Week 2b Flashcards
Bipolar leads (3)
I, II, III
Unipolar leads (9)
avF, aVL, aVR (augmented) and V1-V6
Septal wall and ventricle leads
V1 and V2
Anterior surface of the heart leads
V3 and V4
Left ventricle (especially lateral) leads
V5 and V6
Inferior leads
II, III, aVF
Lateral Leads
I and aVL
Normal WRS axis: positive in? negative in?
positive I and II, negative III (-30 to +90 degrees)
L.A.D: positive in? negative in?
Predominantly negative in Lead II and positive I, negative III
R.A.D.: positive in? negative in?
Predominantly negative in Lead I and positive III, negative II
ECG findings in left bundle branch block
Late depolarization of LV
Away from V1 (R sided leads) and toward V6 (left sided leads), widened QRS
Hemiblocks
axis shift without widening of QRS
Anterior hemiblock: _AD
LAD
Posterior hemiblock: _AD
RAD
ECG of right bundle branch block
Late depolarization of RV
Towards V1 and Towards V6, widened QRS
What does hypertrophy cause in an ECG finding?
more conduction, thus more voltage on ECG
ECG left ventricular hypertrophy
V5,6 have greater voltage
ECG right ventricular hypertrophy
V1,2 greater voltage
ST depression=
- transient ischemia during times of high O2 demand
OR
- subendocardial infarct (if lasting 2-3 days)
Inverted T waves =
transient ischemia due to acute coronary blockage
ST elevation =
- transmural injury in acute coronary blockage (typically due to acute MI)
OR
- Acute pericarditis (if in all leads!)
Q waves (sizeable in at least two adjacent leads)
transmural necrosis
Location of Q wave indicates where infarct is
Anatomy and function of aortic valve (3)
i. Trileaflet
ii. Allows blood flow out of LV into aorta during systole
iii. Prevents blood backflow into LV during diastole
Anatomy and function of pulmonic valve
i. Trileaflet
ii. Allows blood flow from RV into pulmonary artery during systole
iii. Prevents blood backflow into RV during diastole
3 aortic diseases
- bicuspid aortic valve
- aortic stenosis
- aortic insufficiency
Bicuspid aortic valve disease (5)
- Congenital cardiac malformation
- Most common congenital cardiac defect
- Often familial (1st degree family members should be screened)
- Common cause of other valvular complications (aortic stenosis, aortic insufficiency, endocarditis)
- Causes vascular complications → aortic dilation, aneurysms, dissection
Treatment of bicuspid aortic valve disease
close monitoring of valve disease, and aortic size
Aortic stenosis
decreased aortic valve opening during systole, causing LV outflow obstruction → increased LV pressure, decreased CO
Causes of aortic stenosis (3)
a. Congenital (bicuspid)
b. Calcific (in elderly) → calcium build up
c. Rheumatic → fusion
Symptoms of aortic stenosis (3)
a. Dyspnea on exertion (due to elevated LV pressures and CHF)
b. Exertional lightheadedness or syncope (due to decreased CO)
c. Exertional angina
Diagnosis of aortic stenosis (3 techniques and findings of each)
a. ECHO: shows calcification of aortic valve
b. Cardiac catheterization: direct, invasive, hemodynamic measurements to determine aortic valve gradients
c. Physical Exam: Harsh, crescendo-decrescendo systolic murmur heard best over RUSB
i. Radiation to carotids
ii. Longer, late peaking murmur associated with more severe disease
Treatment of aortic stenosis
a. Medical therapy:
i. Diuretics - reduce preload (problem is AS pts may be preload dependent)
ii. B-blockers - reduce contractility
iii. Vasodilators - HARMFUL, may cause hypotension
b. Aortic valve intervention (when symptoms develop and EF less than 50%)
i. Surgical aortic valve replacement, balloon valvuloplasty, transcatheter aortic valve replacement (TAVR)
Aortic insufficiency
insufficient valve closure so blood flows backwards into LV from aorta during diastole → increased LV volume load
→ LV dilation, systolic dysfunction, heart failure
Causes of aortic insufficiency
a. Valve disease: bicuspid AV, Calcific disease, Endocarditis, Rheumatic Disease
b. Aortic disease: dissection, Marfan, Aneurysm/dilation
Symptoms of aortic insufficiency (5)
a. Water hammer pulse (rapidly swelling and falling arterial pulse)
b. DeMusset’s sign: head bob with each heartbeat
c. Quincke’s pulses: capillary pulsations in fingertips
d. Mueller’s sign: systolic pulsations of uvula
e. Corrigan’s pulse: rapid forceful carotid upstroke followed by rapid decline
Diagnosis of aortic insufficiency
a. Physical Exam:
i. Early diastolic murmur (L sternal border)
ii. Austin-Flint Murmur: diastolic murmur at apex due to turbulent diastolic blood flow across mitral valve
iii. Systolic murmur may occur due to increased flow across aortic valve (mimics aortic stenosis)
ECHO: LV size and function, evaluate aortic pathology
Clinical presentation of aortic insufficiency
a. Long asymptomatic phase
b. Severe AI → LV dilation and dysfunction → CHF (dyspnea, pulmonary edema, orthopnea
Treatment of aortic insufficiency
a. Close monitoring
b. Medications: treat CHF (ACEI, ARB, BB, diuretics)
c. Surgical intervention: symptomatic severe AI with systolic EF less than 50%
Pulmonic valve disease is typically due to _____
congenital heart disease
Pulmonic stenosis is usually found in ______
children or early adolescents
Clinical presentation of pulmonic stenosis (4)
a. RVH and RV enlargement → RV failure
b. Long asymptomatic phase
c. Dyspnea on exertion, CP, syncope
d. Peripheral edema
Auscultation finding of pulmonic stenosis
a. Systolic ejection murmur (loudest at L upper sternal border)
i. Longer and late peaking → more severe disease
b. Split S2
c. Right sided S4 may be present
Primary causes of pulmonic insufficiency
a. Infectious, Rheumatic, Carcinoid
b. Congenital abnormality
c. Iatrogenic (surgical valvotomy or balloon valvuloplasty)
Clinical manifestations of pulmonic insufficiency (5)
a. Long asymptomatic phase
b. RV volume overload
c. RV volume dysfunction
d. Atrial and ventricular arrhythmias
e. Mild-moderate PI is a common finding on echo and does not warrant further testing or monitoring if asymptomatic with normal RV
Auscultation findings ion pulmonic insufficiency
Early diastolic murmur (best heard over L 2nd and 3rd IC spaces
- May increase in intensity with inspiration
Anatomy and function of mitral valve
i. Open in diastole to allow blood flow from LA to LV
ii. Closed in systole to prevent blood backflow from LV to LA
iii. Anatomy: Annulus, Leaflets, Chordae, Papillary muscles
Anatomy and fuction of tricuspid valve
i. Open in diastole to allow blood flow from RA to RV
ii. Closed in systole to prevent blood backflow into RA
iii. 3 leaflets + 3 papillary muscles
Mitral stenosis
decreased mitral valve opening → obstruction of flow from LA to LV during diastole → increased pressure in LA, pulmonary vasculature and right heart
Causes of mitral stenosis
a. Rheumatic (80-99% of MS cases) - occurs years after acute rheumatic fever
b. Calcific (advanced age, renal disease)