Effects of Changes in Intraluminal Pressure on Inotropic and Chronotropic Responses of Isolated Mammalian Hearts

Pathak, C. L.

doi:10.1152/ajplegacy.1958.194.1.197

Cited by 37 publications

(17 citation statements)

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“…Intracellular records showed reduced diastolic potential in sinus preparation as well as in Purkinje fibers during stretch. Sjostrand [1964], in agreement with Pathak [1958b] observed stretch acceleration in iso lated atria.…”

Section: Am M Alssupporting

confidence: 74%

“…Change of temperature from 20 to 40 °C and administration of cocaine, procaine, T E A and veratramine in isolated rabbit atrial preparations did not change the pressure-acceleration response significantly. Pathak [1958b] investigated the effect of increased intraluminal pres sure in the right heart upon the activity of isolated dog hearts perfused through the coronary arteries and the effect of distension of the isolated right atrium in dogs, rabbits, guinea pigs and albino rats. He observed a direct relationship between right atrial pressure and both inotropic and chronotropic responses of whole hearts and right atria up to a critical pressure between 5 and 15 mm Hg.…”

Section: Am M Alsmentioning

confidence: 99%

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Autoregulation of Chronotropic Response of the Heart Through Pacemaker Stretch

Pathak¹

1973

Cardiology

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Mechanical stretch is a fundamental biological stimulus for pacemaker activity. Stretch-sensitiveness enables the heart to autoregulate its rate in relation to venous return. Phylogenetically the importance of this primitive mechanism has been diminished by the emergence of neurohumoral influences which permit a quicker and more effective adaptation of cardiac performance. Nevertheless, the intrinsic autoregulatory mechanism is capable of independent operation and may support extrinsic neurohumoral influences under various conditions.

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Section: Am M Alssupporting

confidence: 74%

Section: Am M Alsmentioning

confidence: 99%

Autoregulation of Chronotropic Response of the Heart Through Pacemaker Stretch

Pathak¹

1973

Cardiology

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“…A positive chronotropic response has been induced by several mechanisms including mechanical stretch of sinus nodal tissue in isolated perfused hearts (52) or of sinus node (53), atrial pressure increase in isolated denervated hearts (54,55), and perfusion pressure reduction of the sinus nodal artery (56). Similarly, it was shown that the positive chronotropic effect produced by traction on the sinus nodal region or on atrial appendages is purely sympathetically mediated (57,58).…”

Section: Figure 3 Normal Post-ectopic Blood Pressure and R-r Intervalmentioning

confidence: 99%

Heart Rate Turbulence: Standards of Measurement, Physiological Interpretation, and Clinical Use

Bauer¹,

Malík

Schmidt³

et al. 2008

Journal of the American College of Cardiology

397

432

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This consensus statement has been compiled on behalf of the International Society for Holter and Noninvasive Electrophysiology. It reviews the topic of heart rate turbulence (HRT) and concentrates on technologies for measurement, physiologic background and interpretation, and clinical use of HRT. It also lists suggestions for future research. The phenomenon of HRT refers to sinus rhythm cycle-length perturbations after isolated premature ventricular complexes. The physiologic pattern of HRT consists of brief heart rate acceleration (quantified by the so-called turbulence onset) followed by more gradual heart rate deceleration (quantified by the so-called turbulence slope) before the rate returns to a pre-ectopic level. Available physiologic investigations confirm that the initial heart rate acceleration is triggered by transient vagal inhibition in response to the missed baroreflex afferent input caused by hemodynamically inefficient ventricular contraction. A sympathetically mediated overshoot of arterial pressure is responsible for the subsequent heart rate deceleration through vagal recruitment. Hence, the HRT pattern is blunted in patients with reduced baroreflex. The HRT pattern is influenced by a number of factors, provocations, treatments, and pathologies reviewed in this consensus. As HRT measurement provides an indirect assessment of baroreflex, it is useful in those clinical situations that benefit from baroreflex evaluation. The HRT evaluation has thus been found appropriate in risk stratification after acute myocardial infarction, risk prediction, and monitoring of disease progression in heart failure, as well as in several other pathologies.

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“…A change in right atrial pressure (RAP) will alter heart rate (HR) through mechanisms that do not use nervous pathways 1–6 . This phenomenon, termed intrinsic cardiac rate regulation (ICRR), may facilitate the adjustment of right heart function to handle fluctuations in venous return.…”

Section: Introductionmentioning

confidence: 99%

Tertiapin‐Q removes a mechanosensitive component of muscarinic control of the sinoatrial pacemaker in the rat

Han

Wilson

Bolter

2010

Clin Exp Pharma Physio

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1. In an isolated right atrial preparation, an increase in right atrial pressure (RAP) produces an increase in atrial rate. This rate response is larger and occurs faster when there is background vagal or muscarinic stimulation. 2. We hypothesized that in the latter situation, an increase in RAP antagonizes the effect of muscarinic stimulation through stretch inactivation of the mechanosensitive muscarinic potassium current I(K,ACh). 3. In two groups of bath-mounted right atria isolated from male Wistar rats (control n = 12; 300 nmol/L tertiapin-Q treated (to block I(K,ACh)) n = 10), we examined the change in atrial rate when RAP was raised from 2 to 8 mmHg; oxotremorine-M (oxo-M; from 10 to 500 nmol/L) was added to incrementally activate muscarinic receptors. 4. In both control and tertiapin-Q-treated groups, oxo-M reduced atrial rate, but its effect was less ( approximately 40-50%) in the latter group (P < 0.001). In control preparations, responses to an increase in RAP became progressively larger and quicker as the concentration of oxo-M was increased, whereas in tertiapin-Q treated preparations oxo-M did not affect either the amplitude or the speed of the response (P < 0.0001 for both). 5. The results support the hypothesis that atrial stretch antagonizes muscarinic slowing by its effect on I(K,ACh). We suggest that through this mechanism, parasympathetic control of heart rate may be modulated continuously by RAP.

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Effects of Changes in Intraluminal Pressure on Inotropic and Chronotropic Responses of Isolated Mammalian Hearts

Cited by 37 publications

References 0 publications

Autoregulation of Chronotropic Response of the Heart Through Pacemaker Stretch

Autoregulation of Chronotropic Response of the Heart Through Pacemaker Stretch

Heart Rate Turbulence: Standards of Measurement, Physiological Interpretation, and Clinical Use

Tertiapin‐Q removes a mechanosensitive component of muscarinic control of the sinoatrial pacemaker in the rat

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