15 terms

cardiac pathology

sources of cardiac stress
brought about when the heart is forced to work harder in order to maintain output
indirect stress
disorders external to the heart that increases the workload of the heart indirectly
direct stress
disorders that alter the heart either structurally or functionally so as to reduce pumping effectiveness
causes of indirect stress
1. volume imbalances
2. restriction defects
3. vascular diseases
volume imbalances
volume of the blood falls (hypovolemia), the heart has to work harder to maintain normal cardiac output. any condition that decreases the flow to the right side of the heart such as hemorrhage, severe dehydration, or excessive pooling of blood in the venous vessels can bring this about
restrictive defects
external pressure that exerted upon the heart in such a way as to obstruct cardiac filling
vascular pathology
inability of the blood vessels to adequately service cellular needs.
causes of direct stress
1. ischemia
2. infection
3. arrythmias
4. congenital defects
this is a reduction of blood supply to a particular area of the body. in the heart, it refers to inadequate myocardial circulation
causes of ischemia
1. spastic constriction of coronary vessels
2. occlusion caused by thrombus or embolus
spastic constriction of coronary arteries
caused by frigid, windy conditions; anxiety producing situations; caffeine; nicotine; and physical exertions
inflammation of the visceral or parietal pericardium or both. it is usually caused by bacteria in the following genera: staphylococcus, pneumococcus, streptococcus, and meningococcus. viral agents can also be a cause. may also be associated with "MI" systemic lupus erythematosus, rheumatic fever chest trauma and neoplasms. cardiac restrictions may occur.
symptoms of pericarditis
chest pain, pericardial frictional rub (detected by stethoscope), fever, leukocytosis, chills and tachycardia
inflammation of the myocardium. caused by acute pericarditis, acute endocarditis, diphtheria, influenza, poliomyelitis, measles, mumps toxoplasmosis, trichinosis and especially rheumatic fever
symptoms of myocarditis
fever, malaise, anorexia, fatigue leukocytosis, and chest pain. may cause acute heart failure and sudden death.