Effect of acute ventricular pressure changes on QRS duration

Sideris, Dimitris A.; Toumanidis, Savvas; Kostopoulos, Konstantinos; Pittaras, Andreas; Spyropoulos, George; Kostis, Evangelos; Moulopoulos, Spyridon D.

doi:10.1016/s0022-0736(94)80002-2

Cited by 4 publications

(2 citation statements)

References 17 publications

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“…This is most likely a consequence of conduction speed typically being more sensitive to changes in membrane capacitance (24) than intercellular coupling (51). The relative contributions of these two competing effects may explain some of the discrepant reports of faster conduction during stretch in several different isolated myocardial tissue preparations (9,11,29,36), although the discrepancy may also lie in the definition of CV used (26), as several reports (7,12,43,54) in whole chamber preparations have observed slowed conduction during stretch.…”

Section: Discussionmentioning

confidence: 99%

Mechanisms of conduction slowing during myocardial stretch by ventricular volume loading in the rabbit

Mills

Narayan²,

McCulloch³

2008

American Journal of Physiology-Heart and Circulatory Physiology

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Acute ventricular loading by volume inflation reversibly slows epicardial electrical conduction, but the underlying mechanism remains unclear. This study investigated the potential contributions of stretch-activated currents, alterations in resting membrane potential, or changes in intercellular resistance and membrane capacitance. Conduction velocity was assessed using optical mapping of isolated rabbit hearts at end-diastolic pressures of 0 and 30 mmHg. The addition of 50 microM Gd3+ (a stretch-activated channel blocker) to the perfusate had no effect on slowing. The effect of volume loading on conduction velocity was independent of changes in resting membrane potential created by altering the perfusate potassium concentration between 1.5 and 8 mM. Bidomain model analysis of optically recorded membrane potential responses to a unipolar stimulus suggested that the cross-fiber space constant and membrane capacitance both increased with loading (21%, P = 0.006, and 56%, P = 0.004, respectively), and these changes, when implemented in a resistively coupled one-dimensional network model, were consistent with the observed slowing (14%, P = 0.005). In conclusion, conduction slowing during ventricular volume loading is not attributable to stretch-activated currents or altered resting membrane potential, but a reduction of intercellular resistance with a concurrent increase of effective membrane capacitance results in a net slowing of conduction.

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Section: Discussionmentioning

confidence: 99%

Mechanisms of conduction slowing during myocardial stretch by ventricular volume loading in the rabbit

Mills

Narayan²,

McCulloch³

2008

American Journal of Physiology-Heart and Circulatory Physiology

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show abstract

“…The relationship between the change of heart hemodynamic conditions and action potential conduction velocity (CV) was previously investigated in isolated rabbit heart [1], isolated rabbit papillary muscle [1] and canine heart in vivo [2]. The results vary in the statement of clear relationship's existence.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Hemodynamic Related Changes in High Frequency Content of QRS Complex in Working Isolated Rabbit Heart

Novotná

Hejc

Ronzhina

et al. 2017

Computing in Cardiology Conference (CinC)

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Aim: High frequency content of QRS complex (HF-QRS) is thought to be related to local conduction velocity (CV). There also exists the evidence suggesting the coupling between CV and mechanical stretch via socalled mechano-electric feedback. The aim of this study was to investigate possible relationship between left ventricular (LV) load and the most common HF-QRS parameters. Methods: Six isolated rabbit hearts in working mode underwent an experimental protocol consisting of upward and downward steps in preload (8-11 cmH 2 O). Eight unipolar pseudo-ECGs, left atrial pressure, and flow rate were recorded at f s =10 kHz and 16-bit resolution. QRS complexes from hemodynamically stable experiment phase were clustered, aligned, and decomposed into 3 HF-QRS bands followed by the assessment of power envelope RMS, the tallest peak value and its position. Results: No statistically significant changes associated with LV load alteration were observed in HF-QRS parameter. Conclusion: No evidence of load dependent changes in conduction velocity was found in the study. However, HF signal may represent a complex spatial depolarization behavior. Low sensitivity of used metrics should also be taken into consideration.

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Wall stress-induced dysrhythmias in the isolated working rat heart perfused through a cannula placed in the left ventricle via aorta

Igić

Teplitz

1999

Journal of Pharmacological and Toxicological Methods

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Effect of acute ventricular pressure changes on QRS duration

Cited by 4 publications

References 17 publications

Mechanisms of conduction slowing during myocardial stretch by ventricular volume loading in the rabbit

Mechanisms of conduction slowing during myocardial stretch by ventricular volume loading in the rabbit

Analysis of Hemodynamic Related Changes in High Frequency Content of QRS Complex in Working Isolated Rabbit Heart

Wall stress-induced dysrhythmias in the isolated working rat heart perfused through a cannula placed in the left ventricle via aorta

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