Anatomy and physiology Flashcards
What is normal AO pressure
120/80
What is normal RA pressure
A mean of 6mmHg
What is normal PA pressure
25/10
What is normal RV pressure
25/5
What is normal wedge pressure
Mean 10mmH
What is normal LA pressure?
Mean 10
What is normal LV pressure
120/7
What makes up the Triangle of Koch?
TA, CS, tendon of Todaro, HIS
What constitutes the fibrous skeleton of the heart?
Tricuspid annulus, mitral, aortic and pulmonary valves
Fast pathway anatomy:
Anterior-superior aspect of the tricuspid valve, close to the HIS.
What is normal CO?
4-8L/min
CO = HR x SV
What is normal EF?
65%
SV/EDV
What is the time from the mitral valve closing to the opening of the aortic valve?
Isovolumic contraction
What describes the resistance that the heart must overcome to eject blood?
After load
Infranodal block is conduction block involving?
The HIS purkinje system
Characteristics of 1st degree heart block
Slowing in AVN with a PR >200
1:1 relationship a to v
Characteristics of 2nd degree AV block
PR gradually prolongs and a V is dropped.
AKA Wenckebach
Mobitz 1
Characteristics of 3rd degree HB
Disassociation of A and V.
Mobitz type 2
What are the prerequisites for reentry?
- Two circuits with a common connection.
- Different conduction velocities
- Different refractory PDA
What is orthodromic tachycardia?
Down the node up the pathway
What is Antidromic tach?
Down the pathway and up the node
What are characteristic of AFL?
Negative in inferior leads
Counter-clock
What is triggered activity caused by?
Afterdepolarizations
Acceleration in late phase 3 or early phase 4 of leakage of positive ions into the cell.
When would Signal averaged ECG used?
Pts post MI.
To look for ventricular late potentials using modified 6lead to high frequency QRS duration (normal 20)
What does T-wave alternans screen for?
SCD risk stratifier.
What are the normal parameters for signal average ECG, including duration, root mean square and low amplitude signals
Dur35ms; LAS <30-35
28yo pt with orthostatic hypotension and 3 episodes of sudden syncope in last 3mo. Physical exam, labs and ECG normal. What test is used to determine the cause of syncope?
Tilt table test
What tachycardia terminates with carotid massage?
Typical AVNRT via a regrade slow pathway
How do you convert BPM to MS?
Take the number you have (BPM or ms) and divide it into 60000
What is normal AH?
50-140ms
What is normal HV?
35-55ms
What is relative refractory period?
The longest s1-s2 coupling interval that conducts.
What is effective refractory period?
Longest coupling interval that fails to capture.
What is functional refractory period?
Min distance that is observed between s1 and s2 that captures and produces an impulse.
With normal retrograde conduction, the earliest atrial activation is observed where?
HIS
An AH jump is —-ms.
50ms
The longest coupling interval for which. Premature impulse fails to propogate through tissue is the—.
Effective refractory pd.
What is the typical AVNRT conduction?
Jump - down slow- up fast
Concealed pathway only has —- conduction.
Retrograde
If delta wave is positive in the inferior leads it is likely where
Anterior
If delta is neg in inferior leads where is AP located?
Posterior
If delta is neg in lead II, the AP is located where?
In a vein or Epicardial
What are the ECG characteristics of BB reentry?
Left BBB (neg QRS V1) with superior axis (neg II, III, aVF).
What type of VT is verapamil sensitive
Left fascicular VT
What are the characteristics of superior axis?
Neg in inferior leads.
What are the ECG characteristics of LVOT VT?
RBBB, inferior axis (+II, III, aVF), precordial leads are concordat with positive peaked QRS
What is a typical characteristic of concealed bypass tract?
Incapable of a regrade conductionz
Preexcitation of the atrium with ventricular pacing is strong evidence of?
AV pt pass tract
The earliest site of activation of a qRS during VT is referred to as?
Presystolic signal
An atrial echo results from?
Retrograde atrial activation from within the AVN
