ekg rounds elizabeth haney 19 october 2006. case 32 y.o. caucasian male presents w/ 4 hours sharp...
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EKG Rounds
Elizabeth Haney
19 October 2006
Case
32 y.o. Caucasian male presents w/ 4 hours sharp RSCP
Radiation to Lt shoulder and arm Worse with deep inspiration, no exertional change
PMHx: healthy, URTI Sx x 5/7 Meds: occasional tylenol NKDA
Case (cont’d)
Vitals: HR 120 reg, RR 24, BP 124/82 bilat,
T 37.1, O2 sat 99%
O/E: sitting up in bed, moderate distress, otherwise exam normal
EKG
Pericarditis
Overview of the pericardium and pericarditis
4 EKG stages
Differentiating between pericarditis and early repolarization
Pericardium
Back to basics: Pericardium: fibroelastic sac,
composed of parietal and visceral layers with narrow potential space between
Normally contains 15-60ml plasma ultrafiltrate.
Drainage via thoracic duct and right lymphatic duct into Rt pleural space
Pericarditis
Inflammation of
pericardium
Etiology: Most cases idiopathic, with specific etiology in only 22%
Pericarditis
Classical features: RSCP (varies w/ respiration, sharp, worse w/ lying down, relieved w/ sitting up, may radiate to trapezius), EKG abnormalities, +/- pericardial friction rub (~25% of cases)
EKG Findings Changes reflect superficial inflammation of the
epicardium
~90% will show STE, most commonly in leads I,II,V5-6 (70% of patients)
PR depression in all leads except aVR (elevation) may be 1st sign, reflecting repolarization abnormality of atria
Changes follow typical 4 stage evolution over weeks to months
Demangone,D., ECG Manifestations: Noncoronary Heart Disease., Emerg Med Clin N Am 24 (2006) 113-115
4 Stages of EKG changes
Stage I: Typically occurs during the first hours – days. Diffuse concave-upward ST segment elevation with concordance of T waves; ST-segment depression in aVR or V1; PR segment depression
Stage II: Normalization of ST and PR segments; T wave flattening. Days – weeks.
Stage III: Symmetric T wave inversion. ~ 3 weeks -2 months
Stage IV: Gradual resolution of T-wave inversion (may remain inverted). May last 3 months
What causes STE in the Emerg? LVH with Strain (25%) Undefined STE (17%) Acute MI (15%) LBBB (15%) Benign Early repolarization (12%) RBBB (5%) Non-specific BBB (5%) LV aneurysm (3%) Pericarditis (1%)
Retrospective review of 202 patients with chest pain and STE >1mm in limb leads, >2mm precordial leads, 2 or more contiguous leads
Brady WJ et al. Cause of ST Segment Abnormality in ED Chest Pain Patients. Am J Emerg Med 2001; 19: 25-28.
Benign Early Repolarization
Normal EKG variant
May be related to enhanced vagal tone
Prevalent in patients with high (T5 or higher) spinal cord injuries where sympathetic flow interrupted
Males > Females
Predominantly age <50
Incidence 1-2%
Rosen’s, Mehta, et al. Early Repolarization. Clin.Cardiol. 1999; 22, 59-65
Early Repolarization
Characterized by:1. Diffuse ST segment elevation on EKG2. Upward concavity of the initial portion of the ST segment3. Notching of the terminal portion of the QRS complex at the J point
(jcn of QRS with ST)4. Symmetrical, concordant T waves of large amplitude5. Relative temporal stability over time
Maximal STE typically in precordial leads V2-V5
Rosen’s
How can we distinguish between Early Repolarization and Pericarditis?
ST/T Ratio Tool
ER vs. PericarditisPericarditis Early
ST Concave up Concave up
ST:T in V6 >0.25 <0.25
ST elevation location limb and precordial leads
precordial leads
PR depression present absent
Temporal change in EKG
present absent
Summary
4 stages of Pericaritis EKG changes
Ddx of STE
Early Repolarization
Use of the ST/T wave ratio to help differentiate pericarditis from early repolarization
References
www.uptodate.com Marx: Rosen’s Emergency Medicine: Concepts and Clinical Practice, 6th ed.,
2006; Ch. 81: 1280-88 Demangone,D., ECG Manifestations: Noncoronary Heart Disease., Emerg
Med Clin N Am 24 (2006) 113-115 Brady WJ et al. Cause of ST Segment Abnormality in ED Chest Pain
Patients. Am J Emerg Med 2001; 19: 25-28. Mehta, et al. Early Repolarization. Clin.Cardiol. 1999; 22, 59-65
Pericarditis vs. AMIPericarditis MI
ST Concave Up Convex
Reciprocal Changes Absent Present
ST elevation Limb and precordial Specific coronary territory
Q waves Absent/no evolution Evolution
T wave inversion After ST segments return to baseline
Before/as ST segments elevate
PR depression Present Absent unless atrial infarct