Heart Rate/Stroke Volume Relationship During Upright Exercise in Long-Term Diabetics

1993 ◽  
Vol 18 (2) ◽  
pp. 148-162
Author(s):  
R. G. Haennel ◽  
K. K. Teo ◽  
A. Suthijumroon ◽  
M. P. J. Senaratne ◽  
M. Hetherington ◽  
...  
Keyword(s):  
Heart Rate ◽  
Stroke Volume ◽  
Cardiac Function ◽  
Autonomic Function ◽  
Valsalva Maneuver ◽  
Peak Exercise ◽  
Initial Increase ◽  
Key Words Diabetes Mellitus ◽  
Key Words Diabetes ◽  
Deep Breathing

The changes in stroke volume (SV) during upright exercise were studied in 20 insulin-dependent diabetics (IDDM) and 20 age- and sex-matched controls. None of the diabetics had any cardiovascular symptoms. In addition, tests of autonomic function were conducted in the diabetics, assessing changes in heart rate (HR) during deep breathing and the Valsalva maneuver. During exercise the SV in the controls gradually increased and then remained essentially unchanged until maximum HR was achieved. Seven of the diabetics failed to sustain an initial increase in SV (fall > 15%), eight showed a "delayed" increase in SV, and the remaining five demonstrated an increasing SV over the range from rest to peak exercise. Abnormal autonomic function results were found during deep breathing (four diabetics) and the Valsalva maneuver (four diabetics). Findings indicate that cardiac function could be abnormal in IDDM without evidence of autonomic dysfunction. This abnormality could be due to a specific cardiomyopathy. Key words: diabetes mellitus, cardiac function, upright exercise, autonomic neuropathy, cardiomyopathy

Abstract 17165: Natural History of Cardiac Function in Patients With Atrial Fibrillation Pre- and Post- Ablation

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Lisa YW Tang ◽  
Kendall Ho ◽  
Nathaniel Hawkins ◽  
Roger Tam ◽  
Michael Lim ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Heart Rate ◽  
Natural History ◽  
Cardiac Function ◽  
Older Patients ◽  
Autonomic Function ◽  
Pronounced Increase ◽  
Success Group ◽  
History Of ◽  
Future Work

Intro: The natural history of cardiac function in atrial fibrillation (AF) patients undergoing pulmonary vein isolation (PVI) is incompletely described, as are heart rate patterns pre- and post-ablation. Goals: Examine autonomic status pre- and post-ablation using cardiac data (n=346) captured by implanted recorders Methods: Daily records (90-day pre to 365-day post ablation) were analyzed to extract parameters viz. heart rate variability (HRV), daytime heart rate (DHR) and nighttime heart rate (NHR). Analysis of variance was used to assess relationships between covariates (age, sex, etc.) and pre-post changes in parameters. We define "success" as patients who had no recurrence during post-ablation period per guidelines (“failed” otherwise). Results: Prior to ablation, mean DHR, NHR, and HRV were 69±10bpm, 60±9bpm, 122±32msec, respectively. After PVI, there was an immediate increase of ~5bpm in DHR (P<1e-4) and a more pronounced increase of ~11bpm in NHR (P<1e-4). HRV exhibited an immediate post-ablation peak decreasing by ~60msec (P<1e-4), with rapid recalibration over the first 10 post ablation days (increase of 20-25msec). Antiarrhythmic drug-use was a significant factor only in explaining changes in HRV (P=0.0126), while age was a significant factor only for the changes in DHR (P<1e-4). Comparing between subgroups, DHR and NHR were generally higher in the success than the failed group. At baseline, older patients (92 patients were of age>65years) had a significantly lower DHR and NHR than younger patients (117 were of age<56years). These age-based differences were amplified post ablation in DHR and NHR, but not HRV. Conclusions: PVI results in significant and sustained changes in heart rate parameters related to autonomic function. This relationship was observed globally, with the success group having significantly greater rises in DHR and NHR when compared to the failed group. Future work will explore whether these patterns exist in different cohorts.

scholarly journals CARDIAC FUNCTION DURING MINI-INVASIVE REPAIR OF PECTUS EXCAVATUM WITH THE NUSS PROCEDURE

2021 ◽  
Vol 74 (8) ◽  
pp. 1809-1815
Author(s):  
Ulbolhan A. Fesenko ◽  
Ivan Myhal
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Cardiac Index ◽  
Stroke Volume ◽  
Cardiac Function ◽  
Epidural Anaesthesia ◽  
Pectus Excavatum ◽  
Stroke Volume Index ◽  
Volume Index ◽  
Nuss Procedure

The aim of the study was to analyze cardiac function during Nuss procedure under the combination of general anesthesia with different variants of the regional block. Materials and methods: The observative prospective study included 60 adolescents (boys/girls=47/13) undergone Nuss procedure for pectus excavatum correction under the combination of general anaesthesia and regional blocks. The patients were randomized into three groups (n=20 in each) according to the perioperative regional analgesia technique: standart epidural anaesthesia (SEA), high epidural anaesthesia (HEA) and bilateral paravertebral anaesthesia (PVA). The following parameters of cardiac function were analyzed: heart rate, estimated cardiac output (esCCO), cardiac index (esCCI), stroke volume (esSV) and stroke volume index (esSVI) using non-invasive monitoring. Results: Induction of anesthesia and regional blocks led to a significant decrease in esCCO (-9.4%) and esCCI (-9.8%), while esSV and esSVI remained almost unchanged in all groups (H=4.9; p=0.09). At this stage, the decrease in cardiac output was mainly due to decreased heart rate. At the stage of sternal elevation we found an increase in esSV, which was more pronounced in the groups of epidural blocks (+23.1% in HEA and +18.5% in SEA). After awakening from anesthesia and tracheal extubation esSV was by 11% higher than before surgery without ingergroup difference. Conclusions: The Nuss procedure for pectus excavatum correction lead to improved cardiac function. increase in stroke volume and its index were more informative than cardiac output and cardiac index which are dependent on heart rate that is under the influence of anaesthesia technique.

scholarly journals Comparison of Autonomic Function using Valsalva Ratio, Heart Rate, and Blood Pressure in Meditators and Nonmeditators

2017 ◽  
Vol 1 (1) ◽  
pp. 6-9
Author(s):  
Roopam Bassi ◽  
Kiran   ◽  
Kawalinder Girgla
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Autonomic Function ◽  
Valsalva Maneuver ◽  
Well Being ◽  
Control Group ◽  
Relaxation Techniques ◽  
Mean Values ◽  
The Mean ◽  
The Difference

ABSTRACT Introduction In recent years, the various health benefits of meditation have been acknowledged by the scientific community as well as by the public. Apart from its physiological benefits, it can also improve the psychological and spiritual well-being. A case–control study was planned to investigate the effect of Rajyoga Meditation on cardiovascular autonomic activity in meditators and nonmeditators. Materials and methods The study was conducted on 100 subjects, randomized into two groups: meditators (n = 50; age 35.80 ± 7.69 years) and nonmeditators (n = 50; age 36.76 ± 6.38 years). The meditator group practiced meditation for 30 minutes in the morning as well as in the evening. The control group did not practice any type of meditation or relaxation techniques. The cardiovascular parameters – heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP), and Valsalva maneuver tests – were performed in both the groups in the same environmental conditions. The data were compiled and analyzed using unpaired t test. Results The mean values of HR in meditators and the control group were 77.08 ± 5.39 and 80.68 ± 5.71 respectively, and the difference was statistically significant (p < 0.001). The mean values of SBP in meditators and nonmeditators were 124.60 ± 5.39 and 129.56 ± 4.30 mm Hg respectively, while those for DBP were 77.84 ± 4.65 and 80.80 ± 4.78 mm Hg respectively. The difference in both was statistically significant. In meditators, Valsalva ratio was 1.60 ± 0.20, while in nonmeditators, it was 1.33 ± 0.13, and the difference was highly significant. Conclusion Significant improvement is seen in physiological, cardiac, and parasympathetic parameters in Rajyoga meditators. A shift of the autonomic balance toward the parasympathetic side is seen. By purposefully energizing the parasympathetic system by meditation, we can combat the ill effects of stress and help heal many health conditions. How to cite this article Kiran, Thaman RG, Bassi R, Girgla K. Comparison of Autonomic Function using Valsalva Ratio, Heart Rate, and Blood Pressure in Meditators and Nonmeditators. Curr Trends Diagn Treat 2017;1(1):6-9.

Mechanisms for increasing stroke volume during static exercise with fixed heart rate in humans

1997 ◽  
Vol 83 (3) ◽  
pp. 712-717 ◽  
Author(s):  
Antonio C. L. Nóbrega ◽  
Jon W. Williamson ◽  
Jorge A. Garcia ◽  
Jere H. Mitchell
Keyword(s):  
Heart Rate ◽  
Stroke Volume ◽  
Knee Extension ◽  
Left Ventricular ◽  
Voluntary Contraction ◽  
Peak Exercise ◽  
Ventricular Contractility ◽  
Static Exercise ◽  
Systolic Volume ◽  
End Diastolic Volume

Nóbrega, Antonio C. L., Jon W. Williamson, Jorge A. Garcia, and Jere H. Mitchell. Mechanisms for increasing stroke volume during static exercise with fixed heart rate in humans. J. Appl. Physiol. 83(3): 712–717, 1997.—Ten patients with preserved inotropic function having a dual-chamber (right atrium and right ventricle) pacemaker placed for complete heart block were studied. They performed static one-legged knee extension at 20% of their maximal voluntary contraction for 5 min during three conditions: 1) atrioventricular sensing and pacing mode [normal increase in heart rate (HR; DDD)], 2) HR fixed at the resting value (DOO-Rest; 73 ± 3 beats/min), and 3) HR fixed at peak exercise rate (DOO-Ex; 107 ± 4 beats/min). During control exercise (DDD mode), mean arterial pressure (MAP) increased by 25 mmHg with no change in stroke volume (SV) or systemic vascular resistance. During DOO-Rest and DOO-Ex, MAP increased (+25 and +29 mmHg, respectively) because of a SV-dependent increase in cardiac output (+1.3 and +1.8 l/min, respectively). The increase in SV during DOO-Rest utilized a combination of increased contractility and the Frank-Starling mechanism (end-diastolic volume 118–136 ml). However, during DOO-Ex, a greater left ventricular contractility (end-systolic volume 55–38 ml) mediated the increase in SV.

scholarly journals Abnormal cardiovascular response to nitroglycerin in migraine

Cephalalgia ◽  
2019 ◽  
Vol 40 (3) ◽  
pp. 266-277
Author(s):  
Willebrordus PJ van Oosterhout ◽  
Guus G Schoonman ◽  
Dirk P Saal ◽  
Roland D Thijs ◽  
Michel D Ferrari ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Total Peripheral Resistance ◽  
Cardiovascular Response ◽  
Peripheral Resistance ◽  
Cardiovascular Responses ◽  
Initial Increase

Introduction Migraine and vasovagal syncope are comorbid conditions that may share part of their pathophysiology through autonomic control of the systemic circulation. Nitroglycerin can trigger both syncope and migraine attacks, suggesting enhanced systemic sensitivity in migraine. We aimed to determine the cardiovascular responses to nitroglycerin in migraine. Methods In 16 women with migraine without aura and 10 age- and gender-matched controls without headache, intravenous nitroglycerin (0.5 µg·kg−1·min−1) was administered. Finger photoplethysmography continuously assessed cardiovascular parameters (mean arterial pressure, heart rate, cardiac output, stroke volume and total peripheral resistance) before, during and after nitroglycerin infusion. Results Nitroglycerin provoked a migraine-like attack in 13/16 (81.2%) migraineurs but not in controls ( p = .0001). No syncope was provoked. Migraineurs who later developed a migraine-like attack showed different responses in all parameters vs. controls (all p < .001): The decreases in cardiac output and stroke volume were more rapid and longer lasting, heart rate increased, mean arterial pressure and total peripheral resistance were higher and decreased steeply after an initial increase. Discussion Migraineurs who developed a migraine-like attack in response to nitroglycerin showed stronger systemic cardiovascular responses compared to non-headache controls. The stronger systemic cardiovascular responses in migraine suggest increased systemic sensitivity to vasodilators, possibly due to insufficient autonomic compensatory mechanisms.

Maximum cardiac performance of rainbow trout (Oncorhynchus mykiss) at temperatures approaching their upper lethal limit

1996 ◽  
Vol 199 (3) ◽  
pp. 663-672 ◽  
Author(s):  
A Farrell ◽  
A Gamperl ◽  
J Hicks ◽  
H Shiels ◽  
K Jain
Keyword(s):  
Heart Rate ◽  
Rainbow Trout ◽  
Stroke Volume ◽  
Cardiac Function ◽  
Cardiac Performance ◽  
Preferred Temperature ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Lethal Limit ◽  
Q10 Values

Numerous studies have examined the effect of temperature on in vivo and in situ cardiovascular function in trout. However, little information exists on cardiac function at temperatures near the trout's upper lethal limit. This study measured routine and maximum in situ cardiac performance in rainbow trout (Oncorhynchus mykiss) following acclimation to 15, 18 and 22 &deg;C, under conditions of tonic (30 nmol l-1), intermediate (60 nmol l-1) and maximal (200 nmol l-1) adrenergic stimulation. Heart rate increased significantly with both temperature and adrenaline concentration. The Q10 values for heart rate ranged from 1.28 at 30 nmol l-1 adrenaline to 1.36 at 200 nmol l-1 adrenaline. In contrast to heart rate, maximum stroke volume declined by approximately 20 % (from 1.0 to 0.8 ml kg-1) as temperature increased from 15 to 22 &deg;C. This decrease was not alleviated by maximally stimulating the heart with 200 nmol l-1 adrenaline. Because of the equal and opposite effects of increasing temperature on heart rate and stroke volume, maximum cardiac output did not increase between 15 and 22 &deg;C. Maximum power output decreased (by approximately 10-15 %) at all adrenaline concentrations as temperature increased. This reduction reflected a poorer pressure-generating ability at temperatures above 15 &deg;C. These results, in combination with earlier work, suggest (1) that peak cardiac performance occurs around the trout's preferred temperature and well below its upper lethal limit; (2) that the diminished cardiac function concomitant with acclimation to high temperatures was associated with inotropic failure; (3) that Q10 values for cardiac rate functions, other than heart rate per se, have a limited predictive value at temperatures above the trout's preferred temperature; and (4) that heart rate is a poor indicator of cardiac function at temperatures above 15 &deg;C.

Cardiovagal Reflexes

2009 ◽  
pp. 661-676
Author(s):  
William P. Cheshire
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Phase Ii ◽  
Heart Rate Response ◽  
Valsalva Maneuver ◽  
Human Subjects ◽  
Simultaneous Recording ◽  
Deep Breathing ◽  
Noninvasive Technique ◽  
Phase Iv

Noninvasive cardiovascular tests are reliable and reproducible and are widely used to evaluate autonomic function in human subjects. The heart rate response to deep breathing is probably the most reliable test for assessing the integrity of the vagal afferent and efferent pathways to the heart. This is because respiratory sinus arrhythmia is a relatively pure test of cardiovagal function, whereas many other conditions, such as plasma volume, antecedent rest, and cardiac and peripheral sympathetic functions, factor into the Valsalva response. Heart rate variability to deep breathing is usually tested at a breathing frequency of 5 or 6 respirations per minute and decreases linearly with age. The Valsalva maneuver consists of a forced expiratory effort against resistance and produces mechanical (phases I and III) and reflex (phases II and IV) changes in arterial pressure and heart rate. When performed under continuous arterial pressure monitoring with a noninvasive technique, the Valsalva maneuver provides valuable information about the integrity of the cardiac parasympathetic, cardiac sympathetic, and sympathetic vasomotor outputs. The responses to the Valsalva maneuver are affected by the position of the subject and the magnitude and duration of the expiratory effort. In general, it is performed at an expiratory pressure of 40 mm Hg sustained for 15 seconds. The Valsalva ratio, the relationship between the maximal heart rate response during phase II (straining) and phase IV (after release of straining), has been considered a test of cardiac parasympathetic function. However, without simultaneous recording of arterial pressure, this may be misleading. An exaggerated decrease in arterial pressure during phase II suggests sympathetic vasomotor failure, whereas an absence of overshoot during phase IV indicates the inability to increase cardiac output and cardiac adrenergic failure.

Cardiovascular Reflexes in Patients With Vascular Headache

Cephalalgia ◽  
1992 ◽  
Vol 12 (6) ◽  
pp. 360-364 ◽  
Author(s):  
Rosario Martín ◽  
Cristina Ribera ◽  
Jose Manuel Moltó ◽  
Carolina Ruiz ◽  
Luz Galiano ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Healthy Volunteers ◽  
Migraine Without Aura ◽  
Autonomic Function ◽  
Heart Rate Response ◽  
Cardiovascular Reflexes ◽  
Deep Breathing ◽  
Vascular Headache ◽  
Cardiovascular Reflex

We have investigated the autonomic function of 75 patients with migraine by examining cardiovascular reflex function. The results were compared with those of 78 healthy volunteers. Measurements were made between attacks. Patients with migraine showed a smaller heart-rate response to deep breathing but a greater heart-rate response and higher blood pressure to standing when compared to controls. Migraine patients had a higher percentage of established sympathetic lesions (51% vs 17%) and severe (25% vs 5%) or atypical (24% vs 11.5%) global autonomic dysfunction. No significant differences were found among patients with migraine with aura, migraine without aura, and migraine with prolonged aura. Our findings indicate that patients with migraine have sympathetic hypofunction.

Operation Everest II: preservation of cardiac function at extreme altitude

1987 ◽  
Vol 63 (2) ◽  
pp. 531-539 ◽  
Author(s):  
J. T. Reeves ◽  
B. M. Groves ◽  
J. R. Sutton ◽  
P. D. Wagner ◽  
A. Cymerman ◽  
...  
Keyword(s):  
Heart Rate ◽  
Stroke Volume ◽  
Cardiac Function ◽  
Barometric Pressure ◽  
Right Atrial ◽  
O2 Uptake ◽  
Arterial Blood ◽  
Extreme Altitude ◽  
Chronic Hypoxemia ◽  
Ventricular Filling

Hypoxia at high altitude could depress cardiac function and decrease exercise capacity. If so, impaired cardiac function should occur with the extreme, chronic hypoxemia of the 40-day simulated climb of Mt. Everest (8,840 m, barometric pressure of 240 Torr, inspiratory O2 pressure of 43 Torr). In the five of eight subjects having resting and exercise measurements at the barometric pressures of 760 Torr (sea level), 347 Torr (6,100 m), 282 Torr (7,620 m), and 240 Torr, heart rate for a given O2 uptake was higher with more severe hypoxia. Slight (6 beats/min) slowing of the heart rate occurred only during exercise at the lowest barometric pressure when arterial blood O2 saturations were less than 50%. O2 breathing reversed hypoxemia but never increased heart rate, suggesting that hypoxic depression of rate, if present, was slight. For a given O2 uptake, cardiac output was maintained. The decrease in stroke volume appeared to reflect decreased ventricular filling (i.e., decreased right atrial and wedge pressures). O2 breathing did not increase stroke volume for a given filling pressure. We concluded that extreme, chronic hypoxemia caused little or no impairment of cardiac rate and pump functions.

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