Analysis of Left Ventricular Function by Atrial Pacing
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TLDR
In individual patients the pacing ventricular function curve appears useful in assessment of the effect of interventions that augment or depress ventricular performance.Abstract:
With the technique of right atrial pacing, left ventricular function was assessed in 21 normal subjects and in 13 patients with elevated left ventricular filling pressures. Since cardiac output does not change significantly with atrial pacing, the stroke volume decreases as an inverse function of the pacing rate. Stroke volume can thus be varied over a wide range, and by simultaneous measurement of left ventricular end-diastolic pressure, pacing ventricular function curves can be obtained. The calculated average slope for the ventricular function curve relating stroke volume index to left ventricular end-diastolic pressure was steeper in the normal subjects than in the group with elevated left ventricular end-diastolic pressure, but considerable overlap occurred between the groups. However, in individual patients the pacing ventricular function curve appears useful in assessment of the effect of interventions that augment or depress ventricular performance.read more
Citations
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The influence of heart rate on augmentation index and central arterial pressure in humans
TL;DR: An inverse, linear relationship between AIx is demonstrated, likely due to alterations in the timing of the reflected pressure wave, produced by changes in the absolute duration of systole, which may explain the lack of rise in central systolic pressure during incremental pacing despite an increase in peripheral pressure.
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Myocardial function during atrial pacing in patients with angina pectoris and normal coronary arteriograms. Comparison with patients having significant coronary artery disease.
TL;DR: Right atrial pacing at 140 beats/min for 8 minutes induced an electrocardiographic “ischemic pattern” in 10 patients with normal coronary arteriograms and chest pain usually typical of angina pectoris, and patients of group X showed a significant rise in cardiac index.
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Effects of heart rate on ventricular size, stroke volume, and output in the normal human fetus: a prospective Doppler echocardiographic study.
TL;DR: It is demonstrated that increases in heart rate within the physiologic range in the normal human fetus result in a decrease in ventricular size and stroke volume but no change in Ventricular output or ventricular shortening.
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Relation between QT interval and heart rate. applications and limitations of Bazett's formula.
TL;DR: It is concluded that atropine, isoproterenol and exercise actually shorten the QT interval.
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Effects of propranolol on myocardial oxygen consumption, substrate extraction, and haemodynamics in hypertrophic obstructive cardiomyopathy.
TL;DR: The results do not demonstrate a direct effect of propranolol upon myocardial metabolism in patients with HOCM, but emphasise the potential value of beta-blockade in protecting these patients from excessive increases in heart rate.
References
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Stanley J. Sarnoff,Erik Berglund +1 more
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The Study of Left Ventricular Function in Man by Increasing Resistance to Ventricular Ejection with Angiotensin
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Journal ArticleDOI
Effects of Changing Heart Rate in Man by Electrical Stimulation of the Right Atrium Studies at Rest, during Exercise, and with Isoproterenol
TL;DR: These studies indicate that in the absence of augmented metabolic requirements, homeostatic mechanisms maintain cardiac output relatively constant despite large induced changes in the heart rate, however, when metabolic demands are increased by muscular exercise, or the circulation is stimulated by catecholamines, cardiac output can rise through an increase in stroke volume, even when alterations in theheart rate are prevented.