5856588
Descripción
Fichas por Rachel Nall, actualizado hace más de 1 año
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Creado por Rachel Nall
hace más de 8 años
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| Pregunta | Respuesta |
| What is the most common cause of death in the United States? | Ischemic heart disease. It is the cause of death in 35 percent of the population. |
| What percentage of patients who undergo surgery in the US have IHD? | 30 percent |
| Name modifiable risk factors for IHD. | 1. Cigarette smoking 2. Obesity - reduce triglycerides, cholesterol intake; Help for those with Diabetes 3. Sedentary lifestyle - can lead to low HDL levels 4. Hypertension |
| Name three IHD risk factors that aren't modifiable | 1. Genetic predisposition/family history 2. Increasing age 3. Male gender |
| How does C-reactive protein correlate to heart disease risk? | C-reactive protein -- or CRP -- appears to be correlated to heart disease risk. Inflammation (swelling) of the arteries has been linked to an increased risk of heart disease, heart attack, stroke, and peripheral arterial disease. |
| The myocardial blood supply is derived entirely from what? | The right and left coronary arteries |
| In a right-dominant person, name the major coronary blood supplies: | 1. Right atrium 2. Most of right ventricle 3. Left ventricle inferior wall (varies) PLUS 1. Posterior descending artery (PDA) 2. Posterior left ventricle |
| What percentage of people are right-dominant? | 70 to 80 percent |
| What percentage of people are left-dominant? | 10 to 15 percent |
| If a person is left-dominant, how is blood supply different from if the person was right-dominant? | If a person is left-dominant, the circumflex supplies the PDA. |
| If a person is co-dominant, how does this affect the coronary arteries? | In co-dominant, both the circumflex and the RCA supply the posterior descending artery |
| What percentage of people are co-dominant? | 15 to 20 percent |
| Name the aspects of the left coronary artery blood supply. | Left atrium. Most of 1. Intraventricular (IV) septum 2. Left ventricle 3. Septum 4. Anterior wall 5. Lateral wall The LCA bifurcates to the LAD and circumflex. |
| What comes after the bifurcation of the left coronary artery? | The left anterior descending artery (LAD) and the circumflex artery |
| How would you sum up the LAD and circumflex's coronary blood supply? | The LAD supplies the septum and anterior wall The Circumflex supplies the lateral wall. In left-dominant circulation, the Circ wraps around the AV groove and supplies most of the posterior septum and inferior wall |
| What are the two options for blood supply of the SA node? | In 60 percent of people, the RCA supplies blood flow to the SA node. In 40 percent of people, the LAD supplies blood flow. |
| What coronary arteries supply the Bundle of His? | A dual blood supply - the LAD and PDA |
| What are the two options for coronary blood supply of the AV node? | 85 to 90 percent of people have an AV node that's supplied by the RCA. 10 to 15 percent have one that's supplied by the circumflex. |
| What are the anterior papillary muscle of the mitral valve blood supply fed by? | 1. Diagonal branches of the LAD 2. Marginal branches of the circumflex. |
| What are the posterior papillary muscles supplied by? | The PDA alone. |
| Which is more prone to ischemic dysfunction: the anterior or posterior papillary muscles? Why? | The posterior papillary muscle; Because it only has one blood supply source. |
| What is the normal resting coronary blood flow? | 225 to 250 ml/minute |
| What are the two sources of blood flow to the muscles of the heart? | Inner 0.1 mm of endocardial surface is supplied by the blood in the heart chamber's. The largest portion is supplied by epicardial vessels, which are outer surface vessels that supply most of the muscle. |
| What are the subendocardial arteries? | They are plexus of vessels located immediately beneath the endocardium. |
| What makes coronary perfusion unique when compared with other organs? | `Coronary perfusion is intermittent. In other organs, it is continuous. |
| What happens to the left ventricle during contraction in regards to intramyocardial pressures? | The left ventricle's pressure approaches systemic arterial pressure. |
| What do you know about changes in flow during the cardiac cycle? | The coronary perfusion pressure is usually determined by the difference between aortic pressure and ventricular pressure, and the LV is perfused almost entirely during diastole |
| When is the Left ventricle mostly perfused? What about the right ventricle? | The left ventricle is perfused almost entirely during diastole. The right ventricle is perfused during both systole and diastole |
| Coronary blood flow is what percent of total cardiac output? | 5 percent |
| How do decreases in diastolic time affect flow? | Heart rate increases result in decreased coronary perfusion due to disproportionate reduction in diastolic time (% of cardiac cycle) as heart rate increases AKA: The faster the heart rate, the less diastolic (filling) time. |
| How is coronary perfusion determined? | Coronary perfusion is determined by the difference between aortic pressure and ventricular pressure. |
| In terms of myocardial blood flow, which is more important, aortic diastolic pressure or mean arterial pressure? | Aortic Diastolic Pressure (ADP) |
| What is the formula for calculating coronary perfusion pressure? | ADP - LVEDP = CPP. Decreases in Aortic Pressure or increases in ventricular end-diastolic pressure can reduce CPP. |
| Name the factors that control the demand of coronary blood flow. | 1. Basal requirements 2. Heart rate 3. Wall tension (A. Preload and B. Afterload) 4. Contractility |
| What is the most important determinant of myocardial blood flow? | Myocardial 02 demand (basal requirements) These includes basal requirements, electrical activity, volume work, and pressure work |
| What percentage of oxygen does the myocardium extract? How does this compare to other tissues? | The myocardium extracts 70 percent of oxygen. Usually, it is 25 percent in most tissues. |
| What is the coronary sinus oxygen saturation? | 30 percent |
| What happens when there is an increase in myocardial metabolic demand? | The myocardium can't extract more 02 from hemoglobin. Therefore increases in myocardial metabolic demand must be met by an increase in coronary blood flow. |
| Name the vasodilator substances that are released to increase coronary blood flow to the heart. | 1. Adenosine (because of ATP degradation) 2. Potassium ions 3. Hydrogen ions 4. Carbon dioxide 5. Bradykinin 6. Prostaglandins 7. Nitric oxide |
| How does the nervous system contribute to coronary blood flow? | The nervous system causes direct effects of acetylcholine from vagus nerves & sympathetic nerves secrete EPI and NE Indirect (most important): Offsetting the deleterious responses caused by Epi, NE, and acetylcholine (they cause increased metabolic requirements, to stimulate regulatory mechanisms) |
| What is the effect of aCh on coronary blood flow? | aCh release from the parasympathetic nerves produces coronary artery dilation. However, the parasympathetic nervous system effect is minimal (because there are few parasympathetic nerves in the autonomic system) |
| What do you know about the sympathetic innervation of the heart? | A1receptors: located in the epicardial vessels. Excess stimulation can produce vasospastic myocardial ischemia and angina. B1 receptors cause cardioacceleration & positive inotropy B2 Receptors are dilators and located mainly in smaller intramuscular & Subendocarial vessels |
| Tell me about the energy supply of the heart. | Fat metabolism is 70 percent of the heart's energy supply (body tissues are usually carbs) Glycolysis: Under ischemic conditions, cardiac metabolism will convert to anaerobic glycolysis |
| Tell me about the venous drainage of the heart | 1. Coronary sinus: Most of the venous blood flow returns from left ventricle to r. atrium by way of coronary sinus 2. |
| What does SAD stand for? What does it refer to? | Syncope, Angina, and Dyspnea. These are the most common symptoms of aortic stenosis. |
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