E. (1) sea shell fossils (2) it is made of old ocean floor that got uplifted during collision. 4. At convergent plate boundaries, the volcanic mountain chains that form are called (1) ________ in an ocean-. ocean setting and (2) __________ in an ocean-continent setting.
Poor R wave progression is a vague term used to describe the transition in voltage in the precordial leads of an electrocardiogram (ECG). It is not a diagnosis but simply describes a pattern frequently noted. In a normal individual there is a progressive increase in the magnitude of the voltage in the leads from V1 to V4.
The QRS complex is made up of three waves. These waves indicate the changing direction of the electrical stimulus as it passes through the heart's conduction system. The largest wave in the QRS complex is the R wave. As you can see from the diagram, the R wave represents the electrical stimulus as it passes through the main portion of the ventricular walls. The wall of the ventricles are very thick due to the amount of work they have to do and, consequently, more voltage is required.