Hello and welcome back to InterpreterPrep.com THE CARDIOVASCULAR SYSTEM-PART 2 In this second presentation on the CARDIOVASCULAR SYSTEM we're going to be covering diagnostic procedures and treatments used to study and treat the diseases of the cardiovascular system. SOME DIAGNOSTIC PROCEDURES 1) BLOOD PRESSURE MONITORING: it can be done at the doctor's office or at home using a self-monitoring device. As we mentioned before anything over 140/90 is considered high blood pressure. Readings that are close to but not quite that high are considered PREHYPERTENSION. 2) ELECTROCARDIOGRAPHY: is the study of the electrical activity in the heart done by placing 10 ELECTRODES on the body: one on each extremity and 6 on the chest. Used to diagnose arrhythmia, ischemia and a heart attack. These disorders change the form and/or intervals of the heart waves seen on the ELECTROCARDIOGRAM (EKG). 3) CHEST X-RAY: which we already mentioned when we talked about heart failure. 4) CARDIAC STRESS TEST: at times the doctor orders that an EKG be obtained while the patient is doing some exercise like walking on a treadmill for example. Because the exercise increases the heart's need for oxygen it can detect ischemia that was not seen on a resting EKG. At other times the patient will be sent home wearing an ambulatory electrocardiography device known as a: 5) HOLTER MONITOR: which continuously records the heart's electrical activity. Like a 24 hour EKG. It may be worn up to 2 weeks. 6) ECHOCARDIOGRAPHY: is the name given to an ultrasound study of the heart. It creates images of the heart using sound waves and provides information about the walls of the heart (i.e. wall thickness), the valves and on how well it's pumping. The image provided by this study is called an ECHOCARDIOGRAM. DOPPLER ULTRASOUND, which uses the Doppler Effect, is used to provide information on blood flow or abnormal communication between the heart chambers. It is also very useful to study the vasculature (carotid arteries for example). 7) CORONARY ANGIOGRAPHY: is a diagnostic procedure done using a catheter that is introduced through an artery in the arm or groin. This is done under fluoroscopy (which permits real time x-ray imaging). When the catheter reaches the coronaries, contrast is injected which makes any area of stenosis in the coronaries visible. Angiography is also done to study the vasculature of the legs or the brain for example. The image produced by this study is
called an ANGIOGRAM. 8) NUCLEAR VENTRICULOGRAPHY: for this study a radioactive tracer (TECHNETIUM 99) is injected into the bloodstream and then images of the heart are obtained using a scanner known as a GAMMA CAMERA. It shows the flow of blood through the heart chambers and indirectly indicates how well the ventricles are pumping. When an infarction has taken place or there is ischemia the sick ventricle doesn't pump well and this can be seen with this study. When further information is necessary a : 9) NUCLEAR STRESS TEST is done. A different radioactive tracer is injected-which is absorbed by the live heart cells but not picked up by dead ones. This test measures blood flow into the heart muscle both at rest and while doing exercise. By looking at the images formed, doctors can detect the presence of low blood flow (ischemia) or damaged heart cells (infarction). In contrast to angiography, these studies (the nuclear ventriculography and the nuclear stress test) have the advantage of being NON-INVASIVE. And I'd like to mention that when radioactive substances are used for treatment or diagnostic purposes this belongs to the field of NUCLEAR MEDICINE. 10) CARDIAC EMZYMES: CPK-MB TEST: CPK (MB) is an enzyme found in the heart muscle which increases in blood after a heart attack. TROPONIN TEST: troponins are heart proteins that also increase after a heart attack. The dosing of these cardiac enzymes is included in the work-up of patient with acute chest pain. 11) LIPID PROFILE : cardiologists like to order blood tests for TOTAL CHOLESTEROL TRYGLICERIDES, and LDL and HDL CHOLESTEROL (this last one: the HDL is also known as good cholesterol as it scavenges off the LDL that is the bad cholesterol). This profile is used to determine the risk of developing heart disease. 12) SWAN-GANZ CATHETER: also known as a pulmonary catheter, the Swan-Ganz is a catheter that has a balloon on its tip. It goes in through a large vein like the JUGULAR, the one Dracula likes most, and reaches the right side of the heart where doctors can measure the blood pressure in the pulmonary artery, the central venous pressure, etc. which are all very useful in the management of a patient who is in shock or had a severe heart attack. SOME TREATMENTS 1) CARDIOPULMONARY RESUSCITATION (CPR): sometimes treatment starts outside the hospital with CPR. Chest compressions are done at a rate of about 100 per minute (to the beat of the song Staying Alive by the Bee Gees for example) and rescue breaths are also performed until the PARAMEDICS arrive with a DEFIBRILLATOR.
2) DEFIBRILLATION: is the application of an electrical shock to the heart to get it out of fibrillation and re-set it back to a normal heartbeat called SINUS RHYTHM. It's sort of like jump starting the heart. Also used electively to treat atrial fibrillation where the electrical shock is given at a specified moment of the cardiac cycle and is called CARDIOVERSION. 3) DRUGS USED IN CARDIOLOGY: I'll just go over a few: -TO TREAT HIGH BLOOD PRESSURE: we have 3 drug groups commonly prescribed to treat high blood pressure DIURETICS: commonly known as water pills because these drugs make people urinate. An example of a diuretic is : HYDROCLOROTHIAZIDE (HCTZ) BETA BLOCKERS: these block beta receptors and that slows the heart, an example of a beta blocker is: ATENOLOL ACE INHIBITORS (ACEI): which block the formation of a substance that causes the arteries to constrict elevating blood pressure. A typical example of an ace inhibitor is ENALAPRIL. This group of drugs all end in pril. -TO TREAT HEART FAILURE: here we have DIGOXIN which strengthens the heart s ability to pump blood. It's to the heart what spinach was to Popeye! -TO TREAT ARRHYTHMIAS- there are way too many drugs in this category which include: ANTIARRHYTHMICS like: AMIODARONE and FLECAINIDE for example. CALCIUM BLOCKERS: calcium blockers block access to calcium and since the SA and AV nodes need calcium to generate electrical impulses, calcium blockers like VERAPAMIL are useful to treat arrhythmias. -TO PREVENT CLOTS: doctors prescribe ANTICOAGULANTS like: WARFARIN ( better known by its commercial brand name: Coumadin which is taken by mouth in contrast to HEPARIN which is administered by injection only. Vitamin K is the antidote to warfarin OVERDOSE These drugs mentioned are used to prevent clots in veins. We have other drugs used to prevent clots in arteries called ANTIPLATELET AGENTS like: ASPIRIN: that's why they say to start chewing an aspirin while waiting for the paramedics to come during a heart attack. CLOPIDOGREL (bka Plavix ) -HYPOLIPIDEMICS: These drugs are used to reduce cholesterol in blood for example: ATORVASTATIN bka Lipitor and SIMVASTATIN which both belong to a group of drugs known as STATINS.
And before we close here with drugs: I just want to mention a group of drugs used in the CORONARY CARE UNIT to treat a heart attack by trying to dissolve the clot in the coronaries. These clot buster drugs are called: FIBRINOLYTICS. An example of this type of drug is: STREPTOKINASE. At other times a patient will need invasive treatment like: 4) PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY (PTCA): This procedure is done using a catheter similar to an angiography and is often done at the same time. A little coiled tube called a STENT is placed into the coronary to dilate it and restore blood flow. At other times the patient's coronaries may be in very bad shape and a 5) CORONARY ARTERY BYPASS GRAFT (CABG): is needed. In this case the surgeon bypasses the blockages in the coronaries to restore blood flow by using an artery like we see there on the right or a vein called the SAPHENOUS VEIN harvested from a leg, like we see on the left of the image. Angioplasty and Bypass surgery both aim to restore the flow of blood to the heart so they are both REVASCULARIZATION techniques. Now when there's a problem inside the heart, like a valve that needs to be replaced then they do what's called: 6) OPEN HEART SURGERY: where the chest and heart is cut open and the damaged valve is replaced by a mechanical PROSTHETIC VALVE or a biological valve harvested from pigs. 7) HEART VALVE REPAIR (VALVULOPLASTY): we have already mentioned before that plasty means to surgically repair or replace something, in this case valvuloplasty refers to the widening of a stenotic valve using a BALLOON CATHETER (a catheter that has an inflatable balloon on its tip). The balloon is inflated to dilate the stenotic valve. 8) PACEMAKER: a pacemaker looks like this. It's a medical DEVICE that delivers electrical impulses to the heart in order to speed up the HEART RATE when it's too slow due to a heart block. The pacemaker has a long electrode that is placed into the heart through a vein. The pacemaker itself is implanted below the skin and here in this Chest X-ray we see the pacemaker highlighted in pink and then if you look closer you will see the electrode (which looks white cable there) going into the heart. 9) PERICARDIOCENTESIS: if the pericardium fills with a lot of fluid, the procedure used to remove that fluid (effusion) is called a pericardiocentesis. 10) COMPRESSION STOCKINGS: which are indicated to help improve the blood flow in the legs of patients who suffer from varicose veins. The doctors who specialize in diseases of the cardiovascular system are CARDIOLOGISTS and CARDIOVASCULAR SURGEONS. The medical specialties that treat the diseases of the cardiovascular system are CARDIOLOGY and CARDIOVASCULAR SURGERY.
In this presentation we have gone over many terms related to CARDIOLOGY and CARDIOVASCULAR SURGERY while we discussed some diagnostic procedures and treatments used to diagnose and treat diseases of the CARDIOVASCULAR SYSTEM. I hope you've enjoyed this lesson and come away with a better understanding of the fields of CARDIOLOGY AND CARDIOVASCULAR SURGERY and the terms related to these fields of medicine. Thank you for choosing InterpreterPrep.com