Heart Investigations Flashcards
DDx for left axis deviation
Left anterior hemiblock Inferior MI WPW RV pacing Normal variant Elevated diaphragm Lead misplacement Endocardial cushion defect
DDx for right axis deviation
RVH Left posterior hemiblock PE COPD Lateral MI WPW Dextrocardia Septal defects
What are the types of pacemakers + how do they appear on ECG?
Demand = discharge (vertical spike) prior to widened QRS
Atrial = discharge prior to P wave
Triggered = discharge following P wave, prior to QRS
Atrial + ventricular = discharge before P + QRS
What are the SE of digitalis?
Palpitations, fatigue, visual changes (yellow vision), decreased appetite, hallucinations, confusion, depression
DDx for ST elevation
I HELP A PAL Ischemia Hypothermia (osborne waves) Early repolarisation LBBB Post-MI Acute STEMI Prinzmetal's angina Acute pericarditis Left/ right ventricular aneurysm
DDx for ST depression
WAR SHIP WPW Acute NSTEMI RBBB/ LBBB STEMI w/ reciprocal changes Hypertrophy Ischemia Post MI
When does troponin peak, how long is it elevated for + what causes it to rise?
1-2 days = peak
Elevated for 2 weeks
MI, CHF, PE, AFib, myocarditis, CKD, sepsis, hypovolemia
When does CK-MB peak, how long is it elevated for + what causes it to rise?
1 day = peak
Elevated for 3 days
MI, myocarditis, pericarditis, muscular dystrophy, cardiac defibrillation, CKD
What is TTE + what is it used for?
Transthoracic Echo
Used to evaluate chamber size, LVEF, myocardial ischemia, valve morphology, wall thickness
What is TEE + what is it used for?
Transoesophageal Echo
Invasive procedure, US probe into oesophagus
Better visualisation of posterior structures (left atrium, mitral + aortic valves)
Used 1st line for aortic dissection
Evaluating aortic + mitral valve
What is a stress echo + what are the indications?
Using exercise or dobutamine as stress mechanism
Post ACS to decide on efficacy of revascularisation
Evaluate significancy of valve disease or heart disease
What is a contrast echo with agitated saline?
Improves resolution + provides real-time assessment of intracardiac blood flow
Allows visualisation of right heart + shunts, ie PFO
What is a contrast echo with transpulmonary contrast agents?
Agents cross pulmonary bed - improves visualisation of endocardial borders + enhance evaluation of LVEF
What is the Bruce protocol?
7 stage test with each stage = 3 mins
Treadmill increases in speed + grade with each stage
What is exercise testing + what are the indications?
ECG + BP monitoring during exercise
Pts with intermediate (10-90%) probability of CAD
ST depression <1mm at rest, no LBBB, no digoxin or estrogen use
How do the results of exercise testing affect the pt?
Low risk = can be treated medically w/o invasive testing
Intermediate risk = may need additional testing (exercise imaging studies or cardiac catheterisation)
High risk = cardiac catheterisation
What are the CI to exercise testing?
Acute MI, aortic dissection, pericarditis, myocarditis, PE
Severe AS, arterial HTN
Inability to exercise adequately
ECG changes in hypothermia
Sinus bradycardia
Prolonged QRS + QT
AFib with slow ventricular response
Osborne J waves = hump like waves at junction of J point + ST segment
ECG changes in pericarditis
Early = diffuse ST segment elevation + PR segment depression, upright T waves Later = isoelectric ST segment, flat or inverted T waves
What is nuclear cardiology?
Myocardial perfusion imaging with ECG gated CT
Evaluates myocardial perfusion, function + any ischemia
What is right heart catheterisation?
Swan-Ganz catheter used to obtain measurements of pulmonary arteries
Can estimate cardiac output, systemic vascular resistance, O2 delivery + uptake
What is cardiac index?
CO/ body surface area
Measure of cardiac function
What is pulmonary capillary wedge pressure?
Obtained by advancing catheter to wedge distal pulmonary artery
Records pressure in pulmonary venous system
Reflects LA pressure
Indications for right heart catheterization
Unexplained volume status in shock
Severe cardiogenic shock
Suspected pulmonary HTN
