Cardiovascular System Anatomy

Anatomy Review

• The heart has three layers: the pericardium, the myocardium, and the endocardium.

Blood Flow

• Blood flow throughout the cardiac valves is essential to heart function.

Understanding Blood Pressure

• During diastole, the ventricles are relaxed
• During systole, the ventricles are contracted

Cardiac Output

• Cardiac output (CO) is the amount of blood pumped in one minute.
• CO = Stroke Volume (SV) x Heart Rate (HR)

Stroke Volume

• Stroke volume is the amount of blood pumped from the heart with each contraction.
• Stroke volume is influenced by preload, afterload, contractions, compliance, and contractility.

Electric Conduction

• The SA Node causes contractions of the atria
• Next, the AV node passes the impulse through bundle branches
• Finally Purkinje fibers cause ventricular contractions.

ECG - PQRST Waves

• ECGs use PQRST waves to trace electrical activity.

Cardiac Examination

• Physical cardiac examination includes specific steps and observations.
• Inspect the jugular vein for distention.
• Auscultate then palpate the carotid arteries.
• Inspect the pulsations on the anterior chest.
• Palpate the apical pulse.
• Palpate for abnormal pulsations.
• Auscultate for S1 and S2 heart sounds, plus any extra heart sounds.
• Auscultate for murmurs.
• Examine the lower extremities and pulses.
• Assess the patient's general appearance, skin color, and breathing effort via inspection and assessment.
• Palpate the temporal pulse.
• Listen for bruits with the bell of the stethoscope.
• Palpate the carotid artery.

Pulses - Rate, Rhythm and Contour

• Pulse rhythm should have equal spacing between beats.
• Pulse contour should be smooth and rounded.
• Pulse amplitude is rated from 0+ (absent) to 4+ (full volume, bounding hyperkinetic)

Specialized Palpations

• Examine the anterior chest wall for abnormal pulsations
• Palpate for the apical pulse and location
• Palpate for abnormal pulsations, thrills and heaves.

Heart Sounds

• Auscultate heart sounds S1 & S2 for rate, rhythm, pitch, and splitting.
• Use the diaphragm of the stethoscope first, then the bell.
• Reposition the patient as needed.

Heart Sound Locations

• Aortic auscultation region is at the Right 2nd intercostal space at the sternal border (2 ICS PSL)
• Pulmonic sounds are best heard at the Left 2nd intercostal space at the sternal border (2 ICS PSD).
• The tricuspid valve is examined best at the Left 4th intercostal space at the sternal border (4 ICS PSL).
• The mitral valve is best examined in the Left 5th intercostal space at the midclavicular line (5 ICS MCL).
• Erb's point is located in the 3rd intercostal space on the left sternal border

Examination of Lower Extremeties

• When examining extremities, look for symmetry, skin integrity, color and temperature, hair distribution, capillary refill, tenderness, and superficial veins.
• Note any edema present.
• Palpate lower extremity pulses including the femoral, popliteal, posterior tibial, and dorsalis pedis pulses; then assess their respective amplitude.

Extra Heart Sounds S3 and S4

• S3 sounds occur after S2
• S4 sounds ocure right before S1

Murmurs

• Murmurs are blowing or swooshing noises caused by blood flow through chambers.
• These sounds may result from wall defects, narrowed valves, or regurgitation.
• Murmur grades range from I (barely audible) to V (very loud with palpable thrill).

Systolic and Diastolic Murmurs

• Systolic murmurs include aortic stenosis, mitral regurgitation, and tricuspid regurgitation.
• Diastolic murmurs include aortic regurgitation, pulmonic regurgitation, and mitral stenosis.

Important Heart Sounds

• Important heart sounds to know include regular S1 and S2 sounds, S3 and S4 sounds.
• Important murmurs to know include systolic and diastolic.