Deceleration capacity of heart rate and periodic repolarization dynamics during normobaric hypoxia

2020 ◽  
Vol 30 (6) ◽  
pp. 1087-1089
Author(s):  
Wolfgang Hamm ◽  
Florian Maier ◽  
Sari Kassem ◽  
Dominik Schüttler ◽  
Axel Bauer ◽  
...  
Keyword(s):  
Heart Rate ◽  
Normobaric Hypoxia ◽  
Deceleration Capacity ◽  
Repolarization Dynamics ◽  
Periodic Repolarization Dynamics

Deceleration Capacity and Periodic Repolarization Dynamics As Predictors of Acute Mountain Sickness

2020 ◽  
Vol 21 (4) ◽  
pp. 417-422
Author(s):  
Wolfgang Hamm ◽  
Sari Kassem ◽  
Lukas von Stülpnagel ◽  
Florian Maier ◽  
Mathias Klemm ◽  
...  
Keyword(s):  
Acute Mountain Sickness ◽  
Deceleration Capacity ◽  
Mountain Sickness ◽  
Repolarization Dynamics ◽  
Periodic Repolarization Dynamics

scholarly journals Periodic repolarization dynamics in a patient with subacute myocarditis

2021 ◽  
Author(s):  
Dominik Schüttler ◽  
Wolfgang Hamm ◽  
Ulrich Grabmaier ◽  
Adrian Curta ◽  
Axel Bauer ◽  
...  
Keyword(s):  
Repolarization Dynamics ◽  
Periodic Repolarization Dynamics

scholarly journals P5521Impaired circadian properties of Beat to Beat Deceleration Capacity of heart rate predict arrhythmic events in heart failure patients

2017 ◽  
Vol 38 (suppl_1) ◽  
Author(s):  
P. Arsenos ◽  
G. Manis ◽  
K.A. Gatzoulis ◽  
P. Dilaveris ◽  
S. Sideris ◽  
...  
Keyword(s):  
Heart Failure ◽  
Heart Rate ◽  
Deceleration Capacity ◽  
Heart Failure Patients

scholarly journals The Diagnostic Value of Cardiac Deceleration Capacity in Vasovagal Syncope

2020 ◽  
Vol 13 (12) ◽  
Author(s):  
Lihui Zheng ◽  
Wei Sun ◽  
Shangyu Liu ◽  
Erpeng Liang ◽  
Zhongpeng Du ◽  
...  
Keyword(s):  
Heart Rate ◽  
Vasovagal Syncope ◽  
Diagnostic Value ◽  
Control Group ◽  
Vagal Activity ◽  
Tilt Table Test ◽  
Tilt Table ◽  
Good Tool ◽  
Deceleration Capacity ◽  
Vagal Control

Background: Increased parasympathetic activity is thought to play important roles in syncope events of patients with vasovagal syncope (VVS). However, direct measurements of the vagal control are difficult. The novel deceleration capacity (DC) of heart rate measure has been used to characterize the vagal modulation. This study aimed to assess vagal control in patients with VVS and evaluate the diagnostic value of the DC in VVS. Methods: Altogether, 161 consecutive patients with VVS (43±15 years; 62 males) were enrolled. Tilt table test was positive in 101 and negative in 60 patients. Sixty-five healthy subjects were enrolled as controls. DC and heart rate variability in 24-hour ECG, echocardiogram, and biochemical examinations were compared between the syncope and control groups. Results: DC was significantly higher in the syncope group than in the control group (9.6±3.3 versus 6.5±2.0 ms, P <0.001). DC was similarly increased in patients with VVS with a positive and negative tilt table test (9.7±3.5 and 9.4±2.9 ms, P =0.614). In multivariable logistic regression analyses, DC was independently associated with syncope (odds ratio=1.518 [95% CI, 1.301–1.770]; P =0.0001). For the prediction of syncope, the area under curve analysis showed similar values when comparing single DC and combined DC with other risk factors ( P =0.1147). From the receiver operator characteristic curves for syncope discrimination, the optimal cutoff value for the DC was 7.12 ms. Conclusions: DC>7.5 ms may serve as a good tool to monitor cardiac vagal activity and discriminate VVS, particularly in those with negative tilt table test.

Periodic repolarization dynamics as a risk predictor after myocardial infarction: Prospective validation study

Heart Rhythm ◽  
2019 ◽  
Vol 16 (8) ◽  
pp. 1223-1231 ◽  
Author(s):  
Konstantinos D. Rizas ◽  
Angela J. Doller ◽  
Wolfgang Hamm ◽  
Nikolay Vdovin ◽  
Lukas von Stuelpnagel ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Validation Study ◽  
Risk Predictor ◽  
Repolarization Dynamics ◽  
Periodic Repolarization Dynamics

Effect of repeated normobaric hypoxia exposures during sleep on acute mountain sickness, exercise performance, and sleep during exposure to terrestrial altitude

2011 ◽  
Vol 300 (2) ◽  
pp. R428-R436 ◽  
Author(s):  
Charles S. Fulco ◽  
Stephen R. Muza ◽  
Beth A. Beidleman ◽  
Robby Demes ◽  
Janet E. Staab ◽  
...  
Keyword(s):  
Heart Rate ◽  
Exercise Performance ◽  
Hypobaric Hypoxia ◽  
Sham Group ◽  
Acute Mountain Sickness ◽  
Time Trial ◽  
Normobaric Hypoxia ◽  
Performance Decrement ◽  
Mountain Sickness ◽  
End Tidal

There is an expectation that repeated daily exposures to normobaric hypoxia (NH) will induce ventilatory acclimatization and lessen acute mountain sickness (AMS) and the exercise performance decrement during subsequent hypobaric hypoxia (HH) exposure. However, this notion has not been tested objectively. Healthy, unacclimatized sea-level (SL) residents slept for 7.5 h each night for 7 consecutive nights in hypoxia rooms under NH [ n = 14, 24 ± 5 (SD) yr] or “sham” ( n = 9, 25 ± 6 yr) conditions. The ambient percent O2 for the NH group was progressively reduced by 0.3% [150 m equivalent (equiv)] each night from 16.2% (2,200 m equiv) on night 1 to 14.4% (3,100 m equiv) on night 7, while that for the ventilatory- and exercise-matched sham group remained at 20.9%. Beginning at 25 h after sham or NH treatment, all subjects ascended and lived for 5 days at HH (4,300 m). End-tidal Pco2, O2 saturation (SaO2), AMS, and heart rate were measured repeatedly during daytime rest, sleep, or exercise (11.3-km treadmill time trial). From pre- to posttreatment at SL, resting end-tidal Pco2 decreased ( P < 0.01) for the NH (from 39 ± 3 to 35 ± 3 mmHg), but not for the sham (from 39 ± 2 to 38 ± 3 mmHg), group. Throughout HH, only sleep SaO2 was higher (80 ± 1 vs. 76 ± 1%, P < 0.05) and only AMS upon awakening was lower (0.34 ± 0.12 vs. 0.83 ± 0.14, P < 0.02) in the NH than the sham group; no other between-group rest, sleep, or exercise differences were observed at HH. These results indicate that the ventilatory acclimatization induced by NH sleep was primarily expressed during HH sleep. Under HH conditions, the higher sleep SaO2 may have contributed to a lessening of AMS upon awakening but had no impact on AMS or exercise performance for the remainder of each day.

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