Cardio Exam 2 Flashcards
What is the underlying pathophysiology that results in MI?
- Rupture or erosion of vulnerable plaque. Blood is exposed to inner plaque material and platelets activate, thrombin is generated and thrombi form.
- Note: vulnerable plaques are often non-obstructive, stenosing vessel by between 40 and 60%. These typically don’t produce abnormal stress test if identified prior to MI
What is ACS?
- Acute coronary syndrome: unstable angina, non-STE MI (caused by non-occlusive platelet rich “white” thrombus) or STE MI (caused by occlusive fibrin rich “red” thrombus.
Which populations present atypically with MI? Symptoms?
- Diabetics, women and elderly.
- Sx: without chest pain, with SOB, nausea, vomiting or fatigue
Treatments for MI
- Immediate reperfusion via
a. Thrombolytic therapy OR
b. PCI: percutaneous coronary intervention (cath lab)
STE in the following leads suggest what anatomic area for MI with what culprit artery:
a. V1-4
b. II, III and aVF
c. I, aVL and/or V5, 6
a. Anterior: LAD
b. Inferior: RCA (65%), LCX (35%)
c. Lateral: diagonal branches of LAD or obtuse marginal branches of LCX
What are the results if perfusion is not restored in MI?
- Myocardial damage w/shock
- Reduced EF, early infarct expansion, ventricular remodeling = cardiomyopathy
- Chronic heart failure
- Ventricular arrhythmias
- Sudden death
Describe presentation of inferior STEMI from proximal occlusion leading to right ventricular infarct. What does ECG show? What medication should be avoided in these individuals?
- Hypotension with elevated neck veins and clear lung fields
- ECG changes in lead V4R?
- Avoid preload reducers such as NTG. Be cautious with beta-blockers. If hypotensive, try IV fluids.
What does non-STE MI result from? What does ECG show? Can thrombolytics be used in this condition?
- Ruptured/eroded plaque with acute thrombus formation and incomplete obstruction of blood flow. Plaque is platelet rich.
- ECG: normal or exhibit ST depression, T wave inversion. ST depression doesn’t localize to anatomic territory/culprit artery – just shows subendocardial.
- Thrombolytics are contraindicated. Not complete obstruction. These exposure more platelets and favor clot formation.
Does normal ECG r/o ACS?
- No. Could be non-STE MI.
Describe medical therapy for STEMI vs NSTEMI?
- All: o2, 325 mg ASA + (P2Y12 inhibitor or GP 2b3a inhibitor), sublingual NTG, anticoag
- If angina persists, give either: beta-blocker, IV nitro, CCB. Give morphine for analgesia.
1. STEMI - O2 to maintain 92%
- ASA (+/- P2Y12 inhibitor: some places might prefer to wait until artery IDd)
- SL NTG (or IV for pain)
- Anti-ischemic: +/- beta-blocker (metoprolol): if tachy w/HTN or v arrhythmias
- Anticoagulant (unfractionated heparin of LMWH)
- Reperfusion via cath lab (w/in 90 minutes) or thrombolytic
- NSTEMI
- O2 to maintain 92%
- ASA (+/- GP 2b3a inhibitor: if angina refractory)
- SL NTG (or IV for pain)
- Anti-ischemic: Beta-blockers
- Anticoagulant (unfractionated heparin of LMWH)
- No thrombolytics!
- Cardiac cath electively in next 24-48 hours.
Describe post MI medical therapy
- ASA for life (81 or 162 mg)
- P2Y12 inhibitor for a year
- Beta-blockers
- ACEi if EF less than 40% class I or less than 50% class II
- Aldosterone antagonist for HF and EF
Criteria for defining MI
- Symptoms
- New or presumed new ST segment, T wave changes OR new LBBB
- Development of pathological Q waves
- Imaging: evidence of loss of myocardium or regional wall abnormality
- ID of thrombus
Classification of MI
- Spontaneous MI caused by primary coronary event: plaque erosion or rupture
- MI secondary to increased o2 demand or decreased supply
- Sudden unexpected cardiac death
What is the Bezold-Jarisch reflex?
- Sudden bradycardia associated with hypotension, decreased inotropy and coronary vasodilation. Can occur after MI.
Killip risk classification / stratification of MIs
Class 1: no rales, no S3 = lowest mortality
Class 2: rales 50%
Class 4: shock = highest mortality
Differential dx for chest pain
- Cardiac: MI, pericarditis, myocarditis
- Pulmonary: PE, pneumonia, asthma, COPD, pleuritis, pneumothorax, mediastinitis
- Aortic syndromes: dissection, perforated ulcer, intramural hematoma
- Chest wall: costochondritis, MSK
- Esophagus: spasm, rupture/perforation, GERD
- RUQ pathology
- Anxiety
Compare and contrast utility of Trop and CK-MB in MI. When do values peak? When do they return to normal?
- Troponin: rise within 3 hour of acute MI, peak 24-48 hours, remain elevated for up to two weeks (depending on I vs T components)
- CK-MB: exceeds nml in 4-8 hrs, peak 24 hours, returns to normal in 2-3 days
Absolute contraindications to thrombolytic therapy for MI
- Prior ICH
- Known cerebral vascular lesion (eg. AV malformation)
- Known malignant intracranial neoplasm
- Ischemic stroke within 3 months
- Suspected aortic dissection
- Active bleeding or bleeding diathesis (tendency): excl menses
- Significant closed head trauma or facial trauma w/in 3 months
- IC or intraspinal surgery w/in 2 months
- Severe uncontrolled HTN
Gestational and natal history that can make one suspicious of cardiac issues in neonate
- Infections: rubella, CMV, coxsackievirus B
- Maternal meds: retinoids, valproate
- Maternal smoking or etoh intake
- Maternal conditions such as DM, lupus
Is RR > 60 normal in baby?
- Abnormal in any age
Incidence of congenital heart disease? Recurrence risk?
- About 1% (8-12 out of 1000) = incidence
- Recurrence risk for sibs = ~ 3%
BP changes suggestive of aortic coarctation
- Normal is leg BP >= arm BP
- If arm BP > leg BP: suggestive of coarctation
Correct cuff size in peds patients
- Width of cuff = 125-150% diameter of arm
Splitting of S1 is likely what?
- Systolic ejection click