PET3932 (SECTION 2): EXERCISE & DISEASEEXAM 1 STUDY GUIDE Assessment/Diagnosis of CAD/CHD (looking for underlying Coronary Artery Disease) Risk factors Signs & symptoms Resting ECG Cardiac biomarkers Exercise ECG including in the ER Exercise nuclear imaging (perfusion, nuclear, thallium, cardiolite) Pharmacological (dobutamine, dipyridamole, adenosine) Echocardiography CT scan (electron beam computed tomography) Coronary aniography Autopsy P. 114 quote “Standard graded exercise tests (GXT) are used clinically to assess a patients’ ability to tolerate increasing intensities of aerobic exercise…” Classification of coronary risk factors Primary non-modifiable Advancing age Male gender Family Hx Primary modifiable Dyslipidemia Hypertension Tobacco smoking Diabetes mellitus Overweight or obesity Sedentary lifestyle Atherogenic lifestyle Emerging risk factors (lipids) Lipoprotein (α) Lipoprotein remnants Small LDL particles HDL subspecies Apolipoproteins B & A-1 TC/HDL ratio Emerging Risk factors (non-lipids) Homocysteine (amino acid – LDL, clot) (metabolic syndrome*) Thrombogenic & hemostatic factors Inflammatory markers (C-reactive protein) Impaired glucose tolerance * Subclinical atherosclerosis & plague burden Risk Assessment tool for estimating 10-year risk of developing hard CHD Framing Hand Ten Year Risk Major signs or symptoms suggestive of cardiovascular, pulmonary or metabolic disease Angina (symptom of ischemia –hard/soft/silent) SOB at rest or with mild exertion Dizziness or syncope Orthopnea or paroxysmal nocturnal dyspnea Ankle edema Palpitations or tachycardia Intermittent claudication Known heart murmur Unusual fatigue or SOB with usual activities Prizmental (random heat problems – coronary spasms) Claudication → diabetes ECG reading (p.148 *see images) P wave: electrical impulse going through atria (superior aspect of heart) Atrial depolarization (atria – pacemaker of the heart) QRS complex: electrical impulse going though the ventricles Ventrical depolarization T wave Ventrical repolarization – electrical recovery (repolarization) of the ventricles ST depression: subendocardial ischemia ST elevation: transmural ischemia (acute MI) Will come back down as an inverted T wave Evidence of ischemia or recent MI Significant Q wave Old MI Q wave width: >40 msec Q wave height: > ¼ of R wave EKG – important pointers when performing test Magnitude: amount (1 ml, 2 ml, etc.) – the greater the amount, the worse it is Slope: upsloping (best)→horizontal→ downsloping (worst) Number of leads Duration EKG – severity of ischemia ≥ 1 mL horizontal or downsloping ST depression is positive for ischemia If you see 2 mL → stop testing Use 2-lead to check for arythmia → arythmia can result in ischemia RPP: Rate Pressure Product “double product” RPP = Heart Rate [HR] x Systolic Blood Pressure [SBP] Signs of an acute MI Symptomology (myocardial infarctions, indigestion, etc.) EKG (ST elevation) Cardiac biomarkers – levels of myoglobin, troponin I, LDH, total CK, CK-MB Difference between MIs Acute MI – recently happened Major MI – larger MI Depression comes before elevation Clinical exercise ECG (GXT) – (p. 128; p.144 Box 6.1) Insult the myocardium Want to evoke abnormal BP, ischemia, etc. in order to decide what test to give (based on level of fitness – bad hip, etc.) >85% max age HR → enough effort- (220-age) (APMHR: Age Predicted Max Heart Rate) ECG (1 mL depression horizontal, etc) Stop at 2 mL BP (systolic BP should increase with workload) Silent ischemia (no symptoms) Diastolic BP should be stable (± 10 mL mmHg) at rest Gas exchange & ventilatory response Best predictor of mortality Arterial blood gases VO2 (METs) – indirect or estimated 1 MET = 3.5 mL/min (of oxygen per kg of body weight per minute) 5 METs are needed for ADLs (Activities for Daily Living)- 1 MET = rest; 10 METs = sedentary college female; 12 METs = sedentary college male Btwn 12-14 METs for work →pretty low mortality, despite other problems MET (metabolic equivalent)- One MET is a big deal in a clinical setting (ability to function, etc.) RPE & other scales RPE (Rating of Perceived Exertion) 6 to 20 Borg Scale (p.80)- Not as good (overall level of fatigue – perception of effort) RPE 0 to 10 scale- Better than 6 to 20 scale Angina Scale (p.132)- 1+: mild, barely noticeable- 2+: moderate, bothersome- 3+: moderately severe, very uncomfortable- 4+: most severe or intense pain ever experienced Dyspnea – shortness of breath (p.132)- 1+ to 4+ scale- Limiting factor in COPD or asthma patient Claudication – leg pain (p.132)- Grade 0: no pain- Grade I: definite discomfort or pain- Grade II: moderate discomfort- Grade III: intense pain- Grade IV: excruciating Signs/Symptoms Clinical Exercise ECG might be combined with other tests/diagnostic modalities such as echocardiography or radionuclide imaging Might need/use pharmacological test to insult myocardium (especially if too unfit) Exercise Nuclear Imaging (p.134) Angina Anesthesia & surgery MI damage Symptoms after treatment for CAD- Use thallium instead of EKG b/c of lack of blood flow. Thallium is a tracer picked up by blood Thallium is much more sensitive of a test- Compare to at rest vs. active (detect defect – cardio light)- Ischemia →defect shows up hours later- Old MI (nachrosis) →defect immediately post (hours later)- 1-2 weeks post MI →ischemia around nachrosis (defect immediately post hours later)- Where arrhythmias can start (irritable) Pharmacologic Test (p. 135) Can’t exercise Vasodilator (adenosine or dipyridamole) Positive inotropic/chronotropic (dobutamine) Low sensitivity →always combined with imaging May be combined with “light” exercise Echocardiogram – structural & hemodynamics (p.134) Heart valves Congenital heart disease Pericarditis Endocarditis Pumping function Source of blood clot TEE (transesophageal echocardiogram) Electron-Beam Computed Tomography (EBCT) Heart Scan “coronary calcium scale” (p.136) Angiogram →detect blockage
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