Cardiology > Hypotension

   Background

Hypotension is defined as abnormally low blood pressure, typically considered as systolic blood pressure (SBP) <90 mmHg and/or diastolic blood pressure (DBP) <60 mmHg. It may be transient and benign (e.g., in healthy young adults) or pathologic, reflecting underlying volume depletion, autonomic dysfunction, cardiac impairment, or sepsis. When it leads to impaired organ perfusion, hypotension becomes a medical emergency. 

II) Classification or Types 

By Clinical Context: 

• • Orthostatic (Postural) Hypotension: A drop in SBP ≥20 mmHg or DBP ≥10 mmHg within 3 minutes of standing. 

• • Neurogenic Hypotension: Due to autonomic dysfunction, often seen in diabetes, Parkinson’s disease, or spinal cord injury. 

• • Shock-related Hypotension: Includes hypovolemic, cardiogenic, distributive (e.g., septic, anaphylactic), and obstructive shock. 

• • Postprandial Hypotension: Occurs after meals, especially in older adults or those with autonomic failure. 

• • Drug-induced Hypotension: Caused by antihypertensives, diuretics, sedatives, or vasodilators. 

By Duration: 

• • Acute: Sudden drop, often due to volume loss, cardiac events, or sepsis. 

• • Chronic: Persistent low BP without acute distress, often asymptomatic or due to autonomic disorders. 

III) Epidemiology 

• • Sex: Orthostatic hypotension more common in elderly women; drug-induced hypotension affects both sexes. 

• • Age: Increases with age due to impaired baroreflex and medication use. 

• • Geography: More prevalent in areas with higher cardiovascular medication usage. 

• • Comorbidities: Diabetes, Parkinson’s disease, heart failure, adrenal insufficiency, sepsis, dehydration. 

   Etiology

I) What Causes It 

• • Volume Depletion: Hemorrhage, dehydration, diarrhea, diuretics. 

• • Cardiac Causes: Myocardial infarction, arrhythmias, heart failure, valvular disease. 

• • Vasodilation: Sepsis, anaphylaxis, adrenal insufficiency. 

• • Medications: Antihypertensives, beta-blockers, nitrates, opioids, antipsychotics. 

• • Autonomic Failure: Parkinson’s disease, diabetic neuropathy, multiple system atrophy. 

• • Endocrine Causes: Addison’s disease, hypothyroidism. 

II) Risk Factors 

• • Age >65 years 

• • Use of antihypertensive or psychotropic medications 

• • Diabetes mellitus 

• • Dehydration or fluid restriction 

• • Recent surgery or trauma 

• • Sepsis or infection 

• • Neurodegenerative diseases 

 Clinical Presentation

I) History (Symptoms) 

• • Dizziness or lightheadedness, especially upon standing 

• • Syncope or near-syncope 

• • Blurred vision 

• • Fatigue 

• • Nausea 

• • Cold or clammy skin 

• • Palpitations 

• • Chest pain or shortness of breath (if secondary to cardiac causes) 

II) Physical Exam (Signs) 

Vital Signs: 

• • SBP <90 mmHg and/or DBP <60 mmHg 

• • Tachycardia in hypovolemia; bradycardia in neurogenic causes 

• • Orthostatic changes in BP and HR 

Cardiac Exam: 

• • May reveal murmurs (e.g., aortic stenosis) 

• • Irregular rhythm in arrhythmia-related hypotension 

Pulmonary Exam: 

• • Rales or crackles if CHF is contributing 

Peripheral and Skin: 

• • Cool extremities, mottling 

• • Delayed capillary refill 

• • Diaphoresis (shock) 

Neurological: 

• • Altered mental status or confusion in severe hypotension or shock 

   Differential Diagnosis (DDx)

• • Syncope (vasovagal, orthostatic, cardiogenic) 

• • Sepsis or systemic inflammatory response syndrome (SIRS) 

• • Hypovolemic shock 

• • Adrenal insufficiency 

• • Myocardial infarction 

• • Arrhythmias (e.g., bradyarrhythmia, tachyarrhythmia) 

• • Autonomic neuropathy (diabetes, Parkinson’s) 

   Diagnostic Tests

Initial Tests: 

• • Orthostatic Vital Signs: Measure BP and HR supine and after standing 

• • Electrocardiogram (ECG): Evaluate for arrhythmias or ischemia 

• • CBC: Anemia, blood loss 

• • Basic Metabolic Panel: Electrolyte disturbances, renal function 

• • Blood Glucose: Hypoglycemia 

• • TSH/Cortisol: Endocrine causes 

• • Cardiac Enzymes: Rule out myocardial infarction 

• • Urinalysis: Dehydration or infection 

• • Lactate: Marker of tissue hypoperfusion 

• • Echocardiogram: If cardiac etiology suspected 

• • Tilt Table Test: For autonomic dysfunction 

   Treatment

I) Medical Management 

General Measures: 

• • Supine positioning with legs elevated (Trendelenburg) 

• • IV fluid resuscitation for volume depletion 

• • Discontinue or adjust offending medications 

Specific Therapy: 

• • Volume Depletion: Isotonic saline infusion 

• • Sepsis: IV fluids + antibiotics ± vasopressors (e.g., norepinephrine) 

• • Cardiac Causes: Treat underlying arrhythmia or ischemia 

• • Adrenal Insufficiency: Hydrocortisone 

• • Autonomic Dysfunction: 

• • Fludrocortisone (volume expansion) 

• • Midodrine (alpha-agonist vasoconstrictor) 

• • Compression stockings 

• • Increased salt and fluid intake 

II) Interventional/Surgical 

• • Pacemaker for bradycardia-related hypotension 

• • Cardioversion for tachyarrhythmias 

• • Coronary angioplasty or bypass in ischemic heart disease 

• • Surgery for hemorrhage control (e.g., GI bleed, trauma) 

   Patient Education, Screening, Vaccines

• • Educate on rising slowly from bed or chair 

• • Adequate hydration and salt intake (if not contraindicated) 

• • Medication review and adherence 

• • Compression garments if recurrent orthostatic hypotension 

• • Monitor for recurrence of symptoms 

• • Vaccinations: 

• • Influenza annually 

• • Pneumococcal vaccination 

• • COVID-19 vaccination 

  Consults

• • Cardiology: Suspected cardiac etiology or refractory hypotension 

• • Endocrinology: Adrenal or thyroid dysfunction 

• • Neurology: Autonomic failure, Parkinson’s disease 

• • Infectious Disease: Sepsis 

• • Geriatrics/Internal Medicine: Polypharmacy or recurrent orthostatic hypotension 

• • Electrophysiology: Bradyarrhythmias or syncope work-up 

   Follow-Up

• • Re-evaluate orthostatic vitals and symptoms 

• • Adjust medications contributing to hypotension 

• • Monitor for recurrence, especially in elderly 

• • Regular BP checks at home 

• • Manage comorbidities: diabetes, CHF, adrenal insufficiency 

• • Reinforce lifestyle modifications: hydration, slow position changes, meal planning