Ecg And Cardiac Output Flashcards
(30 cards)
Q: What does an ECG measure?
A: Potential difference between electrodes, represented as waves
Q: How many limb leads are there in an ECG?
A: 6 (3 bipolar: I, II, III; 3 unipolar: aVR, aVL, aVF)
Q: What are the chest leads in an ECG?
A: V1-V6
Q: What is Einthoven’s Law?
A: Lead II = Lead I + Lead III
Q: What do augmented unipolar leads measure?
A: One limb (+) vs. remaining limbs (-), amplified 15x
Q: Which leads represent the anterior wall?
A: V3, V4
Q: Which artery supplies the anterior wall?
A: Left Anterior Descending (LAD)
Q: What does the P wave represent?
A: Atrial depolarization
Q: Normal PR interval duration?
A: 0.12-0.22 seconds
Q: What does a prolonged PR interval indicate?
A: 1st-degree heart block
Q: Normal QRS duration?
A: <0.12 seconds
Q: What does the QRS complex represent?
A: Ventricular depolarization
Q: Corrected QT duration in men/women?
A: ≤0.45s (men), ≤0.47s (women)
Q: What does ST elevation indicate?
A: Myocardial infarction/ischemia
Q: Reference for ST-segment measurement?
A: PR segment (not TP interval)
Q: What is the J point?
A: Junction between QRS and ST segment
Q: Formula for heart rate using RR interval?
A: HR = 60/RR (in seconds)
Q: Normal ejection fraction percentage?
A: 55-70%
Q: Formula for stroke volume?
A: SV = EDV - ESV
Q: What does S3 heart sound indicate?
A: Rapid ventricular filling (normal in kids, post-exercise)
Q: What causes S4 heart sound?
A: Stiff ventricles (e.g., hypertension)
Q: Which valve closure causes S1 sound?
A: Mitral/tricuspid valves
Q: Phases of ventricular systole?
A: Isovolumetric contraction → Rapid ejection → Slow ejection
Q: EDV and ESV in aortic regurgitation?
A: EDV↑↑, ESV normal
