Читать книгу Practical Cardiovascular Medicine - Elias B. Hanna - Страница 92

1 * A very small group of individuals have heterophile antibodies that agglutinate with the murine antibodies used in the troponin assay, causing the very rare “falsely positive troponin elevation”. These patients have chronic troponin elevation, sometimes severe, discrepant with the stable clinical setting. An alternative troponin assay or a special heterophilic blocking reagent is used for confirmation.

2 ** Late gadolinium enhancement and/or edema on T2 may be seen with myocarditis or infarction. Only edema may be seen in takotsubo, not late gadolinium enhancement. The distribution of the anomaly distinguishes myocarditis from an ischemic pattern:²⁶Distribution not consistent with an arterial territory + subepicardial or mid-wall predominance → myocarditisDistribution consistent with an arterial territory + subendocardial or transmural predominance → infarction

3 * The GRACE risk score accounts for troponin and ST changes, but also for increasing age, history of HF, tachycardia, hypotension, and renal function.TIMI risk score:1. Age ≥65 years----2. ≥ Three risk factors----3. History of coronary stenosis ≥50%4. ≥ Two episodes of pain in the last 24 hrs----5. Use of aspirin in the prior 7 days (implying aspirin resistance)6. Elevated troponin---- 7. ST deviation ≥0.5 mmA score of 3 or 4 is intermediate risk; 5–7 is high risk. Risk of mortality/MI/urgent revascularization at 14 days: 13% if score = 3; 20% if score = 4; 26% if score = 5; 40% if score = 6/7.

4 * Also, always avoid β-blockers acutely and chronically in cases of second- or third-degree AV block, PR interval > 240 ms, bradycardia < 55 bpm, or active bronchospasm. Beyond the first day, SBP below 100 mmHg, rather than 120 mmHg, is the contraindication to β-blockers.