Lecture 2 - HTN and Hypertensive Heart Disease Flashcards
define ‘blood pressure’
pressure generated by the left ventricle ejecting blood into the aorta
define ‘cardiac output’
the volume of blood pumped per minute by each ventricles of the heart (5L) (HRxSV = CO)
how does kidney failure result in hypertension?
kidney failure prevents the elimination of excess fluid that over burdens the circulatory system, increasing the volume, so blood has to be pumped at a higher pressure
what 2 factors can increase cardiac output?
increased contractility
tachycardia
what does adrenaline increase?
contractility of the heart (secreted by adrenal glands during stress)
what does the thyroid hormone increase?
heart rate
what is peripheral resistance mainly regulated by?
arterioles (constriction = stronger ventricle contraction = higher BP)
what is the most important regulator of arteriolar tonus?
renin- angiotensin- aldosterone system
angiotensin II produces what outcome?
arteriolar constriction = HTN
what is does atrial natriuretic peptide do?
lowers BP (natural antagonist of angiotensin II)
what is the BP range for mild/stage 1 HTN?
140-159/ 90-99
what is the BP range for moderate/stage 2 HTN?
160-179 / 100-109
what is the BP range for severe/stage 3 HTN?
> 180 / >110
what are 4 NON modifiable risk factors of essential hypertension?
family hx
over 55
gender
black, Hispanic
what are 5 causes of secondary HTN?
underlying disease (kidneys) medication (the pill) physiological events (pregnancy) endocrine (adreno-cortical tumors) neurogenic (psychological)
how can diuretics help treat secondary HTN caused by kidney failure?
the may increase urine output, which drops the blood volume and lowers BP
what are 5 main complications of HTN?
stroke HTN retinopathy cardiac hypertrophy (cardiomegaly) renal disease accelerated atherosclerosis
what is the principal consequence of HTN?
cardiomegaly - enlargement of the heart as a consequence of LV hypertrophy
what happens physiologically when the left ventricle becomes hypertrophic?
cardiac cells die by ischemia and replaced by fibrous tissue and RV becomes insufficient (veins overloaded) causing PULMONARY HTN
what does renal ischemia trigger?
renin-angiotensin-aldosterone system (due to renal arteries atherosclerosis)
what change is the first sign of HTN?
retinal changes (HTN retinopathy)
what is the most common complication and a major feature of the rheumatic fever?
rheumatic heart disease
define ‘rheumatic fever’
inflammatory, systemic disease affective children and young adults that develops some time after infection by the streptococcus pyogens (via throat or skin)
what can result from antibody cross-reactivity due to rheumatic fever?
damage to heart valves, joints, skin and brain