Preload			Afterload			Contractility			Synergy of Contraction			Distensibility of Ventricles
blood volume			sympathetic & parasympathetic impulses			sympathetic & parasympathetic impulses			arrhythmias			ventricular compliance
posture			static muscle contraction			force frequency relations (Bowditch)			tachycardias			ventricular elasticity
venous tone			anatomical impedance			circulating catecholamines
cardiac output			intrathoracic pressure			pharmacologic depressants
atrial 'kick'						inotropic drugs
muscle pump						loss of myocardium
intrathoracic pressure						Ca++ -ATPase activity
heart rate						heart rate hypertrophy