Heart Problems Flashcards
congenital defects are
present at birth
congenital defects can come from
environmental influences, maternal infections, maternal drug use during second month of pregnancy
coarctation of the aorta
involves a segment that is too narrow
septal defects involve
holes in the interatrial or interventricular septum
Tetralogy of fallot
- interventricular septal defect lets oxygen poor blood travel from right to left ventricle and into systemic circulation
- aorta emerges from both ventricles which reduces cardiopulmonary circulation
- narrowing of pulmonary valve reduces cardiopulmonary circulation
- right ventricle is enlarged
rheumatic fever is caused by
a bacterial infection, such as strep throat, that triggers the immune system to produce antibodies that can damage the bicuspid and aortic valves
cardiac tamponade occurs
if pericardial cavity fills with fluid and compresses the heart
cardiomyopathy refers to
any disease that results in deterioration of the heart wall or abnormal thickening of the interventricular septum
valvular insufficiency refers to
any valve disorder that may lead to heart murmur
aortic stenosis results from
narrowing of aortic valve
mitral valve prolapse occurs
when portion of mitral valve is pushed back into left atrium during ventricular systole
a heart attack or myocardial infarction involves
the sudden death of heart muscle and its replacement with scar tissue because of ischemia (a reduction in blood flow)
process of heart attack
-blood supply to an area of the heart wall is interrupted, plaque is deposited along wall of coronary artery, platelets aggregate and release chemicals that trigger vasospasm, common pathway of coagulation is activated, coronary artery gets occluded by a clot and blood flow decreases
angina pectoris is
severe pain or tightness or pressure in the chest that accompanies ischemia of the myocardium
pain of angina pectoris is described as
constricting, squeezing, or chokin or knife like
because anaerobic respiration in cardiac muscle cells produces lactic acid
nitroglycerin is used to
treat angina because it is a potent vasodilator that can improve blood flow to myocardium
congestive heart failure results from
the failure of ventricles to pump blood effectively
in congestive heart failure
blood backs up in the lungs causing pulmonary edema or blood backs up in the systemic vessels causing peripheral edema
the SA node establishes the
typical sinus rhythm of one’s heart rate
ectopic focus is produced by
spontaneous generation of action potentials outside of SA node
an arrhythmia is
any abnormal or irregular heartbeat due to the faulty production of electrical impulses or the poor conduction of impulses through the heart
if the SA node becomes diseased or damaged and fails to set the sinus rhythm,
the AV node can take over and establish a nodal rhythm at a much slower rate
AV node produces only
40 to 50 beats per minute instead of 70-80 beats per minute by the SA node
artificial pacemaker can be implanted
under skin to electrically stimulate ventricles to contract
a heart block is the
failure of the cardiac conduction system to transmit signals along the right and left bundle branches, which results in missed heart beats or reduced heart rate
bradycardia is a
resting heart rate of less than 60 beats per minute
atrioventricular block involves
prolonged or intermittent or missing conduction of nerve signals between atria and ventricles
total heart block damages the
AV node and reduces ventricular contractions to between 20 and 40 bpm
during atrial flutter
ectopic foci in the atria cause atrial rhythm to reach 240 to 360 beats per minute
tachycardia is
a resting heart rate in excess of 100 bpm
premature ventricular contractions can occur when
action potentials are initiated independent of the SA node and cause occasional abnormal heart beats
extrasystole occurs because
the impulse is generated more quickly from the SA node and heart has a longer time for ventricular filling
extrasystole can be triggered if
the heart is irritated by certain drugs or by lack of sleep or by stress
ventricular fibrillation is a
life threatening condition caused by nerve signals arriving at different parts of the myocardium at different times
in ventricular fibrillation blood is
not pumped so blood does not flow to the myocardium and an MI occurs
-strong brief electric defibrillation depolarizes the entire heart so the SA node can resume its normal rhythm
