CARDIO PART III

Flashcards covering coronary blood flow, stable and variant angina, antianginal pharmacology, Acute Coronary Syndrome (unstable angina, NSTEMI, STEMI), diagnostics, and reperfusion interventions.

What three primary factors increase myocardial oxygen demand?

Heart rate

contractility

wall stress (preload and afterload).

During which phase of the cardiac cycle does the majority of left ventricular coronary perfusion occur?

Diastole

why does ischemia occur?

because of lack of O2 produced

prolonged insufficient blood flow leads to necrosis

How does collateral circulation develop in coronary artery disease and what is its benefit?

slow growth of new blood vessels leads to improved blood flow at ischemic regions

what is angina pectoris?

chest discomfort from myocardial ischemia

cellular hypoxia w/out cell death

What is the key pathological difference between myocardial ischemia and myocardial infarction?

Ischemia = insufficient O2, but no cell death; reversible Infarction = prolonged ischemia causes cell death; irreversible

What are the key clinical characteristics of stable angina?

fixed, predictable narrowing

relieved by rest/nitroglycerin

What is variant angina and how does its cause differ from stable angina?

vasospasm at rest

possible elevated ST segment

Which antianginal medication class should be avoided in patients with variant (vasospastic) angina?

Beta blockers can worsen coronary vasospasm.

What are the key clinical characteristics of unstable angina?

unpredictable plaque rupture

worsening sxs = emergency

What three major classes of medications are used to treat stable angina according to the "NBC" acronym?

Nitrates, Beta blockers, and Calcium channel blockers.

What is the primary hemodynamic mechanism of action of nitrates in relieving angina?

Venodilation

what is ACS?

sudden plaque disruption + thrombus → abrupt flow reduction → acute ischemia at rest

What three clinical entities constitute Acute Coronary Syndrome (ACS)?

Unstable angina

Non-ST-segment elevation myocardial infarction (NSTEMI)

ST-segment elevation myocardial infarction (STEMI)

What laboratory and electrocardiographic findings differentiate NSTEMI?

elevated troponin

no ST elevation

What laboratory and electrocardiographic findings differentiate STEMI?

elevated troponin

persistent ST elevation

Why are serial troponins and serial ECGs required when assessing suspected Acute Coronary Syndrome?

troponin marks if there’s injury

ECG marks where/how bad ischemia is

why does unstable angina need urgent eval despite no necrosis?

still an ACS that could develop into MI

no troponin ≠ safe

what are the four treatment goals of ACS?

1. relieve ischemia w/ anti-ischemic therapy

2. limit thrombus growth w/ antiplatelets and anticoagulants

3. reduce further injury w/ statins

4. consider revascularization w/ PCI

why are fibrinolytics not indicated for UA/NSTEMI?

fibrinolytics increase risk of bleeding (intracranial hemorrhage)

only used for COMPLETE block - STEMI

what are typical symptoms of MI?

• persistent chest pressure/tightness/heaviness at rest

• radiating to arm/shoulder/jaw/neck/back

• dyspnea, diaphoresis, nausea, dizziness

what are the consequences of MI?

location and size matters

• necrotic tissue can’t contract

• decreased SV, CO, and EF

• electrical instability (dysrhythmias)

• ventricular remodeling

• HF

Which patient groups are most likely to experience atypical or "silent" myocardial infarction symptoms?

Women, older adults, and individuals with diabetes.

What post-procedure requirement is necessary after PCI performed via the femoral artery?

The patient must remain completely flat without bending at the waist for at least $6\,\text{hours}$ to minimize the risk of bleeding and hematoma formation.