Download 1. Regarding the auscultation of the heart: A murmur is always

1. Regarding the auscultation of the heart:
a) A murmur is always pathologic
b) A third heart sound is usually pathologic
c) A fourth heart sound is usually pathologic
d) None of the above
Answer: c) page 512 - 3. The fourth sound is rare in normal individuals. Its presence indicates
increased resistance to filling of the left or right ventricle because of a reduction in ventricular wall
compliance, and it is accompanied by a disproportionate rise in ventricular end-diastolic pressure.
2. Regarding cardiac output:
a) it decreases in sleep
b) with exercise it can increase no greater than 4x
c) it is calculated as heart rate x afterload
d) it will decrease when standing after lying
Answer d) page 514 table. The drop in BP/CO on standing has turned up in previous MCQ’s, and
seems confusing (especially in Ganong!) As I understand it there is a decrease in central blood-pool
by ~400ml – this is the main issue with standing, and why the reflexes exist to maintain BP. Note BP
= CO x resistance, so BP = SV X HR x resistance. Thus on standing, the stroke volume drops
(because reduced venous return/EDV) -> then decreased baroreceptor activity -> decrease in vagal
stimulation and increase in sympathetic stimulation -> increase HR and increased peripheral
resistance so it balances the BP out eventually (may even increase slightly).
3. Regarding stroke volume:
a) decreases with systolic dysfunction due to increased end diastolic volume
b) decreases with diastolic dysfunction due to decreased end diastolic volume
c) of the left ventricle is 130ml in a typical individual
d) has a linear relationship to end diastolic volume
Answer a) page 517: pressure volume loops and the Frank-Starling curve.
4. Regarding the jugular pulse
a) the c wave is caused by bulging of the mitral valve during ventricular systole
b) the a wave is caused by ventricular systole
c) the v wave is seen in diastole
d) will be higher in inspiration due to increased thoracic pressure
Answer c) Page 512
5. Regarding the O2 consumption of the heart
a) at rest it is only about 2mL/100g/min
b) is typically affected more by aortic stenosis than by aortic regurgitation
c) is increased by an increased preload, but decreased by an increased afterload
d) is primarily determined by the heart rate and contractile state of the heart only
Answer b) page 519 – Pressure load increases O2 consumption more than volume load, thus AS
causes more angina than AR. Reason not well understood. A: The resting rate of O2 consumption is
9ml/100g/min (2 is for the basal consumption of a non-contracting heart). C: The O2
consumption/work will be increased by increases of both afterload and preload. D: The
intramyocardial tension is the other key factor (one could argue SV and MAP also)