What is the cause and appropriate management of dizziness and palpitations?

Dizziness and Palpitations: Diagnostic and Management Approach

Dizziness with palpitations requires immediate evaluation with a 12-lead ECG and assessment for hemodynamic instability, as this combination suggests potential cardiac arrhythmia that may require urgent intervention. 1, 2, 3

Immediate Risk Stratification

Patients with palpitations accompanied by dizziness require urgent evaluation for life-threatening conditions. 2, 3, 4

Red Flags Requiring Emergency Care:

• Syncope or near-syncope with palpitations 1, 2
• Chest pain or pressure 2
• Severe dyspnea or signs of heart failure 2
• Palpitations occurring during exertion 2
• Hemodynamic instability 1, 5

Initial Assessment:

• Obtain 12-lead ECG immediately - this is the gold standard for diagnosis when symptoms are present 2, 3, 4
• Measure orthostatic vital signs - lying and standing blood pressure and heart rate at 3 minutes (or 10 minutes if POTS suspected) 2
• Assess symptom characteristics: sudden onset/offset suggests reentrant tachycardias (AVNRT/AVRT), while gradual onset suggests sinus tachycardia or anxiety 2
• Determine rhythm pattern: irregular suggests atrial fibrillation or premature beats; regular rapid rhythm suggests supraventricular or ventricular tachycardia 2

Common Etiologies

Cardiac Arrhythmias (Most Concerning):

Supraventricular Tachycardia (AVNRT):

• Most common SVT, typically presents with sudden onset palpitations, shortness of breath, dizziness, and neck pulsations 1
• Ventricular rate typically 180-200 bpm but ranges from 110 to >250 bpm 1
• Rarely life-threatening but requires specific treatment 1

Atrial Flutter:

• Regular atrial rate of approximately 300 per minute with typical 2:1 conduction 5
• Dizziness indicates potential hemodynamic compromise 5
• Carries significant stroke risk similar to atrial fibrillation 5

Sick Sinus Syndrome and AV Block:

• Syncope due to long pauses from sinus arrest or sinoatrial block, most frequently when atrial tachyarrhythmia suddenly stops (brady-tachy syndrome) 1
• Mobitz II block, high-grade, and complete AV block most closely related to syncope 1

Orthostatic Causes:

Classical Orthostatic Hypotension:

• Symptoms occur 30 seconds to 3 minutes after standing 1
• Presents with dizziness, pre-syncope, fatigue, weakness, palpitations, visual and hearing disturbances 1
• Common in elderly, drug-induced (vasoactive drugs and diuretics) 1

Postural Orthostatic Tachycardia Syndrome (POTS):

• Excessive heart rate increase (>30 bpm or >120 bpm) within 10 minutes of standing 2
• Commonly affects young women 2
• Symptomatic marked heart rate increases with blood pressure instability, but typically no syncope 1

Reflex Syncope:

• Prolonged prodrome (dizziness, fatigue, weakness, palpitations, visual/hearing disturbances, hyperhydrosis, low back pain, neck/precordial pain) followed by rapid syncope 1
• Can be triggered by standing, with initial normal adaptation followed by rapid fall in venous return and vasovagal reaction 1

Diagnostic Workup

Essential Initial Tests:

• 12-lead ECG looking for conduction abnormalities, QT prolongation, signs of ischemia, ventricular ectopy, or arrhythmias 2, 6
• Orthostatic vital signs with lying and standing measurements 2
• Detailed medication review including over-the-counter drugs, supplements, and stimulants 2, 6

Additional Testing When Initial Evaluation Non-Diagnostic:

• Ambulatory ECG monitoring (Holter 24-48 hours) if palpitations occur daily 4
• Two-week continuous closed-loop event recording if palpitations occur unpredictably or not daily 4
• Implantable loop recorders especially useful in elderly patients with unexplained syncope 6
• Echocardiography for abnormal ECG, suspected structural heart disease, or frequent PVCs (>10,000/day) 2
• Exercise stress testing if palpitations occur with exertion or concern for ischemia-induced arrhythmia 2

Acute Management

For Supraventricular Tachycardia (AVNRT):

First-line intervention:

• Vagal maneuvers (Valsalva, carotid sinus massage, ice-cold wet towel to face) performed with patient supine 1
• Valsalva: bearing down against closed glottis for 10-30 seconds, equivalent to 30-40 mmHg 1
• Carotid massage: steady pressure over carotid sinus for 5-10 seconds after confirming absence of bruit 1

If vagal maneuvers fail:

• Adenosine IV - terminates AVNRT in approximately 95% of patients 1

If hemodynamically unstable:

• Synchronized cardioversion when adenosine and vagal maneuvers fail or not feasible 1

For Atrial Flutter with Hemodynamic Compromise:

• Immediate synchronized cardioversion if showing signs of acute hemodynamic collapse, congestive heart failure, or cannot tolerate rhythm 5
• Rate control with IV beta blockers (esmolol) or calcium channel blockers (diltiazem) 5
• Rhythm control if onset <48 hours: electrical cardioversion or pharmacological cardioversion with oral dofetilide or IV ibutilide 5

For Orthostatic Hypotension:

• Mild hypotension: IV normal saline to maintain systolic BP >100 mmHg 1
• Dehydration-related symptoms: fluid resuscitation via oral or IV bolus 2

Ongoing Management

POTS Management:

• Increased salt and fluid intake 2
• Physical reconditioning with gradual exercise program 2
• Compression stockings 2
• Midodrine for refractory symptoms 2

Benign Premature Contractions (PVCs/PACs):

• Lifestyle modifications: eliminate triggers (caffeine, alcohol, stimulants) 2
• Beta-blockers for symptomatic relief if lifestyle modifications insufficient 2

Atrial Flutter Definitive Treatment:

• Catheter ablation of cavotricuspid isthmus is preferred definitive treatment for symptomatic atrial flutter 5
• Prevents tachycardia-mediated cardiomyopathy and provides long-term cure 5
• Anticoagulation based on CHADS₂ score due to significant stroke risk 5

Medication-Related Palpitations:

• Review and withdraw offending medications 2, 6

Critical Pitfalls to Avoid

• Do not administer first-generation antihistamines (diphenhydramine) or vasopressors for minor infusion reactions, as these can convert minor reactions into hemodynamically significant events including exacerbation of hypotension, tachycardia, and shock 1
• Untreated atrial flutter with excessive ventricular rate can promote cardiomyopathy 5
• Patients with impaired cardiac function can experience hemodynamic deterioration even if ventricular rate is not excessively rapid 5
• 22-50% of patients develop atrial fibrillation within 14-30 months after treatment for atrial flutter, requiring ongoing monitoring 5
• Beta blockers and calcium channel blockers should be avoided in severe conduction abnormalities, sinus node dysfunction, advanced heart failure, or severe bronchospastic pulmonary disease 1, 5