Cardiology Combined Flashcards
Which artery supplies the SA and AV nodes?
RCA
When do coronary arteries fill?
During diastole
What inhibits the Na/K ATPase creating less extracellular Ca and more intracellular thus increasing contractility?
Digoxin/digitalis
How to calculate EF?
What heart can pump out over what can hold. SV/EDV.
2 Equations for CO
CO = SV X HR. CO= rate of O2 consumption / (arterial O2 - Venous O2)
Equation for SV
EDV-ESV
Do polycythemia, hyper proteinemic states, hereditary spherocytosis increase or decrease resistance in vessel?
Increase resistance because increase viscosity.
S3 heart sound
rapid ventricular filling. Dilated cardiomyopathy(ventricles) CHF, Mitral regurg, Left to right shunt.
S4 heart sound (right before S1)
High atrial pressure. LVH with atrial kick. Hypertrophic cardimyopathy, aortic stenosis, chronic HTN with LVH, after MI.
At Carter’s Xing Vehicles Yield
JVP Pulse order.
Normal S2 splitting happens with….
inspiration because it causes more venous return to right ventricle (negative pressure in chest due to diaphragm lowering) so pulmonic valve takes longer to close than aortic
Phase zero of cardiac action potential
Upstroke, voltage gated Na+ channels open. Sodium channel blockers would affect this.
Phase one of cardiac action potential
inactivation of sodium channels, K+ channels begin to open.
Phase 2 of cardiac action potential
Calcium influx through voltage gated calcium channels. Plateau.
Phase 3 of cardiac action potential
Rapid repolarization with massive efflux of K+ with opening of voltage gated slow K+ channels and closing of Ca2+ channels. Potassium channel blockers would affect this.
Phase 4 of cardiac action potential
RMP with K+ permeability.
Pacemaker action potential
Phase 4- RMP (K+ permeable). Na+ channels gradually open until threshold causes opening of voltage gated Ca2+ channels and phase 0 happens (upstroke). No plateua and now Potassium brings it back down in phase 3.
What inhibits phase zero of pacemaker action potential?
Calcium channel blockers.
What suppresses the slope of phase 4 in pacemaker action potential.
Beta blockers.
4 classes of antiarrhythmics
No Bad Boy Keeps Clean. 1- Na+, 2- Beta Blockers. 3-K+. 4- Calcium channel blockers.
Sodium channel blockers
Class 1 antiarrhythmics. Increase slope of phase 0 for cardiac action potential (sodium depolarization) so increase refractory period thus decreasing heart rate
Sodium channel blocker used for Wolf Parkinson White
Procainamide. Can cause SLE (antihistone antibodies).
Quinidine toxicity
Cinchonism (headache and tinnitus), thrombocytopenia, torsades (arrhythmia).
Beta blockers
Class 2 antiarrhythics. Suppress abnormal pacemakers by decreasing slope of phase 4 (Calcium influx).
Sotalol and amiodarone
Class 3 antiarrhythmics. Potassium channel blockers. Used for atrial fib. Amiodarone for WPW.
Pulmonary fibrosis, hepatotoxicity, hypo/hyperthryoidism are side effects of……
Amiodarone. Check PFTs, LFTs, TFTs
Class 3 antiarrhythmics
K+ channel blockers. Class 3 phase 3…. (repolarization due to K+)
Verapamil and diltiazem
Class 4 antiarrhythmics, Calcium channel blockers. Non-Dihydropyridine CCB’s. Prolong phase 0 of pacemaker cells (depolarization due to calcium).
Adenosine
Pushes K+ out of cells hyperpolarizing the cell and preventing depolarization causing flat line. Diagnose and abolish supraventricular tachycardia.
Conduction delay through AV node on ECG
PR Segment
Mechanical contraction of ventricles on ECG
QT interval
T wave inversion on ECG
Indicative of MI
QRS complex
Depolarization of ventricles. Less than 3 little boxes (120 msec).
Drugs which can prolong QT interval (possibly leading to torsades)
Macrolides (erithromycin), haloperidol and risperidone, methadone, protease inhibitors, chloroquine and primaquine, antiarrhythmics.
How to treat torsades
magnesium
Electrical signal not going through AV node
Wolf Parkinson White
Early ventricular depolarization with a delta wave on ECG
Wolf Parkinson White can lead to reentry current and supraventricular tachycardia.
How to treat WPW
Procainamide (NA channel blocker), Amiodarone (calcium channel blocker)
Irregularly irregular ECG with no discrete P waves how do you treat?
Atrial fibrillation and treat with Digoxin with beta blocker or CCB
Sawtooth appearance on ECG how do you treat?
Atrial flutter so use Na+ channel blocker or K+ channel blocker (Sotalol and amiodarone).
Completely erratic rhythm with no identifiable waves
Ventricular fibrillation. Leads to death.
Which baroreceptor (and which nerve is it on) responds to only increase in BP
Aortic arch (vagus nerve)
Which baroreceptor (and which nerve is it on) responds to both increase or decrease in BP
Carotid sinus (glossopharyngeal nerve)
HTN, bradycardia, respiratory depression. Also what kind of receptors are this sensed by.
Cushing triad due to Increased ICP sensed by CHEMORECEPTORS.
What releases NO which can lead to vasodilation?
Endothelial Cells.
What stimulates endothelial cells to release NO leading to vasodilation?
Bradykinin, Ach, alpha 2 agonist, histamine, serotonin, shear stress
Inhibits cGMP phosphodiesterase
Sildenafil. Leading to more cGMP and thus more vasodilation.
Which drug do you give for HTN but patient has renal stones?
Thiazide diuretics because thiazides retain Ca. Loops lose calcium so don’t give with renal stones.
Which drug increases cGMP (decreasing afterload because it works on arterioles>veins) for use for HTN in pregnancy
Hydralazine
What drug is a K+ channel opener relaxing hyperpolarizing and relaxing vascular smooth vessels for use in HTN?
minoxidil (hypertrichosis side effect)
Calcium channel blocker for use in HTN (reduces vascular smooth muscle contraction)
Nifedipine (verapamil and diltiazem are antiarrhythmics at the heart).
With smooth muscle spasm (prinzmetal’s angina, raynaud’s) what kinds of drug do you use?
Dihydropyridine Ca Channel Blocker (-dipines)
Releases NO in endothelial cells of smooth muscles (increasing cGMP) dilating veins more than arteries and decreasing preload.
Nitroglycerin
What drug can cause cyanide toxicity and vasodilates both arterioles and veins for use in malignant HTN?
Nitroprusside. (Labetolol also used in malignant HTN)
What antihypertensive drug has a first dose orthostatic hypotension?
Alpha Blockers (-zosins)
What anti-HTN drugs are ototoxic (especially with aminoglycosides)?
Loop Diuretics. And loops lose calcium.
What class of anti-HTN drugs can cause angioedema (swollen lips, eyes, face)?
ACE inhibitors
Anti HTN drugs that can result in hypercalcemia, hypokalemia?
Thiazide diuretics. Thiazides DON’t lose CA2+.
First line treatment for aortic dissection?
Beta blockers.
Tearing chest pain radiating to the back (or scapula), CXR shows mediastinum widening?
Aortic Dissection
Main risk factor for AAA?
Atherosclerosis of descending aorta (most common site)
To have angina must have narrowing of at least…..
75% of Coronary Artery
What drugs lower LDL the most?
HMG-CoA Reductase inhibitors (statins)
Side effects of statins?
Rhabdomyolysis (muscle breakdown), hepatotoxicity (increased LFT’s), myositis (muscle inflammation), myalgia (muscle pain)
What drug raises HDL the most?
Niacin
Red, flushed face, hyperglycemia, hyperuricemia side effects
Niacin
Drug that tastes really bad and lowers LDL
Bile acid resines(cholestyramine)
What drug causes liver to use more cholesterol?
Bile acid resins (block intestinal reabsorption of bile acids so liver must use cholesterol to make more)
What drug can cause cholesterol gallstones?
Bile acid resins
Which drug blocks cholesterol absorption? (Blocks at small intestine brush border.)
Ezetimibe.
Which drugs decrease triglycerides most?
Fibrates
Which drug upregulates LPL?
Fibrates
What can lead to pancreatitis?
Increased TG’s.
Which lipid lowering drug binds to C. Dificile?
Cholestyramine (bile acid resin)
How can you prevent the flushing reaction of Niacin?
Aspirin
Which anti-HTN drug can cause hyperkalemia?
ACE inhibitors. Don’t have us much aldosterone which helps excrete potassium.
Chest pain at rest (secondary to coronary artery spasm) with ST elevation on ECG?
Prinzmetal’s angina
How to treat prinzmetal’s angina?
Nifedipine (dihydropyridine ca channel blockers.
What most commonly leads to aortic dissection?
HTN
What can lead to sharp chest pain that is relieved by sitting forward?
Pericarditis which can be caused by Rheumatic fever among other conditions. Also fibrinous pericarditis from an MI (presents with friction rub).
Best treatment for angina?
Nitrates + Beta blockers
Contraction bands seen…….
at least 2 hours since MI.
What are the cells of acute inflammation in an MI (2-4 days)
Neutrophils
What kind of necrosis occurs in an MI?
Coagulative necrosis
Compression of heart by blood leaking into pericardium
Cardiac Tamponade.
Cells of inflammation in an MI 5-10 days after?
Macrophages come in and degrade things.
After 10 days from an MI at risk for……..
Ventricular aneurysm at bulging scar.
When does toponin I rise after an MI?
After 4 hours and elevated 7-10 days.
ECG changes of ST elevation can indicate what type of MI?
Transmural infarct
ECG changes of ST depression can indicate what type of MI?
Subendocardial infarct/
ECG changes of t wave inversion can indicate what type of MI?
Transmural infarct
What persists on ECG weeks after MI?
Q wave
Most specific marker of an MI (gold standard).
Troponin I
Severe MI then five days later have mitral regurg what happened?
Macrophages came and degraded things and we had rupture of the papillary muscle.
What drugs directly aid conversion of plasminogen to plasmin (which degrades fibrin)?
Thrombolytics. Streptokinase, Urokinase, tPA.
When do you use thrombolytics?
STEMI MI.
What do you treat thrombolytic toxicity?
Aminocaproic acid
What does aspirin do?
Irreverisbly inhibits COX-1 and COX-2 to prevent conversion of arachidonic acid to thromboxane A2 (clotting).
How do you treat aspirin toxicity?
NaHCO3
What do Clopidogrel and Ticlopidine do?
ADP receptor blockers which inhibits platelet aggregation. Inhibits figrinogen binding by preventing glycoprotein IIb/IIIa expression
Which drugs inhibit platelet aggregation by preventing glycoprotein IIb/IIIa expression? (what other drug also does this)
Clopidogrel and Ticlopidine. Abciximab is the other drug (monoclonal ab binds glycoprotein Iib/IIIa receptor).
Which drug inhibits platelet aggregation by binding to the glycoprotein IIb/IIIa receptor on activated platelets?
Abciximab
Balloon appearance on x ray of heart (big and circular)?
Dilated Cardiomyopathy.
Most common cause of US of myocarditis?
Coxsackie Virus. (also eckovirus and influenza virus)
Lymphocytes with myocyte necrosis?
Myocarditis (viral infection).
Cause of sudden death in young athletes?
Hypertrophic cardiomyopathy
Disoriented, tangled, hypertrophied myocardial fibers?
Hypertrophic cardiomyopathy
What can you hear with hypertrophic cardiomyopathy?
S4 heart sound.
Endomyocardial fibrosis with eosinophilic infiltrate?
Loffler’s Syndrome
How to increase contractility and cardiac output?
Digoxin/digitalis
Which artery supplies the SA and AV nodes?
RCA
Which artery supplies the inferior portion of the left ventricle and posterior septum?
Posterior descending (80% off the RCA, 20% off the circumflex)
Where does coronary artery occlusion occur most commonly?
LAD
What does the LAD supply?
apex and anterior interventricular septum
When do coronary arteries fill?
during diastole
Where is the most posterior portion of the heart and what can it cause?
The LA, can cause dysphagia because of compression of the esophageal nerve or hoarseness by compressing the the recurrent laryngeal nerve
What supplies the posterior left ventricle?
CFX (left circumflex coronary artery)
stroke volume x HR =?
CO
rate of 02 consumption/ arterial 02 - venous 02 ccontent=CO
fick principle
CO x Total peripheral resistance
mean arterial pressure
2/3 diastolic + 1/3 systolic
MAP
systolic - diastolic
pulse pressure
EDV - ESV
stroke volume
SV CAP means?
Stroke volume affected by contractility, afterload, and preload
How do catecholamines increase contractility?
Increasing activity of Ca pump in SR
What does increasing intracellular Ca do?
increase contractility
What happens with a decrease of extracellular Na
decrease in activity of Na/Ca exchanger and increase in contractility
How does digitatlis increase contractility?
Increase intracellular Na, resulting in increased Ca
How do beta blockers decrease contractility?
decrease in cAMP
Why is contractility decreased in heart failure?
systolic dysfunction
How does acidosis affect contractility?
decreased
Do dihydropyridine or non-dihyrdropyridine Ca channel blockers decrease contractility
Non
What cardiac change occurs in pregnancy?
increased SV
What 4 things drive myocardial 02 demand?
inc afterload, inc contractility, inc heart rate, inc heart size (inc wall tension)
If HR is too fast (V tach) what happens during diastole?
filling is incomplete and CO falls
EDV is also known as
Preload
MAP is also known as
Afterload (proportional to peripheral resistance)
Which class of drugs decrease preload
venodilators (nitrogylcerine)
Which class of drugs decreases afterload?
Vasodilators, (hydrAlAzine)
Exercise, overtransfusion and excitiment causes and increase in…?
Preload
What does the starling curve show?
changes in CO as a function of preload
When does EF decrease
in HF
What is the formula for EF?
SV/ EDV
What is a normal EF
at least 55%
Given P = QR, what factors influence resistance?
proportional to viscosity and inversely proportional to the radius to the 4th power
Which vessels account for the most total peripheral resistance
arteriorles
Which lab value indicates blood viscosity?
hematocrit
In what disease states is blood viscosity increased?
polycythemia, hyperproteinemic states (multiple myeloma), hereditary spherocytosis
In the cardiac and vascular function curves, in what instance is the vascular curve shifted to the left?
hemorrhage
In the cardiac and vascular function curves, in what instance is the vascular curve shifted to the right?
transfusion
What is indicated when CO and venous return are equal?
The operating point of the heart
What causes the CO curve to shift upwards?
pos inotropy, exercise
what causes the CO curve to shift downwards?
neg inotropy, HF, narcotic overdose
In the cardiac cycle, which period has the highest 02 consumption?
isovolumetric contraction