Physio/simple/cardio

Front 1

regarding positions of the ECG leads, these arrows indicate the axes between the negative and positive electrodes. TRUE/FALSE

Back 1

TRUE. cardiac depolarization that spreads in the direction of an arrow, i.e. toward a positive electrode, results in a positive(upward) deflection on the ECG above the baseline. Those travrling away from the positive electrode will have a negative deflection(downward) below the baseline.

Front 2

Since depolarization normally spreads from upper right to lower left, this places the depolarization as spreading, for the most part, toward positive electrodes, except for AVR and sometimes V1. TRUE/FALSE

Back 2

TRUE.

Front 3

What can be said regarding vertical and horizontal planes of the body?

Back 3

The net result of the various electrode positions is that the ECG looks at the heart from a variety of positions. Leads 1,11, 111, aVR, aVL, aVF look at the heart along the vertical(frontal) plane, whereas leads V1-V6 look at the heart along the horizontal(transverse) plane.

Front 4

Why is there a downward deflection of the Q wave?

Back 4

It occurs because septal depolarization proceeds from left to right, arising from connections from the left bundle branch.
ventricular depolarization spreads from the subendocardial to the subepicardial surface.

Front 5

List one simple way for calculating heart rate?

Back 5

Count the number of QRS complexes between three markers(6 seconds) and multiply by 10. If we count 6 QRS complexes between 3 markers(found on top of the ECG paper) we would have a rate of 60.

Front 6

In the above example, we have a rate of 60, yet what would a 2:1 block look like in theory?

Back 6

A 2:1 block in which there is only one of every 2 P waves gets through and generates a QRS complex.
The atrial rate, as measured by P waves, is about 110-120.

Front 7

What can the cardiogram actually show?

Back 7

It can depict heart rate, rhythm, axis of heart rotation, heart muscle hypertrophy, and cardiac muscle ischemia.