Anatomy Cardiac Surgery Anterior and posterior view of the heart displaying normal distribution of coronary arteries. (Porth CM, 1998: Alterations in cardiac function. In Pathophysiology: Concepts of Altered Health states, ed. 5, p 390. Philadelphia Lippincott Williams & Wilkins) Richard J. Nadan, MBA,MS,RN,ACNP-BC,CCRN,CEN Acute Coronary Syndrome Uncontrolled exacerbation of cardiac muscle ischemia or injury, during which portions of ventricular myocardium are jeopardized but not yet damaged irreversibly Acute Coronary Syndrome z Infarction, Injury, Ischemia Includes the following conditions: z Unstable angina z Acute pulmonary edema z Ventricular tachycardia z Evolving MI z Completed MI with unstable post-infarction angina Ischemia z z z z Imbalance between O2 supply & demand Angina / chest pain Often mistaken for “heartburn” The “four Es” z Exercise, emotion, eating, exposure (to cold) (Woods SL, Underhill, SL, Cowan, M, 1991: Coronary heart disease. In Patrick ML, Woods SL, Craven RF, et al. {eds}: Medical-Surgical Nursing: Pathophysiological Concepts, ed. 2, p.695, JB Lippincott) 1 Myocardial Infarction z z z z z Treatment of MI Irreversible necrosis of cardiac muscle Peak incidence early to late AM Higher incidence in Winter Transmural – extends through all layers of cardiac muscle Infarct location corresponds to the occluded coronary artery z z z z z z z z z Enzyme Elevations After MI Complications of MI z Finding CK CK-MB LDH Rises (hours) 4 – 8 3 – 12 10 Peaks (hours) 24 24 – 48 6 – 8 Returns to Normal (days) 2–3 2–3 24 Troponin 3.5 10 - 14 5 –6 z Complications of MI z z z z Ventricular aneurysm Thromboembolism z DVT and Pulmonary Acute mechanical defects z MR z Rupture of LV free wall or septum Depending on severity of MI, patient may require IABC (intra aortic balloon counter-pulsation) PROMT !!! Differentiate ischemia from infarction Monitor closely Pain (0 – 10) MONA z Morphine, O2, Nitrates, ASA Heparin Thrombolytics, emergent PCTA or CABG Daily ECG, labs, CXR CCU Ventricular dysfunction z Wall motion abnormality z Hypo- dys- or akinesis z CHF, pulmonary edema, cardiogenic shock z Compromised EF Dysrhythmias z VT, VF Etiology of Coronary Artery Disease z z z z z Major cause of CAD is atherosclerosis Chronic, progressive, multifocal Dz of vessel intima Fatty streaks present in almost all people after age 20 Fibrous plaques appear around the third decade Complicated lesions and their clinical manifestations develop in fourth decade 2 Risk Factors for CAD z z Major Modifiable Risk Factors z Hypercholesterolemia z Hypertension z Cigarette smoking Non-modifiable Risk Factors z Heredity z Increasing age z Male Risk Factors for CAD z Diagnosis of CAD z z z z First symptoms often fatal Goal is to reduce morbidity & mortality z Preventative therapy, screening high risk patients, early Dx & Tx EST, ECG, TTE, TEE Cardiac catheterization z Most definitive Diagnostic Evaluation Noninvasive z Invasive z Diagnostic Evaluation (Noninvasive) z z z z ECG Holter monitor Exercise stress testing Echocardiography z TTE or TEE Contributing Risk Factors z Diabetes z Obesity z Sedentary life style z Cocaine Common Indications for EST z z z z Screen high-risk individuals for CAD Document exercise induced ischemia in individuals with symptoms suggestive of CAD Evaluate functional capacity after MI or CABG Document exercise induced arrhythmias or determine HR response to exercise 3 Information Provided by Echocardiography z z Cardiac valves z Characteristics z Quantification of gradient, valve area, regurgitant flow Ventricular wall and interventricular septum z Systolic & diastolic ventricular dimensions & volumes z Myocardial thickness & segmental wall motion z EF Information Provided by Echocardiography z z Presurgical Diagnostic Evaluation (Invasive) Indications for TEE z z z z z z Obese patients Patients with COPD Intraoperative studies Inadequate information from TTE Patients with suspected Ao dissection Detailed valvular anatomic assessment in infective endocarditis z z z Left Coronary Angiogram The LM divides into the LAD and Cx. The Cx gives rise to OM branches Structural abnormalities z Intracardiac shunts (e.g., atrial septal defect) z Intracavitary lesions (e.g., myxoma, vegetation) Pericardium z Effusions z constrictions PCI z Angiography z IVUS (intravenous ultrasound) Electrophysiologic studies Endomyocardial biopsy Treatment of CAD z z z z z Chronic disease No cure Goal is to slow progression and prevent MI Treatment is individualized to the patient Modifiable risk factors Courtesy of Dr. John J. Smith, Division of Cardiology, NEMC 4 Medical Therapy z z z z z z z Attempts to slow progression or cause regression Controlled diet Exercise Stress reduction Quit smoking z 50% reduction in mortality rates Cholesterol lowering agents Treatment of HTN Percutaneous Coronary Intervention (PCI) z z z z z Based on anatomic appearance, location, number, & severity of coronary artery lesions Ideal for one or two major coronary arteries First done in 1977 More than 480,000 done each year in USA Achieved via femoral or brachial artery Revascularization Therapy z z z Percutaneous Coronary Intervention (PCI) z Percutaneous transluminal coronary angioplasty (PTCA) z Stenting Coronary Artery Bypass Grafting (CABG) TMR (transmyocardial revascularization) Percutaneous Transluminal Coronary Angioplasty (PTCA) A guide catheter is positioned left coronary artery ostium; deflated balloon catheter is advanced over a guide-wire through the stenosis in the LAD; the balloon is then inflated (Vlietstra RE, Holmes DR, 1998: PTCA. J. Cardiac Surg 3:55) Left Coronary Angiogram Stent The ACS Multilink Duet™ Stent, one example of a commercially available device used for stenting the coronary during PCI to decrease incidence of restenosis Tight LM stenosis Courtesy of Dr. John J. Smith, Division of Cardiology, NEMC (Courtesy of Guidant Corporation, Santa Clara, CA) 5 Indications for Surgical Revascularization z z Indications for Surgical Revascularization Three large, randomized, prospective studies in the 1980s z Coronary Artery Surgery Study (CASS) z Veterans Administration Cooperative Study z European Cooperative Study Conclusion: benefits of CABG over medical therapy is greatest in patients with more severe ischemia, more diseased vessels, and more severe LV dysfunction z z Indications for Surgical Revascularization z Best candidates for revascularization (PCI / CABG) z Significant coronary lesions z Stable angina refractory to adequate medical therapy z Angina or s/s interfere with ADL z Exercise induced hypotension, ventricular dysrhythmias 2° to ischemia z Unstable angina z Evolving MI Preoperative Interview : Areas of Focus z z z z z z z Evaluation of Angina Canadian Cardiovascular Society Functional Classification System z z z z I Angina occurs with strenuous or rapid or prolonged exertion at work or recreation II Slight limitation of ordinary activities by angina III Marked limitation of ordinary activities by angina IV Angina with any physical activity or at rest Medical therapy achieves most of its beneficial effect through reduction in the demand side of the supply-demand coronary blood supply mismatch Revascularization therapies (PCI, CABG) affect the supply side of the mismatch attempting 3 goals: z Control of ischemic symptoms z Prevention of MI z Prolongation of life HPI Presence of cardiac risk factors Functional Status Associated medical diseases Current Rx regimen and drug allergies Understanding of illness & planned procedure Family support system Evaluation of Heart Failure New York Heart Association Functional Classification System z z z z I Ordinary Physical Activity does not cause fatigue, palpitation, dyspnea, or angina II Ordinary physical activity causes undue fatigue, palpitation, dyspnea, or angina III Less than ordinary physical activity causes undue fatigue, palpitation, dyspnea, or angina IV Fatigue, palpitation, dyspnea, or angina occur at rest 6 Preoperative Physical Assessment: Areas of Focus z z z Preoperative Physical Assessment: Areas of Focus Cardiac auscultation z Rate & rhythm z Heart sounds z Murmurs, clicks, rubs Auscultation of carotid arteries Auscultation of the lungs z Respiratory rate z Breath sounds z Adventitious sounds z z z z z Preoperative Teaching z z z z z z z Palpation of peripheral pulses Blood pressure Weight Temperature Examination of extremities z Edema z Arterial Insufficiency / venous stasis z Prior vein ligation Intraoperative Management Basic anatomy & pathologic condition Description of operative procedure Common diagnostic & preoperative studies Description of perioperative course Assistive catheters and tubes Visiting procedures Pulmonary hygiene z z z Always begins with preoperative evaluation Intra-op ECG, SpO2, prophylactic Abx, prep / drape in sterile fashion, NIBP, ABP, PAP, Temp, urine output, capnometry General anesthesia ASA Physical Status Classification Intraoperative Management Characteristics of Inhalation & Narcotic Agents z z z z z I Normal healthy patient II Mild systemic disease III Severe systemic disease that is not incapacitating IV Incapacitating systemic disease that is a constant threat to life V Moribund patient that is not expected to survive for 24° with or without operation z Inhalation agents z z z z Dose-dependant myocardial depression Vasodilatation Rapid induction Early emergence z Narcotic agents z z z Potent anesthesia & analgesia Minimal hemodynamic effects Slow emergence 7 Intraoperative Management z Cardiopulmonary Bypass Stages of Anesthesia z Three Stages z Induction z Maintenance z Emergence CPB (extracorporeal circulation) – a system used temporarily to perform the functions of the heart and lungs during operative procedures on the heart or great vessels. Any cardiac operation that involves use of CPB is correctly termed an open heart operation regardless of whether a cardiac chamber is opened during the procedure *CPB is eliminated in “off-pump” CABG Myocardial Protection Cardiopulmonary Bypass z z z z z z First used in 1953, Pioneered by Dr. John Gibbon Exposes blood to nonendothelial surfaces z Can damage blood elements, e.g.: Platelets, RBC, WBC, plasma proteins Post perfusion syndrome – a rare severe inflammatory reaction “Pump head” Higher incidence of post-op bleeding Higher incidence of CVA z z Blood Conservation in Cardiac Surgery z z z z z z Avoid preoperative ASA and clopidogrel (NOT necessary if OP-CABG) Autologous donation Priming CPB circuit with crystalloid Cell saver device Cardiotomy suction Hemoconcentration Hypothermia (Patients DO NOT require being hypothermic when OP-CABG is preformed) z Reduces oxygen demand z Can contribute to platelet dysfunction which leads to post-operative bleeding Cardioplegia (NOT used in OP-CABG) z Arrests the heart z Reduces oxygen demand Blood Conservation in Cardiac Surgery z z z z z z Adequate heparin reversal Surgical hemostasis Hemostatic agents Postoperative auto-transfusion Avoid post-op hypertension Tolerance of post-op anemia 8 Typical CABG Operation LIMA has been used to construct a pedicle graft to the LAD; saphenous vein grafts have been constructed to bypass lesions in the RCA & Cx. Conduits for CABG Radial Artery Loop, FD, 1998: Coronary artery bypass surgery. In Topol EJ {ed}: Comprehensive Cardiovascular Medicine, p. 2294. Philadelphia, Lippincott Williams & Wilkins) (Preparing for Cardiac Surgery. Division of Cardiothoracic Surgery & Department of Nursing. Northwestern Memorial Hospital Conduits for CABG The gastroepiploic artery is mobilized from the greater curvature of the stomach, brought through the diaphragm, & is usually used to graft a branch of the RCA Loop, FD, 1998: Coronary artery bypass surgery. In Topol EJ {ed}: Comprehensive Cardiovascular Medicine, p. 2294. Philadelphia, Lippincott Williams & Wilkins) Conduits for CABG The greater saphenous vein is harvested from one or both legs using multiple short incisions and meticulous technique to avoid damaging the vein segments (Loop FD, 1979: Saphenous vein bypass graft. In Cohn LH [ed]: Modern Techniques in Surgery, p. 10-2. Mount Kisco, NY, Futura) Conduits for CABG The inferior epigastric artery may be sewn proximally to an arterial conduit and distally to a secondary target coronary artery Loop, FD, 1998: Coronary artery bypass surgery. In Topol EJ {ed}: Comprehensive Cardiovascular Medicine, p. 2294. Philadelphia, Lippincott Williams & Wilkins) Endarterectomy An occluded RCA is considered for endarterectomy (Cooley DA, 1984: Revascularization of the ischemic myocardium. In Techniques in cardiac Surgery, ed. 2. P.232. Philadelphia, WB Saunders 9 Endarterectomy An arteriotomy is preformed just above the crux and the atheromatous core is brought out through the incision (Cooley DA, 1984: Revascularization of the ischemic myocardium. In Techniques in cardiac Surgery, ed. 2. P.232. Philadelphia, WB Saunders Endarterectomy Endarterectomy The distal vessels are cleared individually of plaque (Cooley DA, 1984: Revascularization of the ischemic myocardium. In Techniques in cardiac Surgery, ed. 2. P.232. Philadelphia, WB Saunders Endarterectomy The proximal portion is removed by gentle traction until it breaks free The atheromatous specimen after extraction from the artery (Cooley DA, 1984: Revascularization of the ischemic myocardium. In Techniques in cardiac Surgery, ed. 2. P.232. Philadelphia, WB Saunders (Cooley DA, 1984: Revascularization of the ischemic myocardium. In Techniques in cardiac Surgery, ed. 2. P.232. Philadelphia, WB Saunders Endarterectomy OP-CABG A saphenous vein graft is anastomosed to the RCA to bypass atheromatous material in the proximal portion of the vessel (Cooley DA, 1984: Revascularization of the ischemic myocardium. In Techniques in cardiac Surgery, ed. 2. P.232. Philadelphia, WB Saunders 10 Newest CABG Techniques z MIDCAB (Minimally Invasive Direct Coronary Artery Bypass Grafting) z Generally done for 1 or 2 vessel bypasses z Often LIMA – LAD z Generally done “off pump” z Can be done via “Heart-port” technique (minibypass) MIDCAB Minimally Invasive Direct Coronary Artery Bypass. A left thoracotomy incision is made in the 4th ICS. The LIMA, located at the medial aspect of the incision, is mobilized to the 1st ICS. The pericardium is opened & the LIMA is sewn to the LAD on a beating heart. (Bojar, RM, 1999: Manual of perioperative care in cardiac surgery. 3rd ed. P. 10. Malden, MA: Blackwell Science, Inc.) Sternotomy Sparing MID-CABG Incisions Mini Sternotomy & Subxyphoid BIMA – RCA, LAD & PDA Transabdominal CABG RCA, LAD, Distal Circumflex Mid-Lateral MIDCAB for Left Main Stenosis (LAD, OM1, D1, RI ) Anterior MIDCAB (LAD & Diag) Lateral MIDCAB (PLA, OM1, OM2) Newest CABG Techniques z z Lateral MID-CABG Incision TE-CABG (Totally Endoscopic) Robotics z Eliminate Surgeon hand tremor z Done through very small laparoscopic incisions z Only used for 1 or 2 vessel bypasses at this time, still under FDA trials TMR (Transmyocardial Revascularization) z Used to promote collateral circulation 11 Open vs. Endoscopic Saphenous Vein Harvest Newest CABG Techniques z Endoscopic conduit harvesting z 1 – 2 inch incision made at radial artery site or saphenous vein site, vein is harvested with fiber-optic scope z Less than 0.5% infection rate z Reduced edema of lower extremities z Most often preformed by PAs and NPs z Cost effective z Fast recovery for patient Endoscopic Radial Artery Harvest Factors Associated With Increased Operative Mortality & Morbidity in Patients Undergoing CABG z z z z z z z z z Long-Term Results of CABG According to the ACC / AHA Guidelines: Percent at Outcome Freedom from Death Angina MI Sudden Cardiac Death 5 years 10 years 15 years 92 81 85 – 90 60 96 97 Ejection fraction < 30% Age > 70 years Elevated serum creatinine LVEDP >25 mmHg Female Failed PCI Associated MV disease Previous cardiac procedure Associated peripheral arterial occlusive disease 57 64 z z z z Survival rate of surgical pts. After 10 yrs. Of followup was 4.3 months longer than the survival rate of medically treated pts. 15 yr cumulative survival rate for LM CAD was 44% in pts. who were Tx medically Pts. With 3v CAD (50% or more stenosis in all 3) overall extension of survival was 7 months in surgical pts. Compared with medically Tx pts. With severe LAD stenosis, the relative risk reduction caused by CABG, compared with medical therapy, was 42% @ 5 yrs & 22% @ 10 yrs. 12 According to the ACC / AHA Guidelines: z z z The most striking difference between CABG & PTCA was the 4 – 10 fold increased likelihood of reintervention after PTCA CABG was associated with longer survival in pts. With sever stenosis of the pLAD & / or 3v CAD Pts. With 1v CAD that did not involve the LAD had improved survival with PTCA TMR Transmyocardial Revascularization “The process of creating channels through the myocardium resulting in an opening into the left ventricle which allows oxygen rich blood from within the left ventricle to perfuse out into the ischemic area of the myocardium” The Heart Laser™ CO2 TMR System TMR Sole Therapy Procedure TMR in Combination with CABG •Beating Heart •Left Thoracotomy •General Anesthesia •90 Minute Procedure •30 Day Mortality of 1% The Heart Laser™ CO2 TMR System The Heart Laser™ CO2 TMR System TMR Using the CO2 Laser Hand-piece is placed on the epicardial surface of the left ventricle The Heart Laser™ CO2 TMR System TMR Using the CO2 Laser Laser is synchronized to the R-wave of the heartbeat 20 – 40 transmyocardial channels are created The Heart Laser™ CO2 TMR System 13 TMR Using the CO2 Laser Epicardial surface of the channel seals TMR Using the CO2 Laser z CO2 Single pulse technique z Minimal myocardial tissue damage z Evidence suggests that the intra-myocardial portion remains patent and / or active z YAG Laser z Significant amount of “charring” New blood vessels form in conjunction with these channels The Heart Laser™ CO2 TMR System US Market Statistics 12 million angina suffers z 1.1 million cases of ACS z 450,000 patients candidates for CABG z 80,000 patients candidates for TMR z Patient Population Stable CCS Class III or IV angina pectoris Objectively demonstrated coronary artery atherosclerosis not amenable to direct coronary revascularization z Reversible ischemia of the left ventricular wall z Most patients have end-stage CAD z z End-Stage CAD z Risk Factors z z z z z DM HTN Tobacco Obesity Lipids z Comorbid Conditions z z z z Cerebrovascular Dz PVD COPD Ischemic mitral valve insufficiency Clinical Cautions Severe LV dysfunction, EF < 0.20 Ongoing myocardial injury z MR, > 2+ z COPD z PVD z z 14 Intraoperative Complications of TMR Accidental laser hit z Arrhythmias z Bleeding z Low CO z Hypotension z Heart Valve Surgery Summary z z The unique aspects of TMR require careful patient education and pre-operative preparation Due to the presence of comorbid conditions and a tendency towards myocardial ischemia in response to postoperative stress, this group of end-stage patients require early recognition and rapid treatment of potential complications in order to insure a smooth post-operative course Heart Valve Surgery Always requires CPB z Requires opening the chambers of the heart z Valves can be repaired or replaced z Replacement z z z Mechanical Biological z Porcine, Bovine, Human Heart Valve Surgery Heart Valve Surgery Valve stenosis – Valve does not open fully. Scaring or deposits of calcium may make the valve stiff. The heart muscle has to work harder to “push” the blood through. Normal opening and closing of a heart valve 15 Heart Valve Surgery Heart Valve Surgery Valve insufficiency or regurgitation – Valve does not close tightly. Valves should be “one-way.” With regurgitation blood moves backward. The heart has to “move” some of the same blood over again. Heart Valve Surgery MVR (mitral valve replacement) with St. Jude valve General Surgical Complications Respiratory Insufficiency z CVA z Renal failure z Infection z Bleeding z ICU Considerations Report of TMR operation Baseline hemodynamics z Respiratory management z Pain management z Fluid & electrolyte management Report of Operation Preoperative history Intra-operative events z IV medications / fluids z Hemodynamics z TEE findings z z z z 16 Baseline Hemodynamics HR z BP z Filling pressures z CI z IAPB / Pressors Assessment of the Postoperative Patient z z Neurologic Status z LOC z Pupils z Ability of move extremities z Orientation z Presence of deficits? Respiratory Management Assessment of the Postoperative Patient z Cardiovascular Status z HR, Rhythm z ABP, sys / dia (mean) z PAP, sys / dia (mean) z PCWP z MVG z CVP z CO / CI z SVR z Heart sounds z Pacing wires z Pulse generator z Peripheral perfusion z Chest tube output z Airway Assessment z z z Gas Exchange z z z z z Respiratory Status z RR (vent and patient) z Breath sounds z Symmetry of chest movement z Vent settings z ABG, SpO2 z Respiratory effort FIO2 ABG Mechanics z Assessment of the Postoperative Patient Intubated Extubated RR Vt Assessment of the Postoperative Patient z z Gastrointestinal Status z Bowel sounds z NGT function / output z Abdominal distention / tenderness z Postoperative diarrhea Renal Status z Output minimum 0.5ml / kg / hr z color 17 Pain Management Assessment of the Postoperative Patient z z Other z Pain control z Sedation z IVF, Rx z CXR, ECG z Labs z Incisions Pain Recognition Differentiate angina vs. incisional pain z Pain scale z z Pain Control Thoracic epidural PCA z NSAIDS z IV opioids z Intercostal nerve block z z Fluid & Electrolyte Management Careful observation of I/O z Maintain adequate filling pressures z Diuresis (anticipate mobilization of third space fluids) z Optimize electrolytes z Post-Operative Complications Acute MI z Myocardial ischemia / angina z Low CO z Arrhythmias z CHF z K+ levels > 4.5 mEq / L z Mg++ levels > 2 mg / dl z Angina Pectoris Following TMR z Preventative Measures Resumption of baseline anti-anginal Rx z Maintain adequate Hb z IV NTG z Stress reduction z z Diagnostics Angina Pectoris Following TMR z Treatment IV NTG / heparin Β & Ca++ channel blockers z Maintain adequate filling pressures z IABP z z ECG ST segment analysis z TTE / or TEE z z 18 Low Cardiac Output z Recognition z Clinical Signs Low Cardiac Output z Myocardial ischemia z Myocardial edema & inadequate ventricular filling z Pericardial tampanade z Delayed chordae rupture z Sympatholytic effect of epidural z z Skin changes z Neurologic status z Diminished distil pulses z Decreased UO, < 0.5 ml /kg /hr z Etiology Hemodynamics z Hypotension / tachycardia <2 z Decreased SVO2 , metabolic acidosis z CI Arrhythmias Following Low Cardiac Output z Treatment Optimize electrolytes (K+, Mg++) z R/O ischemia z Confirm PAC position z Ventricular irritability z Volume infusion IAPB z Pressors z Relief of tampanade / PTX z Correction of ischemia z Correction of mitral insufficiency z z z Operative z Afterload reduction Criteria for Extubation z z z z z z z pH 7.35 – 7.45 or at post operative baseline PaCO2 < 45, PaO2 > 60, or at baseline on FiO2 0.40 RR < 30 bpm NIF > -20 Vt > 4 – 5 ml / kg Vm < 10 L / min CPAP < / = 5 cm H2O Criteria for Extubation z z z z z z z RSBI (RR/Vt (in Liters) < 80 b/m/L Awake / alert, able to protect airway Hemodynamically stable Absence of increased WOB, use of accessory muscles CT drainage < 100 ml / hr Temp > 36°C (96.8°F), not shivering Minimal secretions 19 Discharge Instructions Postoperative Management z z z z z Majority of patients transferred from ICU to stepdown / telemetry floor with 24 – 48 hours Some robotics may transfer to telemetry within 6 hours and be d/c home on POD 2 Majority of patients will be d/c home in 3 – 5 days. Some MIDCABs sooner Daily showers imperative Daily weights & strict I/O Report temperature > 100.5°F, chills, SOB, & angina not responding to usual measures z Incentive spirometer use at home z No driving until after return visit (generally 3 – 5 weeks) z No lifting greater than 10 - 15 pounds for the first 3 – 5 weeks z Discharge Instructions Discharge Instructions Patients may go up / down stairs Must shower every day z No baths, swimming z No treadmills / bicycles z Frequent walks z Daily weights z Can generally resume sexual activity in 3 – 5 weeks z z z z Discharge Instructions Continue anti-anginals if indicated Continue to avoid activities which caused angina prior to the operation z Observe wounds for erythema, warmth, drainage z Mood swings are normal, depression should resolve in few weeks z Anticoagulation z z Individualize Gradual to avoid angina producing activities Heart Healthy Diet Home medications z Risk factors z Visiting Nurse z z Suggested References z z z Gradual benefit of TMR Activity z z Bojar RM. (1999). Manual of perioperative care in cardiac surgery (3rd ed.). Malden, MA: Blackwell Science, Inc. Eagle KA. et al. (1999). ACC / AHA guidelines for coronary artery bypass graft surgery: a report of the american college of cardiology / american heart association task force on practice guidelines (committee to revise the 1991 guidelines for coronary artery bypass graft surgery). Journal of the American College of Cardiology, 34(4), 1262 – 347. Finkelmeier BA. (2000). Cardiothoracic surgical nursing (2nd ed.). Philadelphia: Lippincott, Williams & Wilkins. 20 The End 21