05 The Heart

The Heart

By Carlos Suárez-Quian, Ph.D. • Mediastinum, dfn • Coronary circulation • Heart: Structure & Function

Mediastinum: Anterior View Lungs

Heart

Int. thoracic art.

Remnants of thymus

R. Lung in pleural cavity

Pericardium

Mediastinum: Sagittal Plane Superior Mediastinum SVC Brachiocephalic v. Arch of aorta Thoracic duct Trachea Esophagus Thymus Vagus n. L. recurrent laryngeal n. Phrenic n. Anterior Thymus Lymph nodes Connective tissue

Inferior

Middle Pericardium Heart Roots of great vessels Arch azygos v. Main bronchii

Posterior Esophagus Thoracic aorta Azygos Hemiazygos Vagus n. Symphathetic trunks Splanchnic nerves

Physiological Systems

Peter Houghton 1938-2007, was the longest surviving artificial heart transplant patient in the UK

My heart is fixed, O God, my heart is fixed: I will sing and give praise. -- Psalms 57:7 The heart has its reasons which reason knows nothing of. -- Blaise Pascal Nobody has ever measured, even poets, how much a heart can hold. -- Zelda Sayre Fitzgerald Everybody's at war with different things. . . . I'm at war with my own heart sometimes.

-- Tupac Shakur As a man thinks in his heart, so is he. -- Proverbs 23:7

Heart Disease Facts •

One in five males and females has some form of cardiovascular disease

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Congenital and acquired diseases of the heart are the leading causes of morbidity and mortality in the U.S. and other developed countries

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There are approximately one million deaths per year in the U.S. due to heart disease of some form

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Since 1900, CVD has been the number one killer in the U.S. every year except 1918

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CVD claims almost 10,500 more lives each year than the next six leading causes of death combined

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90% of sudden death fatalities (approximately 460,000 per year) are due to heart disease

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Approximately 75% of all sudden cardiac deaths occur in men

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90% of victims are males between the ages of 45-64

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Approximately 15,000 hearts are needed annually for transplantation, but only about 1-2,000 are available

Problems with Heart Disease • Estimated that 60,800,000 Americans have one or more types of cardiovascular disease (CVD) • High blood pressure – 50,000,000 • Coronary artery disease – 12,400,000 • Myocardial infarction – 7,300,000 • Angina pectoris – 6,400,000 • Stroke – 4,500,000 • Congenital cardiovascular defects – 1,000,000 • Congestive heart failure – 4,700,000

Pericardial Sac Serous pericardium Parietal layer

Fibrous pericardium •

Fused to tunica adventitia of great vessels

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Bound to central tendon of diaphragm

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Attached to posterior surface of sternum

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Function: Protects heart against sudden over filing

Visceral layer

Potential space

Pericardial Sac Pathology •

Pericarditis: (inflammation of pericardium)

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Possible causes:

1. Virus 2. Bacteria (prophylaxis treatment by dentists)

Cardiac Tamponade: Fluid or Blood (Hemopericardium) accumulation in pericardial cavity Patient is variable degrees of shock or in extremis

Neck veins distended Heart sounds distant Venous pressure elevated (pathognomonic)

Decreased arterial & pulse pressures often exist but not pathognomonic

Causes • Ruptured aortic aneurism

Pericardial tap at Larrey’s point (diagnostic & decompressive)

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Ruptured myocardial infarct

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Penetrating injury

Pericardiocentesis

Pericardiocentesis

Cardiac Sinuses Transverse pericardial sinus

Transverse pericardial sinus

Oblique pericardial sinus

Location of transverse pericardial sinus is exploited during coronary by-pass surgery. Surgical clamp is introduced into the space and blood flow of aorta and pulmonary trunk stopped momentarily before great vessels are connected to bypass machine.

Inspection of Heart Anterior

R. atrium

Posterior L. auricle

L. atrium

Coronary sulcus

R. auricle

R. ventricle

Ant. & Post. Interventricular Grooves

L. ventricle

Coronary Veins & Arteries Sinuatrial node branch Ant. cardiac v. Great cardiac v. L. coronary art. Circumflex R. coronary art.

L.A.D.

Coronary sinus

Small cardiac v. Middle cardiac v.

R. marginal branch Post. interventricular branch: Dominance of the coronary arterial system is defined by which artery gives rise to this branch.

Left Coronary Arteriogram Left coronary art.

Circumflex art.

catheter Anterior interventricular art.

Right Coronary Anteriogram Sinuatrial nodal art.

R. Coronary art.

Post. Interventricular art.

catheter

Coronary Artery Occlusion

Coronary By-Pass Surgery Grafting of Internal thoracic Artery

Grafting of saphenous veins

R. coronary L.A.D. L.A.D

R. coronary Plaques

Percutaneous transluminal angioplasty

Stents

Left atrium The Heart

R. atrium (receiving)

Right auricle

L. atrium (receiving) Right ventricle

Right atrium

R. ventricle (discharging)

Right ventricle

L. Ventricle (discharging) Left ventricle

Right Atrium

Musculi pectinati Anterior wall

Crista terminalis Fossa ovalis Valve of coronary sinus

Right Ventricle Pulmonary trunk

Interventricular septum Trabeculae carneae

Anterior cusp

Tendinous cords Anterior papillary muscle

Septomarginal trabecula (moderator band)

Left Ventricle Orifice R. coronary art. Post. cusp of aortic valve Orifice L. coronary art.

Mitral valve cusps Tendinous cords Posterior papillary muscle

Anterior papillary muscle Trabeculae carneae

Blood Flow Through Heart

“dub”

Cardiac Cycle

“lub”

Conduction System of Heart Sinuatrial node Atrioventricular node

Opening of coronary sinus R. & L. bundle branches

Ant. papillary muscle Moderator band

Interventricular septum

Subendocardial branches (Purkinje fibers)

Conventional Chest Film SVC A RA

Pa Pt

RV

LV