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.
To meet criteria for LGL, the 12-lead ECG taken during a period of normal sinus rhythm must demonstrate a PR interval less than or equal to 0.12 second and a normal QRS upstroke and duration, as in the image below. ECG demonstrating a short PR interval of approximately 100 ms and normal QRS. One of the most useful diagnostic tools is a 12-lead ECG recorded during a paroxysm of tachycardia.