CIRCULATION STUDY GUIDE

• Atrial kick


  Increase force generated by the atria during contraction
• Cardiac output


  Amount of blood ejected from the left ventricle each minute
• Stroke volume


  Amount of blood ejected from the left ventricle with each contraction
• Ejection fractions


  Measurement expressed as % of blood that the left ventricle pumps out during contractions
• Preload


  The end diastolic volume
• Afterload


  Resistance to left ventricular ejection
• Myocardial contractility


  Affects stroke volume and cardiac output
• Semilunar valves


  Valve at the base of the aorta
• AV valves


  Separate the atria from the ventricles
• SA node


  A cluster of myocytes with pacemaker activity
• AV node


  Located in Koch triangle [1] near coronary sinus
• ECG


  Reflects the electrical activity of the conduction system
• ECHO


  Scan used to look at the heart and nearby blood vessels
• Dyspnea


  Clinical sign of hypoxia
• Edema


  Swelling cause by excess fluid
• Dysrhythmia


  A deviation in an otherwise normal sinus heart rhythm
• Atrial fibrillation (A. Fib)


  Common dysrhythmia in older persons, has unpredictable conduction of ventricles
• Ventricular tachycardia


  Life threatening rhythms that need medical attention because of decreased output
• Hypertrophy


  Increase in muscle size
• Hypertension


  High blood pressure
• Primary hypertension


  No identifiable cause of high blood pressure
• Secondary hypertension


  High blood pressure caused by another medical condition
• Myocardial ischemia


  Supply of blood to myocardium from coronary arteries is insufficient to meet O2 needs of organ
• Myocardial infarction (MI)


  Results from sudden decrease in coronary blood flow
• Angina


  Chest pain/discomfort in the heart that does not get enough oxygen rich blood
• Acute coronary syndrome (ACS)


  Imbalance between O2 supply and demand to the myocardium
• Murmur


  Blowing whooshing or rasping sound during a heartbeat
• CAD (coronary artery disease)


  Coronary arteries struggle to send enough blood, oxygen and nutrients to the heart muscles
• Asystole


  Lethal rhythm associated with no apparent electrical signals
• Tachycardia


  High heart rate
• Bradycardia


  Slow heart rate
• Blood flow through the heart and lungs

  1. Pulmonary Circuit: blood flows through right atrium to right ventricle through pulmonary trunk to arteries to carry blood to lungs to become oxygenated then pumped back to the heart

  2. Systemic Circuit: blood returned to left atrium pumped to left ventricle and out to the body
• Frank-Starling's law of the heart


  Mandates that the heart is able to match cardiac ejection tot the dynamic changes occurring in ventricular filling and thereby regulates ventricular contraction and ejection
• S1 sound (aka "lub") and the S2 sound (aka "dub")

  1. Lubb: atrioventricular (mitral and tricuspid) valves closing

  2. Dubb: closure of semilunar valves
• Myocardial perfusion occurs during which cardiac phase
• The AV valves are located between the atria and the ventricles
• The semilunar valves are located at the connections between he pulmonary artery and the right ventricle and the aorta and the left ventricle
• Importance of the left ventricle (LV)

  Because it connects and send blood to all the organ systems in the body
• How CO might be affected in older persons

  Age-related Changes in Heart Structure and Function, reduced heart rate response, increased preload and afterload
• Factors that influence preload and afterload


  Changes to the heart, body fluid volume and blood vessels