Ch 19 Disorder Of Cardiac Function Flashcards
Days after a myocardial infarction
The area that undergo necrosis begins to gradually replaced with scar tissue an acute inflammatory response occurs macrophages engulf necrotic tissue are replaced by vascular granulation tissue. It becomes less vascular and more fibrous the center of the infraction becomes yellow + soft + lack ability to contract and initiate or conduct action potential
What happens during a myocardial infarction?
During MI- Heart attack atherosclerotic disease or the coronary arteries area affected is determined by the coronary arteries affected the vessel is occupied the heart tissue has inadequate supply ischemia
Severe crushing Chest pain
Sympathetic nervous system response GI distress nausea vomiting tachycardia anxiety feeling of impending doom hypotension + shock weakness in arms and legs
Chronic stable angina
Is fixed coronary obstruction that produces disparity bet. Blood flow and demands of myocardium
Typically provoked by exercise pain when the heart oxygen demand increased relieved within minutes by rest
What are implications of Acute Coronary Syndrome (ACS)
ACS represents the spectrum of acute ushering heart diseases that classified by the ECG Changes Q-wave abnormal T-wave inversion
S-T wave inversions 90 mins to get to the cath lab
Serum cardiac markers -proteins released from necrotic heart cells into the blood BNP and ANP
Determinants of coronary perfusion
Vessel diameter cholesterol/ plague build up
Stroke volume/ejection fraction
Good diastolic pressure it supports coronary perfusion
Heart compensate for increased workload such as in aortic stenosis
In aortic stenosis the left ventricular wall thickens (hypertrophied) to get the blood across the valve
Normal ejection fraction is maintained
But normal chamber volumes is not maintained
Endocarditis and rheumatic heart disease impact the heart
Endocarditis infection of the endocardium by pathogen it produces lesions on the endocardial surface the lesion permits the organism to disseminate throughout systemic circulation
Rheumatic heart disease: caused by rheumatic fever systemic inflammatory disease that sometimes follows strep throat
Both can cause vascular dysfunction stenosis and regurgitation as well as endocardium myocardium and pericardium
Potential problem of inter-atrial septal defect
An opening in the atrial septum persist as result of improper septal formation during development of the heart atrial septum doesn’t close
If defect is small it is asymptomatic
If defect is large it symptomatic most cases cause blood flow from left to right
Problems are rare but could cause CHF, failure to thrive (infant) atrial flutter or fibrillation(adolescence) larger defects are treated by surgery
Main causes of left sided heart failure
Effect the left ventricle ACS Impaired gas exchanges Aortic valve stenosis/regurgitation Pulmonary edema Perfusion Obstructive occlusions
LV does not pump enough blood to the body
LV doesn’t accept enough blood from the lungs
Blood backs up left heart lungs rights body locks blood in heart
Main problems with Aortic stenosis and aortic regurgitation
Aortic stenosis is the calcification of the aortic valve cause the LV wall to hypertrophied if calcification occurs to 1/4 of opening this obstruction will block flow
Aortic regurgitation is incomplete valve closure that allows blood to flow back tithe left ventricle. Left vertical must increase in stroke volume accommodate leaking back and flow from pulmonary artery lead to pulmonary edema the heart cannot compensate properly for longest
Dilated cardiomyopathy
Is thinned weakened heart walls and weakens heart ventricles
The heart losses the ability to pump blood efficiently
Cardiomyopathy develops without explanation or follow medical problems
