The “anoxemia test” in the diagnosis of coronary insufficiency

Levy, Robert L.; Williams, Norman E.; Bruenn, Howard G.; Carr, Henry A.

doi:10.1016/s0002-8703(41)90727-5

Cited by 92 publications

(7 citation statements)

References 15 publications

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“…8 Namely, that this technique furnishes electrocardiographic tracings during exercise that are essentially free of base line shift and interference from muscle potentials. The value of this method over the standard one appears to be threefold: (1) it is safer, in that exercise can be stopped at the first sign of myocardial ischemia or abnormal cardiac rhythm; (2) it provides greater information with which to evaluate early or occult atherosclerotic heart disease, since it permits monitoring RS-T segment changes that occur during exercise, but which may be completely absent in the immediate postexercise period; (3) as the results of this evaluation indicate, it can be used to determine more accurately and quantitatively the effect of therapeutic measures on exercise-induced changes in the electrocardiogram.…”

Section: Resultsmentioning

confidence: 99%

Continuous Electrocardiographic Recording During Exercise: Its Use in Evaluating the Effect of Pentaerythritol Tetranitrate

Krasno¹,

Kidera²

1963

Angiology

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Virtually all the objections that have been voiced against the Master Two-Step postexercise electrocardiogram are predicated on the following four factors: (1) the safety of this procedure in patients with atherosclerotic heart disease; (2) the occurrence of false positive responses; (3) the inability to determine exactly when ischemic changes occur during exercise; (4) the inability to determine whether the absence of ischemic changes in the immediate postexercise period represents false negative information. Improved instrumentation and interpretation of electrographic tracings have partially obviated objections based on the first two factors, and presumably, also account for the growing acceptance of this diagnostic procedure in recent years. Despite these improvements and the outgrowths of their use, however, the latter two factors continue to represent basic shortcomings.Attempts to overcome these shortcomings have been concerned with the development of techniques which, instead of exercise, employ the use of anoxemial or drugs2-4 to induce electrocardiographic changes. Additionally, refinements in electrocardiographic instrumentation and technique have also been advanced that allow continuous recording of the electrocardiogram during exercise and the immediate postexercise period.The earliest of these refinements were beset with numerous technical difficulties, particularly those responsible for the presence of artifacts in the tracings, 6 Recently, however, an excellent procedure has been devised,7 , which appears to have successfully eliminated practically all of the earlier difficulties.The purpose of this report is to describe several refinements to the electrocardiographic instrumentation employed with this new procedure, and to demonstrate their utility in evaluating the activity of pentaerythritol tetranitrate, a widely used coronary vasodilator. MATERIAL AND METHODElectrocardiographic equipment. Refinements to the instrumentation employed with the original procedure7 > 8 are shown in figure 1 and described as follows.1. The 2 by 2 cm2 stainless-steel wire mesh (no. 80 and 0.0055 of an inch in thickness) ear electrode was made in the form of an earring with a thumb-screw attachment (A). This facilitated attachment of the electrode to the ear, and provided for a more stable electrode-to-skin contact during exercise. 2. The chest electrodes, identical to the ear electrode in size, shape and composition, were recessed (about 1,~ of an inch) in a small sponge rubber &dquo;shield&dquo; (B) instead of hard rubber tubing. This eliminated the more cumbersome foam rubber cushion originally utilized.3. All the electrodes were connected to the appropriate lead cables by a 36-in. length of extremely lightweight, silk-covered, 105-strand flexible wire (C) ; this is not shown for the ear electrode. The RCA plug jackphono input described in the original procedure was replaced with a lightweight friction collet jack plug (D), which was soldered to the end of the flexible wire opposite the electrode. The lead cables ...

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Section: Resultsmentioning

confidence: 99%

Continuous Electrocardiographic Recording During Exercise: Its Use in Evaluating the Effect of Pentaerythritol Tetranitrate

Krasno¹,

Kidera²

1963

Angiology

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“…(This would be instead of the more usually considered asphyxia i.e., hypoxia with hypercapnia). Early studies using inspiration of hypoxic gas mixtures (8-12% oxygen) in angina patients did consistently produce pronounced ST and T wave ECG changes (Levy et al, 1939(Levy et al, , 1941Turner and Morton, 1952;Haarstad and Broch, 1958;Broch, 1972) and angina (Levy et al, 1939(Levy et al, , 1941Turner and Morton, 1952;Haarstad and Broch, 1958). Initially this was considered as a possible diagnostic test for early coronary artery disease.…”

Section: Implications For the Search For Non-invasive Tests Of Early mentioning

confidence: 99%

“…Initially this was considered as a possible diagnostic test for early coronary artery disease. Its sensitivity and specificity was believed as good or better than exercise testing (Levy et al, 1941;Turner and Morton, 1952;Stewart and Carr, 1954;Haarstad and Broch, 1958). But severe hypoxia was abandoned in the 1950s because hypoxia did induce angina (Levy et al, 1939(Levy et al, , 1941Turner and Morton, 1952;Haarstad and Broch, 1958), patient distress, and had the potential for adverse risks including myocardial infarction or death (Stewart and Carr, 1954).…”

Section: Implications For the Search For Non-invasive Tests Of Early mentioning

confidence: 99%

Hypocapnia Alone Fails to Provoke Important Electrocardiogram Changes in Coronary Artery Diseased Patients

et al. 2020

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Background: There is still an urgent clinical need to develop non-invasive diagnostic tests for early ischemic heart disease because, once angina occurs, it is too late. Hypocapnia has long been known to cause coronary artery vasoconstriction. Some new cardiology tests are accompanied by the claim that they must have potential diagnostic value if hypocapnia enhances their cardiac effects in healthy subjects. But no previous study has tested whether hypocapnia produces bigger cardiac effects in patients with angina than in healthy subjects. Methods: Severe hypocapnia (a PetCO 2 level of 20 mmHg) lasting >15 min was mechanically induced by facemask, while conscious and unmedicated, in 18 healthy subjects and in 10 patients with angina and angiographically confirmed coronary artery disease, awaiting bypass surgery. Each participant was their own control in normocapnia (where CO 2 was added to the inspirate) and the order of normocapnia and hypocapnia was randomized. Twelve lead electrocardiograms (ECG) were recorded and automated measurements were made on all ECG waveforms averaged over >120 beats. 2D echocardiography was also performed on healthy subjects. Results: In the 18 healthy subjects, we confirm that severe hypocapnia (a mean PetCO 2 of 20 ± 0 mmHg, P < 0.0001) consistently increased the mean T wave amplitude in leads V1-V3, but by only 31% (P < 0.01), 15% (P < 0.001) and 11% (P < 0.05), respectively. Hypocapnia produced no other significant effects (p > 0.05) on their electro-or echocardiogram. All 10 angina patients tolerated the mechanical hyperventilation well, with minimal discomfort. Hypocpania caused a similar increase in V1 (by 39%, P < 0.05 vs. baseline, but P > 0.05 vs. healthy controls) and did not induce angina. Its effects were no greater in patients who did not take β-blockers, or did not take organic nitrates, or had the worst Canadian Cardiovascular Society scores.

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“…A normobaric hypoxic test using gas mixture containing 10 % oxygen and 90 % nitrogen for 20 minutes was used for the first time in 1939 by P. Ber and R. Levy to estimate the status of coronary blood flow [1]. In 1970, R. B. Strylkov formulated the concept of the possibility of protection from ionizing radiation by hypoxic gas mixture (HGM) with an oxygen content of 10.0±1.0 % [2].…”

Section: Introductionmentioning

confidence: 99%

The Use of Intermittent Normobaric Hypoxia in Children's Neurology (Review)

Lisukha

2017

EUREKA: Health Sciences

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The present review summarizes the data about the use of intermittent normobaric hypoxia (INH) in the treatment and prevention of both acute and chronic diseases of the nervous system in children. The INH method is used in pregnant women with fetoplacental insufficiency, anemia and for mental disorders correction. The INH efficiency in relation to such pathology as cerebral palsy, epilepsy, enuresis, sleep disturbances, autonomic dysfunction is proved. The age dependence of bioelectric activity of the brain in practically healthy persons (age from 8 to 21 years) on hypoxic factor and the most sensitive period of age from 13 to 16 years is shown. The results the own studies have shown that the children which are born and live in radioactive contaminated areas (RCA), the course of INH sessions led to the restoration of somatovegetative status: activation of higher vegetative centers, optimization of sympathetic and parasympathetic links; positive influence on the activity of the cardiovascular system; ventilatory capacity of lungs; blood parameters.

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The “anoxemia test” in the diagnosis of coronary insufficiency

Cited by 92 publications

References 15 publications

Continuous Electrocardiographic Recording During Exercise: Its Use in Evaluating the Effect of Pentaerythritol Tetranitrate

Continuous Electrocardiographic Recording During Exercise: Its Use in Evaluating the Effect of Pentaerythritol Tetranitrate

Hypocapnia Alone Fails to Provoke Important Electrocardiogram Changes in Coronary Artery Diseased Patients

The Use of Intermittent Normobaric Hypoxia in Children's Neurology (Review)

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