Cardiac Reference

Normal Hemodynamic Values

Parameter Normal Range Units
CO 4–8 L/min
CI 2.5–4.0 L/min/m²
SVR 800–1200 dyn·s/cm⁵
PVR 150–250 dyn·s/cm⁵
CVP 2–6 mmHg
PAP systolic 15–25 mmHg
PAP diastolic 8–15 mmHg
PAP mean 10–20 mmHg
PCWP 6–12 mmHg
MAP 70–105 mmHg
EF 55–70 %

Heart Sounds

Sound Location Description
S1 Apex (mitral area) Closure of AV valves (mitral, tricuspid); marks start of systole; "lub"
S2 Base (aortic, pulmonic areas) Closure of semilunar valves (aortic, pulmonic); marks start of diastole; "dub"
S3 (ventricular gallop) Apex Early diastole; rapid ventricular filling; may indicate HF in adults
S4 (atrial gallop) Apex Late diastole; atrial contraction into stiff ventricle; may indicate hypertrophy
Murmurs Varies Classified by timing (systolic/diastolic), location, intensity (1–6), pitch, quality

EKG/ECG Basics

Normal Intervals

Interval Normal Range
PR interval 0.12–0.20 s
QRS <0.12 s
QT interval 0.36–0.44 s

Common Rhythms

Rhythm Rate Regularity Description
Normal Sinus 60–100 Regular Normal; P before each QRS, PR <0.20s
Sinus Brady <60 Regular Slow but normal conduction
Sinus Tach >100 Regular Fast but normal conduction
A-fib Variable Irregularly irregular No P waves; chaotic atrial activity
A-flutter Variable (often 150) Regular or variable Sawtooth flutter waves
SVT 150–250 Regular Narrow QRS; often P buried in QRS
V-tach 100–250 Regular Wide QRS; no P waves; life-threatening
V-fib — Chaotic No organized rhythm; CPR + defibrillation
Asystole — — Flat line; no electrical activity
PEA Any Any Organized electrical activity but no pulse

Cardiac Enzymes Timeline

Marker Onset Peak Duration
Troponin I 2–4 hours 12–24 hours 5–10 days
CK-MB 3–6 hours 12–24 hours 2–3 days
Myoglobin 1–2 hours 4–8 hours 24 hours

Coronary Arteries

Artery Supplies
LAD (Left Anterior Descending) Anterior wall
LCx (Left Circumflex) Lateral wall
RCA (Right Coronary Artery) Inferior wall