BME 301Lecture EighteenOutline The burden of heart disease The cardiovascular system How do heart attacks happen? How do we treat atherosclerosis? Open heart surgery Angioplasty Stents What is heart failure? How do we treat heart failure? Heart transplant Left ventricular assist devices Artificial heartEarly Warning Signs of Heart Attack Many heart attacks start slowly; symptoms may come and go Chest discomfort Most heart attacks involve discomfort in the center of the chestthat lasts for more than a few minutes, or goes away and comes back. The discomfort can feel like uncomfortable pressure, squeezing, fullness, or pain Discomfort in other areas of the upper body Can include pain or discomfort in one or both arms, the back, neck, jaw, or stomach Shortness of breath Often comes along with chest discomfort. But it also can occur before chest discomfort Other symptoms May include breaking out in a cold sweat, nausea, or light-headednessHeart Attack Video http://www.heart1.com/attack/guidant.cfmHeart AttacksDiagnosis of AtherosclerosisDetection of AtherosclerosisHeart AttacksTreatment of AtherosclerosisHow Do We Treat Atherosclerosis?CABGhttp://www.learnaboutbypass.com/images/illustrations/bodybypasses.gifCABG Procedure Patient is prepped, general anesthesia Chest access is gained, through sternum Graft vessel is retrieved Expose heart through pericardium Divert blood through heart lung machine Stop heart Insert graft Return circulation to heart Close incisionhttp://www.ctsnet.org/doc/3311Heart-Lung Machine The heart-lung machine: Consists of a chamber that receives the blood from the body Blood is pumped by machine through an oxygenator Oxygenator removes CO2 and adds oxygen Pump then pumps this newly oxygenated blood back to the body Connected to patient by a series of tubes that the surgical team placesHeart Lung Machinehttp://www.brucemindich.com/images/bypass1.gifHeart Lung Machinehttp://www.davidfary.com/hlm_small.jpgHeart Lung Machinehttp://engr.smu.edu/~cd/EE5340/lect31/sld011.gif http://engr.smu.edu/~cd/EE5340/lect31/sld014.gifCABG Effectiveness 2001: 516,000 CABG procedures performed Procedure takes 4-6 hours, 5-7 day hospital stay Grafts remain open & functioning for 10-15 yrs Risks: Heart attack (5%) Stroke (5%) (risk greatest in those over 70 years old) Death (1-2%) Sternal wound infection (1-4%) “Post-pericardiotomy syndrome“ (30%) Occurs few days to 6 months after surgery Symptoms are fever and chest pain Some people report memory loss and loss of mental clarity or "fuzzy thinking" following CABGInnovations Off-pump CABG: http://www.surgery.usc.edu/divisions/ct/videos-mpeg-offpumpcoronaryarterybypassgrafting.html Closed chest CABG: http://www.hsforum.com/stories/storyReader$1537How Do We Treat Atherosclerosis?AngioplastyPTCA: Effectiveness Cannot always successfully perform procedure Diffuse disease Total occlusion Calcified disease Restenosis Occurs in 25-54% of patients Usually occurs within 6 monthsHow Do We Treat Atherosclerosis?StentStentshttp://www2.cajun.net/~wpharo/stent.jpghttp://www.insel.ch/kardio/kardiorehab/bilder/stent.jpghttp://www.wbamc.amedd.army.mil/images/newsphotos/stent%20implantation.jpgStentshttp://www.priory.com/cmol/stent3.jpghttp://www.hybridmedicalanimation.com/media/mdtrnc_stent.jpgDrug Eluting Stents http://www.npr.org/features/feature.php?wfId=1452217Comparison of RX Methods Hospital Stay: CABG – 4-7 days Angioplasty – 1-2 days Stent – 1-2 days Restenosis: CABG – 5-6%, usually after 5 years Angioplasty – 25-45%, usually within 6 months Stent – 15-20%, usually within 6 monthsComparison of RX Methods Cost CABG $35,000 Angioplasty $17,000 Stent $19,000 Cost-effectiveness Additive procedures: Within 5 years, 20-40% of patients have second PTCA, 25% have CABG Additive costs: 0 years: per patient costs of PTCA 30-50% those of CABG 1 year: 50-60% 3 years: 60-80% >3 years: >80% Moving Target ProblemWhat Would You Do? Angioplasty Stent CABGCost-EffectivenessTherapy Patient Group $ per yr life savedtPA Post MI high risk $3,600tPA Acute MI, large infarct, treatment started >2 hours post$24,200Counseling Smoking cessation $1300-$3900CABG Two vessel disease, severe angina$9,200-$42,500http://www.sciencedirect.com/science?_ob=ArticleURL&_aset=B-WA-A-A-A-MsSAYZA-UUA AUYWDCBYZYAUYUBBVZZYBWAUBWEUBAU&_rdoc=1&_fmt=full&_udi=B6T1048NJXK25&_coverDate=5%2F22%2F2003&_cdi=4876&_orig=search&_st=13&_sort=d&view=c&_acct=C000004378&_version 1&_urlVersion=0&_userid=108429&md5=5f493caa5f65762c23c0d90eaea8b92dPrevention or Treatment? http://www.nytimes.com/2004/03/21/health/21HEAR.htmlProgression of Heart DiseaseHigh Blood PressureHigh Cholesterol LevelsAtherosclerosisIschemiaHeart AttackHeart
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