Coronary Artery Disease

CAD refers to a group of diseases which includes stable angina, unstable angina, myocardial infarction, and sudden cardiac death

1. CORONARY ARTERY DISEASE Presented by : Ms Garima Bhardwaj ( MSc Ist Year )

2. Introduction CAD refers to a group of diseases which includes stable angina, unstable angina, myocardial infarction, and sudden cardiac death. Also known as ischemic heart disease It is caused by the narrowing of the large blood vessels that supply the heart with oxygen. fatty deposits called plaque ( Atherosclerosis ) build up inside the coronary arteries.

3. CAD includes : Atherosclerosis Acute Coronary Syndrome ( A spectrum of clinical conditions from unstable angina to ST-elevation MI and sudden cardiac death ) Angina Pectoris Myocardial Infarction ( STEMI , NSTEMI )

4. Collateral circulation It is a network of tiny blood vessels, and, under normal conditions, not open. When the coronary arteries narrow to the point that blood flow to the heart muscle is limited, collateral vessels may enlarge and become active . This allows blood to flow around the blocked artery to another artery nearby or to the same artery past the blockage, protecting the heart tissue from injury. Two factors contribute to growth and extent of collateral circulation : • The inherited predisposition of develop new blood vessels ( angiogenesis ) •The presence of chronic ischemia

5. A survey conducted by the Charlotte Housing Authority (CHA) in Charlotte, NC, found that many public housing residents had risk factors for heart disease, such as high blood pressure, high cholesterol, diabetes, physical inactivity, overweight/obesity, and cigarette smoking.

6. Atherosclerosis It begins as fatty streaks, lipids that are deposited in the intima of the arterial wall plaques , protrude into the lumen of the vessel, narrowing it and obstructing blood flow .

7. Pathophysiology Injury to endothelial lining due to various factors like (tobacco use , hypertension , hyperlipidaemia etc. ) Accumulation of lipoproteins in the vessel wall – Mainly LDL Monocyte adhesion to the endothelium – Followed by migration into the intima and transformation into macrophages and foam cells.

8. Cont.…. Platelets adhesion takes place at the site of injury smooth muscles cell proliferation occurs The proliferation results in deposits, called atheroma's or plaques, which protrude into the lumen of the vessel, narrowing it and obstructing blood flow .

9. Clinical manifestations :

10. Angina Pectoris It is a Clinical syndrome characterized by transient episodes of substernal chest pain or discomfort caused by myocardial ischemia . Chronic stable angina is the most common manifestation of CAD . Relieved by Nitroglycerine .

11. Types of Angina

12. Characteristics of pain Location : left-sided or Retrosternal Radiation : radiating to the left arm, neck, jaw, or back Duration : 30 sec to 15 min

13. Myocardial Infarction

14. Myocardial infarction (MI) refers to tissue death (infarction) of the heart muscle (myocardium). It is a type of acute coronary syndrome, which describes a sudden or short-term change in symptoms related to blood flow to the heart . It occurs as a result of thrombotic occlusion of the coronary artery and causes irreversible cell injury and necrosis . it may be classified as an : ST elevation myocardial infarction (STEMI) Non-ST elevation myocardial infarction (NSTEMI) based on the results of an ECG .

15. Classification ( based on location ) Anterior myocardial infarction – results from the occlusion of the left anterior descending coronary artery . Inferior and posterior MI – occlusion of the right coronary artery that supplies these regions . Lateral MI – occlusion of coronary branches supplying the lateral wall of the left ventricle . Includes left circumflex branch and diagonal branch of the LAD . Right ventricular MI - occurs in corelation with inferior MI . Results from occlusion of the RCA proximal to the marginal branches .

16. Characteristics of pain Severe , immobilizing chest pain . Usually described as heaviness, pressure, tightness, burning. Location : Substernal , Retrosternal or Epigastric . Radiation : It may radiate to neck, jaw, arm or back . Duration : Lasts for 20 minutes or more.

17. Killip classification It was published in 1967 categorizes patients with an acute MI based upon the presence or absence of simple physical examination findings that suggest LV dysfunction . The higher the Killip class on presentation, the greater the subsequent mortality

18. TIMI,S Classification The Thrombolysis in Myocardial Infarction (TIMI) Score It is used to determine the likelihood of ischemic events or mortality in patients with angina or myocardial infarction (STEMI).

19. Complications of MI Sudden death Left ventricular aneurysm Left ventricle failure Mitral regurgitation Ventricular septal rupture Arrhythmias Heart failure

20. Management of MI A 12 lead resting ECG should be obtained immediately in patients with ongoing chest pain as rapidly as possible with in 10 minutes of presentation Morphine - Reduces pain & anxiety, decreases sympathetic tone, systemic vascular resistance and oxygen demand . 2–4 mg IV every 5–10 minutes until pain is relieved Oxygen - 2–4 L/min by nasal cannula to maintain oxygen saturation Nitro glycerine - Dilates coronary vessels—increase blood flow & reduces systemic vascular resistance and preload . Sublingual : sorbitrate 5-10 mg every 5 min, up to 3 doses (If SBP >100 mmHg ) Aspirin - Irreversibly inhibits platelet aggregation, stabilizes plaque and arrests thrombus, reduces mortality in patients with STEMI . Dosage : 150-300 mg chewed at presentation, then 150 mg PO OD .

21. Cont..… β- Blocker - o ral beta-blocker therapy should be initiated in the first 24 hours (metoprolol 25-50 mg every 12 hours ) ACE inhibitors - Reduces systemic vascular, resistance and cardiac afterload, also reduce aldosterone release with consequent reduction of circulating fluid load and lower cardiac preload. low dose oral administration and increase steadily to achieve a full dose within 24 to 48 hours. (Captopril 6.2 mg TID, Ramipril 2.5-5mg BD) Heparin – LMWH , subcutaneous Enoxaparin 1mg/kg BD .

22. Diagnostic Evaluation

23. Physical Examination History taking for assessing co morbidity General appearance and behavior Vital signs Skin turgor – cold and clammy Auscultate for heart sounds – S3 gallop may be present as well as crackles (indicates LV failure ) Assess for level , location of pain . Many patients have normal pulse rate and blood pressure within the first hour of STEMI . Patients with large infarctions have hypotension (SBP <100 mmHg or sinus tachycardia >100/min)

24. ECG ( Electrocardiography ) ST elevation – indicates infarction ST depression – indicates ischemia Q wave presence T wave inversion RVMI is diagnosed with ST segment elevation in lead V4R, ST elevation in V1 in the presence of ST elevation in inferior leads . Posterior ST depression in V1-V2 ( RCA or LCA ) Inferior wall MI - II, III, aVF

25. Stress echocardiography Patient will exercise on a treadmill or stationary bike while doctor monitors the blood pressure and heart rhythm . When heart rate reaches peak levels, doctor will take ultrasound images of the heart to determine whether heart muscles are getting enough blood and oxygen while patient exercise . Provides location and extent of MI

26. Nuclear stress test It is a nuclear imaging test that shows how well blood flows into your heart while you’re exercising or at rest . Also known as thallium stress test

27. Lipid profile Fasting lipid profile, including total cholesterol, HDL, triglycerides, and calculated LDL cholesterol . A composite of lipid and non lipid risk factors of metabolic origin, called metabolic syndrome, is another risk factor for CAD. Metabolic syndrome includes abdominal obesity, an elevated triglyceride level, low HDL level , elevated blood pressure, and impaired function of insulin . LDL exerts a harmful effect on the arterial wall and accelerates atherosclerosis

28. Cardiac Markers CK-MB - increases 3-6 hrs after onset of chest pain, peaks in 12-18 hrs & return to normal within 3-4 days. LDH - it increases 14-24 hrs after onset of MI, peak within 48-72 hrs & slowly return to normal over next 7-14 days . Cardiac troponin T/ I - increases 7-14 hrs after MI & persists for 5-7 days

29. Trop T kit

30. Coronary Angiography coronary catheterization is a minimally invasive procedure to access the coronary circulation and blood filled chambers of the heart using a catheter . It is performed for both diagnostic and interventional (treatment) purposes Done under local anaesthesia

31. Nursing Management Pre procedure : Before the patient undergoes cardiac catheterization a pre cardiac catheterization patient teaching plan must be established and initiated . Explain the procedure to the patient Alleviate anxiety of the patient Assess for allergies complete pre procedure checklist before shifting the patient to lab check and document the status of peripheral pulses.

32. Post procedure : Assess the peripheral vascularity of the lower extremities . monitor vital signs, and distal pulses every 15 min Maintain the patient on hourly intake and output Check the puncture site for any signs of bleeding

33. Pharmacological Management Statins - to help lower cholesterol E . g - Lovastatin , simvastatin block cholesterol synthesis, lower LDL and triglyceride levels, and increase HDL levels ACE inhibitors - Reduces systemic vascular, resistance and cardiac afterload . Captopril 6.25 mg TID. Nitrates – Nitroglycerine sublingually 5-10 mg every 5 minutes, up to 3 doses (If SBP > 100 mmHg ) Thrombolytics - The purpose of thrombolytic is to dissolve and lyse the thrombus allowing blood to flow through the coronary artery again (reperfusion) . E. g - Aspirin , Clopidogrel , streptokinase

34. Chest pain for longer than 20 minutes, unrelieved by nitroglycerin ST-segment elevation in at least two leads that face the same area of the heart Less than 24 hours from onset of pain Absolute Contraindications Active bleeding Known bleeding disorder History of haemorrhagic stroke History of intracranial vessel malformation Recent major surgery or trauma Uncontrolled hypertension Pregnancy Indications for thrombolytics

35. Nursing Considerations Avoid intramuscular injections . Monitor for acute dysrhythmias, hypotension, and allergic reaction . Check for signs and symptoms of bleeding Treat major bleeding by discontinuing thrombolytic therapy Treat minor bleeding by applying direct pressure if accessible

36. Surgical Management PTCA ( Percutaneous transluminal coronary angioplasty ) CABG (Coronary artery bypass grafting )

37. PTCA Coronary balloon angioplasty, also referred to as percutaneous (through the skin) coronary intervention (PCI ) . The purpose of PTCA is to improve blood flow within a coronary artery by “cracking” the atheroma . The coronary arteries are examined by angiography

38. Risk and complications : Embolization Arterial rupture Hematoma or pseudo aneurysm formation at the access site Radiation Injuries Radiation induced injuries (burns) from the X-Rays used .

39. Coronary Artery Bypass Grafting It is a surgical procedure to restore normal blood flow to an obstructed coronary artery . The 2004 AHA CABG guidelines state CABG is the preferred treatment for: • Disease of the left main coronary artery (LMCA). • Disease of all three coronary arteries (LAD, LCX and RCA). • Diffuse disease not amenable to treatment with a PCI .

40. Nursing Management Acute Pain related to Decreased myocardial blood flow Increased cardiac workload/oxygen consumption . Risk for Decreased Cardiac Output Impaired gas exchange related to trauma of extensive chest surgery Risk for deficient fluid volume and electrolyte imbalance related to alterations in blood volume Acute pain related to surgical trauma and pleural irritation caused by chest tubes and/or internal mammary artery dissection