Chest conformation spuriously influences strain parameters of myocardial contractile function in healthy pregnant women

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Andrea Sonaglioni ◽  
Valentina Esposito ◽  
Chiara Caruso ◽  
Gian Luigi Nicolosi ◽  
Stefano Bianchi ◽  
...  
1996 ◽  
Vol 270 (5) ◽  
pp. R955-R962
Author(s):  
C. D. Mazer ◽  
B. Naser ◽  
K. S. Kamel

We examined the impact of alkali therapy on myocardial contractility in a model of myocardial ischemia in dogs using direct measurements of myocardial contractile function. Myocardial ischemia in the left anterior descending (LAD) artery territory was induced using a perfusion circuit from the internal carotid artery to the LAD artery. Myocardial contractile function was assessed using sonomicrometry for measurement of percent systolic shortening (%SS), preload recruitable stroke work (PRSW) slope, and end-systolic pressure-length relationship (ESPLR) area. Because the blood flow in LAD artery was diminished by approximately 70%, there was a significant decrease in O2 delivery and uptake by the ischemic myocardium. Ischemia led to a significant fall in LAD regional contractile function with %SS decreasing from 15 +/- 2 to 7 +/- 2%, PRSW slope from 82 +/- 10 to 37 +/- 5 mmHg, and ESPLR area from 121 +/- 2 to 48 +/- 14 mmHg.mm (P < 0.05). In six dogs, the intracoronary administration of NaHCO(3) resulted in a significant increase in pH in LAD arterial and venous blood. There was, however, no significant increase in %SS (6 +/- 2), PRSW slope (43 +/- 10 mmHg), or ESPLR area (60 +/- 13 mmHg.mm). Since administration of NaHCO(3) resulted in a significant increase in PCO2 in LAD arterial and venous blood, similar experiments were carried out in five dogs, but with the intracoronary infusion of the amine buffer THAM [tris(hydroxymethyl)aminomethane (Tris) buffer; 2-amino-2-hydroxyl-1,3-propandiol] instead of NaHCO3. Although administration of THAM resulted in a significant increase in pH and a significant decrease in PCO2, in both LAD arterial and venous blood, there was no significant improvement in any of the parameters used to assess myocardial contractile function. In conclusion, administration of alkali (NaHCO3 or THAM) does not enhance the contractile function of the ischemic myocardium.


PLoS ONE ◽  
2012 ◽  
Vol 7 (10) ◽  
pp. e45365 ◽  
Author(s):  
Dhwajbahadur K. Rawat ◽  
Peter Hecker ◽  
Makino Watanabe ◽  
Sukrutha Chettimada ◽  
Richard J. Levy ◽  
...  

2007 ◽  
Vol 103 (2) ◽  
pp. 511-517 ◽  
Author(s):  
Patricia A. Gwirtz ◽  
Jerry Dickey ◽  
David Vick ◽  
Maurice A. Williams ◽  
Brian Foresman

Studies tested the hypothesis that myocardial ischemia induces increased paraspinal muscular tone localized to the T2–T5 region that can be detected by palpatory means. This is consistent with theories of manual medicine suggesting that disturbances in visceral organ physiology can cause increases in skeletal muscle tone in specific muscle groups. Clinical studies in manual and traditional medicine suggest this phenomenon occurs during episodes of myocardial ischemia and may have diagnostic potential. However, there is little direct evidence of a cardiac-somatic mechanism to explain these findings. Chronically instrumented dogs [12 neurally intact and 3 following selective left ventricular (LV) sympathectomy] were examined before, during, and after myocardial ischemia. Circumflex blood flow (CBF), left ventricular contractile function, electromyographic (EMG) analysis, and blinded manual palpatory assessments (MPA) of tissue over the transverse spinal processes at segments T2–T5 and T11–T12 (control) were performed. Myocardial ischemia was associated with a decrease in myocardial contractile function and an increase in heart rate. MPA revealed increases in muscle tension and texture/firmness during ischemia in the T2–T5 segments on the left, but not on the right or in control segments. EMG demonstrated increased amplitude for the T4–T5 segments. After LV sympathectomy, MPA and EMG evidence of increased muscle tone were absent. In conclusion, myocardial ischemia is associated with significant increased paraspinal muscle tone localized to the left side T4–T5 myotomes in neurally intact dogs. LV sympathectomy eliminates the somatic response, suggesting that sympathetic neural traffic between the heart and somatic musculature may function as the mechanism for the interaction.


2018 ◽  
Vol 7 (2) ◽  
pp. 121-128 ◽  
Author(s):  
G. V. Lisachenko ◽  
A. V. Budaev ◽  
S. V. Bannih

Aim. To assess myocardial contractile function in dogs after clinical death following acute myocardial infarction and to determine its role in the development of hemodynamic derangements after cardiopulmonary resuscitation. Methods. 180 dogs included in the experiment received pentobarbital anesthesia to assess contractile function and systemic hemodynamics after a 5-min clinical death caused by myocardial infarction. Results Dogs had phase changes in the myocardial contractile function with its initial increase, subsequent depression and normalization in the early postresuscitation period after myocardial infarction. Depressed cardiac contractile function was accompanied by a decrease in the myocardial functional reserve. A similar tendency was found in the restoration of systemic hemocirculation. Conclusion. Similar phase alterations in the myocardial contractile function and systemic hemodynamics developed in the postresuscitation period of acute myocardial infarction. Immediately after recovery, the parameters of systemic hemoperfusion increased due to the activation of the cardiac contractile function. The subsequent initial (3 – 60 min) decrease in the volumetric perfusion parameters was mainly caused by the depressed cardiac contractile function. Rhythm disturbances affected on-going circulatory insufficiency 4 - 5 hours after the recovery. The subsequent progressive decrease in the volumetric perfusion was caused by the extracardiac factors.


1985 ◽  
Vol 66 (4) ◽  
pp. 308-308
Author(s):  
S. A. Obydennov ◽  
A. A. Agafonov ◽  
V. A. Kuznetsov ◽  
F. G. Bikkineev

The aim of this work was to study the effect of various methods of surgical treatment of strangulated intestinal obstruction on the contractile function of the myocardium.


1988 ◽  
Vol 255 (4) ◽  
pp. H699-H703 ◽  
Author(s):  
L. W. Smith ◽  
K. H. McDonough

In early sepsis, maintenance of in vivo cardiovascular performance is at least partly dependent on sympathetic support to hearts with intrinsic contractile defects. Yet prolonged sympathetic stimulation, as occurs in sepsis, would be expected to alter the heart's ability to respond to this stimulation. We have investigated myocardial inotropic sensitivity to beta-adrenergic stimulation in a model of sepsis in which animals, at the time studied, exhibited bacteremia, normal arterial blood pressure and cardiac output, elevated heart rate, and elevated plasma catecholamines. Intrinsic myocardial contractile function, as assessed by the maximal rate of left ventricular pressure development (LV dP/dtmax) in an isovolumically contracting heart preparation, was significantly depressed in septic animals. To determine whether hearts from septic animals could respond normally to beta-adrenergic stimulation, we studied inotropic response to a bolus of isoproterenol in these isolated hearts. With maximal isoproterenol stimulation, hearts from septic animals were able to attain the same dP/dtmax as were hearts from control animals. With lower levels of isoproterenol, there was also no difference in inotropic indexes between the two groups when response was expressed as a percent of the maximal increase in dP/dtmax achieved with isoproterenol. These results suggest that in early sepsis, despite intrinsic myocardial contractile dysfunction, the ability of the heart to modulate its inotropic state in response in beta-adrenergic stimulation is intact.


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