Unstable Angina.pptx

An overview of unstable angina

1. Unstable Angina Erfan Amirazami

2. Unstable Angina Unstable angina is chest discomfort or pain caused by an insufficient flow of blood and oxygen to the heart. It is part of the acute coronary syndromes and may lead up to a heart attack

3. Etiology The most common cause of unstable angina is due to coronary artery narrowing due to a thrombus that develops on a disrupted atherosclerotic plaque and is nonocclusive. A less common cause is vasospasm of a coronary artery (variant Prinzmetal angina).

4. Pathophysiology Unstable angina deals with blood flow obstacles causing a lack of perfusion to the myocardium.

5. History and physical Patients will often present with chest pain, shortness of breath. The chest pain will often be described as pressure-like , tightness , burning , sharp type of pain The pain will often radiate to the jaw or arms , both left and right sides can be affected. Constitutional symptoms such as nausea , vomiting , diaphoresis , dizziness , and palpitations may also be present. Exertion may worsen pain and rest can ease the pain. Nitroglycerin and aspirin administration may also improve the pain.

6. Physical Examination The exam will likely be normal, although the patient may be clutching at their chest , sweating , have labored breathing, their heart sounds may be tachycardic , and rales may be heard due to pulmonary edema. Findings suggestive of a high-risk situation include: Dyskinetic apex Elevated JVP Presence of S3 or S4 New apical systolic murmur Presence of rales and crackles Hypotension

7. Evaluation The patient should have an ECG to evaluate for ischemic signs or possible STEMI . The ECG in unstable angina may show hyperacute T-wave, flattening of the T-waves, inverted T-waves, and ST depression. Any number of arrhythmias may be present in acute coronary syndrome including junctional rhythms, sinus tachycardia, ventricular tachycardia, ventricular fibrillation, left bundle branch block, and others.

8. The patient should also have lab work that includes: complete blood count evaluating for anemia, platelet count , and basic metabolic profile evaluating for electrolyte abnormalities.

9. A troponin test should be performed to determine if any of the myocardium has infarcted. A pro-brain natriuretic peptide (Pro-BNP) can also be checked, as an elevated level is associated with higher mortality. Coagulation studies may be appropriate if the patient will be anticoagulated or anticoagulation is anticipated. Often, a chest x-ray will show the heart size and the size of the mediastinum so the physician may screen for dissection and other explanations of chest pain.

10. The patient should be kept on a cardiac monitor to evaluate for any rhythm changes. Further testing may include any number of cardiac stress tests (walking treadmill stress test, stress echocardiogram, myocardial perfusion imaging, cardiac CT/MRI, or the gold standard, cardiac catheterization).

11. Treatment The mainstay of treatment focuses on improving perfusion of the coronary arteries. This is done in several ways: Patients are often treated with aspirin for its antiplatelet therapies, 162 to 325 mg orally, or 300 mg rectally if the patient is unable to swallow. The aspirin should be administered with 30 minutes .

12. 2. Nitroglycerin improves perfusion by vasodilation of the coronaries allowing improved flow and improved blood pressure. This will decrease the amount of work the heart has to perform, which decreases the energy demand of the heart.

13. Clopidogrel is an option for patients not able to tolerate aspirin. Prasugrel is more effective than clopidogrel but is associated with a higher risk of bleeding.

14. Supplemental oxygen should be given as well via nasal cannula to maintain appropriate oxygen saturation. Anticoagulation with low or high molecular weight heparin . Beta-blockers also can decrease the energy demand by decreasing blood pressure and heart rate.

15. Cardiac angiography is indicated in unstable angina if the patient has: Cardiogenic shock Depressed ejection fraction Angina refractory to pharmacological therapy New MR Unstable arrhythmias Early PCI in NSTEMI (within 6 hours) has been shown to have lower mortality than those who undergo delayed PCI.