Presentation on theme: "ST Segment – The Thing You Can’t Miss"— Presentation transcript:
1 ST Segment – The Thing You Can’t Miss Nick SparacinoCardiology Study Group
2 ST Segment J-Point to beginning of T wave Isoelectric in limb leads in 75% of “normal” EKGUp to 90% of all EKG’s have some ST elevation precordially>1mm elevation abnormalAny depression abnormal
3 Baseline? I don’t need no stinking baseline! Three potentially isoelectric portionsPR, ST, TPPR can be unreliable, particularly if pericarditis is on differentialGenerally use TPNone can be completely relied on with standard EKG
4 Mechanism of ischemic/injurious ST Changes 2 “phases” of electrical activityIschemic tissue depolarizes and repolarizes less vigorously than healthy tissue
10 Early Repolarization Traditionally considered benign 1-5% of general populationMore common with young males, African AmericansLarge T waves, concave ST contour, no other evidence of LVH or other causesMimics hyperkalemia2008 NEJM found 2.1 HR for SCD!
12 LVH Covered in last installment High points: Estes-Romhilt is best criteriaLook for big QRS, negative P in V1, clinical history of htn, stim abuse
13 DigoxinDerangements in Na/Ca movement produces changes in action potentialCauses characteristic “scooped” inverted ST-TLooks like check-mark
14 Wellen’s Sign1996 Wellen described a series of acute proximal LAD lesions with no ST elevation or troponin riseBiphasic anterior T waves the only unifying featureA case was missed by one of us at the VA recently – can’t lean on trops!
15 PericarditisDiffuse ST elevationLook at PR interval!
17 BrugadaMost well known of a series of inherited ion channel pathologiesProduce a characteristic pattern of precordial ST elevation3 described types, type 1 is the classicVery high J point, smoothly descends to an inverted THigh risk of sudden cardiac deathMost common in southeast Asian males – up to .5-1% in a Japanese study
18 Neurologic insult Most often described with strokes Trauma, tumor, metabolic derangements
19 When in doubt Call for help! Fellow residents, senior residents, chiefs, fellows, IM attendings, cards attendings“Better to wake someone up than put someone to sleep”Practice!
20 Over to you, Mo www.goodsamcsg.wikispaces.com Cardiostudy@gmail.com Powerpoints, articles, calculators, Oh My!EKG reference cards