Etiology
Arrhythmia/Conduction Disturbance
Bradyarrhythmia Tachyarrythmia
Primary Cardiomyopathies (Predominantly Involving the Heart) Genetic Arrhythmogenic Right Ventricular Cardiomyopathy (Arrhythmogenic Right Ventricular Dysplasia) (see Arrhythmogenic Right Ventricular Cardiomyopathy ) Conduction System DiseaseLenegre Disease Sick Sinus Syndrome Glycogen Storage Diseases Hypertrophic Cardiomyopathy Ion ChannelopathiesBrugada Syndrome Catecholaminergic Polymorphic Ventricular Tachycardia Idiopathic Ventricular Fibrillation Long-QT Syndrome Short-QT Syndrome Left Ventricular Noncompaction Mitochondrial Myopathies Mixed (Predominantly Non-Genetic; Familial Disease with a Genetic Origin has been Reported in a Minority of Cases) Dilated Cardiomyopathy: this is a heterogeneous group of disorders characaterized by ventricular dilation and decreased myocardial contractility in the absence of abnormal loading (valvular heart disease, hypertension) Restrictive Cardiomyopathy (Non-Dilated and Non-Hypertrophied) Acquired Cardiomyopathy in Infants of Insulin-Dependent Diabetic Mothers Myocarditis (Inflammatory Cardiomyopathy) (see Myocarditis ) Peripartum Cardiomyopathy Tachycardia-Induced Cardiomyopathy Takotsubo Cardiomyopathy (Stress Cardiomyopathy) (see Takotsubo Cardiomyopathy ) Secondary Cardiomyopathies Cardiofacial Lentiginosis Noonan Syndrome Endocrine/Metabolic Endomyocardial Hematologic Disease Infiltrative (Accumulation of Abnormal Substances in Extracellular Space Between Myocytes) Amyloidosis (see Amyloidosis ) Gaucher’s Disease Hunter’s Syndrome Hurler’s Syndrome Infectious/Inflammatory Hantavirus Cardiopulmonary Syndrome (see Hantavirus Cardiopulmonary Syndrome ): unusually produces sepsis with a low CO and high SVR physiologyHantavirus Genus: Sin Nombre Virus (SNV) is the most commonly associated Hantavirus in the US Hemorrhagic Fever with Renal Syndrome (HFRS) (see Hemorrhagic Fever with Renal Syndrome )Hantavirus Genus: Hantaan Virus, Dobrova Virus, Seoul Virus (Baltimore Rat Virus) Sarcoidosis (see Sarcoidosis ) Sepsis-Induced Myocardial Depression (see Sepsis ) Ischemic Acute Myocardial Infarction (MI) (see Coronary Artery Disease )Physiology: involving >40% of left ventricular myocardium or right ventricular infarction Myocardial Ischemia Stunned Myocardium (from Prolonged Ischemia) Neoplasm Neuromuscular/Neurologic Becker Muscular Dystrophy (see Becker Muscular Dystrophy ) Chronic Progressive External Opthmoplegia (Kearns-Savre) Duchenne Muscular Dystrophy (see Duchenne Muscular Dystrophy ) Emery-Dreifuss Muscular Dystrophy Familial Centronuclear Myopathy Fascioscapulohumeral Dystrophy (Landouzy-Dejerine) Friedrich’s Ataxia Humuloperitoneal Ataxia Juvenile Progressive Spinal Muscular Atrophy (Kugelberg-Welander) Limb-Girdle Muscular Dystrophy Myotonia Atrophica (Steinert) Myotonic Dystrophy Neurofibromatosis (see Neurofibromatosis ) Tuberous Sclerosis (see Tuberous Sclerosis ) Nutritional Carnitine Deficiency (see Carnitine ) Keshan’s Disease Kwashiorkor Niacin Deficiency (Pellagra) (see Niacin ) Selenium Deficiency (see Selenium ) Thiamine Deficiency (Beriberi) (see Thiamine ) Vitamin C Deficiency (Scurvy) (see Vitamin C Rheumatologic Storage (Accumulation of Abnormal Substances Intracellularly Within Myocytes) Traumatic Drug/Toxin Other
Increased Afterload
Increased Intrathoracic Pressure (with Impaired Right-Sided Venous Return)
Herniation of Abdominal Viscera Into Thorax Positive-Pressure Ventilation with High Airway Pressures (see Acute Respiratory Distress Syndrome , [[Acute Respiratory Distress Syndrome]])Tension Pneumothorax (see Pneumothorax , [[Pneumothorax]])
Valvular Disease/Mechanical Disturbance
Aortic Insufficiency (AI) (see Aortic Insufficiency , [[Aortic Insufficiency]])Aortic Stenosis (AS) (see Aortic Stenosis , [[Aortic Stenosis]])Atrial Myxoma (see Atrial Myxoma , [[Atrial Myxoma]])Atrial Thrombus (see Intracardiac Thrombus , [[Intracardiac Thrombus]])Constrictive Pericarditis (see Constrictive Pericarditis , [[Constrictive Pericarditis]])Mitral Regurgitation (MR) (see Mitral Regurgitation , [[Mitral Regurgitation]])Mitral Stenosis (see Mitral Stenosis , [[Mitral Stenosis]])Papillary Muscle Dysfunction/Rupture Pulmonic Stenosis (see Pulmonic Stenosis , [[Pulmonic Stenosis]])Ruptured Left Ventricular Aneurysm (see Left Ventricular Aneurysm , [[Left Ventricular Aneurysm]])Ruptured Sinus of Valsalva Aneurysm (see Sinus of Valsalva Aneurysm , [[Sinus of Valsalva Aneurysm]])Tamponade (see Tamponade , [[Tamponade]])Physiology : produces diastolic dysfunctionTricuspid Regurgitation (TR) (see Tricuspid Regurgitation , [[Tricuspid Regurgitation]])Tricuspid Stenosis (see Tricuspid Stenosis , [[Tricuspid Stenosis]])Ventricular Septal Defect (VSD) (see Ventricular Septal Defect , [[Ventricular Septal Defect]])
Distributive Shock (Vasodilatory Shock)
Anaphylaxis/Anaphylactic Shock
Anaphylaxis (see Anaphylaxis , [[Anaphylaxis]])Physiology : peripheral vasodilation (due to histamine and other vasoactive substances)
Infection
Anaplasmosis Sepsis-Like or Toxic Shock-Like Syndrome (see Anaplasmosis , [[Anaplasmosis]])Ehrlichiosis Sepsis-Like or Toxic Shock-Like Syndrome (see Ehrlichiosis , [[Ehrlichiosis]])Sepsis/Septic Shock (see Sepsis , [[Sepsis]])Epidemiology : sepsis is the most common type of distributive shockPhysiology : third-spacing of fluids (with decreased intravascular volume) and peripheral vasodilationToxic Shock Syndrome (TSS) Types Physiology : peripheral vasodilation
Systemic Inflammatory Response Syndrome (SIRS) (see Sepsis )
Endocrine/Metabolic/Nutritional Deficiency-Associated Hypotension
Acidemia Adrenal Insufficiency (see Adrenal Insufficiency , [[Adrenal Insufficiency]])Physiology : peripheral vasodilationHyperthyroidism (see Hyperthyroidism , [[Hyperthyroidism]])Hypothyroidism/Myxedema (see Hypothyroidism , [[Hypothyroidism]])Physiology : peripheral vasodilationPheochromocytoma (see Pheochromocytoma , [[Pheochromocytoma]])Epidemiology : occurs in some casesClinical Patterns Episodic Hypotension: in rare cases where the tumor secretes only epinephrine Pattern of Rapid Cyclic Fluctuation Between Hypertension and Hypotension (Cycling Every 7-15 min): unclear mechanism Orthostatic Hypotension: due predominantly to decreased plasma volume Thiamine Deficiency (Beriberi) (see Thiamine , [[Thiamine]])Physiology : peripheral vasodilation
Hematologic Disease-Associated Hypotension
Acute Spinal Cord Injury (SCI) (see Acute Spinal Cord Injury )Physiology Interruption of Autonomic Pathways, Resulting in Decreased Systemic Vascular Resistance and Altered Vagal Tone: probably the predominant mechanism Myocardial Depression: may also play a role Acute Blood Loss: may also play a role in some cases Brain Herniation (Due to Foramen Magnum Herniation) (see Increased Intracranial Pressure )Physiology : compression of brainstem and/or upper cervical spinal cordChronic Spinal Cord Injury (SCI) (see Acute Spinal Cord Injury )Guillain-Barre Syndrome (GBS) (see Guillain-Barre Syndrome )Epidemiology Autonomic Dysfunction is Common in GBS (Occurs in Approximately 66% of Cases) Clinical Arrhythmias Blood Pressure Fluctuations Bradycardia/Tachycardia Gastrointestinal Dysfunction Multiple Sclerosis (see Multiple Sclerosis )Epidemiology Autonomic Dysfunction Can Occur Clinical Neuraxial (Spinal) Anesthesia (see Spinal Anesthesia )Transverse Myelitis (see Transverse Myelitis )Traumatic Brain Injury (TBI) (see Traumatic Brain Injury )
Drug/Toxin-Associated Hypotension
Abacavir-Hypersensitivity Reaction (see Abacavir )Pharmacology : peripheral vasodilationAlcohol Intoxications Ethanol (see Ethanol )Pharmacology: peripheral vasodilation Ethylene Glycol Intoxication (see Ethylene Glycol )Pharmacology: peripheral vasodilation Isopropanol Intoxication (see Isopropanol )Pharmacology: peripheral vasodilation Methanol Intoxication (see Methanol , [[Methanol]])Pharmacology: peripheral vasodilation All-Trans Retinoic Acid (ATRA)/Retinoic Acid Syndrome (see All-Trans Retinoic Acid , [[All-Trans Retinoic Acid]])Pharmacology : peripheral vasodilationAmiodarone (see Amiodarone , [[Amiodarone]])Pharmacology : peripheral vasodilation (note: negative inotropy can also occur in patients with preexisting left ventricular dysfunction with EF <35%)Benzodiazepines (see Benzodiazepines , [[Benzodiazepines]])Pharmacology : peripheral vasodilationCapsaicin (see Capsaicin , [[Capsaicin]])Pharmacology : peripheral vasodilationCholinergic Intoxication (see Cholinergic Intoxication , [[Cholinergic Intoxication]])Cigua Toxin Poisoning (see Cigua Toxin Poisoning , [[Cigua Toxin Poisoning]])Physiology : dysfunction of calcium and sodium channels, resulting in peripheral vasodilationCyanide Intoxication (see Cyanide , [[Cyanide]])Pharmacology : mitochondrial dysfunctionClinical : hypotension occurs late in the courseCytokine Release Syndrome (see Cytokine Release Syndrome , [[Cytokine Release Syndrome]])Pharmacology : peripheral vasodilationDexmedetomidine (Precedex) (see Dexmedetomidine , [[Dexmedetomidine]])Pharmacology : peripheral vasodilationDobutamine (Dobutrex) (see Dobutamine , [[Dobutamine]])Pharmacology : myocardial β1-adrenergic receptor agonist (chronotropic/inotropic effects) and vascular β2-adrenergic/α1-adrenergic receptor agonist (if vascular β2-adrenergic effects exceed α1-adrenergic receptor agonist effects, some peripheral vasodilation may occur)Endothelin Receptor Antagonists (ERA’s) (see Endothelin Receptor Antagonists , [[Endothelin Receptor Antagonists]])Pharmacology : peripheral vasodilationEnvenomations Types Scorpion Sting (see Scorpion Sting , [[Scorpion Sting]]) Rattlesnake Bit (see Rattlesnake Bite , [[Rattlesnake Bite]]) Widow Spider Bite (see Widow Spider Bite , [[Widow Spider Bite]])Epidemiology: hypertension is more characteristically seen in widow spider bites, hypotension occurs rarely Estrogen (see Estrogen , [[Estrogen]])Pharmacology : peripheral vasodilationGlyphosate Ingestion (see Glyphosate , [[Glyphosate]])Pharmacology : peripheral vasodilationHemoglobinopathies Carboxyhemoglobinemia (see Carboxyhemoglobinemia , [[Carboxyhemoglobinemia]])Pharmacology: mitochondrial dysfunction Methemoglobinemia (see Methemoglobinemia , [[Methemoglobinemia]])Physiology: peripheral vasodilation Hexoprenaline (Gynipral) (see Hexoprenaline , [[Hexoprenaline]])Pharmacology : β2-adrenergic receptor agonistHydrogen Sulfide Gas Inhalation (see Hydrogen Sulfide Gas , [[Hydrogen Sulfide Gas]])Intravenous Immunoglobulin (IVIG) (see Intravenous Immunoglobulin , [[Intravenous Immunoglobulin]])L-Arginine (see L-Arginine , [[L-Arginine]])Pharmacology : nitric oxide induction, resulting in peripheral vasodilationMagnesium Sulfate (see Magnesium Sulfate , [[Magnesium Sulfate]])Epidemiology : with rapid infusionMetal Intoxications Agents Arsenic Intoxication (see Arsenic , [[Arsenic]]) Iron Intoxication (see Iron , [[Iron]]) Manganese Intoxication (see Manganese , [[Manganese]]) Selenium Intoxication (see Selenium , [[Selenium]]) Thallium Intoxication (see Thallium , [[Thallium]]) Pharmacology : peripheral vasodilationN-Acetylcysteine (Mucomyst, Acetadote, Fluimucil, Parvolex) (see N-Acetylcysteine , [[N-Acetylcysteine]])Epidemiology : associated with oral administrationPharmacology : peripheral vasodilationNerium Oleander Intoxication (see Nerium Oleander , [[Nerium Oleander]])Neuroleptic Malignant Syndrome (NMS) (see Neuroleptic Malignant Syndrome , [[Neuroleptic Malignant Syndrome]])Physiology : autonomic instabilityNitrites and Nitrates (see Nitrites and Nitrates , [[Nitrites and Nitrates]])Pharmacology : nitric oxide induction, resulting in peripheral vasodilationOcrelizumab (Ocrevus) (see Ocrelizumab , [[Ocrelizumab]])Epidemiology : may occur as a component of infusion reactionOpiates (see Opiates , [[Opiates]])Pharmacology : peripheral vasodilationPapaverine (see Papaverine , [[Papaverine]])Pharmacology : peripheral vasodilationPhenytoin (Dilantin/)Fosphenytoin (Cerebyx) (see Fosphenytoin , [[Fosphenytoin]] and (see Phenytoin , [[Phenytoin]])Pharmacology : peripheral vasodilationPhosphodiesterase Type 5 (PDE5) Inhibitors (see Phosphodiesterase Type 5 Inhibitors , [[Phosphodiesterase Type 5 Inhibitors]])Pharmacology : inhibits phosphodiesterase 5/PDE5 (the enzyme which degrades cGMP), resulting in enhanced NO-mediated smooth muscle relaxation and therefore, peripheral vasodilationPropofol (Diprivan) (see Propofol , [[Propofol]])Pharmacology : peripheral vasodilationProstaglandins with Vasodilatory Properties Agents Epoprostenol (PGI2, Prostacyclin, Flolan, Veletri) (see Epoprostenol , [[Epoprostenol]]) Iloprost (Ilomedin, Ventavis) (see Iloprost , [[Iloprost]]) Prostaglandin E1 (Alprostadil) (see Prostaglandin E1 , [[Prostaglandin E1]]) Pharmacology : peripheral vasodilationProtamine (see Protamine , [[Protamine]])Pharmacology : peripheral vasodilationRasburicase (Elitek) (see Rasburicase , [[Rasburicase]])Pharmacology : peripheral vasodilationRuxolitinib (Jakafi) Withdrawal Syndrome (see Ruxolitinib , [[Ruxolitinib]])Epidemiology : occurs 1 day-3 wks after drug withdrawalSalicylate Intoxication (see Acetylsalicylic Acid , [[Acetylsalicylic Acid]])Pharmacology : peripheral vasodilationClinical : pseudosepsis with fever, tachypnea, metabolic acidosis, and hypotensionScombroid (see Scombroid , [[Scombroid]])Pharmacology : peripheral vasodilationSerotonin Syndrome (see Serotonin Syndrome , [[Serotonin Syndrome]])Pharmacology : peripheral vasodilationSevelamer (Renagel, Renvela) (see Sevelamer , [[Sevelamer]])Tetrahydrocannabinol (THC) (see Tetrahydrocannabinol , [[Tetrahydrocannabinol]])Pharmacology : peripheral vasodilationTetrodotoxin Epidemiology : associated with ingestion of tetrodotoxin-contaminated pufferfishPhysiology : tetrodotoxin inhibits sodium channels on vascular smooth muscleTheobromine (see Theobromine , [[Theobromine]])Pharmacology : peripheral vasodilationThrombolytics (see Thrombolytics , [[Thrombolytics]])Transfusion-Associated Acute Lung Injury (TRALI) (see Transfusion-Associated Acute Lung Injury , [[Transfusion-Associated Acute Lung Injury]])Tricyclic Antidepressant Intoxication (see Tricyclic Antidepressants , [[Tricyclic Antidepressants]])Pharmacology : peripheral vasodilationVancomycin-Associated Red Man Syndrome (see Vancomycin , [[Vancomycin]])Pharmacology : peripheral vasodilationVasodilator Antihypertensives Agents α-Adrenergic Receptor Antagonists (see α-Adrenergic Receptor Antagonists , [[α-Adrenergic Receptor Antagonists]])Pharmacology: α2-adrenergic receptor antagonism, resulting peripheral vasodilation α-Methyldopa (Aldomet, Aldoril, Dopamet, Dopegyt) (see α-Methyldopa , [[α-Methyldopa]])Pharmacology: α2-adrenergic receptor agonist, resulting in peripheral vasodilation Angiotensin Converting Enzyme (ACE) Inhibitors (see Angiotensin Converting Enzyme (ACE) Inhibitors , [[Angiotensin Converting Enzyme Inhibitors]])Pharmacology: angiotensin converting enzyme inhibition, resulting in peripheral vasodilation Angiotensin II Receptor Blockers (ARB) (see Angiotensin II Receptor Blockers , [[Angiotensin II Receptor Blockers]])Pharmacology: angiotensin II receptor inhibition, resulting in peripheral vasodilation β-Adrenergic Receptor Antagonists (β-Blockers) (see β-Adrenergic Receptor Antagonists , [[β-Adrenergic Receptor Antagonists]])Pharmacology: β-adrenergic receptor antagonism, resulting in decreased cardiac output and peripheral vasodilation Calcium Channel Blockers (see Calcium Channel Blockers , [[Calcium Channel Blockers]])Pharmacology: calcium channel antagonism, resulting in peripheral vasodilation (and additionally decreased cardiac output with some of the agents) Clonidine (Catapres, Kapvay, Nexiclon) (see Clonidine , [[Clonidine]])Pharmacology: α2-adrenergic receptor agonism, resulting in peripheral vasodilation Hydralazine (see Hydralazine , [[Hydralazine]])Pharmacology: peripheral vasodilation Minoxidil (see Minoxidil , [[Minoxidil]])Pharmacology: direct relaxation of arteriolar smooth muscle (possibly mediated by cAMP), resulting in peripheral vasodilation
Other
Cirrhosis/End-Stage Liver Disease (see Cirrhosis , [[Cirrhosis]])Physiology : characteristically produces a high cardiac output (CO)/low systemic vascular resistance (SVR) stateHepatic Veno-Occlusive Disease (see Hepatic Veno-Occlusive Disease , [[Hepatic Veno-Occlusive Disease]])Pregnancy (see Pregnancy , [[Pregnancy]])Physiology : pregnancy increases plasma volume, increases cardiac output, increases stroke volume, increases heart rate, decreases blood pressure, and decreases SVRPurpura Fulminans (see Purpura Fulminans , [[Purpura Fulminans]])Systemic Arteriovenous Fistula (see Systemic Arteriovenous Fistula , [[Systemic Arteriovenous Fistula]])Types Femoral Arteriovenous Fistula: most common type of acquired arteriovenous fistula (due to the frequency of using the femoral site for percutaneous arterial or venous access) Hemodialysis Arteriovenous Fistula (see Hemodialysis Arteriovenous Fistula , [[Hemodialysis Arteriovenous Fistula]]) Clinical : high output heart failure may occurSystemic Mastocytosis (see Systemic Mastocytosis )Physiology : peripheral vasodilationVasoplegic Syndrome (Post-Cardiac Surgery Vasodilation) (see Vasoplegic Syndrome )Physiology : peripheral vasodilation following cardiac surgeryVasovagal Syncope (see Vasovagal Syncope )Physiology : peripheral vasodilation
Gastrointestinal Hemorrhage (see Gastrointestinal Hemorrhage , [[Gastrointestinal Hemorrhage]])
Intramuscular Hemorrhage (Into Thigh)
Intraoperative/Postoperative Hemorrhage
Trauma with External Hemorrhage
Motor Vehicle Accident (MVA) Traumatic Fall/Assault
Uterine/Vaginal Hemorrhage
Post-Partum Hemorrhage Uterine Tumor Vaginal Laceration
Other
Dermal Fluid Loss
Altered Mental Status with Inadequate Fluid Intake Burns (see Burns )Diaphoresis (see Diaphoresis )Heat Stroke/Environmental Exposure (see Heat Stroke )
Gastrointestinal Fluid Loss
Renal Fluid Loss
Excessive Diuresis Hypoaldosteronism (see Hypoaldosteronism )Epidemiology : although aldosterone normally acts to increase sodium retention, hypoaldosteronism is not usually associated with significant sodium wasting (except in young children)This is due to the compensatory action of other sodium-retaining stimuli (such as angiotensin II and norepinephrine) Pheochromocytoma (see Pheochromocytoma )Epidemiology : occurs in some casesClinical Patterns Episodic Hypotension: in rare cases where the tumor secretes only epinephrine Pattern of Rapid Cyclic Fluctuation Between Hypertension and Hypotension (Cycling Every 7-15 min): unclear mechanism Orthostatic Hypotension: due predominantly to decreased plasma volume Salt-Wasting Nephropathy
Third-Space Fluid Loss
Acute Pancreatitis (see Acute Pancreatitis )Cirhosis (see Cirrhosis )Crush Injury Intestinal Obstruction Post-Operative Intraabdominal Fluid Loss Trauma
Obstructive Shock
Mechanical
Pulmonary Vascular
Diagnostic
Arterial Line (see Arterial Line , [[Arterial Line]])
Bedside Ultrasound
Clinical Efficacy
SHoC-ED International Randomized, Controlled Trial of Bedside Ultrasound in Undifferentiated Hypotension in the Emergency Department (Ann Emerg Med, 2018) [MEDLINE ]: n= 273The Most Common Diagnosis in >50% of the Patients was Occult Sepsis Bedside (Point-of-Care) Ultrasound Did Not Impact the Mortality Rate, ICU or Total Length of Stay, Rate of CT Scanning, Inotrope Use, or Intravenous Fluid Administration in Undifferentiated Hypotension
Clinical Manifestations
Cardiovascular Manifestations
Neurologic Manifestations
Altered Mental Status Fatigue (see Fatigue )Increased Intracranial Pressure (see Increased Intracranial Pressure )Physiology : hypotension causes cerebral vasodilationClinical : potentiation of neurologic injury in traumatic brain injury (TBI), etc
Renal Manifestations
Acute Kidney Injury (AKI) (see Acute Kidney Injury )Physiology Acute Tubular Necrosis (ATN) Impaired Renal Perfusion
Treatment
Vasopressors
References
Does Point-of-Care Ultrasonography Improve Clinical Outcomes in Emergency Department Patients With Undifferentiated Hypotension? An International Randomized Controlled Trial From the SHoC-ED Investigators. Ann Emerg Med. 2018 Oct;72(4):478-489. doi: 10.1016/j.annemergmed.2018.04.002 [MEDLINE ]