Addition of minute ventilation to rate-response pacing improves heart rate score more than accelerometer alone

Heart Rhythm ◽  
2018 ◽  
Vol 15 (11) ◽  
pp. 1730-1735 ◽  
Author(s):  
Mark Richards ◽  
Brian Olshansky ◽  
Arjun D. Sharma ◽  
Nicholas Wold ◽  
Paul Jones ◽  
...  
Keyword(s):  
Heart Rate ◽  
Minute Ventilation ◽  
Rate Score

scholarly journals HEART RATE SCORE, A MEASURE RELATED to CHRONOTROPIC INCOMPETENCE IN PACEMAKER PATIENTS

2021 ◽  
Author(s):  
Arjun D. Sharma ◽  
Mark Richards ◽  
Brian Olshansky ◽  
Nicholas Wold ◽  
Paul Jones ◽  
...  
Keyword(s):  
Heart Rate ◽  
Chronotropic Incompetence ◽  
Rate Score

Cerebral oxygen availability by NIR spectroscopy during transient hypoxia in humans

1990 ◽  
Vol 69 (3) ◽  
pp. 907-913 ◽  
Author(s):  
N. B. Hampson ◽  
E. M. Camporesi ◽  
B. W. Stolp ◽  
R. E. Moon ◽  
J. E. Shook ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Volume ◽  
Near Infrared ◽  
Cerebral Blood Volume ◽  
Minute Ventilation ◽  
Nir Spectroscopy ◽  
Redox Status ◽  
Total Blood ◽  
Arterial Ph

The effects of mild hypoxia on brain oxyhemoglobin, cytochrome a,a3 redox status, and cerebral blood volume were studied using near-infrared spectroscopy in eight healthy volunteers. Incremental hypoxia reaching 70% arterial O2 saturation was produced in normocapnia [end-tidal PCO2 (PETCO2) 36.9 +/- 2.6 to 34.9 +/- 3.4 Torr] or hypocapnia (PETCO2 32.8 +/- 0.6 to 23.7 +/- 0.6 Torr) by an 8-min rebreathing technique and regulation of inspired CO2. Normocapnic hypoxia was characterized by progressive reductions in arterial PO2 (PaO2, 89.1 +/- 3.5 to 34.1 +/- 0.1 Torr) with stable PETCO2, arterial PCO2 (PaCO2), and arterial pH and resulted in increases in heart rate (35%) systolic blood pressure (14%), and minute ventilation (5-fold). Hypocapnic hypoxia resulted in progressively decreasing PaO2 (100.2 +/- 3.6 to 28.9 +/- 0.1 Torr), with progressive reduction in PaCO2 (39.0 +/- 1.6 to 27.3 +/- 1.9 Torr), and an increase in arterial pH (7.41 +/- 0.02 to 7.53 +/- 0.03), heart rate (61%), and ventilation (3-fold). In the brain, hypoxia resulted in a steady decline of cerebral oxyhemoglobin content and a decrease in oxidized cytochrome a,a3. Significantly greater loss of oxidized cytochrome a,a3 occurred for a given decrease in oxyhemoglobin during hypocapnic hypoxia relative to normocapnic hypoxia. Total blood volume response during hypoxia also was significantly attenuated by hypocapnia, because the increase in volume was only half that of normocapnic subjects. We conclude that cytochrome a,a3 oxidation level in vivo decreases at mild levels of hypoxia. PaCO is an important determinant of brain oxygenation, because it modulates ventilatory, cardiovascular, and cerebral O2 delivery responses to hypoxia.

Respiratory and cardiovascular responses to static handgrip exercise in humans

1993 ◽  
Vol 75 (6) ◽  
pp. 2789-2796 ◽  
Author(s):  
G. A. Fontana ◽  
T. Pantaleo ◽  
F. Bongianni ◽  
F. Cresci ◽  
R. Manconi ◽  
...  
Keyword(s):  
Heart Rate ◽  
Time Course ◽  
Minute Ventilation ◽  
Muscle Tension ◽  
Maximum Voluntary Contraction ◽  
Cardiovascular Responses ◽  
Inspiratory Flow ◽  
Electromyographic Activity ◽  
Handgrip Exercise ◽  
Cardiovascular Variables

We studied the time course of respiratory and cardiovascular responses by evaluating changes in the breathing pattern, mean blood pressure (MBP), and heart rate elicited by 3 min of static handgrip at 15, 25, and 30% of the maximum voluntary contraction (MVC) in 15 healthy volunteers. Muscle tension and integrated electromyographic activity remained fairly constant during each trial. During 15% MVC bouts, initially only mean inspiratory flow increased; then, tidal volume and minute ventilation (VI) also rose progressively. No significant changes in MBP and heart rate were observed. During 25 and 30% MVC bouts, not only did mean inspiratory flow, VT, and VI increase but MBP and heart rate increased as well. A slight and delayed rise in respiratory rate was also observed. Unlike 15 and 25% MVC handgrip, 30% MVC handgrip caused a small decrease in end-tidal PCO2. Changes in the pattern of breathing occurred more promptly than those in cardiovascular variables in the majority of subjects. Furthermore, we found a positive correlation between changes in VI and those in cardiovascular variables at the end of 25 and 30% MVC trials. This study indicates that respiratory and cardiovascular responses to static handgrip exercise are controlled independently.

Control of ventilation in elite synchronized swimmers

1987 ◽  
Vol 63 (3) ◽  
pp. 1019-1024 ◽  
Author(s):  
R. L. Bjurstrom ◽  
R. B. Schoene
Keyword(s):  
Heart Rate ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Mean Value ◽  
Heart Rate Change ◽  
Breath Holding ◽  
Breath Hold ◽  
Lung Volumes ◽  
Co2 Partial Pressure ◽  
Control Of Ventilation

Synchronized swimmers perform strenuous underwater exercise during prolonged breath holds. To investigate the role of the control of ventilation and lung volumes in these athletes, we studied the 10 members of the National Synchronized Swim Team including an olympic gold medalist and 10 age-matched controls. We evaluated static pulmonary function, hypoxic and hypercapnic ventilatory drives, and normoxic and hyperoxic breath holding. Synchronized swimmers had an increased total lung capacity and vital capacity compared with controls (P less than 0.005). The hypoxic ventilatory response (expressed as the hyperbolic shape parameter A) was lower in the synchronized swimmers than controls with a mean value of 29.2 +/- 2.6 (SE) and 65.6 +/- 7.1, respectively (P less than 0.001). The hypercapnic ventilatory response [expressed as S, minute ventilation (1/min)/alveolar CO2 partial pressure (Torr)] was no different between synchronized swimmers and controls. Breath-hold duration during normoxia was greater in the synchronized swimmers, with a mean value of 108.6 +/- 4.8 (SE) vs. 68.03 +/- 8.1 s in the controls (P less than 0.001). No difference was seen in hyperoxic breath-hold times between groups. During breath holding synchronized swimmers demonstrated marked apneic bradycardia expressed as either absolute or heart rate change from basal heart rate as opposed to the controls, in whom heart rate increased during breath holds. Therefore the results show that elite synchronized swimmers have increased lung volumes, blunted hypoxic ventilatory responses, and a marked apneic bradycardia that may provide physiological characteristics that offer a competitive advantage for championship performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Optimal Position for a Spinal Tap in Preterm Infants

PEDIATRICS ◽  
1983 ◽  
Vol 71 (1) ◽  
pp. 31-35 ◽  
Author(s):  
Christine A. Gleason ◽  
Richard J. Martin ◽  
John V. Anderson ◽  
Waldemar A. Carlo ◽  
Kathleen J. Sanniti ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Preterm Infants ◽  
Minute Ventilation ◽  
Upright Position ◽  
Neck Extension ◽  
Variable Effect ◽  
Optimal Position ◽  
Major Mechanism ◽  
Transcutaneous Po2

Inasmuch as spinal taps in preterm infants are frequently accompanied by clinical deterioration, the optimal position for this procedure was investigated. Three positions were each randomly assigned for five minutes to 17 healthy preterm infants without a spinal tap actually being performed: (1) lateral recumbent with full flexion (flexed position), (2) lateral recumbent with partial neck extension (extended position), and (3) sitting with head support and spine flexion (upright position). Transcutaneous Po2 and Pco2 were monitored in all infants, minute ventilation (V1) in seven, and heart rate and blood pressure in ten infants. Mean transcutaneous Po2 decreased in each of the three positions. This decrease was significantly greater in the flexed (28 ± 8 mm Hg) as compared with the extended (18 ± 8 mm Hg, P < .001) and upright (15 ± 11 mm Hg, P < .001) positions. Mean transcutaneous Pco2 increased only in the flexed position (3 ± 4 mm Hg, P < .005) and levels were still elevated five minutes after that position had been discontinued. The consistent decrease in transcutaneous Po2 was accompanied by a variable effect of positioning on V1 and there were no episodes of airway obstruction or apnea >10 seconds. Heart rate increased in each position whereas blood pressure remained unchanged. These data suggest that although hypoventilation may contribute to the observed decrease in transcutaneous Po2, ventilation/perfusion imbalance appears to be the major mechanism. As spinal taps performed in the widely accepted flexed position carry the greatest risk of potential morbidity, it is recommended that this position be modified with neck extension or that spinal taps be performed in the upright position.

scholarly journals Comparing Airborne Particulate Matter Intake Dose Assessment Models Using Low-Cost Portable Sensor Data

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1406
Author(s):  
Rok Novak ◽  
David Kocman ◽  
Johanna Amalia Robinson ◽  
Tjaša Kanduč ◽  
Dimosthenis Sarigiannis ◽  
...  
Keyword(s):  
Heart Rate ◽  
Particulate Matter ◽  
Low Cost ◽  
Minute Ventilation ◽  
Dose Assessment ◽  
Sensor Data ◽  
Activity Data ◽  
Time Activity ◽  
Activity Monitors ◽  
Coarse Information

Low-cost sensors can be used to improve the temporal and spatial resolution of an individual’s particulate matter (PM) intake dose assessment. In this work, personal activity monitors were used to measure heart rate (proxy for minute ventilation), and low-cost PM sensors were used to measure concentrations of PM. Intake dose was assessed as a product of PM concentration and minute ventilation, using four models with increasing complexity. The two models that use heart rate as a variable had the most consistent results and showed a good response to variations in PM concentrations and heart rate. On the other hand, the two models using generalized population data of minute ventilation expectably yielded more coarse information on the intake dose. Aggregated weekly intake doses did not vary significantly between the models (6–22%). Propagation of uncertainty was assessed for each model, however, differences in their underlying assumptions made them incomparable. The most complex minute ventilation model, with heart rate as a variable, has shown slightly lower uncertainty than the model using fewer variables. Similarly, among the non-heart rate models, the one using real-time activity data has less uncertainty. Minute ventilation models contribute the most to the overall intake dose model uncertainty, followed closely by the low-cost personal activity monitors. The lack of a common methodology to assess the intake dose and quantifying related uncertainties is evident and should be a subject of further research.

Using heart rate to estimate the minute ventilation and inhaled load of air pollutants

2020 ◽  
pp. 143011
Author(s):  
Qian Guo ◽  
Yuchen Zhao ◽  
Jing Shao ◽  
Suzhen Cao ◽  
Qirong Wang ◽  
...  
Keyword(s):  
Heart Rate ◽  
Air Pollutants ◽  
Minute Ventilation

Heart rate score predicts mortality independent of shocks in ICD and CRT-D patients

2019 ◽  
Vol 58 (1) ◽  
pp. 103-111
Author(s):  
Brian Olshansky ◽  
Mark Richards ◽  
Arjun D. Sharma ◽  
Paul W. Jones ◽  
Nick Wold ◽  
...  
Keyword(s):  
Heart Rate ◽  
Rate Score

Effects of N2O narcosis on breathing and effort sensations during exercise and inspiratory resistive loading

1996 ◽  
Vol 81 (4) ◽  
pp. 1562-1571 ◽  
Author(s):  
D. M. Fothergill ◽  
N. A. Carlson
Keyword(s):  
Heart Rate ◽  
Steady State ◽  
Minute Ventilation ◽  
Esophageal Pressure ◽  
Incremental Exercise ◽  
Time To Exhaustion ◽  
Gas Mixture ◽  
Resistive Loading ◽  
Inspiratory Resistance ◽  
Sufficient Magnitude

Fothergill, D. M., and N. A. Carlson. Effects of N2O narcosis on breathing and effort sensations during exercise and inspiratory resistive loading. J. Appl. Physiol. 81(4): 1562–1571, 1996.—The influence of nitrous oxide (N2O) narcosis on the responses to exercise and inspiratory resistive loading was studied in thirteen male US Navy divers. Each diver performed an incremental bicycle exercise test at 1 ATA to volitional exhaustion while breathing a 23% N2O gas mixture and a nonnarcotic gas of the same [Formula: see text], density, and viscosity. The same gas mixtures were used during four subsequent 30-min steady-state submaximal exercise trials in which the subjects breathed the mixtures both with and without an inspiratory resistance (5.5 vs. 1.1 cmH2O ⋅ s ⋅ l−1at 1 l/s). Throughout each test, subjective ratings of respiratory effort (RE), leg exertion, and narcosis were obtained with a category-ratio scale. The level of narcosis was rated between slight and moderate for the N2O mixture but showed great individual variation. Perceived leg exertion and the time to exhaustion were not significantly different with the two breathing mixtures. Heart rate was unaffected by the gas mixture and inspiratory resistance at rest and during steady-state exercise but was significantly lower with the N2O mixture during incremental exercise ( P< 0.05). Despite significant increases in inspiratory occlusion pressure (13%; P < 0.05), esophageal pressure (12%; P < 0.001), expired minute ventilation (4%; P < 0.01), and the work rate of breathing (15%; P < 0.001) when the subjects breathed the N2O mixture, RE during both steady-state and incremental exercise was 25% lower with the narcotic gas than with the nonnarcotic mixture ( P < 0.05). We conclude that the narcotic-mediated changes in ventilation, heart rate, and RE induced by 23% N2O are not of sufficient magnitude to influence exercise tolerance at surface pressure. Furthermore, the load-compensating respiratory reflexes responsible for maintaining ventilation during resistive breathing are not depressed by N2O narcosis.

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