Treatments



Treatments









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Drug therapy





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▪ Antiarrhythmics

Antiarrhythmics are used to treat disturbances in normal heart rhythm and are grouped in one of four classes.





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Class

Features

Rhythms treated

Examples


I Sodium channel blockers

♥ Largest class


♥ Three subdivisions plus adenosine


♥ Decrease automaticity, conduction velocity, and membrane responsiveness

♥ IA: atrial and ventricular arrhythmias


♥ IB: acute ventricular arrhythmias


♥ IC: severe refractory ventricular arrhythmias


♥ Adenosine: paroxysmal supraventricular tachycardia

♥ IA: disopyramide (Norpace)


♥ IB: lidocaine


(Xylocaine)


♥ IC: flecainide (Tambocor)


II


Betaadrenergic blockers

♥ Slow automaticity of sinoatrial (SA) node


♥ Reduce conduction of atrioventricular (AV) node and pacer cells


♥ Decrease strength of contraction

♥ Atrial flutter and fibrillation


♥ Paroxysmal atrial tachycardia

♥ Atenolol (Tenormin)


♥ Metoprolol (Lopressor)


♥ Propranolol (Inderal)


♥ Carvedilol (Coreg)


♥ Nebivolol (Bystolic)


III Diverse group

♥ Mechanism of action poorly understood


♥ May slow repolarization


♥ May prolong refractory period

♥ Ventricular arrhythmias

♥ Amiodarone (Cordarone)


♥ Dofetilide (Tikosyn)


♥ Sotalol (Betapace)


♥ Ibutilide (Corvert)


IV Calcium channel blockers

♥ Decrease cardiac contractility and oxygen demand


♥ Dilate coronary arteries and arterioles

♥ Supraventricular arrhythmias with rapid ventricular response

♥ Diltiazem (Cardizem)


♥ Nifedipine (Procardia)


♥ Verapamil (Calan)




▪ Inotropic drugs

Inotropics increase the force of the heart’s contractions. There are two types:



  • digoxin (Lanoxin), which slows the heart rate and electrical impulse conduction through the SA and AV nodes


  • phosphodiesterase (PDE) inhibitors, which provide short-term management of heart failure or long-term management in patients awaiting heart transplant surgery. Two examples of PDE inhibitors are inamrinone and milrinone.





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▪ Antianginals

Antianginals relieve chest pain by reducing myocardial oxygen demand, increasing the supply of oxygen to the heart, or both. There are three main types:



  • nitrates (used primarily to treat acute angina)


  • beta-adrenergic blockers (prescribed for long-term prevention of angina)


  • calcium channel blockers (used when other drugs fail to prevent angina).





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How antianginal drugs work

When the coronary arteries can’t supply enough oxygen to the myocardium, angina occurs. This forces the heart to work harder, increasing heart rate, preload, afterload, and the force of myocardial contractility. Antianginal drugs relieve angina by decreasing one or more of these four factors.





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▪ Antihypertensives

Treatment for hypertension begins with modifying diet, encouraging exercise and, if indicated, counseling about weight loss. If these measures aren’t enough, drugs can help.





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Treating hypertension





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Antihypertensives and the RAAS

The renin-angiotensin-aldosterone system (RAAS) regulates the body’s sodium and water levels and blood pressure.

1 Juxtaglomerular cells near the glomeruli in each kidney secrete the enzyme renin into the blood.

2 Renin circulates throughout the body and converts angiotensino-gen, made in the liver, to angiotensin I.

3 In the lungs, angiotensin I is converted by hydrolysis to angiotensin II.

4 Angiotensin II acts on the adrenal cortex to stimulate production of the hormone aldosterone. Aldosterone acts on the juxtaglomerular cells to increase sodium and water retention and to stimulate or depress further renin secretion, completing the feedback system that automatically readjusts homeostasis.





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Adverse reactions of antihypertensive drugs

All



  • Headache


  • Fatigue


  • Angioedema


  • Gl reactions


  • Electrolyte imbalance (specific to drug used)

ACE inhibitors



  • Altered renal function when used with nonsteroidal anti-inflammatory drugs


  • Dry, nonproductive, persistent cough

ARBs



  • Transient elevations of blood urea nitrogen and serum creatinine levels


  • Cough


  • Tickling in throat

Direct renin inhibitors



  • Dizziness


  • Fainting


  • Diarrhea



Antilipemics

Antilipemics lower cholesterol, triglyceride, and phospholipid levels. They’re used in combination with lifestyle changes to decrease the risk of coronary artery disease (CAD).

Cholesterol absorption inhibitors



  • Lower total cholesterol levels


  • Example: ezetimibe (Zetia)

Nicotinic acid (niacin)



  • Water-soluble vitamin


  • Lowers triglyceride levels


  • Increases high-density lipoprotein (HDL) levels


  • Example: niacin (Niacor)





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Bile-sequestering drugs



  • Remove excess bile acids from fat deposits


  • Lower low-density lipoprotein (LDL) levels


  • Example: cholestyramine (Questran)

Fibric-acid derivatives



  • Lower triglyceride levels


  • Minimally increase HDL levels


  • Examples: fenofibrate (Tricor), gemfibrozil (Lopid)

HMG-CoA reductase inhibitors



  • Also known as statins


  • Lower total cholesterol and LDL levels


  • Minimally increase HDL levels


  • Examples: atorvastatin (Lipitor), simvastatin (Zocor), rosuvastatin (Crestor)


Anticoagulants

Anticoagulants reduce the blood’s ability to clot. They’re prescribed for mitral insufficiency or atrial fibrillation or to dissolve clots that block an artery.



























Category

Features

Examples


Heparins

♥ Used in patients with unstable angina, Ml, and deep vein thrombosis (DVT)


♥ Act immediately when given I.V.


♥ Available in regular and low-molecular-weight forms

♥ Heparin (Liquaemin) Low-molecular-weight


♥ Dalteparin (Fragmin)


♥ Enoxaparin (Lovenox)


Coumarin derivative

♥ Antagonizes production of vitamin K-dependent clotting factors


♥ Prevents DVT


♥ Used in patients who have undergone prosthetic heart valve surgery and those with diseased valves


♥ Given orally and takes days to reach effect

♥ Warfarin (Coumadin)


Antiplatelet drugs

♥ Prevent thromboembolism

♥ Aspirin


♥ Clopidogrel (Plavix)


Direct thrombin inhibitors

♥ Treat heparin-induced thrombocytopenia


♥ Used when heparin can’t be


♥ Prophylactically used before angioplasty and stent placement


♥ Available I.V.

♥ Argatroban


♥ Bivalirudin (Angiomax)


♥ Lepirudin (Refludan)


Glycoprotein llb/Ilia inhibitors

♥ Used in patients with unstable angina and before and during angioplasty


♥ Prevent platelets from binding together


♥ Available I.V.

♥ Abciximab (ReoPro)


♥ Eptifibatide (Integrilin)


♥ Tirofiban (Aggrastat)




Thrombolytics

Thrombolytics can dissolve a preexisting clot or thrombus in acute MI, ischemic stroke, or peripheral artery occlusion. They also can dissolve thrombi and reestablish blood flow in arteriovenous cannulas and I.V. catheters. In an acute or emergent situation, they must be administered within 3 to 6 hours after the onset of symptoms. Thrombolytics include alteplase (Activase), reteplase (Retavase), urokinase (Abbokinase), and tenecteplase (TNKase).


How thrombolytics help restore circulation

When a thrombus forms in an artery, it obstructs the blood supply, causing ischemia and necrosis. Thrombolytics can dissolve thrombi in the coronary and pulmonary arteries, restoring the blood supply to the area beyond the blockage.


Obstructed artery

A thrombus blocks blood flow through the artery, causing distal ischemia.


Inside the thrombus

The thrombolytic enters the thrombus and binds to the fibrin-plasminogen complex, converting inactive plasminogen into active plasmin. Active plasmin digests fibrin, dissolving the thrombus. As the thrombus dissolves, blood flow resumes.





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Treatments for CAD


Coronary artery bypass graft surgery

Coronary artery bypass graft (CABG) surgery relieves the symptoms of CAD and decreases risk of future heart attack or heart failure. Watch patients who have had CABG surgery for such complications as severe hypotension, decreased cardiac output, and cardiogenic shock.





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photo op


Performing CABG surgery

CABG surgery is performed either “on pump” (the traditional method) or “off pump” (also called the “beating heart method” or OPCAB). A technician monitors the heart-lung machine (cardio pulmonary bypass pump), shown below.





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The road to recovery

Here are the landmarks that you’ll want to look for on your patient’s postoperative CABG road to recovery.





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Minimally invasive direct coronary artery bypass

Minimally invasive direct coronary artery bypass (MIDCAB) is a less invasive surgical treatment for CAD. Because the procedure is minimally invasive, it results in shorter hospital stays, fewer post-operative complications, earlier extubation, reduced cost, smaller incisions, and an earlier return to work.


The MIDCAB procedure

MIDCAB is performed through several small incisions in the left chest cavity. The internal mammary artery is sewn to the left anterior descending artery in the front of the heart, as shown here. The patient receives only right lung ventilation and drugs to slow the heart rate and reduce heart movement during surgery.





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Comparing types of CABG


























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Related posts:

  1. Anatomy and physiology
  2. Complications
  3. ECC interpretation
  4. Common disorders

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Jun 7, 2016 | Posted by in CARDIOLOGY | Comments Off on Treatments

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Features

On-pump CABG

OPCAB

MIDCAB


Access site

♥ Breastbone severed for heart access

♥ Breastbone severed for heart access

♥ Incisions made between ribs for anterior heart access, no bones cut


Indications

♥ Suitable for multivessel disease, any coronary artery

♥ Suitable for multivessel disease, any coronary artery

♥ Only used for one-vessel diseases in anterior portions of heart, such as left anterior descending artery, or some portions of the right coronary and circumflex arteries


Graft types

♥ Combination of artery and vein grafts

♥ Combination of artery and vein grafts

♥ Arterial grafts (better long-term results)


Complications

♥ Highest risk of postoperative complications

♥ Reduced blood usage, fewer rhythm problems, less kidney dysfunction than on-pump CABG