Final Flashcards
What is the mechanism by which nitrates act. How do they reduce MVO2 (workload of heart)
Venodilation reduces preload due to venous pooling, which decreases end diastolic volume and end diastolic pressure. Arterio-vasodilation decreases SVR and SBP, which decreases afterload. Decreased preload and afterload reduces the work of the heart.
State the ACSM criteria for categorizing subjects as low, medium or high risk for physical activity and list all the CVD risk factors. Provide examples of people who would be low, medium and high risk
Low risk – asymptomatic persons with ≤1 CVD risk factor.
Moderate risk - asymptomatic persons with ≥2 CVD risk factors.
High risk – persons who have known cardiovascular, pulmonary or metabolic disease or one or more signs and symptoms of such diseases (e.g., angina, dyspnea, syncope, ankle edema, intermittent claudication, etc.).
CVD risk factors:
Age: Men ≥45; women ≥55. Obesity.
Family history. Hypertension.
Cigarette smoking. Dyslipidemia.
Sedentary lifestyle. Prediabetes (based on glucose testing).
Provide examples of subjects for whom a medical exam and GXT are not recommended, for those whom both are recommended and for those whom an MD should supervise the GXT.
Low risk – none of the three are necessary.
Medium risk – 1 and 2 recommended for vigorous exercise; 3 recommended for max tests.
High risk – 1, 2 and 3 recommended for anything beyond light exercise.
List the ACSM absolute contraindications for exercise stress testing. Recognize relative contraindications
Recent significant change in the resting ECG suggestive of significant ischemia, recent MI (within 2 weeks), or other acute cardiac event.
Acute myocarditis or pericarditis.
Unstable angina.
Uncontrolled arrhythmias causing symptoms or hemodynamic compromise.
Symptomatic severe aortic stenosis.
Uncontrolled symptomatic heart failure.
Acute pulmonary embolus or pulmonary infarction.
Suspected or known dissecting aneurysm.
Acute systemic infection accompanied by fever, body aches, or swollen lymph glands.
Compare and contrast different exercise testing modalities regarding types of subjects most suited for each modality.
Treadmill - standard testing mode - walking is familiar to most people. Falling is a risk.
Cycle - used for individuals with weight-bearing and/or gait/balance issues.
Upper body (arm) ergometry - used for individuals that cannot perform lower body exercise (joint pain/arthritis, injury, paralysis, disease).
Step test – field test; issues include balance and lower body strength.
Pharmacological stress testing - used to assess heart function when exercise is contraindicated.
List absolute and relative reasons for stopping a GXT
Absolute
Drop is SBP of >10 mmHg from baseline BP despite an increase in workload when accompanied by other signs of ischemia.
Moderately severe angina (3 on the angina scale; see p. 132).
Increasing nervous system symptoms (e.g., ataxia, dizziness or near syncope).
Signs of poor perfusion (e.g., pallor, cyanosis, cold skin).
Technical problems with monitoring the patient.
Patient requests to stop.
Sustained ventricular tachycardia.
ST elevation (+ 1.0 mm) in leads without diagnostic Q waves (other than V1 or aVR).
Relative
Drop in SBP of >10 mmHg from baseline BP despite an increase in workload in the absence of other signs of ischemia.
ST or QRS changes such as ST segment depression 2 mm horizontal or downsloping or marked axis shift.
Arrhythmias other than sustained V tach, including multifocal PVCs, triplets of PVCs, supraventricular tachycardia, heart block or bradyarrhythmias.
Fatigue, shortness of breath, wheezing, leg cramps or claudication.
Development of BB block or intraventricular conduction delay that cannot be distinguished from V tach.
Increasing chest pain.
Excessive SBP response (>250 mmHg and/or DBP>115 mmHg).
Which cardiac drugs are used for treating arrhythmias, angina, hypertension?
Anti-arrhythmics – Na+ blockers, Ca++ blockers, beta blockers, K+ blockers, adenosine, digoxin.
Anti-anginals – nitrates, Ca++ blockers, beta blockers
Anti-hypertenives - Ca++ blockers, beta blockers, labetolol, ACE inhibitors, AII receptor blockers, diuretics, direct vasodilators, alpha1 adrenergic receptor blockers.
Describe/list subjects who would be appropriate candidates for outpatient cardiac rehabilition, according to ACSM guidelines. Describe/list subjects who would NOT be appropriate candidates for outpatient cardiac rehabilition.
Appropriate: Medically stable post MI Stable angina CABG PTCA (angioplasty) Stable heart failure Heart transplantation Valvular heart surgery PAD At risk for CAD with diagnoses of diabetes mellitus, dyslipidemia, hypertension or obesity Others who would benefit based on physician referral and consensus of rehab team
Not appropriate: Unstable angina Uncontrolled hypertension (resting SBP >180; resting DBP >110) Orthostatic BP drop of >20 mmHg with symptoms Significant aortic stenosis Uncontrolled arrhythmias Uncontrolled sinus tachycardia Uncompensated heart failure 3rd degree AV block without pacemaker Active pericarditis or myocarditis Recent embolism Acute thrombophlebitis Acute systemic illness or fever Uncontrolled diabetes mellitus Severe orthopedic conditions Other metabolic conditions
What tissues have a relatively density of the following receptors and what actions occur when the receptors are activated – α1, β1, β2?
α1 – smooth muscle of most blood vessels; vasoconstriction
β1- heart, kidney; increased HR, contractility, and conduction
β2 – lungs, arterioles, GI tract; vasodilation, bronchodilation
What happens to each of the following cardiovascular parameters as exercise intensity increases – VO2, Q, HR, SV, a-vO2 diff, SVR, MVO2?
All increase except SVR, which decreases.
Describe appropriate GXT protocols for elite endurance athletes, average healthy active persons in their 20s, typical cardiac patients, 60 year old couch potatoes.
Elite endurance athletes – start at 10% grade, 5 mph, increase 3-4 METS/stage, 2 min stages.
Average healthy active persons in their 20s – start at 0-5% grade, 5 mph, increase 2-4 METS/stage, 3 min stages.
Typical cardiac patients – start at 0% grade, 3 mph, increase 1-2 METS/stage, 3 min stages.
60 year old couch potatoes – same as cardiac patient.
What is the risk of a cardiac event occurring during exercise testing, an acute MI or cardiac arrest, death if physician supervised, death if not physician supervised?
Cardiac event - 1 in 1,667 tests (6 per 10,000 tests).
Acute MI or cardiac arrest - 1 in 2,500 tests (4 per 10,000 tests).
Death if physician supervised - 1 in 22,727 (0.44 per 10,000 tests).
Death if not physician supervised - 1 in 12,987 (0.77 per 10,000 tests).
What is St. Luke’s (and other hospitals) protocol for a cardiac patient on a beta-blocker who will undergo a GXT for diagnostic purposes?
Stop the drug for 12-24 hours prior to the test.
What is the primary neurotransmitter for the SNS? For the PsNS.
SNS – norepinephrine; PsNS - acetylcholine
Describe, in general terms, dobutamine and atropine and the action of each.
Dobutamine is a synthetic catecholamine that stimulate beta receptors.
Atropine is a PsNS blocker, an anticholinergic drug.
