Cardiovascular and renal disease review Flashcards
Define hypertension
Chronically elevated blood pressure with SBP of 140mmHg or above or a diastolic bp of 90mmHg or above.
If other risk factors present than bp of 135/85 is HTN
What is transient HTN?
Elevations in systolic pressure are normal- eg fever, exercise, emotional upset etc. Will return to normal when cause is eliminated
What is persistent HTN?
Resulting from conditions such as obesity, cushing’s syndrome (excess cortisol), hyperthyroidism
What is blood pressure?
Pressure exerted by the blood on the walls of blood vessels.
What determines BP?
CO (hr x sv) Peripheral resistance (vessel diameter and length), blood volume, blood viscosity
What is MAP and how do you calculate it
Is the pressure that propels the blood through the tissue. MAP=DBP + 1/3 Pulse pressure
What factors cause an increase in MAP?
An increase in both cardiac output and peripheral resistance increase BP and MAP
What mechanisms regulate BP?
The renin angiotensin aldosterone system; natriuretic peptide release; aldosterone release, ADH
What are the five classes of anti-hypertensive drugs?
Diuretics, beta blockers, CCBs, ACE inhibitors, Angiotensin II receptor blockers
How to CCBs work?
Decrease heart rate and contractibility= lower CO
What causes secondary HTN?
Cause identifiable- renal failure/obstruction of renal arteries, pregnancy, hyperthyrodism
What does HTN cause?
1- Damage to the endothelium of the blood vessels.
2- Thickening of the arterial wall and decreased lumen- increased peripheral resistance
3. An increase in peripheral resistance will increase fat deposits, decreasing the lumen further
What is angina pectoris?
Blockage of the coronary artery may result in intermittent ischemia. Results in severe pain caused by a fleeting deficiency in blood delivery to the myocardium (lack of o2 and increased lactic acid stimulate nerve endings).
Myocardial cells are weakened by don’t die; most commonly occur when stressed or during physical activity when the oxygen requirements of the myocardium are not met.
What is an MI?
Myocardial infarct- heart attack. Death of heart muscle resulting from a blockage of coronary arteries. The blockage deprives the heart of oxygen (ischemia), which causes injury to the heart muscle, chest pain and may result in irreversible death of the heart muscle (infarct). Cannot be relieved by vasodilators and rest.
What is ischemic heart disease?
Caused by an imbalance between the myocardial blood flow and the metabolic demand of the myocardium. Reduction in coronary blood flow may be related to progressive atherosclerosis, with increasing occlusion of coronary arteries.
Blood flow can be further decreased by superimposed events such a vasospasm, thrombosis, or circulatory changes leading to hypoperfusion.
What are causes of atherosclerosis?
Response damage of the tunica intima. Damage may be caused by bloodborne chemicals, HTN, components of cigarette smoke, viral or bacterial infections.
Risk factors= increasing age, kidney disease, lack of exercise, high blood cholesterol, HTN, family hx, smoking, being male, obesity, diabetes, stress
What can be done for atherosclerosis?
If the plaque is still soft an angioplasty or stent may be inserted.
Coronary bypass- one end of the blood vessel is attached to the aorta, other end is attached to coronary artery at the point below the blockage.