Clinical Medicine: Cardiovascular System and Angina Pectoris

Anatomy of the Heart

• The precordium is the anterior surface of the chest overlying the heart and great vessels.
• It extends vertically from 2nd-5th intercostal space (ICS) and transversely from the right border of the sternum to the left midclavicular line.
• The base of the heart corresponds to the right and left 2nd ICS close to the sternum.
• The apex of the heart is at the 5th left ICS at or within 1-2 cm medial to the midclavicular line (MCL) or 7-9 cm lateral to the midsternal line (MSL).

Borders of the Heart

• Right border: extends from the upper border of the 3rd costal cartilage 2cm lateral to its junction with the sternum to the 6th right costochondral junction.
• Inferior border: from the 6th right costochondral junction to the 5th left ICS 1-2 cm medial to MCL.
• Left border: from the apex to the 2nd left costal cartilage 1-2cm to the left of its articulation with the sternum.

Clinical Valvular Areas

• 2nd ICS right parasternal line (PSL) - aortic area
• 2nd ICS left PSL - pulmonary area
• 4th-5th ICS left lower sternal border (left xiphisterna junction) - tricuspid area
• 5th left ICS 1-2 cm medial to MCL - mitral area

Heart Sounds

• S1: closure of atrioventricular valves (mitral and tricuspid)
• S2: closure of semilunar valves (aortic and pulmonary)
• S3: ventricular filling/gallop
• S4: atrial filling

Symptoms of Cardiovascular Disease

• Chest pain: think through the range of possible cardiac, pulmonary, and extra-thoracic etiologies
• Palpitations: unpleasant awareness of the heartbeat
• Shortness of breath, orthopnea, or paroxysmal dyspnea
• Swelling or edema

General Physical Examination

• General appearance: age, posture, demeanor, and overall health status
• Is the patient in pain or resting quietly?
• Does the patient choose to avoid certain body positions to reduce or eliminate pain?
• In case of pericarditis, leaning forward improves symptoms.

Specialized Examinations

• Head and neck: assess dentition, oral hygiene, and look for signs of congenital heart disease
• Chest: examine the thoracic cage, look for signs of obstructive lung disease, and assess the lungs
• Extremities: look for signs of peripheral vascular disease, clubbing, and edema
• Abdomen: examine the liver, spleen, and look for signs of ascites
• Jugular venous pressure (JVP): assess the vertical distance between the top of the jugular venous pulsation and the sternal inflection point (angle of Louis)
• Venous pressure: >4.5 cm at 30° elevation is considered abnormal.

Endocarditis Lesions

• Janeway lesions: non-tender, slightly raised hemorrhages on the palms and soles
• Osler's nodes: tender, raised nodules on the pads of the fingers or toes
• Splinter hemorrhages: linear petechiae in the mid-position of the nail bed

Prognostic Significance

• An elevated JVP is associated with a higher risk of subsequent hospitalization for heart failure, death from heart failure, or both.### Venous Insufficiency and Jugular Venous Pulse Waves

• Pitting edema can also be seen in patients who use dihydropyridine calcium channel blockers.

• Muscular atrophy or the absence of hair along an extremity can indicate severe arterial insufficiency or a primary neuromuscular disorder.

Jugular Venous Pressure and Wave Form

• The internal jugular vein is preferred for measuring jugular venous pressure because it is not valved and is directly in line with the superior vena cava and right atrium.
• The jugular venous pressure waveform consists of:
  • A wave: atrial contraction (RA)
  • C wave: closure of tricuspid valve (bulging of tricuspid valve with ventricular contraction)
  • X descent: atrial relaxation
  • V wave: atrial filling (atrial diastole)
  • Y descent: atrial emptying with opening of tricuspid valve
• A prominent a wave can be seen in reduced right ventricular compliance.
• A cannon a wave occurs with atrioventricular (AV) dissociation and right atrial contraction against a closed tricuspid valve.
• X descent is interrupted by the C wave and is followed by a further descent.

Abdominojugular Reflex

• The abdominojugular reflex is elicited with firm and consistent pressure over the upper portion of the abdomen, preferably over the right upper quadrant, for at least 10 seconds.
• A positive response is a sustained rise of more than 3 cm in JVP for at least 15 seconds after release of the hand.

Assessment of Blood Pressure

• Accurate measurement of blood pressure depends on body position, arm size, time of measurement, place of measurement, device, device size, and technique.
• Blood pressure is best measured in the seated position, with the arm at the level of the heart, using an appropriately sized cuff, after 5-10 minutes of relaxation.
• When measured in the supine position, the arm should be raised to bring it to the level of the mid-right atrium.

Kussmaul Sign

• The Kussmaul sign is defined by either a rise or a lack of fall of the JVP with inspiration.
• It can be seen in constrictive pericarditis, restrictive cardiomyopathy, massive pulmonary embolism, right ventricular infarction, and advanced left ventricular systolic heart failure.

BP Measurement

• Blood pressure should be measured in both arms, and the difference should be less than 10 mmHg.
• A blood pressure differential that exceeds this threshold may be associated with atherosclerotic or inflammatory subclavian artery disease, supravalvular aortic stenosis, aortic coarctation, or aortic dissection.

Systolic Leg Pressures

• Systolic leg pressures are usually 20 mmHg higher than systolic arm pressures.

Ankle-Brachial Index

• The ankle-brachial index is a powerful predictor of long-term cardiovascular mortality.
• It is calculated by dividing the higher of the two brachial artery pressures by the lower of the two ankle pressures.

"White Coat Hypertension"

• "White coat hypertension" is defined by at least 3 separate clinic-based and at least 2 non-clinic-based measurements showing a difference of 20 mmHg or more in systolic pressure or 10 mmHg or more in diastolic pressure in response to the assumption of the upright posture from a supine position within 3 minutes.

Arterial Pulse

• The carotid artery pulse occurs just after the ascending aortic pulse.
• The character and contour of the arterial pulse depend on stroke volume, ejection velocity, vascular compliance, and systemic vascular resistance.

Pulsus Paradoxus

• Pulsus paradoxus is a fall in systolic pressure >10 mmHg with inspiration.
• It can be seen in patients with pericardial tamponade, massive pulmonary embolism, hemorrhagic shock, severe obstructive lung disease, or tension pneumothorax.

Peripheral Arterial Pulses

• The pulses should be examined for their symmetry, volume, timing, contour, and amplitude.
• The carotid upstroke should never be examined simultaneously or before listening for a bruit.
• Light pressure should always be used to avoid precipitating carotid hypersensitivity syndrome and syncope in a susceptible elderly individual.

Pulse in Aortic Regurgitation

• With chronic severe AR, the carotid upstroke has a sharp rise and rapid fall-off (Corrigan's or water-hammer pulse).
• Some patients with advanced AR may have a bifid or bisferiens pulse.

Auscultation

• Auscultation for carotid, subclavian, abdominal aortic, and femoral artery bruits should be routine.
• Simultaneous auscultation of the heart can help identify a cervical bruit.

Abnormal Pulse Oximetry

• A >2% difference between finger and toe oxygen saturation can be used to detect lower extremity peripheral arterial disease.

Inspection and Palpation of the Heart

• Sustained, high-amplitude impulse (normally located) can indicate left ventricular hypertrophy from pressure overload.
• Sustained high amplitude impulse displaced laterally can indicate volume overload.
• Sustained low-amplitude (hypokinetic) impulse can indicate dilated cardiomyopathy.
• Palpable presystolic impulse (S4) corresponds to the fourth heart sound (S4) and indicates reduced left ventricular compliance.
• Palpable third sound (S3) indicates a rapid early filling wave in patients with heart failure.### Right Ventricle
• A visible right upper parasternal pulsation may be suggestive of ascending aortic aneurysm disease or atrial septal defect.
• Marked increase in amplitude with little or no change in duration suggests chronic volume overload of the right ventricle.
• Impulse with increased amplitude and duration indicates pressure overload of the right ventricle due to pulmonic stenosis or pulmonary hypertension.
• Palpable pulsation accompanies dilatation or increased flow in the pulmonary artery.

Palpation of Heart

• Heave is a thrusting sensation often used to describe a large area and amplitude with sustained movement.
• A palpable S2 suggests increased pressure in the pulmonary artery, indicating pulmonary hypertension.
• Right 2nd Interspace—Aortic Area: palpable S2 suggests systemic hypertension, while pulsation suggests a dilated or aneurysmal aorta.

LV Impulse

• LV impulse is less than 2 cm in diameter and moves quickly away from the fingers.
• Enlargement of the LV cavity is manifested by a leftward and downward displacement of an enlarged apex beat.
• Apex beat may be displaced upward and to the left by pregnancy or a high left diaphragm.

Heart Sounds

• Ventricular systole is defined by the interval between the first (S1) and second (S2) heart sounds.
• The first heart sound (S1) includes mitral and tricuspid valve closure.
• The second heart sound (S2) includes aortic and pulmonic valve closure.

First Heart Sound (S1)

• The intensity of S1 is determined by the distance over which the anterior leaflet of the mitral valve must travel to return to its annular plane, leaflet mobility, left ventricular contractility, and PR interval.
• Increased amplitude of S1 may also reflect hyperthyroidism, severe anemia, or left ventricular enlargement.

Split S1

• Split S1 is seen in young patients, right bundle branch block, and tricuspid valve closure.
• Reversed or paradoxical splitting occurs due to pathologic delay in aortic valve closure, seen in left bundle branch block, right ventricular apical pacing, severe AS, HOCM, or acute myocardial ischemia.

Third Heart Sound (S3)

• S3 occurs during the rapid filling phase of ventricular diastole and can be a normal finding in children, adolescents, and young adults.
• In older patients, it signifies heart failure.

This quiz covers the anatomy of the cardiovascular system, specifically focusing on angina pectoris and its characteristics, such as exertional chest pain with radiation to the precordium.