Cardiovascular Flashcards
Acute chest pain that radiates to back?
Acute dissecting aortic aneurysm; usually initiated by an intimal tear
wide, fixed splitting of S2 that doesn’t vary with respiration
ASD
What may lead to eye problems following treatment for an inferior MI (ST elevation in inferior leads)?
Inferior lead MIs are associated with bradycardia; so, pts are often given atropine to treat the bradycardia. Side effect of atropine = eye problems!
What artery does coronary artery occlusion most commonly occur in?
LAD = Left Anterior Descending artery
=> anterior wall MI
*LAD comes off the LCA (left main coronary artery), supplies the apex and anterior interventricular septum
Which coronary artery supplies the SA and AV nodes?
Majority of time –> SA and AV nodes are supplied by the RCA
Which coronary artery supplies the right ventricle?
Acute marginal artery (comes off the RCA)
Which coronary artery supplies the posterior left ventricle?
CFX = Circumflex artery (comes off the LCA)
PD = Posterior Descending artery is supplied by? supplies?
“Right Dominant” heart –> majority of cases (about 80%), RCA supplies the PD, which supplies the inferior part of the Left ventricle
*20% of the time, the PD arises from the CFX (Circumflex artery, which arises from the LCA)
Most posterior part of the heart? What may it cause if it enlarges?
- most posterior part of the heart is the Left Atrium
- If enlargement of Left Atrium –> dysphagia (d/t esophageal compression) or Hoarseness (d/t recurrent laryngeal nerve compression)
CO (Cardiac Output) = ?
CO = SV X HR
(CO = Stroke Volume X Heart Rate)
***note: if HR is too high –> diastolic filling is incomplete –> get decreased CO (ie ventricular tachycardia)
Fick Principle:
CO = (rate of O2 consumption) / (arterial O2 content - Venous O2 content)
MAP (mean arterial pressure) = P =?
MAP = CO X TPR P = Q X R
*TPR = R = Total Peripheral Resistance
Pulse Pressure = ?
Pulse Pressure = Systolic Pressure - Diastolic Pressure
Pulse Pressure is proportional to?
Stroke Volume
Stroke Volume = ?
SV = CO/HR = EDV - ESV
EDV vs ESV
EDV = End-Diastolic Volume = full heart ESV = End-Systolic Volume = empty heart (after pumping out!)
What maintains the CO during early stages of exercise? late stages of exercise?
- Early stages of exercise –> CO maintained by SV
* Late stages of exercise –> CO is maintained by HR
Which 3 factors affect Stroke Volume?
Increased SV when these factors increase/decrease?:
SV CAP:
- Contractility
- Afterload
- Preload
Increased SV when:
- Increased contractility
- Decreased afterload
- Increased Preload
4 factors that increase contractility (and thus increase SV):
1) Catecholamines –> increase activity of Calcium pump in Sarcomplasmic Reticulum (act on Beta-1 receptors)
2) Increased intracellular Calcium
3) Decreased extracellular Sodium (b/c decreased activity of Na+/Ca2+ exchanger, so more Calcium stay inside cell)
4) Digitalis (b/c blocks Na+/K+ ATPase, so decreased extracellular Na+ –> decreased activity of Na+/Ca2+ exchanger –> more Calcium stays in cell, so –> increased intracellular Calcium)
5 factors that decreased contractility (and thus decrease SV):
1) Beta-1 blockade (decreased cAMP–>decreased Protein Kinase A –> decrease intracellular Ca)
2) Heart failure (systolic dysfxn)–> decreased SV in heart failure
3) Acidosis
4) Hypoxia/Hypercapnea (decreased PO2/increased PCO2)
5) Non-dihydropyridine Ca2+ channel blockers (ie Verapamil, Diltiazem)
3 states in which have increased SV:
- Pregnancy (b/c increased blood volume, so increased preload)
- Exercise (b/c increased pre-load + increased catecholamines)
- Anxiety (b/c increased catecholamines)
4 factors that increase myocardial O2 demand:
1) increased afterload
2) increased contractility
3) increased heart rate
4) increased heart size
What is the preload? What states may increase preload?
Preload = Ventricular EDV Increased preload with: -Exercise (slightly) -Pregnancy -Increased blood volume (ie over-transfusion) -Excitement (ie sympathetics)
***Preload Pumps up the heart!
Mean arterial pressure = ?
MAP = 2/3 diastolic pressure + 1/3 systolic pressure
Preload and Afterload: Which is proportional to the mean arterial pressure and total peripheral resistance? to central venous pressure?
- Central venous pressure is about equal to the preload
- Total peripheral resistance is about equal to the afterload
Effect of venodilators (ie Nitroglycerin) on heart?
decrease preload
Effect of vasodilators (ie hydralazine) on heart?
decrease afterload
effect of ACE-inhibitors and ARBs on heart?
decrease preload AND decrease afterload
How to decrease O2 demand in a heart attack? (3 ways)
- decrease afterload –> ACE inhibitors
- decrease contractility –> Beta-blockers
- decrease HR –> Beta-blockers
EF = Ejection Fraction = ?
What is it normally? (%)
EF = what heart can pump out / what heart can hold
EF = SV/EDV = (EDV-ESV)/EDV
EF is an index of ventricular contractility
EF is normally > or = 55%
–>get decreased EF is systolic heart failure
Preload and Afterload: Which is proportional to the mean arterial pressure and total peripheral resistance? to central venous pressure?
- Central venous pressure is about equal to the preload
- Total peripheral resistance is about equal to the afterload
Effect of venodilators (ie Nitroglycerin) on heart?
decrease preload
Effect of vasodilators (ie hydralazine) on heart?
decrease afterload
effect of ACE-inhibitors and ARBs on heart?
decrease preload AND decrease afterload
How to decrease O2 demand in a heart attack? (3 ways)
- decrease afterload –> ACE inhibitors
- decrease contractility –> Beta-blockers
- decrease HR –> Beta-blockers
EF = Ejection Fraction = ?
What is it normally? (%)
EF = what heart can pump out / what heart can hold
EF = SV/EDV = (EDV-ESV)/EDV
EF is an index of ventricular contractility
EF is normally > or = 55%
–>get decreased EF is systolic heart failure
delta P (pressure) = ?
delta P = Q X R
Pressure = Flow X Restistance
Effects of Viscosity and Radius on Resistance?
- Resistance is proportional to Viscosity (increase viscosity –> increase R)
- Resistance is inversely proportional to radius^4 (increase radius –> decrease resistance, and visa versa)
What is the main component that determines viscosity?
Hematocrit
3 states in which have increased Viscosity:
1) Polycythemia
2) Hyperproteinemic states (ie Multiple Myeloma)
3) Hereditary spherocytosis
S1 sound:
Mitral and Tricuspid valve closure
-loudest at mitral area
S2 sound:
Aortic and Pulmonary valve closure
-loudest at left sternal border
S3 sound:
“Ken-Tuc-Key” (key = S3) or “Lub-Dub-Ta”
- in EARLY diastole, during rapid ventricular filling phase.
- Associated with: increased filling pressures (MR, CHF), and more common in dilated ventricles
- Normal in children and pregnant women
When is a S3 sound considered normal?
- Children
- Pregnant women
S4 sound:
="atrial kick" "Ten-Nes-See" (ten=S4) or "Ta-Lub-Dub" -in LATE diastole -High atrial pressure -Associated with ventricular hypertrophy (LA has to push against stiff LV wall)
Mitral and Tricuspid Valves
MitraL –> Left! Bicuspid valve
Triscupid –> Right
Isovolumetric Contraction
Period between mitral valve closure and aortic valve opening; period of highest O2 consumption
Systolic Ejection
period between aortic valve opening and closing
Isovolumetric Relaxation
Period between aortic valve closing and mitral valve opening
Rapid Filling
Period just after mitral valve opens
Reduced Filling
Period just before mitral valve closure
S2 Splitting:
Aortic valve closes before pulmonic (inspiration increases this difference)
What may increase the difference in S2 splitting (when aortic valve closes before pulmonic)? When is S2 splitting normal? When is S2 splitting pathologic?
Inspiration
*Note: split S2 on inspiration = normal; split S2 on expiration = pathologic
Jugular Venous Pulse (JVP)
“At Carter’s Xing Vehicles Yield”
- a wave = atrial contraction
- c wave = RV contraction (closed tricuspid bulges into atrium)
- x descent = atrial relaxation (downward displacement of closed tricuspid during ventricular contraction)
- v wave = increased RA pressure, d/t filling against closed tricuspid
- y descent = blood flow from RA to RV
Wide S2 splitting is associated with?
- Pulmonic stenosis
- R bundle branch block
*kind of just an exaggeration of normal splitting
Fixed S2 splitting is associated with?
ASD
Paradoxical S2 splitting is associated with?
- Aortic stenosis
- L bundle branch block
*hear pulmonic closure before aortic!
Systolic murmurs:
- Aortic or Pulmonic stenosis
- Mitral or Tricuspid Regurg
Diastolic Murmurs:
- Mitral or Tricuspid stenosis
- Aortic or Pulmonic Regurg
Which murmurs are worse with inspiration? Worse with expiration?
- Tricuspid = worse with inspiration (b/c increased blood in RA)
- Mitral = worse with expiration (b/c increased blood into LA)
Holosystolic Murmur:
- Tricuspid Regurg
- Mitral Regurg
- VSD
Holosystolic murmur that increases in intensity during inspiration?
-Tricuspid Regurgitation
Murmur that is loudest at apex, radiates toward axilla?
- Mitral Regurgitation
- -> enhanced by: expiration, squatting, hand grip
Murmur that is loudest at tricuspid area and radiates to Right sternal border?
Tricuspid Regurgitation:
–>enhanced by inspiration
Pulsus parvus et tardus
pulse is weak compared to heart sounds
-Aortic stenosis
Bicuspid aortic valve –> what kind of murmur?
Aortic stenosis
Systolic ejection murmur following ejection click
Aortic stenosis
-ejection click is d/t abrupt halting of valve leaflets
holosystolic, harsh-sounding murmur; loudest at tricuspid area (over L sternal border in 3rd or 4th intercostal space)
VSD
Midsystolic click
- Mitral Prolapse
- click is d/t sudden tensing of chordae tendineae
- loudest at S2
- can predispose to infective endocarditis
Diastolic murmur, bounding pulses, head bobbing
-Aortic regurgitation
Murmur with an opening snap
Mitral Stenosis
- snap is d/t abrupt halt of leaflet motion in diastole, after rapid opening d/t fusion at leaflet tips
- enhanced by expiration
continuous machine-like murmur; loudest at S2
PDA
Speed of conduction through heart: fastest –> slowest:
Fastest “Park At Ventura Avenue” Slowest
Purkinje > Atria > Ventricles > AV node
inverted T wave on ECG
indicates recent MI
presence of U wave on ECG?
caused by hypokalemia or bradycardia
Conduction pathway through heart:
SA node –> atria –> AV node –> common bundle –> LAF –> Bundle branches –> Purkinje fibers –> ventricles
Torsades de pointes
- What can it progress to?
- What may predispose to it?
= Ventricular tachycardia; fast, wide QRS of varying amplitudes.
- Can progress to V-fib
- anything that prolongs QT interval can predispose to torsades
Jervell and Lange-Nielsen syndrome
- autosomal recessive
- Torsades de pointes + severe congenital sensorineural deafness
Drugs that can prolong QT interval (and thus predispose to Torsades de pointes)?
- Macrolides
- Antimalarials
- Haloperidol
- Risperidone (atypical antipsychotic)
- Methadone
- Protease inhibitors
- Class 1A antiarrhythmics
What drug can be given to treat torsades de pointes?
Magnesium!
WPW = Wolf-Parkinson White Syndrome
Ventricular pre-excitation syndrome - have an accessory excitation pathway from atria to ventricle that bypasses AV node; so, get early ventricular depolarization and see a Delta wave
- -> may lead to SVT
- -> Treat with Procainamide and Amiodarone
Delta wave
seen with WPW syndrome
Irregularly irregular ECG with no discrete P waves; see irregularly spaced QRS complexes
Atrial fibrillation (no distinct SA node; have several SA nodes acting at once, so no coordinated atrial contractions)
- -> get pooling of blood in atria –> can lead to pulm embolism, stroke, SVT
- Treat with: beta blockers, Ca-channel blockers, or digoxin (plus prophylaxis against thromboembolism with warfarin)
Sawtooth appearance on ECG
Atrial flutter -treat with class IA, IC or III antiarrhythmics, or beta-blockers
PR interval is prolonged by >200 msec on ECG
1st degree AV block
-asymptomatic
ECG with progressive lengthening of PR interval until a beat is “dropped” (so, have a P wave, not followed by a QRS complex)
2nd degree AV block = Mobitz type I = Wenckebach AV block
-asymptomatic
ECG with sudden dropped beats (QRS complexes) after a P wave; no change in PR interval prior to the dropped beat.
- Mobitz type II AV Block (2nd degree AV block)
- pathologic –> may progress to 3rd degree AV block
ECG with both P waves and QRS complexes, but P waves bear no relation to the QRS complexes.
- 3rd degree = Complete AV block
- ->atria and ventricles beat independently of one another
*Lyme disease may result in 3rd degree heart block