HTN Flashcards
What is the most modifiable risk factor of cardiovascular disease?
HTN
What risks increase when BP increases?
Risk for: MI, CVA, HF, Renal disease
Definition of HTN
persistent elevation:
- systolic BP greater than or equal to 130 mm Hg OR
- diastolic BP greater than or equal to 80 mm Hg OR
- current use of anti-HTN medications
- could be persistent elevation of both systolic and diastolic BP but needs to be at least one.
Types of HTN
- primary (essential or idiopathic) = >90% of all cases
- no known cause
- secondary= 5-10% of cases in adults, 80% of cases in children
- usually from underlying causes such as renal failure, heart failure, or adrenal tumor (once you fix underlying cause, BP will normalize)
- isolated systolic hypertension (ISH): average SBP >130 with average DBP <80
- good DBP but systolic is high (systolic is only thing that changes). occurs mostly with elderly pts due to lack of elasticity in arteries (goal is to decrease systolic without dropping diastolic too far). Systolic naturally increases with age, diastolic also increases with age, but at around 55yo it starts to go down because of loss of elasticity.
Normal BP Values
SBP: <120 mm Hg
AND
DBP: <80 mm Hg
Elevated BP Values
SBP: 120-129 mm Hg
AND
DBP: <80 mm Hg
Stage 1 HTN Values
SBP: 130-139 mm Hg
OR
DBP: 80-89 mm Hg
Stage 2 HTN Values
SBP: greater than or equal to 140 mm Hg
OR
DBP: greater than or equal to 90 mm Hg
1 Cause of Death in US
Heart disease
*HTN contributes to heart disease
HTN leads to:
- CAD (coronary artery disease) leading to MI
- heart failure - left ventricular hypertrophy (super enlarged left ventricle)
- worsening atherosclerosis
- PVD (peripheral venous disease)
- Renovascular disease (not enough blood to the kidneys)
- Aortic aneurysms
- Retinal damage
*HTN doesn’t necessarily kill you, it’s the other things it leads to such as those listed above
CO
total blood flow with systemic or pulmonary circulation per minute
CO = SV x HR
SV = amount of blood pumped out of the left ventricle per beat
SVR
systemic vascular resistance
- the force opposing the movement of blood within the vessels (force pushing back on the ❤️ )
- combo of arteries and arterioles and whether they are constricted or dilated
- if vessels are constricted in the feet for example, it’s harder for the heart to pump blood into those vs if they were dilated
- so it’s radius difference of arteries and arterioles that is the primary factor determining SVR
Primary HTN: Pathophysiology
- increased SVR and/or increased CO leading to elevated BP
- may have normal CO, or it may return to NL, but you have consistently elevated SVR which is the hallmark sign of HTN
- altered plasma renin activity leads to vasoconstriction, vascular hypertrophy, increase in aldosterone
- stress causes increase in SNS activity leading to vasoconstriction, increased HR and increased renin (the altered plasma renin pathway)
- insulin resistance
- endothelial cell dysfunction
HTN: Non Modifiable Risk Factors
- Age (usually appears at 30-50yo)
- poorer prognosis the younger the dx
- Male (greater risk in men than women)
- new genetic links found
HTN: Modifiable Risk Factors
- Stress: causes increase in SVR, increased CO, stimulation of SNS
- 60-90% of visits to HCP r/t stress
- Obesity: apple-shaped associated with HTN, pear-shaped associated with decreased risk of HTN
- Diet (increased Na+ intake)
- Substance abuse: Nicotine, cocaine, ETOH, caffeine