Figure 1: Digital subtraction angiographic images from a 69-year-old woman with symptomatic, 90% stenosis of the V4 segment (intradural) of the vertebral artery.

The vertebral artery is divided into four segments (V1–V4; Figure 1). The V1 segment originates at the subclavian artery and extends to the transverse foramina of either the fifth or sixth ...

An anterior myocardial infarction results from occlusion of the left anterior descending coronary artery. This can cause ... in the anterior leads (V3 and V4) and sometimes in septal and lateral ...