Heart Anatomy and Physiology Quiz

Objectives of Health Assessment

• Assess heart and neck vessels
• Locate and auscultate over five specific areas of the heart to listen for corresponding heart sounds
• Identify normal and abnormal findings of heart sounds
• Develop a systematic approach
• Listen selectively and specifically
• Identify the timing of sounds in relation to the cardiac cycle
• Understand and utilize patient positioning and respiratory maneuvers to evaluate findings

Structure and Function of the Heart

• The heart is a cone-shaped muscle, about 12 cm long and 9 cm wide
• Weighs 250-390g in adult males and 200-275g in adult females
• Pumps blood throughout the circulatory system
• Has four chambers: right atrium, right ventricle, left atrium, and left ventricle

Anatomy and Physiology of the Heart

• Right side:
  • Right atrium: receives deoxygenated blood from superior and inferior vena cava
  • Tricuspid valve: between right atrium and right ventricle
  • Right ventricle: pumps blood into pulmonary circuit
  • Pulmonary semilunar valve: between right ventricle and main pulmonary artery
• Left side:
  • Left atrium: receives oxygenated blood from lungs through pulmonary veins
  • Mitral valve: between left atrium and left ventricle
  • Left ventricle: pumps oxygenated blood through systemic circulation
  • Aortic valve: between left ventricle and aorta

Layers of the Heart

• Endocardium: inner layer, smooth and thin
• Myocardium: middle and thickest layer, heart muscle
• Epicardium: outer layer, contains main coronary blood vessels
• Pericardium: sac that surrounds the heart and roots of great vessels

Pulmonary and Systemic Circulation

• Pulmonary circulation: involves blood vessels that circulate blood through lungs and back to the heart
• Systemic circulation: supplies oxygen to every cell in the body through arterial system and returns deoxygenated blood to the heart through venous system

Coronary Circulation

• Supplies the heart with oxygen needed to perform its function
• Consists of right and left coronary arteries and coronary sinus and cardiac veins

###Layers of Arteries and Veins

• Arteries: have three coats (tunica intima, tunica media, and tunica adventitia) and carry oxygenated blood away from the left heart
• Arterioles: carry blood to capillaries and control blood flow
• Capillaries: single layer of microscopic endothelial cells that connect arterial and venous systems
• Veins: have same three layers as arteries, but thinner and with less elastic and collagenous tissue and smooth muscle
• Venules: smallest veins, consisting of endothelium and thin tunica adventitia

Mechanisms of Heart Sounds

• The cardiac cycle comprises the systolic and diastolic phases
• The cardiac cycle includes the valves, hemodynamic events within the heart, and the conduction system working together
• Ventricular diastole: begins with the fling phase, during which the pressure in the ventricles is less than that of the atria
• Cardiac output: controlled by the internal pacemaker of the heart and the autonomic nervous system
• Stroke volume: the volume of blood pumped out of the left ventricle during each systolic cardiac contraction

Heart Valves

• The first heart sound (S1) marks the beginning of systole and results from the closure of the mitral and tricuspid valves
• The second heart sound (S2) marks the end of systole and results from the closure of the aortic and pulmonic valves
• Extra heart sounds:
  • Early ejection click: high-pitched, short systolic sound occurring shortly after S1
  • Midsystolic ejection click: high-pitched, short sound found in mitral valve prolapse (MVP)
  • Opening snap (diastolic): short, high-pitched sound occurring 0.05 to 0.14 second after S2
  • S3 gallop rhythm: sounds like "lub dub dah" and is best heard at the apex
  • S4 gallop rhythm: also called atrial gallop, occurs immediately before the S1 and sounds like "ta-lub dub"

Murmurs

• Defined as a series of audible, prolonged blowing or whooshing sound that signifies turbulent blood flow often caused by a valvular defect
• Murmurs are characterized in terms of quality, frequency, duration, configuration, placement in the cardiac cycle, and location of sound
• Continuous sounds: sounds that are heard during both systole and diastole
• Venous hum: a low-pitched sound heard over the right internal jugular vein in the supraclavicular area
• Friction rub: a high-pitched, scratchy, leathery sound generated when the inflamed parietal and visceral pericardial layers rub together### Blood Pressure Measurement
• Phase 1: loud, clear, tapping sound when blood starts to flow through the artery
• Phase 2: swishing sound as blood flows through the artery
• Phase 3: thumping sound as blood flows through the artery, but cuff pressure is still high enough to occlude flow during diastole
• Phase 4: softer, blowing, muffled sound as cuff pressure is released
• Phase 5: silence when cuff pressure is released enough to allow normal blood flow

Interaction with Other Body Systems

• Respiratory System: works closely with cardiovascular system to supply oxygen and remove carbon dioxide
  • Exchange of gases in respiratory system requires circulatory system to transport gases
  • Respiratory and cardiac rates increase during exercise to meet oxygen needs
  • Disease in one system can affect the other (e.g. COPD can lead to right-sided CHF)
• Endocrine System: sympathetic nervous system activation leads to epinephrine and norepinephrine release, which increases heart rate and contractility
• Nervous System: regulates heart rate through medulla oblongata, cerebrum, and hypothalamus
  • Autonomic nervous system (sympathetic and parasympathetic) affects heart rate

Developmental, Cultural, and Ethnic Variations

• Infants: foramen ovale and ductus arteriosus close after birth, allowing heart to function as a double pump
  • Normal heart rate: 120-160 BPM
• Children: heart lies more horizontally, apical impulse is at 4th intercostal space, and heart sounds are louder
  • Sinus arrhythmia with respiratory variations is common
  • Innocent murmurs and physiological S3 are common findings
• Pregnant Women: cardiac workload increases, leading to systolic murmurs and changes in apical impulse
  • BP is usually lower during first and second trimesters, and heart rate is slightly higher
• Older Adults: changes in BP are common, including postural (orthostatic) hypotension and auscultatory gaps

Health History

• Biographical Data: age, gender, ethnic background, occupation, and support/financial status
  • Age: risk for cardiovascular disease increases with age
  • Gender: men have a greater incidence of cardiovascular disease than women
  • Ethnic background: African American men have a high incidence of HTN
• Current Health Status: chief complaint, symptoms, and medical history
  • Chest pain: most common presenting cardiac symptom, may be cardiac, respiratory, gastrointestinal, musculoskeletal, or psychogenic in nature
  • Palpitations, syncope, edema, fatigue, and extremity changes are other symptoms that may signal cardiovascular problems
• Risk Factors for Coronary Artery Disease: uncontrollable, controllable, and contributing factors
  • Uncontrollable: age, sex, heredity, and race
  • Controllable: smoking, cholesterol, hypertension, physical inactivity, obesity, and diabetes
  • Contributing: stress, homocysteine levels, and type A personality### Cardiovascular Disease Risk Factors and Assessment

Symptoms of Left-Sided CHF

• GI upset and RUQ pain may accompany right-sided CHF
• COPD can result in cardiac involvement, such as pulmonary hypertension and right-sided CHF

Reproductive Health and Cardiovascular Disease

• Increases CAD risk
• Oral contraceptives/estrogen supplements are associated with thrombus formation
• HRT is associated with increased risk of cardiovascular disease

Musculoskeletal and Neurological Associations

• Muscle weakness secondary to decreased use
• Intermittent claudication is associated with arterial insufficiency
• Syncopal attacks may signal vascular problems or cardiac arrhythmias
• Behavioral changes, such as confusion, decreased attention span, or loss of memory, may occur due to hypoxia and impaired cerebral circulation

Lymphatic/Hematologic and Cardiovascular Disease

• Anemia increases the heart's workload
• Polycythemia increases risk for thrombus, hypertension, and cardiopulmonary disease

Psychosocial Profile and Cardiovascular Disease

• Identifying risk factors is essential in developing an effective plan of care
• Chronic cardiovascular disease can affect a patient's lifestyle, forcing them to make changes to adapt to the illness

Risk Factors and Questions to Ask

• Health practices and beliefs
  • Yearly physicals
  • Compliance with treatment program
  • Medications taken and reasons why
• Activities
  • Typical day
  • Activity level and correlation with energy level
• Nutrition and weight patterns
  • Obesity as a risk factor for CAD
  • Diet high in cholesterol and sodium
• Gastrointestinal
  • GI upset and RUQ pain
  • Anorexia, loss of appetite, or nausea
• Musculoskeletal
  • Muscle weakness
  • Intermittent claudication
• Neurological
  • Syncopal attacks
  • Behavioral changes

Physical Assessment

• Approach
  • Assess for physical signs in every system
  • Perform assessment in three positions: sitting, supine, and left lateral recumbent
• Tools
  • Stethoscope with diaphragm for high-pitched sounds and bell for low-pitched sounds
  • Sphygmomanometer scale, metric ruler, thermometer, and marking pen
• Performing general survey
  • General appearance
  • Weight distribution and muscle composition
  • Facial expression
  • Posture or assumed position of comfort
  • Dress and grooming
  • Body stature
  • Muscle wasting
  • Abnormal movements

Vital Signs

• BP: measurements greater than 120/80 may indicate hypertension
• Pulse: strength of pulse may reflect vascular system
• Respiratory rate: changes in respiratory rate and pattern may occur with chest pain
• Temperature: elevated temperature may indicate infectious disease process
• Weight and height: accurate measurements helpful in planning treatment and monitoring fluid retention

Intensity and Grading of Pulse

• Palpation done using fingertips
• Intensity of pulse graded on a scale of 0 to 4+
• 0: no palpable pulse
• 1+: faint, but detectable pulse
• 2+: slightly more diminished pulse than normal
• 3+: normal pulse
• 4+: bounding pulse

Performing a Head-to-Toe Physical Assessment

• Cardiovascular system can affect every other body system
• Inspect for changes in each body system that might signal a cardiovascular problem
• Neck
  • Inspect carotid and jugular venous systems for pulsations
  • Measure jugular venous pressure (JVP)