Cardiology Flashcards
What are 4 signs of Right Ventricular Hypertrophy in ECG?
- R in V1 (<20mm), >25mm in neonates
- (and/or) S in V6 (>7mm)
- Upright T wave in V1 after 72yrs-5yrs
- RAD (-ve I, +ve aVF)
What is an ECG sign of Severe RVH?
T wave goes down in V1 due to strain
What is a sign of Left Ventricular Hypertrophy on ECG?
R wave > 25mm in V6
What is a sign if severe LVH on ECG?
ST depression and T wave inversion in V6
Where do you measure QT on an ECG?
Lead II and V5, QT/sq root of preceding RR interval.
At what age is an upright T wave in V1 considered normal and why?
birth - day 4. Due to high pulmonary pressures in foetal circulation (lungs full of fluid and bypassed mostly by FO and PDA)
What ECG finding indicates Right Atrial dilatation?
Tall P waves >3mm in V1,II
What causes Right Atrial dilatation?
Large ASD, TR (Ebsteins, Rheumatic), Pulmonary atresia, TS (rare), TAPVR, severe PS.
What ECG finding indicates Left Atrial dilatation?
Bifid + long P waves (>0.1/2.5 small squares OR 0.8 in neonate.
What causes Left Atrial Dilatation?
Mitral regurgitation, mitral stenosis, Large VSD
How are normal Q waves differentiated from pathological Q waves?
Normal = thin/narrow and in inferior and lateral leads (II,III, aVF, V5,V6). Pathological = broad + deep in V1. Exception = some newborns have Q wave in V1
What do pathological Q waves indicate?
L-TGA, single ventricle, severe RVH, anterior myocardial infarction
What causes Left Axis Deviation?
LVH, LBBB (rare in paeds), Left anterior hemiblock (superior axis, narrow QRS –> Tricuspid atresia, AV canal defect, congenitally corrected TGA), WPW, PS (Noonan - esp if HCM), single ventricle
What causes RAD?
RVH (e.g. ToF), RBBB, Secundum ASD
What causes superior axis deviation (-ve I + aVF)?
AVSD, Tricuspid atresia, primum ASD, PS (Nooonan’s)
What causes prolonged PR?
(First degree heart block)
- Normal varient
- Myocarditis
- Digitalis Toxicity
- CHD (AVSD, ASD, Ebsteins)
What would cause a shortened PR?
- Pre-excitation (WPW, Lown-Ganong-Levine Syndrome)
- Glycogen storage disease
- Low right atrial pacemaker
What causes a prolonged QRS
- RBBB
- LBBB
- WPW
- Interventricular block
- Pre-mature ventricular beats
- VT
What is the 5,4,3,2,1 rule for RVH?
R wave in V1: >5sq <1month >4sq<1yr >3sq >3yr S wave in V6: >3sq <1month >2sq <1yr >1sq >1yr
What is the 5,4,3,2,1 rule for LVH?
R wave in V6: >3sq <1m >4sq <1yr >5sq >1yr S wave in V1: >1sq <1m >2sq <1yr >3sq >1yr
What causes flat T waves?
Hypothyroidism, Hypokalemia, myocarditis
What is sinus node dysfunction and name 3 causes
SA node unable to be dominant pacemaker. Unable to elevate HR in response to stress. Causes:
- CHD (ASD, AVSD, TGA)
- Post surgery - TGA atrial switch
- Meds (Digoxin, propranolol, verapamil,
- Myocardial disease (cardiomyopathy, myocarditis, pericarditis, Kawsaki’s, MI)
- Neonate: lupus, apnoeas + brady’s of prematurity
What is 1st Degree Heart Block and what are 3 causes?
Constant prolonged PR interval, all beats conducted.
Causes:
Increased vagal tone, Rheumatic fever, Rubella, mumps, metabolic (K,Ca2+,BSL, Mg2+), cardiomyopathy
What is second degree heart block, Mobitz 1?
Progressively longer PR until a beat isn’t conducted. Block at the AV level. Don;t get CHB.
Most caused by raised parasympathetic tone, myocarditis, post cardiac disease surgery
