{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Lab2_ECG_Semmlow

Lab2_ECG_Semmlow - The Electrocardiogram Bekah Gensure...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1 The Electrocardiogram Bekah Gensure [email protected] M.D. / Ph.D. Candidate ECG Lecture Overview Fundamentals of heart electrical activity History of electrocardiogram Cardiac anatomy Cardiac physiology (action potentials) ECG timing and amplitudes Clinical correlations Summary The Heart Is a pump Has electrical activity (action potentials) Generates electrical current that can be measured on the skin surface E LECTRO C ARDIO G RAM (ECG / EKG)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2 Cells of the heart Cardiac myocytes (muscle cells) Contractile machinery Pacemaker cells Electrical power source of heart Spontaneously depolarize Electrical conducting cells Rapid conduction system (hard wiring) Myocyte AP Pacemaker AP Currents and Voltages At rest, V m is constant No current flowing Inside of cell is at constant potential Outside of cell is at constant potential + + + + + + + + + + + + – – – – – – – – – – A piece of cardiac muscle outside inside 0 mV + Depolarization During AP upstroke, V m is NOT constant Current IS flowing Inside of cell is NOT at constant potential Outside of cell is NOT at constant potential + + – – – – – – – – – – – – – + + + + + + + + + + + A piece of cardiac muscle outside inside Some positive potential + current AP An action potential propagating toward the positive ECG lead produces a positive signal
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}