BIOE 301 CABG PTCA Stent Prevention Lecture Sixteen Progression - PDF document

Review of Last Time � How do we treat coronary artery disease? BIOE 301 � CABG � PTCA � Stent � Prevention Lecture Sixteen Progression of Heart Disease High Blood Pressure What is Heart Failure? High Cholesterol Levels Heart Failure Atherosclerosis Heart Attack Ischemia Heart Failure Quantifying Heart Performance � Heart failure: � Ejection Fraction (EF) � Fraction of blood pumped out of ventricle relative to � Occurs when left or right ventricle loses the total volume (at end diastole) ability to keep up with amount of blood flow � EF = SV/EDV � Can involve the heart's left side, right side or � Normal value > 60% both sides � Measured using echocardiography � Usually affects the left side first � Normal echocardiogram � About 5 million Americans are living with � http://www.ardingerphoto.com/pcawebsite/cardiology heart failure /movies/sssmovies/normallao2cycle.html � Dilated cardiomyopathy � 550,000 new cases diagnosed each year � http://www.ardingerphoto.com/pcawebsite/cardiology /movies/sssmovies/dilcardiomyopsss.html

Left Sided Heart Failure � Involves left ventricle � Systolic failure � Left ventricle loses ability to contract � Can't push enough blood into circulation � Diastolic failure � Ventricle loses ability to relax; muscle has become stiff � Can't properly fill during resting period between beats � Pulmonary edema � Blood coming into left chamber from lungs "backs up," causing fluid to leak into the lungs � As ability to pump decreases, blood flow slows, causing fluid to build up in tissues throughout body (edema) � Congestive Heart Failure Symptoms of Heart Failure Symptoms of Heart Failure Symptom Why I t Happens People May Experience: Symptom Why I t Happens People May Experience: Shortness of Blood "backs up" in Breathlessness during activity, Increased To "make up for" loss in Heart palpitations, which feel breath (also pulmonary veins (the at rest, or while sleeping, heart rate pumping capacity, heart like the heart is racing or called vessels that return blood which may come on suddenly beats faster throbbing. dyspnea) from the lungs to the and wake them up. Often have Confusion, Changing levels of blood Memory loss and feelings of heart) because the heart difficulty breathing while lying impaired substances, such as disorientation. can't keep up with the flat; may need to prop up thinking sodium, can cause supply. Causes fluid to upper body and head on confusion leak into lungs pillows Lack of Digestive system receives Feeling of being full or sick to Persistent Fluid builds up in lungs Coughing that produces white appetite, less blood, causing their stomach. coughing or or pink blood-tinged phlegm. nausea problems with digestion wheezing Tiredness, Heart can't pump enough Tired feeling all the time and Buildup of As flow out of heart slows, Swelling in feet, ankles, legs or fatigue blood to meet needs of difficulty with everyday excess fluid in blood returning to heart abdomen or weight gain. May tissues. Body diverts blood activities, such as shopping, body tissues through veins backs up, find that shoes feel tight away from less vital climbing stairs, carrying (edema) causing fluid build up in organs (limb muscles) and groceries or walking. tissues. sends it to heart & brain. How Do We Treat How Do We Treat Heart Failure? Heart Failure? Heart Transplant Cardiac Assist Devices Artificial Heart http://www.cbsnews.com/htdocs/health/heart /framesource.html

Heart Transplant � 1960s: How Do We Treat � First heart transplants performed � 1980s: Heart Failure? � Anti-rejection meds became available (Cyclosporine) � Today: � About 80% of heart transplant recipients are alive Heart Transplant two years after the operation � 50% percent survive 5 years � Need: � 4,000 patients are on the national patient waiting list for a heart transplant � Only about 2,300 donor hearts become available for transplantation each year Surgical Procedure Rejection � Risk of rejection is highest right after � http://www.pbs.org/wgbh/nov surgery a/eheart/transplantwave.html � In one study, first year after transplant: � 37% of patients had no rejection episodes � 40% had one episode � 23% had more than one episode � Induction therapy: � Use of drugs to heavily suppress immune system right after transplant surgery � Patients keep taking some anti-rejection drugs for the rest of their life Remember from our vaccine unit: MHC Receptors � How Do T Cells Identify Virus Infected Cells? � Two types of MHC molecules � Antigen Presentation � Class I MHC molecules are found on all nucleated cells � All cells have MHC molecules on surface � Class II MHC molecules are found on antigen � When virus invades cell, fragments of viral protein are loaded onto MHC proteins presenting immune cells � T Cells inspect MHC proteins and use this as a signal � Self-Tolerance to identify infected cells � T cells which recognize class I MHC-self antigens are destroyed early in development � When this fails: auto-immune disease � Type 1 diabetes

http://cwx.prenhall.com/bookbind/pubbooks/silverthorn2/medialib/Image_Bank/CH22/FG22_14.jpg http://cwx.prenhall.com/bookbind/pubbooks/silverthorn2/medialib/Image_Bank/CH22/FG22_05.jpg Donor MHC Matching Immunosuppressive Rx � Cyclosporine, azathioprine and low-dose steroids � The greater the difference in peptide sequences � Reduce T-cell activation: of MHC receptors between donor and recipient: � T-helper cell � The stronger the immune response � CTL activity � Immuno-compromised state � The greater the chance of organ rejection � Recipient susceptible to virus-related diseases: � Matching: � B-cell lymphomas (Epstein-Barr virus) � 200 different histocompatibility antigens � Squamous cell carcinomas (human papilloma virus) � Kaposi's sarcoma (a herpes virus) � Each person has a certain "set“ � Viral infections (cytomegalovirus) � Odds that 2 unrelated people will have the same set � Graft-versus-host disease: are about 1 in 30,000 � Caused by alloreactive T-cells within the donor tissue � Transplant coordinators try to match that can cause tissue damage in the recipient histocompatibility antigens of the donor and the � Routine heart biopsies to monitor for rejection recipient as well as possible to minimize rejection How To Become An Organ Donor Uniform Donor Card � Three steps: � Department of Public Safety (where you obtain drivers licenses) � Register Online � 1. Speak with your family about your decision � https://www.donatelifetexas.org/TXDear_Secure/default.aspx to donate. Make sure they know about your wish to be an organ donor � 2. Sign a Uniform Donor Card, and have two family members sign the card as witnesses � 3. Carry the card in your wallet at all times.

Why Inform Your Family More About Organ Donation I f you haven't told your family you're an � http://www.organdonor.gov organ and tissue donor -- you're not! � http://www.tdh.state.tx.us/agep/become.htm Sharing your decision with your family is more � http://www.lifegift.org/default.html important than signing a donor card. In the event of � http://www.lifegift.org/UD_Organ_Donation.html your death, health professionals will ask your family members for their consent to donate your organs and � http://www.shareyourlife.org/ tissues. This is a very difficult time for any family, and knowing your wishes will help make this decision easier for them. They will be much more likely to follow your wishes if you have discussed the issue with them. Remember - signing an organ donor card is NOT enough. Discuss your decision with your family! Requirements of Mechanical Support History of Cardiac Devices � 1950s and 1960s: � Non-thrombogenic blood contacting � Heart-lung machine surface � Prosthetic materials to close holes between heart chambers � Replacement valves � Pumping action that avoids blood trauma � Implantable pacemakers � Coronary angiography to diagnose/treat coronary artery disease � Variable output � Intra-aortic balloon pump (IABP) � 1970s and 1980s: � Small enough to fit in chest cavity � IABP gains wide acceptance as temporary cardiac assist system � Cyclosporine, an anti-rejection drug, makes human heart � Reliable transplants feasible � PTCA to treat coronary artery disease with a balloon catheter � External & implantable ventricular assist devices enter clinical trials � 1990s: � External and implantable left ventricular assist devices approved for temporary support as a bridge-to-transplantation Types of Mechanical Support � Temporary: LVADs How Do We Treat � Give heart muscle a chance to rest/recover � Bridge to transplantation Heart Failure? � Failure is not catastrophic � Permanent: Total Artificial Heart Left Ventricular Assist Devices � Replace damaged heart muscle � Failure is catastrophic