Cardiac Anatomy and Physiology Overview

Cardiac Blood Flow Overview

• The heart is centrally located behind the sternum and is vital for overall body function.
• The apex of the heart is positioned at the top during birth and gradually shifts as a person ages.
• The apical pulse correlates with the heart's apex.

Cardiac Function and Circulation

• The right side pumps deoxygenated blood to the lungs (pulmonary circulation) for CO2 removal and O2 replenishment.
• The left side distributes oxygenated blood to the entire body (systemic circulation).
• Perfusion ensures oxygen and CO2 diffusion in tissues and organs.

Cardiac Cycle

• Heart muscle cells can spontaneously generate and conduct electrical impulses, crucial for the cardiac cycle.
• Key heart sounds include:
  • S1: Closure of mitral and tricuspid valves; marks ventricular systole (contraction).
  • S2: Closure of aortic and pulmonic valves; marks ventricular diastole (relaxation).
  • S3: Indicates rapid ventricular filling; common in children and pregnant women.
  • S4: Suggests strong atrial contraction; often signifies heart failure or ischemia.

Auscultation Techniques

• Use diaphragm for high-pitched sounds (S1, S2) and bell for low-pitched sounds (S3, S4).
• Heart sounds can be localized:
  • S2 is louder at the base of the heart.
  • S1 is louder at the apex, coinciding with carotid pulse.

ECG and Electrical Activity

• The normal ECG represents depolarization in heart areas; sinus node functions as a pacemaker with a discharge rate of 60-100 bpm.

Health History Assessment

• Evaluate symptoms such as:
  • Chest pain: Determine origin (cardiac, respiratory, etc.).
  • Arrhythmias: Skipped beats, palpitations.
  • Dyspnea: Breathing difficulties can signal cardiac issues.
  • Orthopnea: Difficulty breathing when lying down.
  • Cough: May indicate pulmonary congestion from cardiac conditions.
  • Edema: Bilateral ankle swelling signifies hypervolemia.
  • Nocturia: Frequent urination at night due to fluid mobilization.
  • Fatigue, cyanosis, and pallor as late signs of heart disease.

Edema Documentation

• Document pitting edema on a scale (1+ to 4+) based on the depression measurement.

Fluid Balance

• Homeostasis requires fluid intake to equal output.
• Imbalances can affect cardiovascular and renal functions.
• Dehydration triggers the hypothalamus to release ADH, reducing urine output.

Hypervolemia Risks

• Poor heart function can lead to fluid overload; at-risk populations include post-operative patients and those with immobilization.
• Prevention strategies: Compression stockings, early ambulation, and elevated legs.

Palpation Techniques

• Assess temperature of extremities; note any unilateral coolness.
• Check capillary refill time: should be <2 seconds.
• Palpate carotid artery one side at a time; assess pulse strength.

Point of Maximal Impulse (PMI)

• Located at the 5th intercostal space near the midclavicular line.
• Normal PMI diameter is 1-2.5 cm; larger diameters suggest left ventricular hypertrophy (LVH).

Capillary Refill and Arterial Pulses

• Capillary refill should return to pink instantly; prolonged time indicates potential hypoxia.
• Arterial pulse grading assists in determining cardiovascular health status.

This quiz covers the essential aspects of cardiac anatomy, including blood flow, circulation, and the cardiac cycle. Participants will explore the heart's structure, its function in pumping blood, and the significance of different heart sounds. Gain a better understanding of how the heart supports overall body function and health.