Cardiac Abnormalities--Nordgren Flashcards
Stenosis
inability of valve to open fully
Insufficiency
inability of valve to close completely
leads to regurgitation
Stenosis can lead to…
hypertrophy
more force required to get blood out
Insufficiency can lead to…
chamber dilation
additional volume requireed to get sufficient forward flow
Aortic stenosis characteristics
large P difference between LV and aorta
very high interventricular P
low systolic aortic pressure
low pulse pressure
systolic murmur
Mitral stenosis characteristics
large P difference across mitral valve during diastole
elevated L atrial P
diastolic murmur
Aortic insufficiency characteristics
aortic P falls faster, further during diastole
low diastolic pressure (blood goes into LV intead of through circulation)
large pulse pressure
increased LV EDV and EDP
Mitral regurgitation characteristics
high LA pressure
high LV EDV and EDP
Two basic types of arrhythmias
supraventricular (originating in atria or AV node)
ventricular
paroxysmal supraventricular tachycarida (PSVT)
regular rhythm
begins and ends suddenly
atria drive ventricles at high rate
low BP and dizziness common
sinus node dysfunction
ie sinus arrest
abnormal SA node
slow heart rate
conduction block
delay/block in pathway from SA node –> ventricles
premature atrial contractions
extra early beats originating in atria
accessory pathway tachycardia
rapid rhythms
extra, abnormal pathway between atria and ventricles
still goes through His-Perkinje system as well
atrial fibrillation
many impulses begin in atria
signals compete for AV node
loss of coordinated atrial contraction
atrial flutter
1+ rapid circuits in atria
more regular/organized than a-fib
bundle branch block
“hemiblock”
either branch of Purkinje system of interventricular septum
MI is major cause
wide QRS > 120 ms
R wave splitting
not directly physiologically consequential
premature ventricular contractions
common
usually benign
if recurrent, may be sign of heart disease
ventricular repolarization time elongation
QT > 450 ms and > 50% of cycle
inappropriate Na+ or prolonged K+ channel openings during phase 2
ventricular tachycardia (T-tach)
rapid rhythm originating in lower heart chambers
chambers do not fill fully
decreased CO
ventricular fibrillation
eratic, disorganized filling of ventricles
CPR + defibrillation
Provocation of long QT syndrome can cause this arrythmia
tosade de pointes
life threatening V-tach
QRS cyclically vary in amplitude, around baseline, rapid V-fib
