Bradycardia causes

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Bradycardia Microchapters

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Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Bradycardia from other Conditions

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

Chest X Ray

CT

Echocardiography

MRI

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Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

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Case #1

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Risk calculators and risk factors for Bradycardia causes

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: M.Umer Tariq [2]; Ogheneochuko Ajari, MB.BS, MS [3]

Overview

Pathologic bradycardias are caused by disorders of impulse generation (impaired automaticity at SA node), impulse conduction (heart block), or escape pacemakers and rhythms. Bradycardia can be underlain by several causes, which are best divided into cardiac and non-cardiac causes or based on the location of the abnormality.

Causes

  • Drugs:

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

Common Causes

Causes by Organ System

Cardiovascular Acute coronary syndrome, Acute myocardial infarction, Acute rheumatic fever, Andersen cardiodysrhythmic periodic paralysis, Aspergillosis myocarditis, Atherosclerosis, Atrial septal defect, Atrioventricular block, Brugada syndrome, Calcific aortic stenosis, Cardiac arrhythmia, Cardiac catheterization, Cardiac glycosides, Cardiac transplantation, Cardiac tumor, Cardioinhibitory syncope, Cardiomyopathy, Cardioversion, Carotid sinus hypersensitivity, Complete heart block, Congenital heart block, Congenital heart disease, Congestive heart failure, Coronary artery bypass grafting, Coronary heart disease, Coronary ischemia, Coronary reperfusion therapy, Diabetes mellitus, Dilated cardiomyopathy, Ebstein’s anomaly, Electrophysiological studies, Endocardial cushion defect, Endocarditis, Enhanced vagal tone, Fontan procedure, High fitness level, Hypersensitive carotid sinus syndrome, Hypertension, Hypertensive heart disease, Hypertrophic cardiomyopathy alcohol septal ablation, Hypertrophic cardiomyopathy, Hypervagotonia, Idiopathic heart block, Idiopathic hypereosinophilic syndrome, Infraclavicular brachial plexus block, Ischemic heart disease, Isorhythmic a-v dissociation, Jervell and lange-nielsen syndrome, Junctional rhythms, Lateral medullary syndrome, Left ventricular noncompaction, Lenegre's disease, Lev's disease, Long qt syndrome, Lown-ganong-levine syndrome, Lqt type 4, Lqt4 mutation, Mahaim fiber tachycardia, Maze procedure, Micturition syncope, Mitral regurgitation, Mitral stenosis, Mitral valve prolapse, Myocardial bridging, Myocardial contusion, Myocardial infarction  , Myocardial ischaemia, Myocardial rupture, Myocarditis, Neurocardiogenic syncope, Noncompaction cardiomyopathy, Normal variants of pr prolongation, Normal variation in vagal tone, Nstemi, Pacemaker malfunction, Paroxysmal supraventricular tachycardia, Pericarditis, Permanent pacemaker, Peroneal muscular atrophy, Post aortic valve replacement, Post catheter ablation for arrhythmias, Post closure of a ventricular septal defect, Post mitral valve replacement, Preexcitation syndrome, Premature atrial beats, Pulmonary embolism, Pulmonary stenosis, Restrictive cardiomyopathy, Rheumatic mitral valve disease, Romano-ward syndrome, Sick sinus syndrome, Sinoatrial block, Sinus arrest, Sinus bradycardia, Sinus node disease, Sinus node fibrosis, Stemi, Subarachnoid hemorrhage, Sustained ventricular tachycardia, Tachycardia-bradycardia syndrome, Takotsubo cardiomyopathy, Tetralogy of fallot, Tilt testing, Timothy syndrome, Trained athletes, Transcatheter aortic valve implantation, Transposition of the great vessels, Vagal maneuvers, Vagal reaction, Valsalva maneuver, Valvular heart disease, Vasovagal syncope, Ventricular septal defect, Wolff-parkinson-white syndrome
Chemical/Poisoning 5-fluorouracil, Alcohol intoxication, All-trans retinoic acid, Carbamate poisoning, Carbamates, Crizotinib toxicity, Digitalis, Dimethyl sulfoxide, Disopyramide, Fentanyl, Heart block, Heart surgery, Heat exhaustion, Isoprenaline infusion, Lily of the valley poisoning, Magnesium, Organophosphate poisoning, Parathion poisoning, Poisonous spider bites, Pyrethroid poisoning, Scorpion toxin, Toluene sniffing
Dental No underlying causes
Dermatologic Dermatomyositis, Obstructive jaundice
Drug Side Effect Acetylcholine, Alfentanil, Ambenonium, Amiodarone, Amlodipine, Amphetamines, Anidulafungin, Anthracyclines, Antiarrhythmic drugs, Atenolol, Atetylcholine, Barbiturate, Berberine, Beta-blockers, Bethanechol, Bortezomib, Bupivacaine, Calcium channel blocker, Cannabis, Carbamazepine, Celecoxib, Ceritinib, Certain medications, Cilobradine, Cimetidine, Citalopram, Clonidine, Cocaine, Dapoxetine, Daunorubicin, Deserpidine, Dexmedetomidine, Digoxin, Diltiazem, Diphenhydramine, Distigmine, Dobutamine, Dolasetron, Donepezil, Doxorubicin, Dronedarone, Drugs, Edrophonium, Ephedrine, Epirubicin, Eslicarbazepine acetate, Febuxostat, Fesoterodine, Fingolimod, Flecainide, Flumazenil, Fluoxetine, Fluvoxamine, Fosphenytoin, Granisetron, Grayanotoxin, Guanethidine, Guanfacine, H2 receptor antagonist, Halothane, Hyoscyamine, Ibutilide, Idarubicin, Isoproterenol, Ivabradine, Labetalol, Lacosamide, Lanatoside c, Lanreotide, Lidocaine, Lithium, Lofexidine, Medications, Mefloquine, Mepivacaine, Mesalamine, Methyldopa, Methylprednisolone, Mexiletine, Morphine, Muscarine, Nadolol, Nefazodone, Nelfinavir, Neostigmine, Nerve agent, Nicorandil, Paclitaxel, Paliperidone, Palonosetron, Phenothiazine, Phenylephrine, Phenytoin, Physostigmine, Procainamide, Propafenone, Propanolol, Propofol, Propoxyphene, Propranolol, Pyridostigmine, Quinidine, Rabeprazole, Regadenoson, Remifentanil, Rescinnamine, Reserpine, Rilmenidine, Ropivacaine, Salbutamol, Sedative, Somatostatin, Sotalol, Sufentanil, Suxamethonium, Sympathomimetic agents, Tacrine, Tacrolimus, Terodiline, Theophylline, Thiamylal, Thiazides, Timolol, Tolterodine, Topical cocaine, Tramadol, Tricyclic antidepressants, Urapidil, Vecuronium, Verapamil, Veratridine (false hellebore), Zaleplon, Zatebradine
Ear Nose Throat Esophageal or nasopharyngeal stimulation, Sjogren's syndrome
Endocrine Cretinism, Cushing's syndrome, Hashimoto's thyroiditis, Hyperthyroidism, Hypothyroidism, Myxedema, Profound hypothyroidism, Thyrotoxic periodic paralysis, Thyrotoxicosis
Environmental No underlying causes
Gastroenterologic Nausea, Vomiting
Genetic Becker muscular dystrophy, Fabry disease, Hcm, Hcn4 mutation, Hereditary neuromuscular disease, Jervell and lange-nielsen syndrome, Kearns-sayre syndrome, Mitochondrial genome inherited conditions, Nail-patella syndrome, Scn5a mutation, Timothy syndrome, X-linked inherited conditions
Hematologic Anemia, Churg-strauss syndrome, Hemochromatosis, Hypercalcemia, Hypercapnia, Hyperkalemia, Hypermagnesemia, Hypocalcemia, Hypoglycemia, Hypokalemia, Hypomagnesemia, Hypoxia, Sepsis, Thalassemia major
Iatrogenic No underlying causes
Infectious Disease Aspergillosis myocarditis, Brucellosis, Chagas disease, Dengue fever, Diptheria, Legionellosis, Leptospirosis, Lyme disease, Malaria, Meningitis, Pneumonia, Protozoal infection, Q fever, Rabies, Rocky mountain spotted fever, Salmonellosis, Sepsis, Septic shock, Trichinosis, Tuberculosis, Typhoid fever, Typhus, Varicella zoster, Viral hemorrhagic fever, Yellow fever
Musculoskeletal/Orthopedic Arnold-chiari malformation, Dermatomyositis, Duchenne's muscular dystrophy, Emery-dreifuss muscular dystrophy, x-linked, Erb's dystrophy, Hereditary neuromuscular disease, Limb-girdle muscular dystrophy type 1b (lgmd1b), Mitochondrial myopathy, Muscular dystrophy, Myotonic dystrophy, Myotonic muscular dystrophy
Neurologic Bezold-jarisch reflex, Degenerative diseases, Diabetic neuropathy, Epilepsy, Friedreich ataxia, Increased intracranial pressure, Miller-dieker syndrome, Neurocardiogenic syncope, Raised intracranial pressure, Severe brain injury, Sleep apnea, Sleep, Timothy syndrome
Nutritional/Metabolic Cerebral edema, Diabetes mellitus, Diabetic ketoacidosis, Diabetic neuropathy, Glycogen storage disease type ii, Glycogenosis type 2b, Hypoglycemia, Kwashiorkor, Malnutrition, Metabolic acidosis, Obesity, Pompe disease, Severe anorexia nervosa, Starvation, Very low birth weight infants
Obstetric/Gynecologic Fetal distress, Pregnancy
Oncologic Hodgkin disease, Hodgkin lymphoma, Multiple myeloma, Pheochromocytoma, Tumor lysis syndrome, Tumor
Ophthalmologic No underlying causes
Overdose/Toxicity No underlying causes
Psychiatric Anorexia nervosa, Severe anorexia nervosa
Pulmonary Acute respiratory failure, Altitude sickness, Breath holding spells, Chronic obstructive pulmonary disease, Cough syncope, Decompression sickness, Drowning, Obstructive sleep apnea, Post lung transplantation, Pulmonary embolism, Pulmonary stenosis, Sarcoidosis, Sleep apnea, Tuberculosis
Renal/Electrolyte Acute renal failure, Amyloidosis, Chronic renal failure, Electrolyte disturbances, Hyperkalemia, Hypokalemia, Renal failure
Rheumatology/Immunology/Allergy Acute rheumatic fever, Ankylosing spondylitis, Churg-strauss syndrome, Neonatal lupus erythematosus, Reiter's syndrome, Relapsing polychondritis, Rheumatic fever, Rheumatic mitral valve disease, Rheumatoid arthritis, Sarcoidosis, Scleroderma, Sinus node fibrosis, Sjogren's syndrome, Systemic lupus erythematosus, Systemic sclerosis
Sexual No underlying causes
Trauma Cervical spine injury, Electric shock, Hypothermia, Pain, Septic shock, Severe brain injury, Spinal cord injury, acute, Starvation, Surgical trauma, Trauma
Urologic No underlying causes
Miscellaneous Aging, Defecation, Idiopathic

Causes Based on Pathophysiologic Origin of Impulse

From the Atria

Respiratory Sinus Arrhythmia

Sinus bradycardia

Sinoatrial block

Sinus arrest

Sick sinus syndrome


First degree AV block

Second degree AV block

Complete or third-degree AV block

Short PR interval

From the AV junction

Junctional bradycardia

From the Ventricles

Isorhythmic A-V dissociation

Idioventricular rhythm

Ventricular escape beat

Combined List of Causes in Alphabetical Order

References

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