Cardiology Flashcards
What are the main history of aortic stenosis
angina, dyspnea and syncope
At the physical examination we found
midsystolic murmur; small and slow rising carotid pulse contour (parvus et tardus)
Other rare causes of aortic stenosis include those associated with connective tissues diseases such as
systemic lupus erythematosus and ochronosis
The most common initial clinical manifestations are a gradual decline in functional capacity and effort related
dyspnea
The primary determinants of left ventricular systolic function are
contractility and afterload
The load on individual myocardial fibers can be best described as left ventricular wall stress and defined by the Laplace equation
wall stress= Pressure X radius / 2X thickness
The presence of aortic stenosis may also result in true depression of myocardial contractility, likely related to
A loss of contractile elements secondary to reduced coranary blood flow
Angina results from
myocardial ischemia
Epicardial coronary disease often coexists with aortic stenosis
02 demand is best estimated clinically by
the product of heart rate and wall stress
syncope those with aortic stenosis usually occurs during
Exercise
The narrowed aortic valve does not permit the appropriate increase in cardiac output necessary to offset the associated reduction in total peripheral resistance associated with exercise
The very high ventricular pressure that develops with exercise ´when sensed by ventricular mechanoreceptors triggers a reflexive vasodepressor response, also leading to a decline in blood pressure
we appreciate a murmur in aortic stenosis
midsystolic murmur “crescendo decrescendo”
Those with a thick ventricle and low end diastolic volume or in the presence of a decline in cardiac function, both of which may result in a low stroke volume, the intensity and pitch of the murmur may be
lower than expected for the given severity of stenosis
the ability to transmit the sound through the chest is impaired in those with
pericardial effusion, emphysema or obesity
Note: one should be cautious in excluding significant aortic stenosis solely based on murmur intensity of pitch
the murmur of aortic stenosis typically is heard loudest in
the right second interspace at the sternal border, and will often radiate into the carotids and along a line from the aortic area toward the left ventricular apex
at the apex, the intensity and pitch of the murmur may change to more resemble those of the murmur of mitral regurgitation. the shape and configuration of the murmur do not change this is known as
Gallavardin phenomenom
