Unit 5 - Cardiovascular Flashcards
T/F: Medications used to restore regular sinus rhythms can also cause other dysrhythmias
True.
What is the biggest food contraindication for most cardiac meds?
Grapefruit and sour orange juice.
Which two cardiac meds should you really not take together?
Nitrates (nitroglycerin) and sildenafil (viagra)
What is the pathway of electrical conduction in the heart?
SA node -> AV node -> Bundle of His -> Bundle branches -> Purkinje fibers.
Which part of the electrical conduction system may be failing if the heart rate is 20-40 bpm?
Both SA and AV nodes are not working and now the Purkinje fibers have taken over.
Action potentials:
depolarization/contraction (sodium and calcium) -> brief repolarization -> plateau -> rapid repolarization/relaxation (potassium)
Cardiac output:
heart rate x stroke volume. Expected CO = 4-8 liters per minute but varies on your metabolic needs.
Sodium Channel Blockers (Quinidine)
MOA: slow conduction and automaticity of the cells by reducing the amount of sodium going through the cells. Quinidine additionally dilates peripheral vessels to make it easier for the heart to pump.
Uses: irregular heart rhythms (V-tach or A-fib).
Side effects: GI upset, dizziness/hypotension, headache, fever/chills, thrombocytopenia (abnormally low platelets), prolonged QT interval (chaotic abnormal rhythm), Lupus photosensitivity (butterfly rash, etc).
Considerations: Be consistent in sodium intake - don’t really restrict it. Monitor ECG in the hospital for the QT interval & crazy rhythm. Monitor BP and HR (specifically apical) as well. Teach pt about thrombocytopenia (watch for bruising & bleeding) & lupus photosensitivity (wear sunscreen!). Teach them to change positions slowly and don’t drive. Don’t give to heart failure or kidney failure patients.
Memory hint: Quinidine causes qwazy rhythyms (prolonged QT), Lupus photosensitivty, thrombocytopenia so watch for bruising and bleeding, heart failure and kidneys.
Lidocaine
MOA: the same as the sodium channel blocker class (slow conduction and automaticity of the cells).
Uses: Only given via IV or injected directly into the heart in emergency situations like heart attack or V-fib.
Side effects: GI upset, CNS effects (drowsiness, slowed speech, delirium, seizures), respiratory arrest.
Considerations: We really don’t use this as much anymore because of the side effects. ONLY in emergencies. Be cautious in COPD or other respiratory risk patients.
Non-selective Beta Blockers (sotalol)
MOA: the same as the sodium channel blocker class (slow conductivity and automaticity of the cells) + slow action potential (slow impulse from SA -> AV nodes) + lower BP and heart rate.
Uses: Ventricular arrhythmias, heart attack.
Side effects: Other arrhythmias, bradycardia, chest pain/palpitations, heart failure (edema, SOB), dizziness/drowsiness, hypotension, bronchospasms, hypoglycemia in diabetics.
Considerations: Don’t give to someone with heart block or heart failure, asthma/COPD (anyone at risk for bronchospasms), or decreased renal function. Monitor I’s & O’s (kidneys), BP, HR, and blood sugar in diabetics. Slow position changes. Take as prescribed (do not stop abruptly!). Watch out for heart failure/heart block symptoms and report to HCP
Potassium channel blockers (Amiodarone)
MOA: slow conduction of impulses and prolong relaxation of the heart by blocking potassium channels. Decreases HR, BP, and CO by vasodilation.
Uses: life-threatening ventricular arrhythmias or A-fib, also tachyarrhythmias.
Side effects: Lots: hypo or hyperthyroidism because it contains iodine. GI upset + weight loss. CNS problems (tremors, confusion, dizziness/drowsiness). Inflammation of lungs. Liver injury.
Adverse - Toxicity: pulmonary fibrosis, dysrhythmias, Blue man syndrome.
Considerations: Can’t take when pregnant or when you have cardiac/kidney/liver problems. Have to monitor ALL vital signs and labs, so usually given IV in an acute care setting. A loading dose is given and then titration is done after measuring response. Can cause photosensitivity so teach the patient about that.
Calcium channel blockers (Diltiazem):
MOA: reduce the amount of calcium entering heart + blood vessels to slow down the heart and vasodilate the vessels (lower blood pressure).
Uses: A-fib, supraventricular tachycardias, angina, irregular heart beats, issues with circulation.
Side effects: Worsening heart failure (edema, weight gain). Hypotension. Skin reactions/CNS effects (pustules, rashes, flushing, dizziness). Watch for hepatic injury.
Considerations: can’t give to a patient with hypertension/heart attack/heart block. Slow position changes.
Adenosine
MOA: slow conduction through AV node to restore normal sinus rhythm.
Uses: paroxysmal SVT (emergency! HR +200 bpm) only given IV.
Side effects: prolonged asystole (the heart will stop to be restarted), hypotension, flushing.
Considerations: Teaching “you will feel really uncomfortable”, because you’re about to stop their heart. Make sure you are monitoring EVERYTHING and have a good IV access because it’s administered hard and fast and then flushed out. After this succeeds and you’re going to discharge them, you will teach them about photosensitivity and slow position changes just like all the other cardiac meds.
Cardio Glycosides (Digoxin)
MOA: increase contractility + CO, but decreases HR and decreases conduction of the cells.
Uses: heart failure.
Side effects: toxicity symptoms (decreased renal function, lower heart rate, GI upset, changes in vision, electrolyte imbalances like diarrhea and arrhythmias).
Considerations: monitor (apical) heart rate, potassium levels, and digoxin levels (to prevent toxicity). Teach pt about signs of toxicity and to take exactly as prescribed.
Antidote to digoxin toxicity:
digibind - MOA:binds to free digoxin with no contraindications
T/F: Angina is chest pain related to too much blood flow
False. Angina is chest pain related to inadequate blood flow which leads to hypoxia -> can lead to infarction and MI.
Nitrates (nitroglycerin, isosorbide, nitroprusside)
MOA: Relaxes smooth muscle to decrease workload, vasodilation AND Arterial dilation, increases available oxygen.
Uses: acute or chronic Angina, atherosclerosis in CAD.
Side effects: mainly just headache. Hypotension, palpitations. Dizziness/weakness.
Considerations: CANNOT be taken with ED medications. Cannot be taken with pregnancy or breastfeeding. Cannot be taken with circulatory failure, increased cranial pressure, or severe anemia. Slow position changes (hypotension).
Nitroglycerin specific uses
- Nitroglycerin is used as a maintenance med usually in transdermal routes (wear gloves and rotate sites when administering. Remove them at night!).
- Can also be used for acute attacks in the form of sublingual or translingual routes. For an acute attack, you should send them to the hospital when they use this.
Isosorbide dinitrate:
MOA: nitrate (Relaxes smooth muscle to decrease workload, vasodilation AND Arterial dilation, increases available oxygen).
Uses: prevents CP or CAD because it’s a vasodilator.
Side effects: headache or hypotension/dizziness.
Considerations: Administered by mouth, usually extended or sustained release - so teach the patient about that. Recommended to take on an empty stomach. Slow position changes (hypotension).
Nitroprusside:
MOA: nitrate (Relaxes smooth muscle to decrease workload, vasodilation AND Arterial dilation, increases available oxygen).
Uses: Hypertensive crisis, heart failure, or post-op uncontrollable bleeding. It works very quickly in an emergency (used a lot on LND floors!).
Side effects: cyanide or thiocyanide poisoning (because it reduces the blood flow and oxygen to vital organs)!
Considerations: Only administered by IV in an emergency. Be careful with people who already have renal/hepatic problems.
Signs of cyanide poisoning and thiocyanide poisoning (nitroprusside)
Cyanide poisoning: hepatic or renal impairment, bitter almond odor, tachypnea, dilated pupils, dysrhythmias, seizures, apnea, coma.
Thiocyanide poisoning: Tinnitus, blurred vision, nausea, loss of consciousness, seizures, coma.
Sildenafil (Viagra):
MOA: relaxes vascular smooth muscle and dilates the pulmonary arteries to increase blood flow to lungs and decrease workload of the heart.
Uses: Erectile dysfunction, and pulmonary arterial hypertension.
Side effects: numbness and tingling, headache, hypotension, prolonged erection (longer than 4 hours), chest pain.
Considerations: Slow position changes. Teach them about priapism (prolonged erection) and their need to go to the ER if it’s longer than 4 hours. Also teach them that chest pain gets reported to HCP. Don’t take it with nitroglycerin!
Diuretics class
MOA: Decrease BP, decrease blood volume (and preload on heart), promote excretion of sodium and chloride (will also expel water and other electrolytes, unless it’s diuretic that holds onto electrolytes like potassium sparing ones).
Uses: Heart and liver failure.
Considerations:
1. Don’t take this with any other hypertensive medications, digoxin/aminoglycosides, or NSAIDs.
2. Watch I’s & O’s and weight because of edema or too much fluid loss.
3. Usually want to supplement with more potassium (unless it’s a potassium sparing one).
4. Monitor electrolytes for all diuretics. Also monitor for going out into hot temperatures because of dehydration.
Side effects: Electrolyte imbalance symptoms (restlessness, muscle cramps), kidney problems (watch for oliguria or no urine output and signs of dehydration).
Furosemide
MOA: LOOP diuretic - Inhibits absorption and promotes loss of some electrolytes like sodium calcium, potassium, magnesium and chloride.
Uses: Same as any diuretic (heart and liver failure)
Considerations: Given oral or IV, but it’s a slow push because it’s extremely potent (4 minute push due to risk of ototoxicity). Don’t take too close to bed time - because the dosing is kind of tricky.
Side effects: Hypokalemia or other low electrolytes, hypotension, hypovolemia/shock/arrhythmias, and Ototoxicity - Ringing in the ears.
