Effects of Heart Rate on Coronary Flow and Cardiac Oxygen Consumption

1956 ◽  
Vol 185 (2) ◽  
pp. 355-364 ◽  
Author(s):  
D. Laurent ◽  
C. Bolene-Williams ◽  
F. L. Williams ◽  
L. N. Katz
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Coronary Flow ◽  
High Energy ◽  
Cardiac Work ◽  
Spontaneous Change ◽  
Ordinary Type ◽  
Relationship Of ◽  
The Relationship ◽  
Oxygen Difference

The effects of electrically-induced heart rate (up to 300 beats/min.) on coronary flow and cardiac oxygen consumption has been studied in an open-chested intact preparation. A significant correlation between heart rate, coronary flow and cardiac oxygen consumption has been found at each level of cardiac work. Coronary flow and cardiac oxygen consumption increase with a rise in heart rate and seem to approach a limit at extremely rapid heart rates. Nomograms relating heart rate, work and oxygen consumption of the heart have been constructed. From these it is seen that heart rate is an important factor in determining the myocardial oxygen consumption; this is true at each level of cardiac work. The significance of these findings have been discussed relative to the unanesthetized animal. Under conditions of excessive heart rate or cardiac load which presumably lead to unusually high energy requirements, a radical departure from the expected ‘normal’ values was found in coronary flow, coronary A-V oxygen difference and cardiac oxygen consumption. This confirms the presence of ‘spontaneous’ change previously described by us. Its meaning and significance is discussed. Under these conditions of ‘spontaneous’ change coronary flow was increased, oxygen consumption decreased and coronary venous oxygen was raised as the coronary A-V oxygen difference declined. This ‘spontaneous’ change shifted the relationship of coronary flow to oxygen consumption. Furthermore, it led to a rise in coronary flow despite an elevation in coronary venous oxygen. It would seem that at this time the energy metabolism of the heart must change in that less oxygen is extracted from the blood despite an increase in its availability. The heart may therefore operate anaerobically in part or may make use of other hydrogen acceptors in the blood. The fact that this kind of metabolism may last as long as an hour or more, excludes the ordinary type of ‘oxygen debt.’

Energy expenditure by elite midget male ice hockey players in small-sided games

2017 ◽  
Vol 12 (4) ◽  
pp. 504-513 ◽  
Author(s):  
Charles-Mathieu Lachaume ◽  
François Trudeau ◽  
Jean Lemoyne
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Ice Hockey ◽  
Training Method ◽  
Hockey Players ◽  
Treadmill Testing ◽  
Effective Training ◽  
Relationship Of ◽  
The Relationship

The purpose of this study was to investigate the energy expenditure and heart rate responses elicited in elite male midget ice hockey players during small-sided games. Nine players (aged 15.89 ± 0.33 years) participated in the study. Maximal progressive treadmill testing in the laboratory measured the relationship of oxygen consumption ([Formula: see text]) to heart rate before on-ice assessments of heart rate during six different small-sided games: 1v1, 2v2, 2v2 with support player, 3v3 with support player, 3v3 with transitions, and 4v4 with two support players. Heart rate was recorded continuously in each game. 3v3 T small-sided game was the most intense for all four intensity markers. All six small-sided games reached 89% HRmax or more with heart rate peaks in active effort repetition. These findings demonstrate that such small-sided games are considered as high intensity games and are an effective training method for ice hockey players.

Effect of Catecholamines, l-Epinephrine and l-Norepinephrine on Coronary Flow and Oxygen Metabolism of the Myocardium

1958 ◽  
Vol 193 (1) ◽  
pp. 151-156 ◽  
Author(s):  
Harold Feinberg ◽  
Louis N. Katz
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Coronary Flow ◽  
Myocardial Oxygen Consumption ◽  
Oxygen Metabolism ◽  
Aortic Pressure ◽  
Coronary Vasodilatation ◽  
Oxygen Difference ◽  
Mean Aortic Pressure

The effect of continuously infused intravenous l-epinephrine and l-norepinephrine (0.1–2.5 gamma/kg/min.) was determined in the open-chest, anesthetized dog prepared for measurement of total coronary flow. Coronary blood flow, myocardial oxygen availability and coronary venous oxygen content consistently increased after catecholamine administration despite wide fluctuations, above and below control values, in heart rate and mean aortic pressure at constant cardiac output. Thus, there was a significant decrease in the coronary arteriovenous oxygen difference after catecholamine administration. The increase in coronary flow and decrease in the coronary A-V oxygen difference were seen even when blood pressure and heart rate were lowered. It is concluded that the departure from the usual relationship between coronary flow and myocardial oxygen consumption is attributable to coronary vasodilatation. However, myocardial oxygen consumption is still the primary factor controlling coronary flow during catecholamine action.

COUNTERPOINT: Theoretical and Empirical Basis for Equating Heart Rate Reserve with V̇o2 Reserve

2021 ◽  
Vol 10 (3) ◽  
pp. 97-101
Author(s):  
David P. Swain ◽  
Barry A. Franklin
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Cardiorespiratory Fitness ◽  
Aerobic Capacity ◽  
Sports Medicine ◽  
Maximal Exercise ◽  
Heart Rate Reserve ◽  
Empirical Basis ◽  
Relationship Of ◽  
The Relationship

ABSTRACT In 1998, the American College of Sports Medicine recommended the use of % heart rate reserve (HRR) and % oxygen consumption reserve (V̇o2R) for providing equivalent exercise intensities based on limited research regarding the relationship of HR and V̇o2 from rest to maximal exercise. It further emphasized that the percentage of aerobic capacity, or %V̇o2max, does not provide equivalent intensities to %HRR and that this discrepancy is greater for individuals with lower levels of cardiorespiratory fitness, especially at low exercise intensities. This point/counterpoint examines additional research to evaluate these relationships.

Role of catecholamines on energetics of the heart and its blood supply

1959 ◽  
Vol 196 (2) ◽  
pp. 394-400 ◽  
Author(s):  
A. Gerola ◽  
H. Feinberg ◽  
L. N. Katz
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Coronary Flow ◽  
Direct Action ◽  
Coronary Vessels ◽  
Mechanical Efficiency ◽  
Oxygen Requirement ◽  
Oxygen Difference

The effects of continuously infused intravenous l-epinephrine and l-norepinephrine (5 gamma/ kg/min.) were determined in the open-chested anesthetized dog prepared for measurement of total coronary flow and myocardial oxygen consumption. When catecholamines were infused at any fixed cardiac output, cardiac oxygen consumption rose in association with increases in blood pressure and heart rate, while cardiac external mechanical efficiency declined. The significance of the product (blood pressure times heart rate) as an index of the total cardiac effort, as indicated by the myocardial oxygen requirement, is considered in view of the alterations brought about by catecholamines in this relationship. The decline in the coronary A-V oxygen difference, the percentage of oxygen extracted by the heart and the ratio (cardiac oxygen consumption/oxygen availability) and the rise in coronary venous oxygen, are all attributed to a direct action of catecholamines on the coronary vessels. Despite their new levels, the coronary venous oxygen, content and the coronary A-V oxygen difference remain fairly constant as the cardiac effort and its oxygen requirement vary during catecholamine infusion.

SOH diagnostic and prognostic of high energy application by the relationship of health indicators

2020 ◽  
Author(s):  
Pyeong-Yeon Lee ◽  
SangUk Kwon ◽  
Deokhun Kang ◽  
SeungYun Han ◽  
Woonki Na ◽  
...  
Keyword(s):  
Health Indicators ◽  
High Energy ◽  
Energy Application ◽  
Relationship Of ◽  
The Relationship

Myocardial oxygen consumption: the role of wall force and shortening

1977 ◽  
Vol 233 (4) ◽  
pp. H421-H430 ◽  
Author(s):  
K. T. Weber ◽  
J. S. Janicki
Keyword(s):  
Coronary Flow ◽  
Myocardial Oxygen Consumption ◽  
Left Ventricular ◽  
Steady State Response ◽  
State Response ◽  
Predominant Factor ◽  
Myocardial O2 Consumption ◽  
The Relationship ◽  
Oxygen Difference

The relationship between the force in the left ventricular wall during systole and myocardial O2 consumption (MVO2) was determined. In addition, the relative influence of the load imposed during shortening and fiber shortening on MVO2 was assessed. For this purpose, 14 servo-regulated, paced, isolated canine hearts were used and the steady-state response in total coronary flow and arteriovenous oxygen difference was measured. For both the isovolumetrically beating and the ejecting ventricle, statistically significant linear relations were observed between MVO2 and the integral of systolic force. These relations were not significantly different from one another, indicating that shortening was not a determinant of MVO2. Moreover, when ejecting an isolumetric beats of equivalent developed force were compared, a difference in MVO2 (deltaMVO2) was found. deltaMVO2 was a function of the force integral difference between these contractions and not fiber shortening. Thus, under the conditions of this experiment, the integral of systolic force that includes developed force and shortening load is the predominant factor regulating MVO2 for any given contractile state, whereas the influence of fiber shortening is negligible.

Relationship of pyruvate and lactate during anaerobic metabolism. V: Coronary adequacy

1961 ◽  
Vol 200 (6) ◽  
pp. 1169-1176 ◽  
Author(s):  
William E. Huckabee
Keyword(s):  
Blood Flow ◽  
Coronary Flow ◽  
Cardiac Tissue ◽  
Anaerobic Metabolism ◽  
Constant Ratio ◽  
Blood Concentrations ◽  
Arterial Blood ◽  
Anesthetized Dogs ◽  
Relationship Of ◽  
The Relationship

Veno-arterial differences of pyruvate and lactate across the myocardium in chloralose-anesthetized dogs were very variable; in any one animal they changed continually with time despite constant blood flow and arterial blood concentrations. There was a systematic tendency of v-a lactate to vary with v-a pyruvate, as expressed in the calculated "Δ excess lactate," which remained nearly constant (or, if blood flow changed, bore a constant ratio to (a-v)O2). No change in Δ excess lactate from control values occurred in nonhypoxic experiments despite marked changes in v-a differences, arterial blood composition, and coronary flow. Cardiac Δ excess lactate became positive in most animals breathing 10% O2 in N2; output of excess lactate was also observed in all those in which moderate muscular exercise was induced. This anaerobic metabolism, or change in the relationship between pyruvate and lactate exchanges, was interpreted as an indication that O2 delivery response was not adequate to meet cardiac tissue requirements during such mild stresses when judged by the standards of adequacy of the basal state.

scholarly journals Heart Rate Dependency and Inter-Lead Variability of the T Peak – T End Intervals

2020 ◽  
Vol 11 ◽  
Author(s):  
Irena Andršová ◽  
Katerina Hnatkova ◽  
Martina Šišáková ◽  
Ondřej Toman ◽  
Peter Smetana ◽  
...  
Keyword(s):  
Heart Rate ◽  
Three Dimensional ◽  
Rate Dependency ◽  
Rate Dependent ◽  
Heart Rate Correction ◽  
Ecg Leads ◽  
Relationship Of ◽  
The Relationship ◽  
Vector Magnitude

The electrocardiographic (ECG) assessment of the T peak–T end (Tpe) intervals has been used in many clinical studies, but several related physiological aspects have not been reported. Specifically, the sources of the Tpe differences between different ECG leads have not been systematically researched, the relationship of Tpe duration to underlying heart rate has not been firmly established, and little is known about the mutual correspondence of Tpe intervals measured in different ECG leads. This study evaluated 796,620 10-s 12-lead ECGs obtained from long-term Holters recorded in 639 healthy subjects (311 female) aged 33.8 ± 9.4 years. For each ECG, transformation to orthogonal XYZ lead was used to measure Tpe in the orthogonal vector magnitude (used as a reference for lead-to-lead comparisons) and to construct a three-dimensional T wave loop. The loop roundness was expressed by a ratio between its circumference and length. These ratios were significantly related to the standard deviation of Tpe durations in different ECG leads. At the underlying heart rate of 60 beats per minute, Tpe intervals were shorter in female than in male individuals (82.5 ± 5.6 vs 90.0 ± 6.5 ms, p < 0.0001). When studying linear slopes between Tpe intervals measured in different leads and the underlying heart rate, we found only minimal heart rate dependency, which was not systematic across the ECG leads and/or across the population. For any ECG lead, positive Tpe/RR slope was found in some subjects (e.g., 79 and 25% of subjects for V2 and V4 measurements, respectively) and a negative Tpe/RR slope in other subjects (e.g., 40 and 65% for V6 and V5, respectively). The steepest positive and negative Tpe/RR slopes were found for measurements in lead V2 and V4, respectively. In all leads, the Tpe/RR slope values were close to zero, indicating, on average, Tpe changes well below 2 ms for RR interval changes of 100 ms. On average, longest Tpe intervals were measured in lead V2, the shortest in lead III. The study concludes that the Tpe intervals measured in different leads cannot be combined. Irrespective of the measured ECG lead, the Tpe interval is not systematically heart rate dependent, and no heart rate correction should be used in clinical Tpe investigations.

scholarly journals Demam pada Penggunaan Analgesia Persalinan Epidural

2020 ◽  
Vol 1 (1) ◽  
pp. 72-9
Author(s):  
Alfan Mahdi Nugroho ◽  
Yusmein Uyun ◽  
Annemarie Chrysantia Melati
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Epidural Analgesia ◽  
Neonatal Seizure ◽  
Increased Temperature ◽  
Fetal Infection ◽  
Labour Epidural Analgesia ◽  
Clinical Consequences ◽  
The Relationship

Analgesia epidural telah diperkenalkan secara rutin sebagai salah satu modalitas analgesia pada proses persalinan sejak lama. Hubungan antara analgesia epidural persalinan dengan demam intrapartum pada maternal sudah disebutkan pada beberapa literatur. Demam didefinisikan sebagai peningkatan suhu tubuh lebih dari 38 oC yang didapat dari dua kali pemeriksaan. Beberapa teori yang disebutkan antara lain perubahan termoregulasi, infeksi pada ibu-janin dan inflamasi non-infeksi yang dimediasi oleh sitokin proinflamasi. Namun demikian berbagai mekanisme analgesia epidural dapat menyebabkan demam masih terus diteliti. Identifikasi demam pada ibu saat persalinan merupakan hal yang penting untuk dilakukan karena memiliki konsekuensi klinis pada ibu dan neonatus. Pada ibu ditemukan suhu yang meningkat dikaitkan dengan peningkatan denyut jantung ibu, curah jantung, konsumsi oksigen, dan produksi katekolamin. Sedangkan pada janin demam intrapartum dapat menyebabkan sepsis, perubahan skor APGAR, peningkatan kebutuhan bantuan napas dan kejadian kejang. Efek demam pada ibu dan janin masih terus dipelajari, sehingga suatu saat didapatkan cara pencegahan yang paling baik yang pada akhirnya menghindarkan keraguan untuk melakukan analgesia persalinan.   Fever during labour epidural analgesia Abstract Epidural analgesia has been routinely introduced as one of the analgesia modalities during labour. Literature has mentioned the relationship between epidural analgesia and intrapartum fever among mothers. Fever is defined as increased temperature above 38 oC in more than two measurements. Several theories have been proposed, inculing thermoregulation changes, mother-fetal infection, and non-infectious inflammation mediated by proinflammatory cytokines. However, these mechanisms have been continued to evolve. Fever identification in pregnant women is essential to recognize clinical consequences to both mothers and neonates. Increased temperature in mothers is associated with increased heart rate, cardiac output, oxygen consumption, and catecholamines production. Meanwhile, in neonates intrapartum fever is related to sepsis, APGAR score changes, the need of respiratory support and incidence of neonatal seizure. Therefore, these consequences are extensively studied in order to determine the appropriate prevention.

Effect of heart rate on the relation between global and regional cardiac work and oxygen consumption

1988 ◽  
Vol 20 (2) ◽  
pp. III-III
Author(s):  
M SCHEINOWITZ ◽  
J SONN ◽  
J KEDEM ◽  
H WEISS
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Cardiac Work
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