RX Questions Flashcards
(99 cards)
Digoxin mechanism
Digoxin works by inhibiting the Na+/K+ ATPase pump, and causes direct increase of Na+ in the cell. This increase inhibits the activity of the Na+/Ca+2 pump which then increases Ca+2. Ca+2 increase causes an increase in contractility
Toxicity can result in hyperkalemia
Adenosine and AV nodal arrhythmia
Adenosine will abolish AV nodal arrhythmia => Narrow QRS suggests that an electrical signal originates above the ventricles. Also, p-wave obscured by the t-wave.
Adenosine mechanism => Hyperpolarizes AV nodal tissue by increasing potassium conductance and reducing calcium, and it has a very short duration of action
Aortic arch embryology
First arch = maxillary artery
Second arch = Stapedial and hyoidal arteries (only in developing embryo)
Third arch = Common carotid and proximal internal carotid arteries
Fourth arch = Ascending arch of the aorta on the left and proximal right subclavian artery on the right
Fifth arch = Regresses (no arteries)
Sixth arch = Proximal pulmonary arteries and ductus arteriosus
STEMI of the RCA
ECG elevation in II, III, and aVF (inferior leads) => inferior segment of the heart
STEMI of the LAD
ECG elevation in V3, V4 (anterior leads) with ST depression in II, III, and avF.
Symptoms of Congestive Heart Failure (CHF)
Dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, peripheral edema with weight gain. Sudden cardiac death or cardiac arrhythmia
Class I antiarrhythmics
Use Dependent block of Na+ channels in the open/inactivated state (they affect tissue that is more frequently depolarized)
All class 1 drugs decrease the slope of phase 0 of the cardiac action potential.
Tearing chest pain is commonly associated with what cardiovascular complication?
Aortic dissection => ascending dissection can cause pericardial tamponade, mediastinal hemorrhage. Descending can cause acute renal failure due to block of the renal artery.
Beck triad of cardiac tamponade
Jugular venous distention, hypotension, and muffled heart sounds.
Also, pulsus paradoxus is typical. (an abnormally large decrease in stroke volume, systolic blood pressure and pulse wave amplitude during inspiration)
Treatment of cardiac tamponade
Pericadiocentesis allows to immediately decompress the pericardial sac
Coarctation of the aorta and blood pressure
Upper extremity blood pressure will be greater than lower extremity blood pressure.
Coarctation of the aorta happens in 3-10% of Turner Syndrome patients
Wolff-Parkinson White syndrome ECG findings
Wide QRS with short PR intervals and slurring of the initial QRS complexes
WPW is due to an accessory conduction pathway that causes pre-excitation of the ventricle. Slurred upstroke of the QRS complex is called a delta wave.
How does carotid sinus massage alleviate SVT?
Baroreceptors in the carotid sinus respond to arterial wall stretching and massage causes these receptors to fire and thus leads to a decreased heart rate via increased parasympathetic activity
Hodgkin lymphoma common treatment regimen
ABVD
Adriamycin (doxorubicin)
Bleomycin
Vinblastine
Dacarbazine
Side effect of doxorubicin therapy
Cardiomyopathy commonly occurs with doxorubicin therapy
What is the cardinal vital sign for a pulmonary embolism?
Tachycardia
Also:
Tachypnea and pain on inspiration
Bleomycin mechanism of action and select side effects
Bleomycin is a mixture of glycopeptides that produce superoxide and hydroxyl radicals that attack DNA bonds to cause fragmentation.
Side effects include pulmonary toxicity and fibrosis, as well as skin changes and alopecia
Mesonephric (Wolffian) duct development in males
The Wolffian ducts develop into most of the male internal genital structures in response to Testosterone. These structures are BEEDS: Bladder Epididymis Ejaculatory duct Ductus deferens Seminal vesicles
The penis, scrotum, and prostate develop under the influence of DHT and are NOT derived from the mesonephric ducts.
Molar pregnancy
Non-viable fertilized egg that implants into the uterus. It is caused by a single sperm (90%) or two sperms (10%) combining with an egg that has lost its DNA.
Ultrasound appearance will show “snowstorm” with lucent and echogenic areas.
There will be markedly elevated B-hCG, and the classic TRIAD of symptoms includes hyperemesis, vaginal bleeding, and hyperthyroidism.
Hyperthyroidism is likely secondary to the homology of the alpha subunit of the B-hCG protein with the TSH protein.
What nerve is typically injured when a patient presents with wrist drop?
Radial nerve => innervates the posterior compartments of the arm and forearm, and allows for extension of the wrist.
It also innervates the posterior cutaneous hand except for the distal digits and the last one and a half fingers.
Importantly, the radial nerve is not affected in carpal tunnel syndrome because it does not pass through the carpal tunnel.
http://slideplayer.com/ slide/ 3898128/13/ images/ 22/ RADIAL+NERVE+IS+NOT+ AFFECTED \+IN+CARPAL+TUNNEL+ SYNDROME.jpg
What types of tumors are Psammoma bodies typically found in?
PSaMMomA: https://i2.wp.com/
www.pathologystudent.com/
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Papillary carcinoma of the thyroid Serous (ovary) Meningioma Mesothelioma Appendiceal carcinoid
Parvovirus B19 infection physical exam findings
Slapped cheek appearance = Erythema of the cheeks = IgG antibody formation to the virus.
Commonly also see anemia, and is particularly dangerous to the fetus of a pregnant woman.
HIV protease inhibitor side effects (-vir drugs)
GI intolerance, lipodystrophy, lipoatrophy peripherally and accumulation of fat within the abdomen, breasts, and cervical vertebrae (cervicodorsal fat pad). Hyperlipidemia is also common.
(Think of similar appearance of corticosteroid treatment)
Methotrexate mechanism of action and side effects
Methotrexate impairs DNA synthesis through its action at the dihydrofolate reductase inhibitor. It blocks folic acid production in healthy and cancerous cells alike and kills both.
Leucovirin can “rescue” normal cells by displacing methotrexate and enabling folic acid production to continue for DNA synthesis to resume