Hypertension- EXSC 462

Definition of hypertension

a transitory or sustained elevation of systemic arteiral blood pressure

Blood pressure equals

cardiac output x total peripheral resistance

Cardiac output is

heart rate x stroke volume

Total peripheral resistnace is

the resistnace blood flow encounters as flowing through arteries

Risk factors of high BP

Aging, obesity, renal impairment, chronic inflammation, stress, sleep apnea, and hyperthyroidism

Atherosclerosis

Plaque formation, tears occur from high BP and these areas form plauqe causing blockages

Arterosclerosis

stiffening or hardening of the artery, unable to expand and recoil to propel blood

Most arterial stiffness occurs in the

tunica media layer

Complications of stiffer arteries

proximal aortas buffer capacity is diminished, SBP increases, DBP decreases, impaires the hearts ability to push and recieve blood

Pulse wave analysis

left ventricular contraction creates a pulse pressure wave that travels along the walls of the arterial system

In normal compliant arteries the forward and reflected-pulse waves travel

slow

What are the beneficial functions of slow pulse waves

further perfusion of peripheral tissue and returns to heart during diastole and aids coronary flow

myocardium receives

95% of blood during diastole

In stiff arteries the pulse waves are

fast

if it returns during systole it will

increase afterload stimulating left ventricular hypertrophy

Diminished coronary blood flow leads to

creating an ischemic environment

Increase in afterload accelerates

risk of left ventricular hypertrophy

Pressure perfusing the coronary arteries during diastole is reduced

increasing risk of myocardial ischemia

SBP increase and DBP decreases in stiffer arteries

increase in pulse pressure

During aerobic exercise what should happen to SBP and DBP

SBP increase and DBP decreases because of vasodilation

During resistance training what should happen to SBP and DBP?

SBP and DBP should increase becuase of skeletal muscle contractions

DASH diet

dietary approach to stop hypertension

Weight loss in an overweight person is

the single most effective lifestyle intervention to reduce BP

Sodium consumption and retention increases blood volume

increasing BP

Potassium

helps reduce BP

Diuretics

first choice of treatment

Beta-blockers

blocking beta adrenergic receptors on the heart muscle and other tissues

ACE inhibitors

inactivating ACE which is needed to convert angiotensis I to II causing vasodilation

ARBs

blocking angotensis II from binding to its receptor on arteries causing vasodilation

CCB

blocking calcium voltage-gated ion channels on the sarcolemma, decreased contractility and vasodilation

Which hypertensive medication has an effect on exercise response

Beta-blockers

Post exercise hypotension

SBP decreases 5 mmHg up to 22 hours post exercise

Resistance training causes a

reduction in BP by decrease of the pressor reflex

Chronic exercise mechanism of action on BP

decrease in SNS activity, decrease in potent vasoconstrictors and inflammatory compounds, increase in diameter of arteries via increase in elastin proteins

Cardiovascular training reccomendations

40-60% VO2R

Exercise is contraindicated if resting

SBP> 200 or DBP> 100 mmHg

Avoid the

valsalva maneuver during exercise