SSS causes retrograde blood flow in vertebral or internal thoracic arteries. More severe than typical vertebrobasilar insufficiency. Symptoms include presyncope, syncope, neurologic deficits, and blood pressure differences. Hands may show circulation problems with blotchy red and white patches
SYNTAX score is a powerful angiographic tool for predicting PCI outcomes. Score relies on visual interpretation of lesion severity. Training beyond online tutorial is essential for accurate scoring
CT scan is primary imaging tool for detecting brain bleeding. MRI may show bleeding in rare cases not detected by CT. Cerebral angiography provides detailed images using catheter. Lumbar puncture may be needed if initial imaging is inconclusive
Stenosis reduces blood flow through renal arteries, occlusion blocks it completely. Most common causes are thromboemboli (90%), atherosclerosis (10%), and FMD (1%). Atherosclerosis affects patients over 45, FMD in younger adults
Waveform analysis helps evaluate subclavian, carotid, and intracranial artery pathology. Vertebral artery stenosis can indicate subclavian steal physiology. Bidirectional flow in vertebral artery may not always indicate steal
Unstable angina occurs without myocardial infarction. Characterized by prolonged chest pain lasting >20 minutes. Symptoms include chest discomfort, dyspnea, nausea, and diaphoresis