Cardio - Phys/Ana/Emb Flashcards
Vitelline veins
Portal system veins
Cardinal veins
systemic circulation veins
Truncus arteriosus
Ascending aorta and pulmonary trunk
Bulbus cordis
Smooth parts (outflow tract) of left and right ventricles
Primitive atrium
trabeculated part of L/R atria
Primitive ventricle
trabeculated part of L/R ventricles
Primitive pulmonary vein
smooth part of left atrium
Left horn of sinus venosus
Coronary sinus
Right horn of sinus venosus
Smooth part of right atrium (sinus venarum)
Right common cardinal vein and right anterior cardinal vein
SVC
When does heart start beating?
4 weeks (first functional organ)
Atrial septation
Septum primum –> Foramen primum –> Foramen secundum —>Septum secundum –>foramen ovale
Outflow tract from?
Neural crest migration + endocardial cushion migration
All valve origins?
Endocardial cushions
Fetal erythropoiesis
Young Liver Synthesizes Blood
- Yolk sac (3-8wks)
- Liver (6wks - birth)
- Spleen (10-28wks)
- Bone marrow (18wks - adult)
HbF unique?
Less avid binding 2,3-BPG
Umbilical vein O2
PO2 = 30mmHg
80% saturation
Ductus venosus
Shunts blood from umbilical vein into IVC
- becomes ligamentum venosum
Allantois–>Urachus
Median umbilical ligament
Ductus arteriosus becomes
Ligamentum arteriosum
Foramen ovale becomes
Fossa ovale
Umbilical arteries
Medial umbilical ligaments
Umbilical vein
Ligamentum teres hepatis contained in falciform ligament
SA and AV node blood supply
SA - RCA
AV - branch of posterior descending artery (RCA or LCA)
LCX
- lateral and posterior walls of LV
- anterolateral papillary muscle
LAD
- ant. 2/3 of IV septum
- anterolateral papillary muscle
- ant surface of LV
PDA
- post 1/3 of IV septum
- post walls of ventricles
- posteromedial papillary muscle
CO =
= SV x HR
= rate of O2 consumption/(arterial O2 content - venous O2 content)
MAP =
CO x TPR
Pulse pressure and SV/arterial compliance
PP is proportional to SV
PP is inversely proportional to arterial compliance
Increased Pulse Pressure
Hyperthyroidism, aortic regurgitation, aortic stiffening (isolated systolic HT in elderly), obstructive sleep apnea (increased sympathetic tone), exercise (transient)
Decreased Pulse Pressure
Aortic stenosis, cardiogenic shock, cardiac tamponade, advanced heart failure (HF)
Increased contractility
- Catecholamine (Increase activity of Ca2+ pump in SR)
- Increased intracellular Ca
- Decreased extracellular Na
- Digitalis
Decreased contractility
- B1 blockage
- HF w/systolic dysfunction
- acidosis
- hypoxia/hypercapnia
- Non-dihydropyridine Ca channel blockers
Increased diameter of ventricle
Increased wall tension –> increased myocardial O2 demand
ACEI/ARBs - preload and afterload?
decrease both
Normal EF
> 55%
Phospholamban
Dephorphorylated phospholamban binds SERCA-2 (SR Ca-ATPase) and decreases affinity for Ca2+
- membrane protein
- decreased rate of muscle relaxation and contractility (decreased HR and SV)
- phosphorylated by PKA (adrenergic)
Organ removal (eg. nephrectomy)…
Increases TPR and decreases CO
Driving pressure =
Q x R
Q=flow velocity x cross sectional area
R=8nl/3.14r^4
TPR on venous return
(+) TPR - decreased
(-) TPR - increased
TPR (increase and decrease)
Increased by: vassopressors (constrictors)
Decreased by: exercise, AV shunt
Period of highest O2 consumption (LV cycle)
Isovolumetric contraction
Jugular venous pulse
a wave - atrial contraction (absent in a-fib)
c wave - RV contraction
x descent - atrial relax + downward tricuspid displacement (absent in tricuspid regurg)
v wave - atrial filling against closed tricuspid
y descent - RA empties into RV
Constrictive pericarditis
rapid y descent that is deeper and steeper w/ inspiration
S1
loudest at mitral area
S2
loudest at left upper sternal border
S3
- @ early diastole
- increased filling pressure (mitral regurg, HF)
- more common in dilated ventricles
- normal in kids and pregos’
- heard best at apex while lying lateral decubitus @ end-expiration
S4
- @ late diastole
- “atrial kick”
- high atrial pressure
- assoc. w/ ventricular hypertrophy (LA must push against stiff LV wall)
- heard best at apex while lying lateral decubitus @ end-expiration
Wide splitting
Delayed RV emptying (ex. pulmonic stenosis, right bundle branch block)
Fixed splitting
ASD
Paradoxical splitting
Delayed aortic valve closure (ex. aortic stenosis, left bundle branch block)
- A2 after P2, decreased gap with inspiration
Left sternal border
Diastolic murmor
- aortic regurg
- pulmonic regurg
Systolic murmor
- hypertrophic cardiomyopathy
VSD murmor
Pansystolic @ tricuspid area
ASD presentation
- pulmonary flow murmur (pulmonary valve)
- diastolic rumble (tricuspid valve)
(later progresses to louder diastolic murmur of pulmonic regurgitation from pulmonary a. dilation)
Bedside maneuver: Inspiration (venous return)
Increased intensity of right heart sounds
Bedside maneuver: Hand grip (afterload)
- Increased intensity of MR, AR, VSD murmurs
- Decreased hypertrophic cardiomyopathy murmurs
- MVP: later onset of click/murmur
Bedside maneuver: Valsalva (phase II), standing up
preload decrease
- Decreased intensity of most murmurs (including AS)
- Increased intensity of hypertrophic cardiomyopathy murmor (LVOT obstruction)
- MVP: early onset of click/murmur
Bedside maneuver: Rapid squatting (preload increase)
- Decreased intensity of hypertrophic cardiomyopathy murmur
- Increased intensity of AS murmor
- MVP: later onset of click/murmur
Pulsus parvus et tardus
pulses are weak w/ delayed peak
- aortic stenosis
Mitral regurg
- Radiates towards axilla
- often d/t MI, MVP, LV dilation
Most frequent valvular lesion
MVP
Best indicator of AR severity
Presence of S3 (high rate of ventricular filling)
AR auscultation
Best heard @ left sternal border b/t 3/4, while patient sitting, leaning forward and at end expiration
Ortner Syndrome
LA dilation impinges on left recurrent laryngeal n.
- can be d/t mitral stenosis
Skeletal vs. cardiac muscle Ca release from SR
- Ryanodine receptor linked L-type Ca channel
- L-type Ca channel causes Ca influx inducing Ca release
Conduction speed
Purkinje fibers > atrial myocytes > ventricular myocytes > AV node
PR interval
less than 200 msec normally
QRS interval
less than 120 msec normally
J point
Junction b/t end of QRS and start of ST segment
U wave
Caused by hypokalemia or bradycardia
AV node delay
100 msec
Torsades de pointes causes
1) Drugs (ABCDE)
- AntiArrhythmics (class IA, III)
- AntiBiotics (eg. macrolides)
- Anti”C”ychotics (eg. haloperidol)
- AntiDepressants (eg. TCA)
- AntiEmetics (eg. ondansetron)
2) Hypokalemia
3) Hypomagnesia
4) Long QT syndrome
Torsades de pointes Rx
Magnesium sulfate
Romano-Ward syndrome
- Congenital long QT syndrome (AD)
- NO deafness
Jervell and Lange-Nielsen syndrome
- Congenital long QT syndrome (AR)
- sensorineural deafness
Brugada syndrome
- ECG pattern of pseudo-right bundle branch block and ST elevations in V1-V3
- AD more common in asian males
- Increased risk of ventricular tachyarrhythmias and SCD
Rx: Prevent SCD w/ implantable cardioverter-defib
Delta wave
Wolff-Parkinson-White syndrome
- associated w/ widened QRS and shortened PR
Binge drinking “Holliday Heart”
A-fib
PR interval >200 msec
1st degree AV block
Wenckebach
Second degree heart block: Mobitz type 1
Lyme disease can cause…
complete (3rd degree) heart block
ANP
- acts via cGMP
- from atrial myocytes
- vasodilation and decreased Na reabsorption in CT
- Renal aff. dilation and eff. constriction (aldosterone escape)
BNP
- ventricular myocytes
- longer half-life than ANP
- GOOD negative predictive value for Dx HF
Nesiritide
Recombinant BNF for treating HF
Aortic arch and carotid sinus nerve relay
AA - vagus n –> solitary nucleus of medulla
CS - glossopharyngeal n –>solitary nucleus of medulla
Cushing reaction
Triad of hypertension, bradycardia, respiratory depression
- Increased ICP constricts arterioles –> decrease pH –> sympathetic reflex –> HYPERTENSION –> baroreflex causes BRADYCARDIA. Pressure on brainstem causes RESP. DEP.
Heart pressures
RA: less than 5 RV: 25/5 PA: 25/10 PCWP: less than 12 LA: less than 12 LV: 130/10 A: 130/90
Mitral stenosis PCWP
PCWP > LV
Hormone permissiveness
When one hormone allows another to exert its maximal effect (the aiding hormone has no intrinsic effect)
Exercise on TPR
DECREAED
Most deoxygenated blood in body
Cardiac venous blood
myocardium has HIGH O2 extraction (60-75%
Ach, Bradykinin, shear stress –>
Argine + O2 —–eNOS—–>NO + citrulline
Sudden deceleration ruptures the….
Aortic isthmus