ISCHEMIC HEART DISEASE Flashcards
(48 cards)
The major determinants of myocardial oxygen demand (MVO2)
heart rate, myocardial contractility, and myocardial wall tension (stress).
the major site of atherosclerotic disease
Epicardial coronary arteries
The condition in which patients with IHD also can present with cardiomegaly and heart failure secondary to ischemic damage of the LV myocardium that may have caused no symptoms before the development of heart failure
ischemic cardiomyopathy
Which of the following is true regarding CSAP?
A. Crescendo-decrescendo in nature typically lasts 2–5 min, and can radiate to either shoulder and to both arms
B. Rarely localized below the umbilicus or above the mandible
C. Typical patient with angina is a man >50 years or a woman >60 years of age who complains of episodes of chest discomfort
D. Chest pain is described as heaviness, pressure, squeezing, smothering, or choking and only rarely as frank pain.
All are true
- Aortic stenosis, aortic regurgitation, pulmonary hypertension, and hypertrophic cardiomyopathy must be excluded, since these disorders may cause angina in the absence of coronary atherosclerosis.
- ischemia can cause transient LV failure with the appearance of a third and/or fourth heart sound, a dyskinetic cardiac apex, mitral regurgitation, and even pulmonary edema.
It is an independent risk factor for IHD and may be useful in therapeutic decision-making about the initiation of hypolipidemic treatment
High sensitivity CRP
*An elevated level of high-sensitivity C-reactive protein (CRP) (specifically, between 1 and 3 mg/L)
* Major benefit of high-sensitivity CRP is in reclassifying the risk of IHD in patients in the “intermediate” risk
TRUE OR FALSE: Presence of LVH is a significant indication of increased risk of adverse outcomes from IHD
True
The most widely used test for both the diagnosis of IHD and the estimation of risk and prognosis
STRESS TESTING
* involves recording of the 12-lead ECG before, during, and after exercise, usually on a treadmill
Indications in discontinuing treadmill stress test
- Evidence of chest discomfort
- Severe shortness of breath
- Dizziness
- Severe fatigue
- ST-segment depression >0.2 mV (2 mm)
- A fall in systolic blood pressure >10 mmHg
- Development of a ventricular tachyarrhythmia
ischemic ST-segment response in stress testing is generally defined as
flat or downsloping depression of the ST segment >0.1 mV below baseline (i.e., the PR segment) and lasting longer than 0.08 secs
Contraindications to exercise stress testing include
- Rest angina within 48 hours
- Unstable rhythm
- Severe aortic stenosis
- Acute myocarditis
- Uncontrolled heart failure
- Severe pulmonary hypertension
- Active infective endocarditis
What is the ISCHEMIA trial?
The ISCHEMIA trial informs decision-making about referral for coronary arteriography (with intent to perform revascularization) in patients with stable IHD and an ejection fraction >35% even in the presence of moderate-severe ischemia on noninvasive functional testing
What are the principal prognostic indicators in patients known to have IHD
- Age
- Functional state of the left ventricle
- Location(s) and severity of coronary artery narrowing
- Severity or activity of myocardial ischemia
specific sinus node inhibiting agent that may be helpful for preventing cardiovascular events in patients with IHD who have a resting heart rate ≥70 beats/ min (alone or in combination with a beta blocker) and LV systolic dysfunction.
Ivabradine
TRUE OR FALSE:
Aspirin should be administered indefinitely and a P2Y12 antagonist daily (dual antiplatelet therapy [DAPT]) for at least 1 year after implantation of a drug-eluting stent
TRUE
Which of the following best describes the typical presentation of stable angina pectoris?
A) Sharp, fleeting chest pain lasting seconds
B) Crescendo-decrescendo substernal discomfort lasting 2–5 minutes
C) Localized left submammary dull ache lasting hours
D) Chest pain that worsens with deep breathing and movement
Answer: B) Crescendo-decrescendo substernal discomfort lasting 2–5 minutes
Rationale: Stable angina is characterized by transient myocardial ischemia that presents as a heaviness, pressure, or squeezing sensation. It typically follows a crescendo-decrescendo pattern, lasts 2–5 minutes, and is triggered by exertion or emotional stress. Sharp, fleeting pain or prolonged aches are not characteristic of ischemic chest pain
Which of the following findings strongly suggests that a patient’s chest pain is NOT due to myocardial ischemia?
A) Chest discomfort relieved by sublingual nitroglycerin
B) Chest pain localized below the umbilicus or above the mandible
C) Pain occurring predictably with exertion
D) Radiation of pain to both arms
Answer: B) Chest pain localized below the umbilicus or above the mandible
Rationale: Myocardial ischemic pain is typically substernal and can radiate to the shoulders, arms, jaw, or epigastrium. Pain localized below the umbilicus or above the mandible is uncommon for ischemia and suggests a non-cardiac cause.
Which of the following laboratory findings is an independent risk factor for ischemic heart disease (IHD) and may aid in therapeutic decision-making?
A) Elevated high-sensitivity C-reactive protein (hs-CRP)
B) Decreased hematocrit
C) Low thyroid-stimulating hormone (TSH)
D) Elevated serum creatinine
Answer: A) Elevated high-sensitivity C-reactive protein (hs-CRP)
Rationale: An hs-CRP level between 1 and 3 mg/L is an independent risk factor for IHD and may help in reclassifying the risk in intermediate-risk patients.
What is the primary purpose of an exercise stress test in patients with suspected ischemic heart disease (IHD)?
A) To determine the patient’s cholesterol levels
B) To assess limitations in exercise performance and detect myocardial ischemia
C) To directly visualize coronary artery stenosis
D) To measure left ventricular ejection fraction
Answer: B) To assess limitations in exercise performance and detect myocardial ischemia
Rationale: The exercise stress test evaluates a patient’s exercise tolerance, detects ischemic ECG changes, and correlates them with chest discomfort. It does not measure cholesterol levels, directly visualize coronary stenosis (which requires coronary angiography), or assess left ventricular ejection fraction (which is done via echocardiography or MRI).
The most widely used test for both the
diagnosis of IHD and the estimation of risk and prognosis involves recording of the 12-lead ECG before, during, and after exercise, usually
on a treadmill
Which of the following ECG findings is considered diagnostic for myocardial ischemia during an exercise stress test?
A) Upsloping ST-segment depression
B) Flat or downsloping ST-segment depression >0.1 mV lasting longer than 0.08 s
C) T-wave inversion without ST-segment changes
D) Premature ventricular contractions
Answer: B) Flat or downsloping ST-segment depression >0.1 mV lasting longer than 0.08 s
Rationale: Flat or downsloping ST-segment depression is a hallmark of myocardial ischemia. Upsloping ST-segment depression, isolated T-wave inversions, and premature ventricular contractions are not considered diagnostic of ischemia.
Which of the following is a contraindication to performing an exercise stress test?
A) History of stable angina
B) Mild hypertension
C) Unstable rhythm and rest angina within 48 hours
D) Hyperlipidemia
Answer: C) Unstable rhythm and rest angina within 48 hours
Rationale: Contraindications to stress testing include recent rest angina (within 48 hours), unstable arrhythmias, severe aortic stenosis, acute myocarditis, uncontrolled heart failure, severe pulmonary hypertension, and active infective endocarditis. Stable angina, mild hypertension, and hyperlipidemia are not contraindications.
Which of the following increases the likelihood of a false-positive stress test result?
A) Severe three-vessel coronary disease
B) Obstructive disease limited to the circumflex artery
C) Resting ST-segment and T-wave abnormalities
D) Achieving target heart rate during the test
Answer: C) Resting ST-segment and T-wave abnormalities
Rationale: False-positive results are more common in patients with resting ST-segment and T-wave abnormalities, intraventricular conduction disturbances, left ventricular hypertrophy, or those taking cardioactive drugs (e.g., digitalis). Obstructive disease limited to the circumflex artery can lead to false-negative results.
What is considered an adverse prognostic sign during an exercise stress test?
A) Progressive increase in blood pressure with exercise
B) ST-segment depression persisting for more than 5 minutes after exercise
C) Achievement of 85% of maximal predicted heart rate
D) Mild fatigue at peak exercise
Answer: B) ST-segment depression persisting for more than 5 minutes after exercise
Rationale: Persistent ST-segment depression (>5 minutes post-exercise) suggests severe IHD and a high risk of adverse cardiac events. A normal response includes a progressive rise in heart rate and blood pressure, while achieving 85% of the maximal heart rate is the target for test completion.
Which of the following cardiac imaging techniques is used when the resting ECG is abnormal, such as in left bundle branch block or a paced ventricular rhythm?
A) Standard exercise stress test
B) Stress myocardial radionuclide perfusion imaging
C) Resting echocardiography
D) Coronary artery calcium scoring
Answer: B) Stress myocardial radionuclide perfusion imaging
Rationale: In cases where the resting ECG is abnormal, an exercise test alone may not be sufficient. Stress myocardial radionuclide perfusion imaging using thallium-201 or 99m-technetium sestamibi improves diagnostic accuracy by assessing myocardial perfusion and detecting ischemia
What is the primary purpose of pharmacologic stress testing with adenosine?
A) To directly measure left ventricular ejection fraction
B) To create a coronary “steal” phenomenon by increasing flow in nondiseased coronary segments
C) To stimulate ischemia by increasing myocardial oxygen demand (MVO2)
D) To evaluate myocardial fibrosis
Answer: B) To create a coronary “steal” phenomenon by increasing flow in nondiseased coronary segments
Rationale: Adenosine induces vasodilation, leading to a “coronary steal” effect where blood flow increases in healthy coronary arteries while diseased segments receive reduced perfusion. This helps identify ischemic areas via imaging.
