scholarly journals A Rare Encounter of Mitral Arcade With Anomalous Papillary Muscles

Cureus ◽  
2022 ◽  
Author(s):  
Ranbir Singh ◽  
Maureen Wang
Keyword(s):  
Papillary Muscles

Effects of digitalis and calcium on papillary muscles in normal and hypoxic states

1976 ◽  
Vol 231 (1) ◽  
pp. 66-72 ◽  
Author(s):  
K Taubert ◽  
G Templeton ◽  
JT Willerson ◽  
W Shapiro
Keyword(s):  
Extracellular Calcium ◽  
Muscle Performance ◽  
Inotropic Effect ◽  
Papillary Muscles

The effects of digoxin and ouabain in 2.5 and 4.0 mM extracellular calcium were studied in well-oxygenated and hypoxic isolated, isometrically contracting cat papillary muscles. Muscle digoxin content was measured at the conclusion of the digoxin experiments. In the well-oxygenated environment muscles in the higher Ca bathing media reached peak glycoside inotropic effect sooner and contained 2.7 times more digoxin. During hypoxia and reoxygenation muscles contracting with glycosides performed no differently than those without a glycoside present. Muscle digoxin content was lowered at the end of hypoxia (P less than 0.05) in 2.5 mM Ca; after reoxygenation digoxin content was significantly greater than either before or after hypoxia (P less than 0.001). Hypoxic depression of muscle performance was attenuated in 4.0 mM Ca but muscles in 2.5 mM Ca showed greater improvement during reoxygenation even though the muscles in 4.0 mM Ca had significantly greater digoxin content at the end of reoxygenation (P less than 0.02). It therefore is concluded that, although altered extracellular calcium can alter performance during hypoxia and reoxygenation, muscle performance is not aided by the presence of digitalis and under these conditions performance cannot be correlated with muscle digoxin levels.

scholarly journals Biomechanical-Structural Correlation of Chordae tendineae in Animal Models: A Pilot Study

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1678
Author(s):  
Justyn Gach ◽  
Izabela Janus ◽  
Agnieszka Mackiewicz ◽  
Tomasz Klekiel ◽  
Agnieszka Noszczyk-Nowak
Keyword(s):  
Mitral Valve ◽  
Complex Structure ◽  
Future Research ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Histopathological Analysis ◽  
Papillary Muscles ◽  
Chordae Tendineae ◽  
Structural Correlation ◽  
Ring Valve

The mitral valve apparatus is a complex structure consisting of the mitral ring, valve leaflets, papillary muscles and chordae tendineae (CT). The latter are mainly responsible for the mechanical functions of the valve. Our study included investigations of the biomechanical and structural properties of CT collected from canine and porcine hearts, as there are no studies about these properties of canine CT. We performed a static uniaxial tensile test on CT samples and a histopathological analysis in order to examine their microstructure. The results were analyzed to clarify whether the changes in mechanical persistence of chordae tendineae are combined with the alterations in their structure. This study offers clinical insight for future research, allowing for an understanding of the process of chordae tendineae rupture that happens during degenerative mitral valve disease—the most common heart disease in dogs.

Electromechanical Effects of bPTH-(1-34) on Rabbit Sinus Node Cells and Guinea Pig Papillary Muscles

1988 ◽  
Vol 11 (5) ◽  
pp. 619-625 ◽  
Author(s):  
Noriaki Kondo ◽  
Shoji Shibata ◽  
Thomas E. Tenner ◽  
Peter K. Pang
Keyword(s):  
Guinea Pig ◽  
Sinus Node ◽  
Papillary Muscles ◽  
Electromechanical Effects

Outward current and repolarization in hypoxic rat myocardium

1983 ◽  
Vol 244 (3) ◽  
pp. H341-H350
Author(s):  
C. H. Conrad ◽  
R. G. Mark ◽  
O. H. Bing
Keyword(s):  
Action Potential ◽  
Action Potentials ◽  
Outward Current ◽  
Iodoacetic Acid ◽  
Mechanical Activity ◽  
Potential Range ◽  
Papillary Muscles ◽  
Rat Myocardium ◽  
Cable Properties ◽  
Sucrose Gap

We studied the effects of brief periods (20-30 min) of hypoxia in the presence of 5 and 50 mM glucose and of glycolytic blockade (10(-4) M iodoacetic acid, IAA) on action potentials, membrane currents, and mechanical activity in rat ventricular papillary muscles using a single sucrose gap voltage-clamp technique. Steady-state outward current (iss) was determined at the end of a 500-ms clamp to the test potential following a 600-ms clamp to a holding potential of -50 mV. In the presence of 5 mM glucose, hypoxia resulted in a decrease in action potential duration (APD) and an increase in iss (on the order of 60% at 0 mV) over the potential range studied. The increase in iss did not appear to be due to an increase in leakage current or to a change in the cable properties of the preparation. Addition of 50 mM glucose prevented the change in both APD and iss with hypoxia. In addition, glycolytic blockade with IAA did not alter iss in the presence of oxygen. We conclude that an increase in iss appears to be a major factor in the abbreviation of rat ventricular action potential seen with hypoxia. Glycolysis appears to be a sufficient (with 50 mM glucose) but not necessary source of energy for the maintenance of normal iss.

scholarly journals Dynamics of normal and ischemic canine papillary muscles.

1994 ◽  
Vol 74 (6) ◽  
pp. 1179-1187 ◽  
Author(s):  
S C Rayhill ◽  
G T Daughters ◽  
L J Castro ◽  
M A Niczyporuk ◽  
M R Moon ◽  
...  
Keyword(s):  
Papillary Muscles
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