NUR 4206 By Linda Self

1. Nursing Care of Patients with Cardiac Problems NUR 4206By Linda Self

2. Assessment of the Cardiovascular System • One in five Americans possess some form of cardiovascular disease • With increase in metabolic syndrome and aging babyboomers, numbers increasing • Cardiovascular disease is the number one cause of death in women in US. • Major cause of mortality in 21st century • Number of cardiovascular problems that can occur

3. Review of Heart A&P • Pericardium • Epicardium • Myocardium • Endocardium

4. Heart Chambers • Right side of heart—workload is light compared to left side; pulmonary circulation • Left side of heart—high pressure system, systemic circulation

5. Heart Sounds • S1 caused by closure of mitral and tricuspid valves • S2 caused by the closure of aortic and pulmonic valves • Splitting of S1 and S2 can be accentuated by inspiration • Gallops=S3 and S4

6. Gallops • S3 is ventricular gallop—normal in children. In those over 35, indicates early heart failure, VSD or decreased ventricular compliance • S4 is an atrial gallop—seen in hypertension, anemia, aortic or pulmonic stenosis and pulmonary emboli

7. Murmurs • Systolic murmurs—aortic stenosis and mitral regurgitation. Occur between S1 and S2. • Diastolic murmurs—aortic or pulmonic regurg and mitral stenosis. Occur between S2 and S1. • Grades I-VI; 1 very faint, 2 faint but recognizable, 3 loud but moderate in intensity, 4 loud w/thrill, 5 loud, thrill, stethoscope partially off chest, 6 audible w/o stethoscope

8. Coronary Arteries • Heart perfused by coronaries during diastole • Right coronary • Left coronary • Circumflex • Must be 60-70 to maintain perfusion of vital organs

9. Coronaries • Left coronary perfuses left ventricle, septum, chordae tendinae, papullary muscle and portion of right ventricle • Right coronary—supplies right atrium, right ventricle, inferior portion of left ventricle

10. Unique characteristics of the heart • Automaticity—intercalated discs • Conductivity • Contractility • Excitability

11. Assessment of Cardiovascular Function • Cardiac conduction system • SA node • Internodal tracts • AV node/junction • Bundle of His • Right and left bundle branches • Purkinje fibers

12. Cardiac action potential • Stimulation of the cardiac working cells (myocytes) is reliant on exchange of ions across particular channels in cell membrane • Channels regulate the movement and speed of the ions, specif., sodium, potassium, and calcium • Sodium travels across fast channels, calcium across slow channels • Potassium is primary intracellular ion, sodium is the primary extracellular ion

13. Action Potential • Phase O—cellular depolarization initiated as positive ions influx into cell. Sodium moves rapidly into myocytes; depolarization of SA and AV nodes via slow calcium channels • Phase 1—Early cellular repolarization occurs as potassium exits intracellular space • Phase 2—plateau phase, rate of repolarization slows, calcium ions enter intracellular space

14. Cardiac Action Potential • Phase 3—Marks completion of repolarization and return of the cell to resting state • Phase 4-resting phase before next depolarization

15. Refractory Period • During this phase, cells are incapable of being stimulated • Absolute refractory period—unresponsive to any electrical stimulus, Phase O to middle of Phase 3 • Relative refractory period—brief period at end of Phase 3. Strong enough impulse can cause depolarization prematurely. This increases the risk for serious dysrhythmias.

16. Refractory Period Factors increasing likelihood of premature depolarization • Hypokalemia • Hypomagnesemia • Hypothermia • Myocardial injury • Acidosis • hypercarbia

17. Quick look analysis of cardiac dysrhythmias • P wave-atrial depolarization • PR-duration of time from SA to AV nodes • QRS-ventricular depolarization • QT-total time needed for depolarization and repolarization • T wave-represents ventricular repolarization • U wave if prominent represents electrolyte abnormality

18. Systematic analysis • Calculate heart rate • Heart rhythm • Analyze P waves • Measure P-R interval • Measure QRS duration • Interpretation

19. Analysis dependent on specific criteria • PR interval <.20 second • QRS interval < or equal to .12 second • QT interval variable, generally less than .42 second • P for every QRS

20. Normal rhythms • Normal sinus rhythm—60 to 100 • Sinus dysrhythmia l

21. Dysrhythmias • Tachydysrhythmias-->120 • Bradydysrhythmias--<60 • Premature complexes • Repetitive rhythms—atrial flutter • Escape complexes—idioventricular rhythm

22. Common dysrhythmias • Sinus tachycardia • Sinus bradycardia • Supraventricular rhythms • Atrial fibrillation or flutter • 1st, 2nd, 3rd degree heart blocks • Vtach, Vfib, asystole

23. Cardiac Hemodynamics • Based on principle that fluid flows from region of higher pressure to one of lower pressure • Right side of heart has lower pressure than does left • Systole-pressure in ventricles increases, forces AV valves to close, forces semilunar valves to open, and blood is ejected • Diastole—ventricles are relaxed, AV valves open, atria fill first, ventricles fill, electrical impulse, atria contract, impulse is propagated to ventricles, ventricles fill then will contract

24. Cardiac Output • HR x SV= CO • Ranges between 4-7 L/min in adults • CI = CO divided by BSA • Amount of blood pumped by each ventricle during given period • Stroke volume is amount of blood ejected per heartbeat, ~70ml

25. Control of Stroke Volume Affected by • preload—degree of stretch of cardiac muscle fibers at the end of diastole, amount of blood returning to right side of heart • afterload –amount of resistance to ejection • contractility—forcegenerated by the contracting myocardium • Ejection Fraction--Percentage of end-diastolic volume that is ejected, ~50-70%

26. Control of Stroke Volume • Pulmonary vascular resistance (PVR)—resistance of the pulmonary BP to right ventricular ejection • Systemic vascular resistance (SVR)—resistance of the systemic BP to left ventricular ejection • Contractility=force of generated by the contracting myocardium

27. Gerontologic Considerations • Increased size of left atrium • Thickening of endocardium • Myocardial thickening • Thickening and rigidity of AV valves • Calcification of aortic valve • Decreased number of SA, AV, Bundle of His, right and left bundle branch cells • Stiffening vasculature • Decreased sensitivity to baroreceptors

28. Heart disease risk factors • Cigarette smoking • Genetics • Physical inactivity • Obesity • Hyperlipidemia • Diabetes mellitus • Hypertension

29. Health History and Clinical Manifestations • History • Chest pain or discomfort • SOB • Peripheral edema and weight gain • Palpitations • Fatigue • Dizziness, syncope, changes in level of consciousness

30. Differing kinds of chest pain • Angina pectoris • Pericarditis • Pulmonary disorders—pneumonia, PE • Esophageal disorders • Anxiety and panic disorders • Musculoskeletal disorders--costochondritis

31. Women and symptoms of MI • Atypical presentation • Fatigue, sleep disturbances, shortness of breath • Historically undertreated due to ambiguous presentation

32. Physical Assessment • General appearance and cognition • Inspection of the skin • Blood pressure—difference between the systolic and diastolic blood pressure is called the pulse pressure. Pulse pressure less than 30 torr signifies a serious reduction in cardiac output and requires evaluation • Postural BP changes • Arterial pulses, pulse quality-check side to side

33. Physical Assessment • JVD when head of bed is elevated 45 to 90 degrees • Heart sounds—S1, S2 ; gallops (vibration), snaps and clicks (stenosis of mitral valve), murmurs (turbulent flow) and friction rubs (harsh grating sound) • Inspection of extremities • Lungs • Abdomen • Skin temperature

34. Physical Assessment • Assess clubbing by the Schamroth method • Blood pressure—hypertension • Prehypertension—120-130/80-89 • Postural hypotension—BP decrease by 20 torr systolic or 10 torr diastolic plus 10-20% increase in heart rate. Supine,sitting, standing. • Ankle-brachial index=assess vascular status of LE. LE SBP divided by brachial BP. Should be 1, .8 moderate disease, .5 severe

35. Gerontologic Considerations • Changes in AP diameter • Isolated systolic hypertension—increases risk for morbidity and mortality • S4 will be present in ~90% of elderly patients due to decreased ventricular compliance • S2 may be split • 60% of elderly have murmurs, reflective of sclerotic changes of aortic leaflets

36. Diagnostic Evaluation Cardiac biomarkers • Creatine kinase and CK-MB—most specific in MI • Myoglobin—heme protein. Released from myocardial tissue within 1-3 hours after injury. Less specific as may be elevated in renal and musculoskeletal disease • Troponin T and I—proteins found only in cardiac muscle, detected within 3-4 hours, peak in 4-24 and remain elevated for 1-3 weeks

37. Blood chemistry, hematology and coagulation studies • Lipid profile—obtain after a 12 hour fast • Brain (B type) Natriuretic Peptide—neurohormone that regulates BP and fluid volume. Level increases as increased ventricular pressure as seen in heart failure. >51.2 is considered abnormal. • C Reactive Protein—protein released by liver and reflects systemic inflammation. Normal is less than 1.0

38. Diagnostic Studies • ECG—graphic recording of the electrical activity of the heart. Up to `18 leads. • Telemetry—radiowaves • Holter monitoring • Wireless mobile cardiac monitoring • Exercise stress test • Pharmacologic stress test—Persantine and adenocard are given, simulate effects of exercise; dobutamine also, helpful on those with bronchospasm

39. Lipids • Total cholesterol 122-200 • Triglycerides—122-200 • HDL—55-60 • LDL—60-180 • HDL: LDL ratio—3:1

40. Blood chemistries cont. • Homocysteine—indicates risk for CVD. Linked to development of atherosclerosis. 12- hour fast needed for reliable monitoring of level. Normal 5-15 micromol/L • Magnesium—necessary for absorption of calcium, maintenance of potassium stores and metabolism of ATP. Low levels predispose to atrial and ventricular dysrhythmias. Increased levels depress contractility and excitability of heart.

41. Diagnostic Testing cont. • Echocardiography—noninvasive ultrasound that is used to examine the size, shape and motion of cardiac structures. • Transesophageal echocardiogram (TEE)—provides clearer images of heart . Fasting for 6 hours. IV line. Sedation. Throat anesthetized. Frequent monitoring. • Thallium or Cardiolite stress test

42. Diagnostic Testing • PET scan can be used to measure cardiac dysfunction • MRI • Cardiac catheterization with angiography—contrast, know BUN/creatinine, INR, PT, PTT • Must be fasting. Have IV access. • Following cath, observe catheter access site for bleeding • Monitor extremity—CSM

43. Cardiac Catheterization cont. • Bedrest for 2-6 hours • Monitor for dysrhythmias • Monitor for contrast agent induced renal failure, I&O, hydration • Ensure patient safety—instruct no lifting for 24h, no straining, avoid tub baths, s/s of bleeding, swelling, bruising, pain or fever

44. Drug Therapy for dysrhythmias • Class IA— Na+ channels.Depress depolarization, prolong repolarization. For atrial and ventricular dysrhythmias. Pronestyl (procainamide). Proarrhythmic. Lupus-like syndrome. • Class IB—minimal depression of depolarization, shortened repolarization. Treats ventricular dysrhythmias. Xylocaine (lidocaine) and Mexitil (mexilitene). CNS changes.

45. Case Studies

46. Anti-Dysrhythmics • Class IC—marked depression of depolarization; little effect on repolarization. Tx of atrial and ventricular dysrhythmias. Tambocor (flecainide) and Rythmol (propafenone). Proarrhythmic, HF, AV blocks • Class II—Beta blockers.Decrease automaticity and conduction. Treats atrial and ventrcular dysrhythmias. Tenormin (atenolol), Lopressor (metoprolol), Inderal (propranolol), bradycardia, heart failure, bronchospasm, masks hypoglycemia

47. Anti-Dysrhythmics • Class III—Potassium channels. Prolong repolarization, for atrial and ventricular dysrhythmias especially when ventricular dysfunction present. Cordarone (amiodarone), Corvert (ibutilide). SE: pulmonary toxicity, corneal microdeposits, bradycardia, AV blocks, heart failure, hypotension with IV administration, peripheral edema.

48. Anti-Dysrhythmics • Class IV—block calcium channels. For atrial dysrhythmias. Cardizem (diltiazem), Calan (verapamil). Bradycardia, AV blocks, Hypotension, peripheral edema

49. Cardioversion and Defibrillation • Timed electrical current to terminate a tachydysrhythmia • Defibrillation-treatment of choice for ventricular fibrillation and pulseless VTach

50. Pacemaker Therapy • Electronic device that provides electrical stimuli to heart muscle • Composed of generator and electrodes • Universal code about function • Appropriate sensing of intrinsic rhythm, appropriate pacing and appropriate capture • Complications include: infection, bleeding,ectopy, performation of myocardium