Principles of Electrocardiograph

Principles of Electrocardiograph

• The electrocardiograph records the electrical activity of the heart.
• The resulting trace is called an electrocardiogram (ECG).

Electrophysiology

• The sinoatrial (SA) node serves as the heart's natural pacemaker.
• Electrical impulses spread across the atria, prompting atrial contraction.
• The impulse reaches the atrioventricular (AV) node for further transmission.
• The impulse travels along the interventricular septum through the Bundle of His.
• The Bundle of His splits into right and left bundle branches.
• Purkinje fibers distribute the impulse throughout the ventricular myocardium.

Electrode Placement

• V1: Positioned at the 4th intercostal space at the right sternal edge.
• V2: Located at the 4th intercostal space at the left sternal edge.
• V3: Placed midway between V2 and V4.
• V4: Positioned over the apex (5th intercostal space at the mid-clavicular line).
• V5: At the same horizontal level as V4, on the anterior axillary line.
• V6: At the same horizontal level as V4 and V5, positioned on the mid-axillary line.

Clinical Significance

• An ECG can reveal ST elevation indicative of a myocardial infarction (MI).

This quiz covers the basics of electrocardiography, including the electrical activity of the heart, the sinoatrial node, and the transmission of electrical impulses across the heart.