week 2 lecture 2 systemic hypertension Flashcards
What is the value for normal BP? For hypertension?
Normal < 120/80
HT >= 140/90
What is Pulse Pressure?
PP is the difference between systolic pressure and diastolic pressure
What could cause PP to be low? high?
Low: poor EF (heart failure), Ao stenosis, blood loss after trauma
High: exercise (normal), antherosclerosis, AI
What is mean Arterial Pressure?
mAP is average BP
it is the perfusion pressure seen by organs;
need > 70mmHg to sustain organs
What are two ways to calculate mAP?
mAP = CO*SVR
SVR is Systemic Vascular Resistance (hard to know!)
mAP = (2*DP + SP)/3
assumes diastole is twice as long as systole
Essential HT versus Secondary (non-essential) HT
Essential HT (90-95%)
has unknown cause but there are lifestyle and genetic risk factors
Secondary HT (5-10%)
is secondary to an underlying health condition such as diabetes, kidney disease, thyroid problems, Ao coarctation, pregnancy
Sign versus Symptom
Sign is objective evidence of disease
eg. LVH is a sign of HT
Symptom is a feeling… the patient complains of…
eg. headaches and vision problems are symptoms of HT
*HT is the silent killer - usually no symptoms
What are the consequences of HT on the heart?
- concentric LVH, which can cause:
- diastolic dysfunction bc LV stiffens
- ischemic bc muscles squish coronaries… and sudden cardiac arrest - Arrythmias (A-fib)
- Ao root dilation
- Stroke
Concentric vs Eccentric hypertrophy
Both: increased wall mass
Concentric: thicker walls (sarcomeres in parallel), caused by pressure overload (HT, Ao stenosis, cardiomyopathy)
Eccentric: thin walls but dilated chamber (sarcomeres in series), caused by volume overload (AI, heart failure)
**LVH means concentric LVH unless otherwise stated
Role of sonography in HT
Do normal echo routine but look for:
- Presence of LVH? need LV mass index and RWT
- Assess systolic function: Expecting normal EF bc strong thick walls… R/o LVOT obstruction bc big IVS (high vel in LVOT?)
- Assess diastolic function: Expecting diastolic dysfunction bc LVH (thickened walls have decreased relaxation and compliance)
- Assess for conditions associated with HT: MAC, AoV sclerosis (and regurg), Dilation of Asc Ao, Atherosclerosis, Sigmoid septum, Pulmonary HT
What measurements do you need for the machine to calculate LV mass indexed?
LV mass: LVID(d), IVS(d), PW(d)
Indexed: BSA (height and weight)
Normal LV mass index for F and M
F <= 95 g/m^2
M <=115
If the LV mass is abnormal, RWT will determine if the increased mass is due to concentric or eccentric LVH
RWT formula and normal value
RWT = 2*PW (d)/LV(d)
Normal is <= 0.42
AoV sclerosis
Calcium build up on valve cusps (looks like bright speckles)
- age - on almost everyone over 40
MAC
Mitral Annular Calcification
- Calcium build up on valve annulus (looks bright spot) bc increased press causes damage to valve
Atherosclerosis
build up of fatty plaques in arteries
Sigmoid septum
Hypertrophy only on basal part of IVS
- unknown cause, associated with HT
What are the treatment options for HT?
lifestyle
meds - diuretics (decr blood vol), beta blockers (decr heart rate and force), vasodilators, ACE inhibitors (which blocks Angiotensin 2, a vasoconstrictor)
Arterial Bruits
Murmur in the artery caused by turbulent blood flow
Know the chart for hypertrophy!
normal LV mass index and normal RWT
normal LV mass index and high RWT
high LV mass index and normal RWT
high LV mass index and high RWT
normal LV mass index and normal RWT
= NORMAL
normal LV mass index and high RWT
= CONCENTRIC REMODELLING
high LV mass index and normal RWT
= ECCENTRIC HYPERTROPHY
high LV mass index and high RWT
= CONCENTRIC HYPERTROPHY
