Effect of intravenous ketanserin on the human action potential duration at fixed heart rate

1988 ◽  
Vol 2 (2) ◽  
pp. 239-243 ◽  
Author(s):  
Angela J. Drake-Holland ◽  
Mark I. M. Noble ◽  
Sara Pugh ◽  
Christopher Mills
Keyword(s):  
Heart Rate ◽  
Action Potential ◽  
Action Potential Duration ◽  
Human Action

scholarly journals Cardiovascular parameters in rat model of chronic renal failure induced by subtotal nephrectomy

2010 ◽  
pp. S81-S88 ◽  
Author(s):  
J Švíglerová ◽  
J Kuncová ◽  
L Nalos ◽  
Z Tonar ◽  
D Rajdl ◽  
...  
Keyword(s):  
Heart Rate ◽  
Renal Failure ◽  
Chronic Renal Failure ◽  
Left Ventricle ◽  
Action Potential ◽  
Action Potential Duration ◽  
Cardiovascular Complications ◽  
Resting Heart Rate ◽  
Cardiovascular Parameters ◽  
Subtotal Nephrectomy

Chronic renal failure (CRF) is associated with high incidence of cardiovascular complications. To clarify pathogenesis of CRF numerous animal models have been developed. The aim of our work was to describe methodology of subtotal surgical renal ablation in rat and to characterize some biochemical and cardiovascular parameters of this animal model. Male rats underwent 5/6 surgical nephrectomy or sham operations in two steps. The following parameters were measured on day 10 and in week 10 after the surgery: plasma concentrations of creatinine and urea, blood pressure, resting heart rate, chronotropic response to atropine and metipranol, heart ventricles weight, contraction parameters and action potential duration in the left ventricle. Increased serum concentrations of creatinine and urea, decreased creatinine clearance, polyuria and alteration of the remnant kidney tissue were found in CRF rats. Changes in cardiovascular parameters identified after subtotal nephrectomy resembled alterations of cardiovascular system in uremic patients and included hypertension, elevated resting heart rate, diminished parasympathetic cardiac tone, hypertrophy of the left ventricle associated with weakened force of contraction, prolonged contraction and relaxation and shortening of action potential duration. These data suggest that the present model can be a useful tool in the study of CRF and its cardiovascular complications.

The dependence on heart rate of the human ventricular action potential duration

1982 ◽  
Vol 16 (10) ◽  
pp. 547-551 ◽  
Author(s):  
L ARNOLD ◽  
J PAGE ◽  
D ATTWELL ◽  
M CANNELL ◽  
D A EISNER
Keyword(s):  
Heart Rate ◽  
Action Potential ◽  
Action Potential Duration ◽  
Ventricular Action Potential

scholarly journals T-Wave Alternans, Restitution of Human Action Potential Duration, and Outcome

2007 ◽  
Vol 50 (25) ◽  
pp. 2385-2392 ◽  
Author(s):  
Sanjiv M. Narayan ◽  
Michael R. Franz ◽  
Gautam Lalani ◽  
Jason Kim ◽  
Ashwani Sastry
Keyword(s):  
Action Potential ◽  
Action Potential Duration ◽  
Human Action ◽  
T Wave ◽  
T Wave Alternans

Heart Rate and Myocardial Action Potential Duration

1981 ◽  
Vol 60 (3) ◽  
pp. 28P-29P
Author(s):  
M. J. Lab ◽  
M. I. M. Noble ◽  
D. Papadoyannis ◽  
J. W. Pidgeon ◽  
W. A. Seed
Keyword(s):  
Heart Rate ◽  
Action Potential ◽  
Action Potential Duration

Effects of heart rate on extracellular [K+] accumulation during myocardial ischemia

1986 ◽  
Vol 250 (6) ◽  
pp. H982-H991 ◽  
Author(s):  
J. Weiss ◽  
K. I. Shine
Keyword(s):  
Heart Rate ◽  
Action Potential ◽  
Action Potential Duration ◽  
Important Determinant ◽  
Interventricular Septum ◽  
Plateau Phase ◽  
Lower Range ◽  
Heart Rates ◽  
Rate Dependent ◽  
Intracellular Microelectrodes

The effect of heart rate on extracellular [K+] ([K+]o) accumulation during total global ischemia was investigated in the isolated arterially perfused (37 degrees C) rabbit interventricular septum using intramyocardial K+-sensitive electrodes (tip diameter, 0.3 mm) and intracellular microelectrodes. The heart rates tested were 0, 25, 75, 125, and 150 beats/min in aqueous-perfused septa and 25, 75, and 125 beats/min in blood-perfused septa. In the lower range of heart rates (0-75 beats/min) the rate and magnitude of [K+]o accumulation during 10 min of ischemia were markedly rate dependent, but in the higher range of rates (75-150 beats/min) the rate dependence was markedly attenuated in both aqueous and blood-perfused preparations. The latter finding could be largely attributed to the more rapid shortening of the action potential duration during ischemia at the higher rates and demonstrates that the amount of time the myocardium spends in the depolarized state is an important determinant of the rate of cellular K+ loss during ischemia. Progressive shortening of the action potential duration during ischemia is also a major factor determining the onset of the plateau phase of [K+]o accumulation. The findings help to resolve previous conflicting reports on the effects of heart rate on [K+]o accumulation during ischemia.

scholarly journals Ventricular gradient and nondipolar repolarization components increase at higher heart rate

2004 ◽  
Vol 286 (1) ◽  
pp. H131-H136 ◽  
Author(s):  
Peter Smetana ◽  
Velislav N. Batchvarov ◽  
Katerina Hnatkova ◽  
A. John Camm ◽  
Marek Malik
Keyword(s):  
Heart Rate ◽  
Action Potential ◽  
Action Potential Duration ◽  
Rate Dependence ◽  
Rr Intervals ◽  
Heart Rates ◽  
Qt Intervals ◽  
Ion Channel Properties ◽  
Transmural Dispersion ◽  
Relationship Of

Differences in action potential duration reflect differences in ion channel properties. These properties also determine rate dependence of action potential duration, and transmural dispersion was confirmed experimentally to increase with cycle length. While several electrocardiographic indexes characterizing repolarization abnormalities have been proposed, studies of their heart rate dependence are missing. This study therefore investigated rate relationship of two repolarization descriptors, namely, the so-called total cosine of the QRS-T angle (TCRT), proposed to characterize global repolarization heterogeneity, and the so-called relative T wave residuum (TWR), linked to regional repolarization dispersion. During 24-h holter recordings in 60 healthy subjects (27 males), a 12-lead ECG was obtained every 30 s. RR intervals, QT intervals, and TCRT and TWR were calculated in each ECG and averaged over RR interval bins ranging from 550 to 1,150 ms in 10-ms steps. Women had uniformly greater TCRT and TWR values than men did over the entire range of investigated RR intervals. Whereas the TCRT in both sexes showed marked rate dependence with higher values at long RR intervals (550 vs. 1,150 ms: women, 0.46 ± 0.31 vs. 0.76 ± 0.18, P = 9 × 10–7; men, 0.08 ± 0.45 vs. 0.49 ± 0.35, P = 9 × 10–8), the rate dependence of TWR was more marked in women than in men, showing higher values at shorter RR intervals (550 ms vs. 1,150 ms: women: 0.29 ± 0.14% vs. 0.08 ± 0.06%, P = 2 × 10–8; men: 0.14 ± 0.12% vs. 0.04 ± 0.02%, P = 2 × 10–15). This suggests that both global and regional repolarization heterogeneity are increased at faster heart rates. Whereas in women at all heart rates the sequence of repolarization more closely replicates the sequence of depolarization, localized repolarization is more heterogeneous than in men especially at fast heart rates.

Relationship between action potential duration of ventricular cells and heart rate in dog under natural breathing

1987 ◽  
Vol 7 (3) ◽  
pp. 148-152
Author(s):  
Tang Ming ◽  
Zhang Guang-lan ◽  
Zeng Xiao-rong ◽  
Zhong Jun-yuan ◽  
Zhang Yi ◽  
...  
Keyword(s):  
Heart Rate ◽  
Action Potential ◽  
Action Potential Duration ◽  
Ventricular Cells ◽  
Natural Breathing
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