scholarly journals Relaxed and Alert: Patterns of T-Wave Amplitude and Heart Rate in a REST Environment

1993 ◽  
pp. 249-260
Author(s):  
Gary Steel
Keyword(s):  
Heart Rate ◽  
Wave Amplitude ◽  
T Wave

Heart activity during experimental diving of snakes

1959 ◽  
Vol 197 (3) ◽  
pp. 604-606 ◽  
Author(s):  
Kjell Johansen
Keyword(s):  
Heart Rate ◽  
Wave Amplitude ◽  
Heart Activity ◽  
Depressant Effect ◽  
T Wave ◽  
Electrocardiographic Findings

Diving bradycardia has been demonstrated in snakes, ( Tropidonotus natrix). The bradycardia was developed rapidly and amounted to a reduction in heart rate of about 85%. The electrocardiographic findings revealed the slowing of the heart rate as effected mainly through a prolongation of the diastole, amounting to 30 times the prediving value. Duration of the electrical systole showed a prolongation of the P-R interval by 15% and the Q-T interval by 130%. A rapid and pronounced shift in the T-wave amplitude occurred upon submersion. The results suggest that the described T-wave shifts are due to changes in concentration of CO2 in the organism. Increased concentrations of CO2 in the respiratory air induced bradycardia and had a depressant effect on respiration.

scholarly journals Electrocardiographic parameters in captive, clinically healthy, Amazona ochrocephala

2015 ◽  
pp. 5037-5045
Author(s):  
Claudia Guerrero S ◽  
Janeth Bolivar B ◽  
Piero Vargas-Pinto ◽  
Pedro Vargas-Pinto ◽  
Claudia Brieva-Rico
Keyword(s):  
Heart Rate ◽  
Wave Amplitude ◽  
P Wave ◽  
S Wave ◽  
Wave Duration ◽  
T Wave ◽  
P Wave Duration ◽  
Electrocardiographic Examination ◽  
Qrs Duration ◽  
Electrocardiographic Parameters

ABSTRACT Objective. To stablish the electrocardiographic parameters of individuals of the species Amazona ochrocephala, from the Unidad de Rescate y Rehabilitacion de Animales Silvestres at the Universidad Nacional de Colombia. Materials and methods. The electrocardiographic examination was performed under inhaled anesthesia with isoflurane. Leads I, II, III, aVL, aVR and aVF were measured. Results. Electrocardiographic parameters obtained in Lead II. P wave Duration: 0.015-0.044 s, P wave amplitude: 0.031 to 0.6 mv, R wave duration: 0.015-0.022 s, amplitude R: 0.034-0.038 mv, S wave Duration: 0.019- 0.042 s, amplitude S: 0.194-0.815 mv, T wave Duration: 0.025-0.064 s, T-wave amplitude: 0.010 to 0.5 mv, PQ Duration: 0.021-0.076 s, QRS Duration: 0.036-0.068 s, QT Duration: 0.070-0.015 s, RR Duration: 0.104-0.324 s, EEM: -111° to -80°, FC: 240-600 ppm. Conclusions. The results showed different values for amplitude and duration of the P, R and T waves in comparison to those obtained in other studies. However, they were similar for heart rate, MEA and duration of the PQ/R, QT and QRS segments.

Heart rate variability and electrocardiogram waveform as predictors of morbidity during hypothermia and rewarming in rats

2002 ◽  
Vol 80 (9) ◽  
pp. 925-933 ◽  
Author(s):  
C B Matthew ◽  
A M Bastille ◽  
R R Gonzalez ◽  
I V Sils
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Wave Amplitude ◽  
Sodium Pentobarbital ◽  
Sprague Dawley ◽  
T Wave ◽  
Sprague Dawley Rats ◽  
Copper Tubing ◽  
Electrocardiogram Ecg

This study examined electrocardiogram (ECG) waveform, heart rate (HR), mean blood pressure (BP), and HR variability as potential autonomic signatures of hypothermia and rewarming. Adult male Sprague–Dawley rats had telemetry transmitters surgically implanted, and 2 weeks were allowed for recovery prior to induction of hypothermia. Rats were lightly anesthetized (sodium pentobarbital, 35 mg/kg i.p.) and placed in a coil of copper tubing through which temperature-controlled water was circulated. Animals were cooled to a core temperature (Tc) of 20°C, maintained there for 30 min, and then rewarmed. Data (Tc, BP, HR from ECG, and 10-s strips of ECG waveforms) were collected every 5 min throughout hypothermia and rewarming. Both HR and BP declined after initial increases with the drop in HR starting at a higher Tc than the drop in BP (29.6 ± 2.4°C vs. 27.1 ± 3.3°C, p < 0.05). Animals that were not successfully rewarmed exhibited a significant (p < 0.05) increase in the normalized standard deviation of interbeat intervals (IBI) throughout cooling compared with animals that were successfully rewarmed. The T wave of the ECG increased in amplitude and area with decreasing Tc. T-wave amplitude and IBI variability show potential as predictors of survival in hypothermic victims.Key words: hypothermia, rewarming, heart rate variability, ECG, blood pressure.

Phasic T-Wave Amplitude and Heart Rate Changes as Indices of Mental Effort and Task Incentive

1984 ◽  
Vol 21 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Hal Scher ◽  
John J. Furedy ◽  
Ronald J. Heslegrave
Keyword(s):  
Heart Rate ◽  
Wave Amplitude ◽  
Mental Effort ◽  
T Wave ◽  
And Task

The effects of anticipatory stress on heart rate and T-wave amplitude

1982 ◽  
Vol 15 (3-4) ◽  
pp. 241-248 ◽  
Author(s):  
Donald B. Penzien ◽  
Karl G. Hursey ◽  
Harry Kotses ◽  
Howard A. Beazel
Keyword(s):  
Heart Rate ◽  
Wave Amplitude ◽  
T Wave

Changes in the arterial blood pressure, heart rate and normal ECG parameters of rat after envenomation with Egyptian cobra (Naja haje) venom

1997 ◽  
Vol 16 (6) ◽  
pp. 327-333 ◽  
Author(s):  
Mohamed Alaa A Omran ◽  
Ismail M Abdel-Nabi
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Electrical Activity ◽  
Arterial Blood Pressure ◽  
Wave Amplitude ◽  
Low Dose ◽  
High Dose ◽  
T Wave ◽  
Arterial Blood ◽  
Naja Haje

1 The effect of Egyptian cobra (Naja haje) venom on the normal electrical activity of the cardiac muscles (ECG) and arterial blood pressure of envenomated rats were investigated in this study. 2 Rats were divided into three groups. The first group was injected im with saline and considered as control group. Rats of the second and third groups were injected IM with 0.02 μg and 0.04 μg cobra venom/ gim b.wt, respectively. 3 Mean blood pressure (MBP), heart rate (HR) and four different ECG parameters (PR and QT intervals, R and T wave amplitudes) were measured over 1 h following envenomation. 4 The low dose (0.02 μg/g) of N. haje venom caused hypotension accompanied by an increase in the HR, whereas hypertension and bradycardia developed after injection of the high dose (0.04 μg/g) of venom. 5 There was a decrease in the P-R interval after administration of the low dose and prolongation of it after the high dose. The Q-T interval and R-wave amplitude were significantly increased after injection of both doses. T-wave amplitude was significantly elevated only after injection of the high dose. 6 The present results indicate that the Egyptian cobra (N. haje) venom significantly alters the arterial blood pressure and ECG parameters of envenomated rats. This suggests that impairment of the electrical activity of cardiac muscle may be one of the reasons why victims of cobra bite die.

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