Haldane, Henderson and Schnei-K-,., der1 in 1911, the physiologic effect of altitude and anoxemia has been the subject of considerable scientific interest; the studies conducted by these physiologists formed the basis for most of the investigative work which has followed. Interest in anoxemia has sprung not only from the frequency of its occurFrom the

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The Use of Electrocardiographic Changes Caused by Induced Anoxemia as a Test for Coronary Insufficiency

Cited by 65 publications

References 0 publications

High Altitude Arrhythmias

High Altitude Arrhythmias

Going High with Heart Disease: The Effect of High Altitude Exposure in Older Individuals and Patients with Coronary Artery Disease

The Cardiovascular Effect of Induced Controlled Anoxemia

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