Chapter 11 Part II: Cardiovascular System Flashcards
Heart: Arrhythmias / dysrhythmias
• Heart block (atrioventricular block)
• Flutter
• Fibrillation
Examples of cardiac arrhythmias: Bradycardia (slow HR) and heart block (atrioventricular / AV block)
Improper conduction of impulses from SA node through AV node to AV bundle?
- SA node damage with weak impulses?? Can result in bradycardia with “skipped” heartbeats. If no impulse reaches AV node, then we have a complete “AV block” that can also result in Rt and Lt bundle branch block (RBBB, LBBB).
- Implantation of cardiac pacemaker.
Examples of cardiac arrhythmias: Flutter
Rapid but regular contraction, usually in the atria.
- May reach 300 BPM
- Tx includes meds, cardioversion
Examples of cardiac arrhythmias: Fibrillation
Very rapid, random, inefficient and irregular contractions of the heart (350 BPM or more).
- Atrial fibrillation (AF, “A fib”): most common arrhythmia, 5-10% in 70-80 YO or >15% in 80 YO’s.
- Pt experiences palpitation (uncomfortable sensations in the chest) that can be paroxysmal or permanent.
Examples of cardiac arrhythmias: Ventricular fibrillation
- Electrical impulses move randomly throughout the ventricles.
- Can be life-threatening and result in sudden cardiac death or cardiac arrest.
- Treat with meds (digoxin, beta-blockers and calcium channel blockers) or if urgent, defibrillation.
Examples of cardiac arrhythmias: Ventricular fibrillation
Implantable cardioverter-defibrillator (ICD)
Implanted inside the chest to sense arrhythmias and terminate them with a shock.
Ventricular Tachycardia
Ventricular rate may be as high as 250 beats per minute. The rhythm is regular, but the atria are not contributing to ventricular filling and blood output is poor.
Ventricular Fibrillation
Notice the abnormal, irregular waves. Ventricles in fibrillation cannot pump blood effectively. Circulation stops and sudden cardiac death follows if fibrillation is not reversed.
Congenital heart disease:
- Coarctation of the aorta (CoA)
- Patent ductus arteriosus (PDA)
- Septal defects (ASD and VSD)
- Tetralogy of Fallot
Contraction of the aorta (CoA)
Localized narrowing of the aorta reduces the supply of blood to the lower part of the body.
Patent ductus arteriosus (PDA)
The ductus arteriosus fails to close after birth, and blood from the aorta flows through it into the pulmonary artery.
Ductus Arteriosus ————>
Ligamentum Arteriosum
Congenital
Born with it.
Septal defect
• Small holes in the wall b/w the atria (atrial septal defect, ASD) or the ventricles (ventricular septal defect, VSD)
- If the holes do not close spontaneously, will require an open heart surgery with a heart-lung machine.
Ventricular septal defect
A hole in the ventricular septum causes blood to flow from the left ventricle to the right and into the lungs via the pulmonary artery.
Congestive heart disease (CHF)
The heart is unable to pump the required amount of blood.
• In the U.S., primarily the result of high blood pressure and coronary artery disease.
• Symptoms include pulmonary edema (fluid accumulation in the lungs), swelling/edema in the legs, feet and ankles.
• Tx includes: meds including diuretics to promote fluid loss, lifestyle modification (less Na intake, diet control) or surgery if others fail.
Pulmonary circulation
- Blood picks up oxygen; blood loses carbon dioxide.
- Blood flow from the heart to lung capillaries and back to the heart.
Systemic circulation
- Blood loses oxygen to cells; blood picks up carbon dioxide.
- Blood flow from the heart to tissue capillaries and back to the heart.
Coronary artery disease (CAD): Atherosclerosis
Plague formation inside of the coronary vessels.
- Thrombotic occlusion (occlusive/mural): obstruction of the vessels through blood clots.
- Ischemia: Blood being held back from reaching the target tissue.
(Zone of ischemia, down to the Zone of injury, down to the Zone of infarction)
- Necrosis: Heart muscle does not receive enough oxygenation and so it starts to die.
- Infarction: once the heart muscle is dead.
Coronary artery disease (CAD): Acute Coronary Syndromes (ACS)
Chest pain because you are exerting.
- Unstable angina: chest pain is very unpredictable.
- Myocardial infarction (MI): permanent death of the myocardium.
Coronary artery disease (CAD): Drug therapies for CAD
- Nitrates (nitroglycerin): take when you experience chest pain, very quick acting and very effective vasodilator. (Take orally under the tongue).
- Aspirin: after you have a heart attack, they ask you to take it for the rest of your life. It can help prevent the blood clot formation.
- Beta-blockers
- ACE inhibitors
- Calcium channel blockers
- Statins: the anti-cholesterol medication that they often prescribe to patients who have already had a heart attack with high cholesterol levels.
Coronary artery disease (CAD): Surgical therapies for CAD
- Coronary artery bypass grafting (CABG): if the stent is not successful they create a bypass to get blood from one point to another.
- Percutaneous coronary intervention (PCI): insert catheter into the aorta in the heart and in a vessel that is obstructed. Then they inflate the balloon to open up the obstructed vessel and leave a metal stent inside the obstructed coronary vessel to keep the vessel open.
Other pathologic conditions:
• Endocarditis (vegetations): inflammation of the endocardium. Inflamed with abnormal vegetations.
• Hypertensive heart disease
• Mitral valve prolapse (MVP)
• Murmur
• Pericarditis
• Rheumatic heart disease
Hypertensive heart disease
HTN or high BP due to increased resistance in the arteries (narrowing, atherosclerosis, etc) resulting in left ventricular hypertrophy (LVH)
Mitral valve prolapse (MVP)
Mitral valve enlarges and prolapses into L. atrium causing mitral regurgitation (blood flowing backwards) during systole. Doctor can hear a mid-systolic click upon auscultation. Can live normal lives.
Murmur
Extra heart sound, heard between normal beats due to valvular defects or disease that disrupts the smooth blood flow in the heart.
- Bruit: abnormal sound heard on auscultation.
- Thrill: vibration felt upon palpation.
Pericarditis
Inflamed pericardial membrane surrounding the heart, often linked to pulmonary infection, bacterial/viral or idiopathic, can hear friction rub (cardiac tamponade: compression of the heart by pericardial fluid), antibiotics if needed.
Rheumatic heart disease
Heart disease caused by rheumatic fever (a childhood disease following a streptococcal infection), heart valves can be inflamed and scarred (with vegetations) so they do not open/close normally leading to many heart conditions.
Rheumatic valvulitis
Small vegetations are visible along the line of closure of the mitral valve leaflet. Previous episodes of rheumatic valvulitis have caused fibrous thickening and fusion of the chordae tendineae of the valves.
Xenograft valve
Tissue that is transferred from an animal of one species (pig) to one of another species (human).
Blood vessels
• Aneurysm
• Deep vein thrombosis (DVT)
• Hypertension (HTN)
• Peripheral vascular disease (PVD)
• Raynaud disease
• Varicose veins
Abdominal Aortic Aneurysm
A dissecting aortic aneurysm is splitting or dissection of the wall of the aorta by blood entering a tear or hemorrhage within the walls of the vessel. Therefore, a bifurcated synthetic graft is put in place.
Berry Aneurysm
Inside the brain tissue, cerebral vessel is severely dilated. If it were to rupture, the patient would have a severe hemmoragic stroke as a result.
Deep vein thrombosis (DVT)
Blood clot (thrombus) forms in a large vein, usually in the leg, if breaks off, can result in a pulmonary embolism, treated with anticoagulant (blood thinner) such as heparin.
HTN (BP greater than 140/90 mm Hg)
Essential (idiopathic, primary, unknown cause) vs. secondary (identifiable cause or renal medical condition)
Varicose veins
Abnormally swollen and twisted veins, usually occurring in the legs, called hemorrhoids if near the rectum.
Failure of valves and pooling of blood in superficial veins.
Hemorrhage: Ecchymosis / Ecchymoses
Big bruise / multiple big bruises
Hemorrhage: Petechia / petechiae
Tiny pin point hemorrhages (multiple small pin point hemorrhages)
Allograft
Heart valve can come from another person (the same species).
Autograft
Tissue from within yourself.
Thrombus
One blood clot.
Thrombi
Multiple blood clot formations.
Thrombosis
Medical condition of blood clot forming.
Embolus
The moving blood clot.
Emboli
Multiple moving blood clots.
Embolism
Condition of presenting a moving blood clot or two.
Thromboembolism
Obstruction of a blood vessel by a blood clot that has become dislodged from another site in the circulation.
