Ch. 9: Disorders of the Heart Flashcards
forward effect of RV heart failire
negligible
what is normall the only avenue for electrical signals to pass from atria to ventricles?
bundle of His
myocardial cells function together like what?
a single large cell…contraction is all or nothing
what ensure one-way BF?
cardiac valves
what supply blood to the heart?
coronary arteries
record the voltage changes with each heartbeat
ECG
what transmits the signal for each heartbeat?
CCS
atria and ventricles are ( )
electrically separated
Heart failure is an inability to ( ) OR demand satisfied only by ( )
- metabolic demand
- ventricular dilation
3 aspects to heart failure
1) systolic or diastolic failure
2) forward and backward effect
3) compensated or uncompensated failure
systolic failure
decreased SV/contractile power (ex. infarct)
siastolic failure
impaired filling (SV and contractile power is okay) – ex. stiff or diseased muscle
forward effect
low CO, downstream hypoxia
backward effect
upstream venous congestion
frank starling curve example of…
compensated or uncompensated failure
what does heart disease manifest as?
- decreased CO
- increased cardiac effort
5 mechanisms of heart disease
1) pump failure
2) obstructed flow (coronary AS or valve stenosis)
3) valve regurgitation
4) shunt
5) abnormal conduction
LV forward effect
low flow, hypoxia, organ failure
LV backward effect
pulmonary congestion, edema
LVF or RVF common?
LVF: caused by infarct, valve disease
RVF forward effect
low pulmonary perfusion (of little clinical consequence)
RVF backward effect
systemic venous congestion (enlarged liver, spleen; dependent edema…ex, legs)
RVF usual cause
lung congestion from LVF; less often due to lung disease(which blocks pulmonary arterial flow, cause pulmonar hypertension and RV hypertrophy– [COR PULMONALE]
heart failure treatment: lessens cardiac demand
weight loss
