Cardiac System-

• Pulsus alternans


  Regular rhythm with strong pulse waves alternating with weak pulse waves
• Pulsus alternans

  Indicates left ventricular failure when present at normal heart rates
• Bigeminal pulses


  Every other pulse is weak and early
• Bigeminal pulses


  Result of premature ventricular contractions (bigeminy)
• Pulsus paradoxus


  Reduction in strength of the pulse with an abnormal decline in blood pressure during inspiration
• Causes of pulsus paradoxus

  • Chronic obstructive lung disease (COPD)
  • Pericarditis
  • Pulmonary emboli
  • Restrictive cardiomyopathy
  • Cardiogenic shock
• Cardiac output


  The amount of blood pumped/discharged from the L ventricle per minute

  CO = HR x SV
• Cardiac index - Heart performance

  The amount of blood pumped per minute per square meter of body mass. Relates heart performance to the size of the individual.

  -Useful marker of how well the heart is.

  -Better used in critical setting

  CI = CO/body surface area
• Normal Cardiac Index is between 2.5 and 4.2 L/min. A Cardiac Index <2.5 L/min represents a marked disturbance in cardiovascular performance and is always clinically relevant.
• ESV: 50 ml

  EDV: 120 ml
• R Coronary Artery Supplies:

  • Right atrium
  • Most of Right ventricle
  • SA node (60% of the population)
  • AV node
  • Bundle of His
• LADA Supplies:

  • Anterior wall of the Left and Right ventricle
  • Interventricular septum
  • Inferior areas of apex
• Circumflex artery Supplies:

  • Lateral wall of the Left ventricle
  • Inferior wall of the Left ventricle
  • Left atrium
  • SA node (40% of the population)
• KOROTKOFF SOUNDS

  1 - faint tapping sound with increasing intensity

  2 - swishing sound (murmur)

  3 - increasing intensity with distinct tapping (crisp, louder)

  4 - sounds become muffled (blowing) - Diastolic pressure in children <13 y.o., adults who are exercising, pregnant or hyperthyroid

  5 - disappearance

  
  

  SBP - 1

  DBP - 4 & 5
• HEART SOUNDS

  S1 - systole, AV valves close

  S2 - diastole, SL valves close

  S3 - physiological heart sound in normal young adults; CHF

  S4 - CABG, HTN, MI, pulmonary disease, coronary heart disease

  Murmurs - mitral regurgitation and aortic stenosis
• Frank Starling Law - the greater the diastolic filling, the greater the quantity of blood pumped out.
• Preload is the amount of stretch on the myocardium during diastole or amount of blood left in the ventricle at the end of diastole.
• Contractility refers to the strength of contraction by the cardiac muscle. If weak contraction (Ex. CHF) -> low SV
• Afterload is the resistance to ejection from the left ventricle into the systemic circulation. Needs to generate 80 mmHg force during systole to overcome aortic pressure to open aortic valve.

  Has an inversely proportional relationship with SV
• Stroke Volume is influenced by 3 factors: Preload, Contractility, and Afterload
• Ejection Fraction - important for LV function

  =SV/LV EDV

  The lower the EF, the more impaired the LV
• Myocardial Oxygen Demand (MVO2) - increases with activity and with HR and BP

  RPP: (SBP X HR)
• The sympathetic and parasympathetic control is located in the medulla oblongata
• Sympathetic control

  Via T1-T4, upper thoracic to superior cervical ganglia

  Parasympathetic control

  via vagus nerve, cardiac plexus
• Sympathetic releases Epinephrine and Norepinephrine

  Parasympathetic releases Acetylcholine
• Baroreceptors/Pressoreceptors

  Location:

  walls of aortic arch and carotid sinus

  • main mechanism in controlling HR

  • excited by stretch of the blood

  vessel
• Chemoreceptors

  Location: carotid and aortic bodies

  Sensitive to changes of:

  O2, CO2 and lactic acid

  Ex:

  Decreased PH

  Increase CO2

  Decreased O2

  =Increased HR
• Difficulty breathing in:

  Orthopnea - supine

  Platypnea - upright

  Tropopnea - sidelying

  "SOPUTS"
• When taking the Heart Rate

  Routine Monitoring: Radial, Apical

  Emergency

  ▪ Adult – Carotid, Radial, Femoral

  ▪ Infant – Brachial, Femoral
• Partial Pressure of Oxygen

  A) 80-100

  B) >100

  C) <80

  D) <55

  E) 50-60

  
• BLOOD PRESSURE

  ➢DO NOT APPLY BP CUFF:

  1. IV line, AV shunt (arteriovenous shunt)
  2. Side where breast and axillary surgery has been performed
  3. Arm traumatized or diseased
  4. Axillary node dissection
• Pulse Pressure - Index of vascular aging

  N: 40 mmhg

  PP = SBP-DBP
• The right hemidiaphragm is protected by the liver.
• The right hemidiaphragm is stronger than the left
• The left hemidiaphragm is more often subject to rupture and hernia.
• Pulsus paradoxus - a pulse that fades during inspiration and strengthens during expiration. Usually seen in COPD and constrictive pericarditis patients
• Pulsus Alterans - A pulse with two beats that occur in rapid succession
• Bigeminal pulses - A pulse with fluctuation in amplitude between beats
• Normal pulse - A pulse that increases during inspiration and decreases with expiration
• PLATELET LEVELS

  >150k

  • Normal

  50k-150k

  • Progressive resistive exercises (as tolerated)
  • Swimming
  • Sexual intercourse
  • Low bench stepping
  • Bicycling (no grade; flat only)

  20k-50k

  • AROM exercise
  • Moderate exercise; light weights
  • Stationary bicycling
  • Walking as tolerated; no prolonged stretching
  • Aquatic therapy

  10k-20k

  • Light exercise; no resistive training; avoid valsalva
  • AROM exercise only
  • Walking as tolerated (guard carefully especially on stairs)
  • Aquatic therapy with physician approval

  <10k

  • No exercise or AROM
  • restricted to ADLs
  • Walking with physician approval