Disorders of Cardiac Function and Rhythm Flashcards
State the role and the timing of atrial systole in the cardiac cycle
atrial systole is the second event of the cardiac cycle, just after atrial diastole and it’s role is to force any residual blood from the upper chambers into the lower chambers of the heart.
Describe characteristics of atrial fibrillation and its risks.
Afib is characterized by rapid and disorganized atrial activation and uncoordinated contraction by the aorta. On an ECG, it is characterized by a grossly disogranized pattern of electrical activity that is irregular with respect to rate and rhythm and the absence of discernable P waves.
the risks of A fib are: pulse deficit and the fact that your heart isn’t pumping right can lead to other complications (eg blood clots, heart attack, etc.)
Differentiate atrial fibrillation from ventricular fibrillation and which one warrants an emergency response from the RN
Afib: disorganized activation of the aorta, on ECG irregular rate and rhythm, no discernable P waves.
Ventricular fibrillation: where the ventricle quivers but does not contract, sine-wave like appearance on the ECG, no identifiable waveforms or intervals,
NO CO, NO PULSES
EMERGENCY RESPONSE
Recall what is happening with S1 & S2 heart sounds and what S3 or S4 may indicate
S1: “lub” occurs with the closure of the AV valves and signals the beginning of systole
S2: “dub” occurs with the closure of the semilunar valves and signals the end of systole.
S3: when ventricles are resistant to filling during pro diastole. Immediately occurs after s2, can be normal or pathologic
S4: end of diastole because the ventricles are resistant to filling. the atria contract and push blood back into a non-compliant ventricle. If s4 is audible, then this can indicate pathology.
can indicate heart failure or again can be normal. important to know the patient and their baseline to identify what is abnormal.
Define a murmur
A sound due to vibrations from the flow of blood through the heart or great vessels. A murmur may be innocent and be of no significance. Or it may be pathologic and reflect disease.
