ACTION POTENTIAL, ELECTRICAL STIMULATION, AND CARDIAC CONTRACTION
The ECG in relation to the Cardiac Cycle
One Complete Cardiac Cycle - Imagine one heartbeat as a loop:
P WAVE, ATRIAL DEPOLARIZATION, ATRIAL CONTRACTION
PR Interval, AV Nodal Delay
QRS Complex, Ventricular Depolarization, Ventricular Contraction
ST Segment, Ventricles Fully Depolarized, Plateau Phase
T Wave, Ventricular Repolarization, Ventricular Relaxation
Relationship to Heart Sounds
The Cardiac Conduction System
SINOATRIAL NODE (SA NODE)
THE CARDIAC ACTION POTENTIALS
The Ventricular Myocyte Action Potential
Mechanism of excitation-contraction coupling and relaxation in cardiac muscle
Differences between Sinus-Nodal and Ventricular Muscle Action Potentials
TRANSMISSION OF CARDIAC IMPULSE THROUGH THE HEART
FUNDAMENTAL CARDIAC ELECTROPHYSIOLOGY PRINCIPLES
Depolarization vs. Repolarization Waves
Conduction through the Bundle Branches and Ventricular Septum
THE STANDARD ELECTROCARDIOGRAM RECORDING (ECG PAPER)
Three Unipolar Augmented Leads
Three Augmented Unipolar Limb Leads:
Six Precordial (Chest) Leads
Limb Leads Axes (The Hexaxial System)
Right-sided and Posterior Chest Leads (Non-standard)
Twelve-Lead ECG Recordings
Arrangement of Leads on the ECG
THE CARDIAC ACTION POTENTIALS
VECTORIAL ANALYSIS AND DETERMINATION OF THE MEAN ELECTRICAL AXIS
DETERMINING THE ELECTRICAL AXIS (SHORTCUT METHOD)
One. PHYSIOLOGIC AXIS DEVIATIONS
Two. PATHOLOGIC AXIS DEVIATIONS
QRS Complexes in Left Ventricular Hypertrophy
Four. CONDITIONS THAT CAUSE ABNORMAL VOLTAGES OF THE QRS COMPLEX
Four. CONDITIONS THAT CAUSE BIZARRE QRS COMPLEX MORPHOLOGIES
ELECTROCARDIOGRAMINATION OF HEART RATE
· Calculating Heart Rate using a twelve-second rhythm strip.
Variable Shapes of ST-segment Elevations in Acute Myocardial Infarction.
E. T WAVE (VENTRICULAR REPOLARIZATION).
F. QT INTERVAL (VENTRICULAR DEPOLARIZATION AND
MYOCARDIAL INFARCTION LOCALIZATION.
Anterior Myocardial Infarction
Lateral Myocardial Infarction
Inferior Myocardial Infarction
Localize the Myocardial Infarction:
ELECTROCARDIOGRAMOSIS OF BUNDLE BRANCH BLOCKS (BBB) - NORMAL IMPULSE CONDUCTION
Complete Right Bundle Branch Block
Complete Right Bundle Branch Block: There is RSR in V1 and V2. Complete Right Bundle Branch Block is common in females in their twenties. Does not cause any hemodynamic abnormalities.
Mobitz Type Two - Second Degree Atrioventricular Block
Third Degree (Complete) Atrioventricular Block
MISCELLANEOUS DISORDERS (CONT'D.)