Review of Hemodynamics, Drugs Acting on the Renin-Angiotensin-Aldosterone System, Calcium Channel Blockers, and Vasodilators - Cardiac 1 Flashcards
What is Hemodynamics?
Study of the movement of blood throughout the circulatory system, along with the regulatory mechanisms and driving forces involved.
What is the circulatory 2 main functions?
- Delivery of oxygen, nutrients, hormones, electrolytes, and other essentials to cells
- Removal of carbon dioxide and metabolic wastes from cells
What is the circulatory system 2 main divisions?
- Pulmonary circulation delivers blood to the lungs.
- Systemic circulation or peripheral circulation delivers blood to all other organs and tissues.
How do arteries and veins differ in terms of distensibility?
- Arteries are muscular and do not stretch easily
- Veins are less muscular and much more distensible, allowing small increases in venous pressure
In an average adult, how is the cardiac output?
about 5 L/min
What is afterload?
The arterial pressure the left ventricle must overcome to eject blood.
Higher afterload decreases stroke volume.
What is preload?
Stretch of the ventricles caused by filling pressure.
More preload increases stroke volume.
What influences afterload?
Peripheral resistance, determined by arteriolar constriction or dilation, affects afterload.
What is Starling’s law?
States that the force of ventricular contraction is proportional to muscle fiber length.
More blood entering the heart increases the force of contraction, leading to more blood being pumped out.
What are the control systems of arterial pressure (AP)?
The ANS, RAAS, and kidneys control AP. The ANS acts quickly, RAAS works slowly, and kidneys control long-term AP.
How does the ANS regulate arterial pressure (AP)?
ANS adjusts heart rate, contractility, and blood vessel tone to regulate AP.
What role does the renin-angiotensin-aldosterone system (RAAS) play in controlling AP?
RAAS increases AP by constricting vessels and promoting water retention.
What is the function of natriuretic peptides in regulating AP?
reduce blood volume, dilate vessels, and promote fluid loss to lower AP.
: What causes first-dose hypotension with ACE inhibitors?
Widespread vasodilation from abrupt angiotensin II reduction.
How can first-dose hypotension be minimized?
Use a low initial dose, stop diuretics 2–3 days before, monitor BP, and lie down if hypotension occurs.
What causes cough in ACE inhibitors?
Accumulation of bradykinin due to kinase II inhibition.
What increases the risk of ACE inhibitor-induced cough?
Advanced age, female sex, and Asian ancestry.
Why do ACE inhibitors cause hyperkalemia?
They inhibit aldosterone, leading to potassium retention.
Why can ACE inhibitors cause renal failure?
Disrupt angiotensin II, reducing filtration in renal artery stenosis.
What fatal injuries are linked to ACE inhibitors?
Hypotension, hyperkalemia, renal failure, skull and lung hypoplasia.
What is angioedema and its treatment?
Severe swelling treated with epinephrine. ACE inhibitors must be stopped permanently.
How do diuretics interact with ACE inhibitors?
Increase first-dose hypotension.
How do NSAIDs affect ACE inhibitors?
Reduce their antihypertensive effect.
What are ARBs used for?
Hypertension, heart failure, diabetic nephropathy, myocardial infarction (MI), stroke prevention, and cardiovascular event prevention.
