January 7, 2016 - Clinical Presentations of IHD

Question 1

Chest Pain

Answer 1

Caused by a wide variety of disease processes involving a number of systems such as cardiac, pulmonary, MSK, GI, vascular etc.

Results in millions of ER visits each year, and can be difficult to sort out.

You need to rule out the causes of chest pain which can kill a patient.

Question 2

DDx for Chest Pain

Answer 2

Life Threatening: MI/Cardiac ischemia, aortic dissection, tension pneumothorax, esophageal rupture, pulmonary embolus, perforating ulcer

Non-Life Threatening: Pericarditis, myocarditis, vasospastic angina, dysrythmia (Afib, SVT) with hypoperfusion

Non-Cardiac: GERD, MSK-related, pleurisy/pneumonia, biliary/pancreatic, neuropathic, anxiety

Question 3

Angina

Answer 3

Angina is pain, discomfort, or pressure localized in the chest caused by an insufficient supply of blood (ischemia) to the heart muscle.

Not everyone gets chest pain.

Can also get “Angina Equivelants” which are symptoms such as dyspnea, SOB, diaphoresis, extreme fatigue, or pain at a site other than the chest. When this occurs in a patient at high cardiac risk, it is considered an angina equivelant.

Question 4

Distinguishing Cardiac from Non-Cardiac Pain

Answer 4

Character/sensation: anything goes

Location and radiation: anything from epigastrium to the teeth

Mode of onset/pattern: usually occurs with activity, stress, post-prandially, or in ice weather

Excaberating/alleviating factors: usually with rest

Severity: anything goes

Question 5

More likely to be cardiac if pain gets worse and better with…

Answer 5

Gets worse with…

Activity

Cold weather

Eating a large meal

Stress

Gets better with…

Rest

Nitroglycerin

Question 6

Typical Angina

Answer 6

Begins gradually and increases over minutes.

Worsened by activity, stress, cold, and/or eating.

Not affected by movement, position, or respiration.

Relieved within 5-10 minutes of rest or NTG.

♦ The more typical the angina, the more likely it is to be due to myocardial ischemia and the more likely the patient has coronary artery disease.

Question 7

Atypical Angina

Answer 7

Lasts for seconds or hours.

Not worsened by activity, cold or eating.

Not relieved by rest or NTG.

Plueritic, focal, or reproduced by movement or palpation.

Question 8

Stable vs Unstable Angina

Answer 8

Stable angina has a predictable pattern, no rest pain, and no change in frequency, severity or duration.

Unstable angina is the new onset of angina, an increase in the frequency, severity or duration of angina, or angina at rest.

Question 9

CCS Classification of Angina

Answer 9

Class I - ordinary phyiscal activity does not cause angina. Angina with strenous, rapid or prolonged exertion.

Class II - slight limitation of ordinary activity. Angina with walking more than two blocks on level or climbing more than one flight of stairs.

Class III - marked limitation of ordinary physical activity. Angina with walking one or two blocks.

Class IV - inability to carry out any physical activity without discomfort; angina may be present at rest.

Question 10

Pathophysiology of Angina

Answer 10

Angina results from myocardial ischemia.

This is a result of imbalance between myocardial oxygen requirements and myocardial oxygen supply.

Question 11

Coronary Vasospasm

Answer 11

Accounts for ~2% of angina - also known as Prinzmetal’s Angina.

Almost always occurs at rest and not usually associated with physical exertion. Triggers can include exposure to cold, emotional stress, smoking, cocaine use, and medications that cause the coronary arteries to narrow (ventolin, epi, etc.)

Usually quickly relieved with NTG. Can be made worse by beta blockers.

If prolonged, untreated coronary vasospasm can result in myocardial infraction, ventricular dysrhythmias, heart failure or death.

Question 12

Acute Coronary Syndromes

Answer 12

1. Unstable angina
2. Non ST-elevation myocardial infarction (NSTEMI)
3. ST-elevation myocardial infraction (STEMI)

Question 13

Making the Diagnosis of ACS

Answer 13

1. History (including pain history)
2. ECG
3. Cardiac markers

Question 14

ECG NSTEMI

Answer 14

Question 15

ECG STEMI

Answer 15

“Tombstoning”

Question 16

Why is ECG Different in UA/NSTEMI vs STEMI

Answer 16

Due to the nature of the cardial injury.

In UA/NSTEMI there is subendocardial injury which causes the current to go towards the damage if the artery is not completely closed, resulting in an ST depression.

In a STEMI there is transmural (epicardial) injury where the current will flow towards the positve node and show ST elevation.

Question 17

Cardiac Necrosis Biomarkers

Answer 17

Most specific markers are cTnT and cTnI

More specific markers are CK-MB and CK isoforms

Troponin takes about 4 hours to rise and will stay elevated for up to 10 days. CK is more short lived and can be useful in determining if the patient had a second MI.

Question 18

Plaques and MI

Answer 18

90% of acute MIs are caused by thrombus formation from rupture of unstable plaques.

Plaques rupture, and when they do fibrin is exposed to clotting factors in the blood which causes a thrombus to form and may block the artery.

Question 19

Clinical Features of UA

Answer 19

Angina is new in onset or more frequent, more severe, or more easily provoked than before.

Symptoms can be progressive over the course of days or weeks (crescendo angina) or can occur acutely. Angina will usually settle with rest and/or medical management.

Question 20

Clinical Features of NSTEMI

Answer 20

Angina will typically begin at rest and last for more than 20 minutes. Patients may have had episodic angina in the preceding weeks. Associated symptoms are often present. Symptoms usually settle with medical management, especially NTG.

Question 21

Clinical Features of STEMI

Answer 21

Generally the sickest of ACS patients. Angina usually persists despite rest and medical management. Patients usually have associated symptoms and look unwell. Angina persists until the occluded artery is opened or until the infract has completed (dead muscle is painless).

Question 22

Pericarditis

Answer 22

An inflammation of the pericardium.

Chest pain is often present. The causes of pericarditis can include infections of the pericardium by viruses and bacteria, uremic pericarditis, post-infarct pericarditis, or Dressler’s syndrome (weeks to months after a heart attack).