Determinants of Stroke Volume.

  I.  Ventricular Preload


  A.  Blood volume

  B.  Distribution of blood volume

•       Body position
•      Intrathoracic pressure
•      Intrapericardial pressure
•      Venous tone
•      Pumping action of skeletal muscles

  C.  Atrial contraction


 II.  Ventricular Afterload

  A.  Systemic vascular resistance

  B.  Elasticity of arterial tree

  C.  Arterial blood volume

  D.  Ventricular wall tension

•       Ventricular radius
•       Ventricular wall thickness

III.  Myocardial Contractility

  A.  Intramyocardial [Ca 2+ ] ↑↓

  B.  Cardiac adrenergic nerve activity ↑↓ 

  C.  Circulating catecholamines ↑↓ 

  D.  Cardiac rate ↑↓ 

  E.  Exogenous inotropic agents ↑

  F.  Myocardial ischemia ↓

  G. Myocardial cell death (necrosis, apoptosis, autophagy) ↓

  H. Alterations of sarcomeric and cytoskeletal proteins ↓

•       Genetic
•      Hemodynamic overload

  I.  Myocardial fibrosis ↓

  J.  Chronic overexpression of neurohormones ↓

  K.  Ventricular remodeling ↓

  L.  Chronic and/or excessive myocardial hypertrophy ↓