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MERCK MANUAL
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HEALTH TOPICS
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Heart and Blood Vessel Disorders
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Heart and Blood Vessel Disorders
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Biology of the Heart and Blood Vessels
Biology of the Heart
Function of the Heart
Blood Supply of the Heart
Regulation of the Heart
Biology of the Blood Vessels
Arteries and arterioles
Capillaries
Venules and veins
Names of blood vessels
Effects of Aging on the Heart and Blood Vessels
Symptoms of Heart and Blood Vessel Disorders
Overview of Heart and Blood Vessel Symptoms
Chest Pain
Causes
Common causes
Life-threatening causes
Evaluation
Warning signs
When to see a doctor
What the doctor does
Testing
Treatment
Key Points
Dizziness or Light-Headedness When Standing Up
Causes
Common causes
Evaluation
Warning signs
When to see a doctor
What the doctor does
Testing
Treatment
Essentials for Older Adults
Key Points
Fainting
Causes
Evaluation
Warning signs
When to see a doctor
What the doctor does
Testing
Treatment
Essentials for Older Adults
Key Points
Limb Pain
Causes
Evaluation
Warning signs
When to see a doctor
What the doctor does
Testing
Treatment
Key Points
Palpitations
Causes
Types of arrhythmias
Causes of arrhythmias
Complications
Evaluation
Warning signs
When to see a doctor
What the doctor does
Testing
Treatment
Essentials for Older Adults
Key Points
Postprandial Hypotension
Treatment
Swelling
Causes
Evaluation
Warning signs
When to see a doctor
What the doctor does
Testing
Treatment
Key Points
Diagnosis of Heart and Blood Vessel Disorders
Introduction to Diagnosis of Heart and Blood Vessel Disorders
Medical History and Physical Examination for Heart and Blood Vessel Disorders
Medical History
Physical Examination
Ambulatory (home) blood pressure monitoring
Electrocardiography
How ECG is done
Smartwatches
Continuous Ambulatory Electrocardiography
Echocardiography and Other Ultrasound Procedures
How echocardiography is done
X-Rays of the Chest
Computed Tomography (CT) of the Heart
Positron Emission Tomography (PET) of the Heart
Magnetic Resonance Imaging (MRI) of the Heart
Radionuclide Imaging of the Heart
Tilt Table Testing
How tilt table testing is done
Electrophysiologic Testing
How electrophysiologic testing is done
Stress Testing
How stress testing is done
Central Venous Catheterization
Pulmonary Artery Catheterization
How pulmonary artery catheterization is done
Cardiac Catheterization and Coronary Angiography
Cardiac Catheterization
Catheterization of the right side of the heart
Catheterization of the left side of the heart
Coronary Angiography
Abnormal Heart Rhythms
Overview of Abnormal Heart Rhythms
Normal electrical pathway
Causes
Fast arrhythmias
Slow arrhythmias
Symptoms
Diagnosis
Treatment
Prognosis
More Information
Medications to Treat Abnormal Heart Rhythms
Artificial Pacemakers
Cardioversion-Defibrillation
Implantable Cardioverter-Defibrillator (ICD)
Destroying Abnormal Heart Tissue (Ablation)
Atrial Fibrillation and Atrial Flutter
Atrial fibrillation
Atrial flutter
Causes
Complications
Symptoms
Diagnosis
Treatment
Slowing the heart rate
Restoring normal heart rhythm
Ablation procedures
Preventing blood clots
More Information
Atrial Premature Beats
Treatment
More Information
Cardiac Channelopathies
Symptoms
Diagnosis
Treatment
More Information
Torsades de Pointes Ventricular Tachycardia
Symptoms
Diagnosis
Treatment
More Information
Long QT Interval Syndromes
Causes
Triggers
Symptoms
Diagnosis
Treatment
More Information
Paroxysmal Supraventricular Tachycardia (SVT, PSVT)
Treatment
More Information
Sinus Node Dysfunction
Symptoms
Diagnosis
Treatment
More Information
Ventricular Fibrillation
Idiopathic ventricular fibrillation
Symptoms
Diagnosis
Treatment
More Information
Ventricular Premature Beats
Symptoms
Diagnosis
Treatment
More Information
Ventricular Tachycardia
Symptoms
Diagnosis
Treatment
Immediate treatment
Long-term treatment
More Information
Wolff-Parkinson-White (WPW) Syndrome
Symptoms
Atrial fibrillation and Wolff-Parkinson-White syndrome
Diagnosis
Treatment
Ablation
More Information
Arrhythmogenic Cardiomyopathies
Overview of Heart Block
Normal electrical pathway
Heart blocks
More Information
Atrioventricular Block
Causes
Classification
First-degree atrioventricular block
Second-degree atrioventricular block
Third-degree atrioventricular block
Diagnosis
Treatment
More Information
Bundle Branch Block
More Information
Diseases of the Aorta and Its Branches
Overview of Aortic Aneurysms and Aortic Dissection
Aortic Aneurysms
Location
Causes
Complications
Aortic Dissection
Abdominal Aortic Aneurysms
Symptoms
Diagnosis
Treatment
Treatment of a ruptured abdominal aortic aneurysm
Aortic Branch Aneurysms
Subclavian artery aneurysms
Aneurysms in the arteries of the abdominal organs
Symptoms
Diagnosis
Treatment
Abdominal Aortic Branch Occlusion
Symptoms
Lower aorta and common iliac arteries
Renal arteries
Superior mesenteric artery
Hepatic and splenic arteries
Diagnosis
Treatment
Lower aorta and common iliac arteries
Renal arteries
Superior mesenteric artery
Hepatic and splenic arteries
Aortic Dissection
Symptoms
Complications of aortic dissection
Diagnosis
Treatment
Prognosis
Aortitis
Thoracic Aortic Aneurysms
Symptoms
Diagnosis
Treatment
Atherosclerosis
Atherosclerosis
Arteriosclerosis
Causes
Plaque formation
Plaque rupture
Risk Factors for Atherosclerosis
Smoking and atherosclerosis
Cholesterol levels
High blood pressure
Diabetes mellitus
Obesity
Physical inactivity
Diet
Alcohol intake
Symptoms
Symptoms of gradual narrowing
Symptoms of sudden artery blockage
Diagnosis
People with symptoms
People without symptoms (screening)
Prevention and Treatment
Treatment of atherosclerosis complications
Cardiomyopathy
Overview of Cardiomyopathy
More Information
Dilated Cardiomyopathy
Causes
Symptoms
Complications
Diagnosis
Imaging of the heart
Biopsy and cardiac catheterization
Treatment
Medications for dilated cardiomyopathy
Device therapy
Heart transplantation
Prognosis
More Information
Hypertrophic Cardiomyopathy
Causes
Complications
Symptoms
Diagnosis
Treatment
Medications for hypertrophic cardiomyopathy
Myectomy
Alcohol ablation
Implantable cardioverter-defibrillator
Prognosis
More Information
Restrictive Cardiomyopathy
Scarring
Accumulation of abnormal substances
Symptoms
Diagnosis
Treatment
More Information
Cardiac Arrest and Cardiopulmonary Resuscitation (CPR)
Cardiac Arrest and Cardiopulmonary Resuscitation (CPR)
First-Aid Treatment for Cardiac Arrest
Compression-Only CPR
Standard CPR
More Information
Coronary Artery Disease
Overview of Coronary Artery Disease (CAD)
Causes
Risk Factors
Treatment
Percutaneous Coronary Intervention
Coronary Artery Bypass Grafting
Other techniques
Prevention
Smoking
Diet
Physical inactivity
Obesity
High cholesterol levels
High blood pressure
Diabetes mellitus
Aspirin
Angina
Causes
Unusual causes of angina
Classification
Symptoms
Silent ischemia
Diagnosis
Stress testing
Echocardiography
Coronary angiography
Continuous ECG monitoring
Imaging of the heart
Treatment
Medication Therapy for Angina
Revascularization Procedures for Angina
Prognosis
Acute Coronary Syndromes (Heart Attack; Myocardial Infarction; Unstable Angina)
Causes
Classification
Symptoms
Complications
Diagnosis
Electrocardiography
Cardiac biomarkers
Other testing
Treatment
Medication treatment
Opening the arteries
General measures
Discharge
Rehabilitation
Prognosis
Prevention
Complications of an Acute Coronary Syndrome
Pumping problems
Rhythm problems
Pericarditis
Myocardial rupture
Ventricular aneurysm
Blood clots
Other problems
Medications for Treatment of Coronary Artery Disease
Nitrates
Morphine
Beta-blockers
Calcium channel blockers
Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers
Statins
Antiplatelet medications
Clot-dissolving medications
Anticoagulants
Ranolazine and ivabradine
PCSK-9 inhibitors
Endocarditis
Infective Endocarditis
Causes
Risk Factors
Symptoms
Diagnosis
Treatment
Prognosis
Prevention
Noninfective Endocarditis
Diagnosis
Treatment
Heart Failure
Heart Failure (HF)
Types of heart failure
Causes
Cardiac causes of heart failure
Non-cardiac causes of heart failure
Compensatory Mechanisms
Hormonal responses
Kidney responses
Enlargement of the heart
Symptoms
Right-sided heart failure symptoms
Left-sided heart failure symptoms
Symptoms of severe heart failure
Diagnosis
Chest x-ray
Electrocardiography
Echocardiography
Blood tests
Other tests
Prevention
Treatment
General measures
Treatment of the cause
Lifestyle changes
Drugs for heart failure
Other measures
Treatment of acute heart failure
End-of-life issues
More Information
Drug Treatment for Heart Failure
Aldosterone antagonists
Angiotensin-converting enzyme (ACE) inhibitors
Angiotensin II receptor blockers (ARBs)
Angiotensin receptor/neprilysin inhibitors
Beta-blockers
Digoxin
Diuretics
Sinus node inhibitors
Sodium-glucose cotransporter-2 inhibitors (SGLT2s)
Vasodilators
Other drugs used for heart failure
Cor Pulmonale
Symptoms
Diagnosis
Treatment
Heart Tumors
Overview of Heart Tumors
Noncancerous primary heart tumors
Cancerous primary heart tumors
Metastatic heart tumors
Symptoms
Diagnosis
Treatment
Noncancerous (benign) heart tumors
Cancerous heart tumors
Pericardial tumors
Myxomas
Symptoms
Complications of myxoma
Diagnosis
Treatment
Cancerous Heart Tumors
Symptoms
Diagnosis
Treatment
Heart Valve Disorders
Overview of Heart Valve Disorders
Changes in heart valves with aging
Heart valve malfunction
Repairing or replacing a heart valve
More Information
Aortic Regurgitation
Causes
Symptoms
Diagnosis
Treatment
Prognosis
More Information
Aortic Stenosis
Causes
Symptoms
Diagnosis
Treatment
Prognosis
More Information
Mitral Regurgitation
Complications
Causes
Symptoms
Diagnosis
Treatment
Prognosis
More Information
Mitral Stenosis
Causes
Symptoms
Diagnosis
Treatment
Prognosis
More Information
Mitral Valve Prolapse (MVP)
Causes
Symptoms
Diagnosis
Treatment
Prognosis
More Information
Pulmonic Regurgitation
Diagnosis
Treatment
More Information
Pulmonic Stenosis
Diagnosis
Treatment
More Information
Tricuspid Regurgitation
Causes
Symptoms
Diagnosis
Treatment
Prognosis
More Information
Tricuspid Stenosis
Diagnosis
Treatment
More Information
High Blood Pressure
High Blood Pressure
Classification of blood pressure
The Body's Control of Blood Pressure
Causes
Primary hypertension
Secondary hypertension
Contributing factors
Symptoms
Complications of high blood pressure
Diagnosis
Diagnosis of cause
Treatment
Treatment goals
Lifestyle changes
Medications
Treatment of secondary hypertension
Treatment of resistant hypertension
Treatment of hypertensive urgencies and emergencies
Prognosis
More Information
Medications for Treatment of High Blood Pressure
Alpha adrenergic modifiers
Beta-blockers and alpha-beta blockers
Angiotensin-converting enzyme inhibitors
Angiotensin II receptor blockers
Calcium channel blockers
Direct renin inhibitor
Direct vasodilators
Diuretics
More Information
Low Blood Pressure and Shock
Low Blood Pressure
Changing the diameter of arterioles and veins
Changing cardiac output
Changing the volume of blood
Changing the body's position
Monitoring and controlling blood pressure
Causes
Symptoms
Diagnosis
Treatment
Shock
Causes
Hypovolemic shock
Cardiogenic shock
Distributive shock
Symptoms
Diagnosis
Treatment
Initial treatment
Treatment of cause
Prognosis
Lymphatic Disorders
Overview of the Lymphatic System
Disorders of the lymphatic system
Swollen Lymph Nodes
Causes
Evaluation
Warning signs
When to see a doctor
What the doctor does
Testing
Treatment
Key Points
Lymphedema
Causes of lymphedema
Primary lymphedema
Secondary lymphedema
Diagnosis
Treatment
Pericardial Disease and Myocarditis
Overview of Pericardial Disease
Acute Pericarditis
Causes
Symptoms
Diagnosis
Tests for the cause of pericarditis
Treatment
Anti-inflammatory medications
Treating the underlying disorder
Surgical treatment
Prognosis
Chronic Pericarditis
Causes
Symptoms
Diagnosis
Treatment
Chronic constrictive pericarditis
Myocarditis
Causes
Giant cell myocarditis
Symptoms
Diagnosis
Diagnosis of cause
Treatment
Peripheral Arterial Disease
Overview of Peripheral Arterial Disease
Causes
Aneurysms of Arteries in the Arms, Legs, and Heart
Causes
Symptoms
Diagnosis
Treatment
Occlusive Peripheral Arterial Disease
Gradual artery narrowing
Sudden blockage of an artery
Symptoms
Diagnosis
Physical examination
Tissue oxygen measurements
Imaging
Other tests for diagnosing occlusive peripheral arterial disease
Treatment
Exercise
Foot care
Medications
Angioplasty
Surgery
Other treatments
Prevention
More Information
Fibromuscular Dysplasia
Treatment
More Information
Thromboangiitis Obliterans
Symptoms
Diagnosis
Treatment
More Information
Overview of Functional Peripheral Arterial Disease
Acrocyanosis
More Information
Erythromelalgia
Treatment
Raynaud Syndrome
Primary Raynaud syndrome
Secondary Raynaud syndrome
Symptoms
Diagnosis
Treatment
More Information
Sports and the Heart
Athlete's Heart
Diagnosis
Treatment
Sudden Cardiac Death in Athletes
Causes
Young athletes
Older athletes
Symptoms
Treatment
More Information
Screening for Sports Participation
Screening for Risk of Sudden Cardiac Death in Athletes
Screening for Other Risks of Sports Participation
Limitations on Activity
Venous Disorders
Overview of the Venous System
Problems With the Veins
Arteriovenous Fistula
Intentional creation of arteriovenous fistulas for medical treatment
Symptoms
Diagnosis
Treatment
Chronic Venous Insufficiency and Post-Thrombotic Syndrome
Causes
Post-thrombotic syndrome
Symptoms
Diagnosis
Treatment
Prevention
More Information
Deep Vein Thrombosis (DVT)
Causes
Injury to the vein
Increased blood clotting tendency
Slowing of blood flow
Complications
Pulmonary embolism
Chronic venous insufficiency
Ischemia (lack of blood flow)
Symptoms
Diagnosis
Treatment
Anticoagulant medications
Clot-blocking filter
Clot-dissolving drugs
Treatment of complications
Prevention
More Information
Spider Veins
Treatment
Superficial Venous Thrombosis
Symptoms
Diagnosis
Treatment
Varicose Veins
Causes
Symptoms
Diagnosis
Treatment
Injection therapy (sclerotherapy)
Laser therapy
Surgery ("vein stripping")
More Information
