Cardiology Flashcards
(37 cards)
what are risk factors of heart disease
- genetic predisposition
- stress
- oral contraceptives, menopause HRT
- homocysteine elevated levels
- male > 45. female >55
- alcohol
- HTN
- Stress
- diabetes
- diet and exercise
what is the widow-maker
L main occlusion before the L coronary artery breaks off into the descending and occlusion.
whats the chemoreceptors:
chemoreceptors:
baroreceptors:
whats the frank starlings law?
great stretch the better contraction till no point of return.
whats preload?
whats after load?
preload: venous return volume of blood in ventricles at the end of diastole
after load: LV has to meet the resistance
Vascular systems assessment:
auscultation
- assess for carotid bruit
- buit is a blowing/swishing sound, it indicates turbulence of blood flow
- auscultation of carotid:
- neck in neutral position
- bell of stethoscope over carotid artery at 3 levels:
- angle of jaw
- midcervical area
- base of the neck
how to estimate a JVP
- hold a vertical ruler on a sternal angle
- align a straight edge on the ruler like a T- square and adjust the level of the horizontal straight edge to the level of pulsation
- read the level of intersection.
(normal is 2cm or less)
a split s1 is?
normal, indicates you are hearing mitral and tricuspid components separately, audible in the tricuspid valve
whats s3?
occurs immediately after S2 when the AV value opens during pre-diastole. conditions that cause resistance to ventricular filling create S3.
whats S4?
occurs at the end of diastole during pre-systole.
conditions that cause resistance to ventricle filling also create s4 sound
conditions causing murmurs includes: 3 things
- increases in blood flow velocity
- decrease in blood viscosity
- structural defects of the valves or unusual opening in the heart chambers
what are the 4 properties of cardiac cells?
- Automatcity: ability of pacemaker cells to initiate an electrical impulse without being stimulated from another source
- excitability (irritability): ability of cardiac muscle cells to respond to an outside stimulus
- conductivity: ability of a cardiac cell to receive an electrical stimulus and conduct that impulse to an adjacent cardiac cell
- contractility: ability of cardiac cells to shorten, causing cardiac muscle contraction in response to an electrical stimulus.
refactoriness:
the period of recovery that cells need after being discharged before they are able to respond to a stimulus
absolute refractory period:
cells cannot be stimulated to conduct an electrical impulse, no matter how strong the stimulus
relative refractory period:
cardiac cells can be stimulated to depolarize if the stimulus is strong enough
supernormal period:
weaker than normal stimulus can cause cardiac cells to depolarize
conduction blocks: partial + complete
partial: slowed - all impulses are conducted but it takes longer than normal to do so.
intermittent- some impulses are conducted
complete: no impulses are conducted through the affected area
R wave
the first positive, upward deflection following the P wave. always positive
S wave
a negative waveform following the R wave. always negative
R and S waves represent depolarization of the right and left ventricles
U wave
represents depolarization of the Purkinje fibres in the papillary muscle of the ventricular myocardium.
normally small, round and symmetric.
mostly seen when the heart rate is slow.
when seen, generally tallest in leads v2 & v3
usually appear in the same direction as the T wave that precedes it.
PR segment
horizontal line between end of P wave and beginning of QRS complex.
normally isometric
ST segment
portion of the ECG tracing between QRS complex and T wave. represents early part of depolarization of right and left ventricles
PR interval: P wave + PR segment.
PR interval reflects depolarization of the R and left atria (P wave) & spread of the impulse through the AV node, AV bundle, right and left bundle branches and the Purkinje fibres (PR segments)
Abnormal PR interval
Long PR interval - indicates the impulse was delayed as it passed through the atria, AV node, or AV bundle
Short PR interval= may be seen when the impulse originates in the atria close to the AV node or in the AV bundle.
