Heart Anatomy: Chambers, Valves, and Circulation

• These notes cover a revision of heart anatomy, including surface anatomy, heart chambers, valves, circulation, heart wall layers, heart borders, conduction system, coronary arteries, cardiac examination, and auscultation.

Surface Anatomy of the Heart

• Point 1 is the lower border of the 2nd left costal cartilage, 1.5 inches from the median plane.
• Point 2 is the upper border of the right 3rd costal cartilage, 1 inch from the median plane.
• Point 3 is the upper border of the right 6th costal cartilage, 1 inch from its junction with the sternum.
• Point 4 is the apex, located at the left 5th intercostal space, 3.5 inches from the median plane.

Heart Chambers, Valves, and Circulation

• The heart consists of atria (right and left) and ventricles (right and left), with valves ensuring unidirectional blood flow.
• Key structures include the superior and inferior vena cava, aorta, pulmonary artery and veins, mitral valve, tricuspid valve, aortic valve, and pulmonary valve.

Layers of the Heart Wall

• Epicardium: The outermost layer of the heart wall.
• Myocardium: The middle layer, consisting of cardiac muscle.
• Endocardium: The innermost layer.

Borders of the Heart

• The heart's borders are defined by the superior vena cava, arch of aorta, right auricle and atrium, right ventricle, left auricle and ventricle, inferior vena cava, and apex.

Conduction System of the Heart

• The conduction system consists of the sinoatrial (SA) node, atrioventricular (AV) node, interatrial pathway, internodal pathway, right and left bundles of His, and Purkinje fibers, ensuring coordinated heart muscle contraction.

Coronary Arteries

• The coronary arteries include the left coronary artery, right coronary artery, circumflex artery, and left anterior descending artery, supplying blood to the heart muscle.

Cardiac Examination - History

• Involves personal history like occupation (stress, HTN), habits (junk food, hypercholesterolemia, atherosclerosis, coronaries, IHD/MI), past surgeries/diseases (open heart/CABG, HTN->heart failure), medications (beta blockers), and family history (IHD/HF).

Cardiac Examination - Assessment

• Includes general and local examinations, assessing the patient's decubitus (squatting position for tetralogy of Fallot), body build, color, mental state, and other problems.
• Tetralogy of Fallot consists of pulmonary stenosis, right ventricular hypertrophy, overriding aorta, and ventricular septal defect (VSD).
• Squatting increases pulmonary blood flow, relieving dyspnea by kinking femoral arteries, increasing systemic vascular resistance, and compressing splanchnic vessels.
• Squatting has two phases: an immediate drop in venous return, followed by a sustained increase in venous return and raised systemic vascular resistance.
• Long sitting position elevated to 45 degrees can help with orthopnea, where main issue is the supine position-induced orthopnea, increases venous return, and elevates the diaphragm.
• Prayers position relieves pain in pericarditis by decreasing venous return and pressure on the heart wall.

Body Build and Color in Cardiac Assessment

• Thin/cachetic build indicates advanced left-side heart failure due to low cardiac output.
• Obese build indicates right-side heart failure due to increased venous return and generalized edema, also suggesting coronary artery disease.
• Inverted pyramid build indicates coarctation of the aorta.
• Marfan's syndrome is characterized by lean body build, thin face, and long spidery fingers.
• Color assessment includes looking for malar flushes, pale color, jaundice, and cyanosis.
• Differential cyanosis results in lower extremity blue coloration but not the upper, seen in patients with patent ductus arteriosus (PDA).

General Examination - Other observations

• Clubbing Fingers: Hypertrophy of nail-bed tissue, Angle disappears, Poor oxygen
• Low Extremities: Edema
• Neck: Vigorous pulsations, head nodding
• Fever: Rheumatic fever, infective endocarditis

Clinical signs and meaning

• Central cyanosis affects lips, nose, hands, ears, with exercise or heat increasing the heart rate. Peripheral cyanosis affects just lips, nose, hands, due to atherosclerosis, with exercise or heat decreasing heart rate

Mental Status

• Includes assessing mood (anxiety, depression), coordination, and consciousness level.

Other Problems

• Osler's nodules: found in endocarditis
• puffy eye lids: indicates heart failure
• Rheumatic chorea: Involuntary jerky movement
• 4-venous pulsation: Differentiate between arterial & venous pulsations

Assessment & Vital Signs

• Assess radial and carotid pulses for rate (60-90 bpm), rhythm, character, and volume.
• Palpate peripheral pulses. Assess for pulse deficit. Measure blood pressure in both arms. Assess for orthostatic symptoms.

Local Examination - Inspection

• Includes previous operations, skeletal deformities, suprasternal pulsation, pericardial/parasternal areas, apex beat, dilated chest wall veins, and epigastric area. Skeletal deformities -> shift heart laterally and so apex pulsation
• Scoliosis
• Kyphosis
• Kyphoscoliosis
• barrel chest
• pectus excavatum (funnel chest)

Types of previous operations that can be observed

• Median sternotomy (heart or chest surgery),
• lateral thoracotomy (valve operation),
• supraclavicular (permanent pacemaker),
• midaxillary line (pacer-cardioverter-defibrillator).

Palpation & Location

• Normally dime-sized, 3-5 inches from misternal line
• If can't see pulse, have patient squat, if still cannot be palpated, turn patient to the left

Palpation: Assessing the apex beat for location, size, character, force, and duration

Other Observations

• Location: -Localized indicates LVH -Diffused indicates RVE
• Character -Tapping or regurge
• If there is no pulse -The patient is obese or muscular -COPD or tumors

Palpation - Other areas

• Also assess: Suprasternal , Epigastric
• Ask pt to stop palpitation
• Palpate the JVP - Jugular Venous Pressure, HEPATOJAGULAR REFLEX (HJR), Tracheal position

Percussion

• Used to confirm normal heart, liver, stomach position. Assesses heart size.
• Dullness= fluid presence
• Determine heart size

• Pulmonary area, Aortic area, Bare area of the hear, Lower third of sternum, Liver, Spleen

Auscultation

• Includes heart sounds, murmurs, and pericardial rub.
• Heart sounds (S1, S2, S3, S4)
• Use both sides of stethoscope: (diaphragmatic: high pitched, (S1 & S2), use bell for low pitch Key points
• S1- Beginning of systole
• S2- Beginning of diastole
• S3- Indicates ventricular gallop
• S4- Indicates Atrial gallop

Sound identification

• S1-DUP-High- Closure of M&T valves
• S2- LUP- High-closure of P&A valves
• ventricular( AR) gallop- LOW Directly after 2nd heart sound (in diastole)- Volume overload
• Atrial gallop-Low- Before first heart sound (end of diastole/ presystolic )- Strong Atrial contr. To pump bl. To stiff ventricles, Atrial gallop, Pressure overload

Problems with S1 & S2

Splitting: Occurs

due to aortic valve close before pulmonary valve( left ventricle is stronger than right ventricle) Sometimes delayed Increase because: Physiologically( in deep inspiration) / Pathologically( pulmonary stenosis) Reversing There is reversing if pulmonary valve closes before aortic( aortic stenosis), and Hypertrophic cardiomyopathy

Gallop /Murmur Notes

Gallop Extra heart sound with: tachycardia -S3-4 or S3 Due to volume of blood or Physiologically (Athlete, Pregnancy) Pathologically (Heart failure) Types of murmers: systolic diastolic machinery Systolic issues Pulmonary/Aortic/Tricuspid/Mitral - Stenos Diastolic issues Aortic/Tricuspid/Mitral/ P - Regurge

Steps with Mumur

• For example what type of murmur in aortic stenosis? /in systole (as aortic valve opens in systole), This is a systolic murmur.For example what type of murmur in pulmonary regurge(problem closing)in disastole then: disastolic
• Palpate carotid pulse with one hand while auscultation for timing-> 51 with carotid upstroke The use diaphragm/ bell
• Mitral murmur @apex in lt lateral position Aortic murmur @aortic area is sitting

Murmurs

• Are A musical sounds of turbulence, the results of passing blood through: stenosed valve/regurged valve/septal defect/ continuous
• Types Pulmonary =stenosis, aortic, tricuspid ,mitra

Machinery= pulmonary , aortic regurge , tricuspid stenosis mitral

Pericardial rub

abnormal sound heard during systole.Occurs in cases of pericarditis:Superficial frictional sound if dull hold breathing (DD For pleurisy)))