CCC1 - Perfusion

What is perfusion?

The flow of blood through arteries and capillaries delivering oxygen and nutrients to cells $

What is central perfusion?

The force of blood movement generated by cardiac output $

What three things are required for adequate central perfusion?

Adequate cardiac function, blood pressure, and blood volume $

What is the formula for cardiac output?

Cardiac Output = Stroke Volume × Heart Rate $

What is stroke volume?

The amount of blood ejected from the ventricle with each heartbeat $

What three factors affect stroke volume?

Preload, afterload, and contractility $

What is preload?

The degree of stretching of the ventricular muscle at the end of diastole $

What is afterload?

The resistance or pressure the ventricle must overcome to eject blood into circulation $

What is contractility?

The force the myocardium generates during contraction $

What is tissue (local) perfusion?

The volume of blood that flows to a specific tissue $

What is required for adequate tissue perfusion?

Patent vessels, adequate hydrostatic pressure, and proper capillary permeability $

What causes impaired central perfusion?

Inadequate cardiac output $

What happens when cardiac output decreases?

Reduced oxygenated blood reaches body tissues $

What severe condition can occur with extreme impaired central perfusion?

Shock $

What can happen if impaired central perfusion is untreated?

Ischemia, cell injury, and cell death $

What causes impaired tissue (local) perfusion?

Loss of vessel patency, abnormal permeability, or inadequate central perfusion $

What happens when tissue perfusion is impaired?

Reduced blood flow to specific tissues $

What is a major consequence of untreated impaired tissue perfusion?

Ischemia and cell death $

What are signs of inadequate central perfusion in infants?

Poor feeding, poor weight gain, failure to thrive, and dusky color $

What are signs of inadequate central perfusion in toddlers and children?

Squatting, fatigue, and developmental delays $

What cardiac enzyme indicates heart muscle damage?

Troponin $

What lab marker is associated with inflammation and cardiovascular risk?

C-reactive protein (CRP) $

What lab tests evaluate blood clotting?

Prothrombin time (PT), partial thromboplastin time (PTT), and INR $

What diagnostic test records the electrical activity of the heart?

Electrocardiogram (EKG) $

What is the purpose of a cardiac stress test?

To evaluate heart function during exercise or pharmacologic stress $

What radiographic tests can evaluate perfusion problems?

Chest X-ray, ultrasound, and arteriogram $

What are common lifestyle interventions to improve perfusion?

Diet modification, smoking cessation, and increased physical activity $

What medications treat abnormal heart rhythms in impaired central perfusion?

Antiarrhythmics $

What are examples of antiarrhythmic medications?

Flecainide, procainamide, amiodarone, and sotalol $

What medications increase cardiac contractility and blood pressure in perfusion problems?

Inotropics or vasopressors $

What are examples of vasopressors or inotropics?

Dopamine and norepinephrine $

What medications help relieve chest pain by dilating blood vessels?

Antianginal agents or vasodilators $

What is a common antianginal medication used for chest pain?

Nitroglycerin $

What are examples of nitrate medications used for angina?

Nitro-Bid, Nitro-Dur, and Isosorbide dinitrate $

What medications prevent blood clot formation in impaired tissue perfusion?

Anticoagulants $

What are examples of anticoagulant medications?

Warfarin (Coumadin), Heparin, Lovenox, and Xarelto $

What medications dissolve existing blood clots?

Thrombolytics $

What are examples of thrombolytic medications?

Alteplase, reteplase, tenecteplase, urokinase, and lanoteplase $

What class of medications lowers cholesterol and plaque buildup in arteries?

Lipid-lowering agents (statins) $

What are examples of statin medications?

Atorvastatin, rosuvastatin, simvastatin, and pravastatin $

What medications prevent platelet aggregation?

Antiplatelet agents $

What are examples of antiplatelet medications?

Aspirin, clopidogrel (Plavix), and dipyridamole (Persantine) $

What collaborative interventions treat impaired central perfusion?

Pacemaker insertion, cardioversion, ablation therapy, intra-aortic balloon pump, valve surgery, and heart transplant $

What procedures treat impaired tissue perfusion caused by blocked arteries?

Bypass surgery, graft surgery, angioplasty, stent placement, and endarterectomy $

What memory trick helps remember ECG lead placement for the right clavicle?

White on the right $

What memory trick helps remember ECG lead placement for the lower rib cage?

Snow on the grass (green on bottom) $

What memory trick helps remember ECG lead placement on the left side?

Smoke over fire (black above red) $

Where is lead V1 placed?

4th intercostal space to the right of the sternum $

What does the P wave represent on an ECG?

Atrial depolarization (atrial contraction) $

What is the normal PR interval?

0.12–0.20 seconds $

What does the QRS complex represent?

Ventricular depolarization $

What is the normal QRS duration?

0.08–0.12 seconds $

What does the T wave represent?

Ventricular repolarization $

What can abnormal T waves indicate?

Cardiac distress such as myocardial infarction or valve problems $

What heart rate defines sinus bradycardia?

Less than 60 beats per minute $

What are causes of sinus bradycardia?

Sleep, vagal stimulation, hypothyroidism, increased intracranial pressure, and medications $

What treatments may be used for sinus bradycardia?

Treat underlying cause, medications, or transcutaneous pacing $

What heart rate range defines sinus tachycardia?

100–160 beats per minute $

What are common causes of sinus tachycardia?

Exercise, excitement, heart failure, hypovolemia, hyperthyroidism, caffeine, nicotine, and nitrates $

What is the treatment for sinus tachycardia?

Treat the underlying cause $

What are premature ventricular contractions (PVCs)?

Early ventricular beats that create an irregular rhythm $

How does a PVC appear on ECG?

Wide, bizarre QRS complex $

Are occasional PVCs dangerous in healthy individuals?

Usually not $

Who is at higher risk for complications from PVCs?

Patients with heart disease $

What are common causes of PVCs?

Heart disease, electrolyte imbalance, alcohol or drugs, stress, exercise, and caffeine $

What is bigeminy?

A PVC occurring every other beat $

What is trigeminy?

A PVC occurring every third beat $

What is junctional rhythm?

Electrical impulse originates from the AV node instead of the SA node $

What ECG feature is missing in junctional rhythm?

P waves $

What heart rate is commonly seen with junctional rhythm?

Usually less than 60 beats per minute $