A. Introduction

1. Very common presenting symptom to primary care physicians (and cardiologists)
2. Palpitations are a strong sensation of feeling the heart beat in the neck and/or chest
   1. "Flip-flopping" in the chest - start and stop sensation (often premature beats)
   2. Rapid fluttering in the chest - tachycardias, either atrial or ventricular
   3. Pounding in the neck - Cannon A waves may be observed
3. Pathogenesis
   1. Multiple etiologies exist (see below)
   2. Catecholamine excess
   3. Hypoxemia / Cardiac Ischemia
   4. Valve Abnormalities
   5. Stress or panic disorders
   6. Medications - usually stimulants

B. Causes [2]

1. Cardiac (43%)
   1. Atrial Fibrillation (AFib) and Flutter
   2. Other SVT
   3. Premature Beats: atrial and ventricular
   4. Ventricular Tachycardias (VTach) including Torsade des Pointes (TDP)
   5. Mitral Valve Prolapse
2. Psychiatric (30%)
   1. Panic Attack
   2. Anxiety
3. Miscellaneous (~10%)
   1. Medications: stimulants, ß-agonists, theophylline, anti-cholinergic agents
   2. Thyrotoxicosis (hyperthyroidism)
   3. Caffeine
   4. Cocaine
4. Unknown (~16%)

C. Diagnosis

1. Careful history and physical examination to rule out above causes when possible
   1. Mid-systolic click of mitral valve prolapse
   2. Cannon A waves (waves seen in jugular due to RA contraction against closed tricuspid)
   3. A brisk walk prior to examination may induce palpitations, including AFib
2. Electrocardiogram (ECG)
   1. Assess for sinus rhythm, premature beats, abnormal voltages
   2. Shortened PR interval with delta waves indicates WPW Syndrome
   3. Septal Q Waves and high voltage suggests hypertrophic obstructive cardiomyopathy
   4. Prolongation of QT interval suggests Long QT Syndromes and possible TDP
3. Further Diagnostic Testing
   1. Complex diagnostic testing should be limited to only a few types of patients including:
   2. History and/or ECG suggest arrhythmia
   3. Patients at high risk for arrhythmias (including post-MI patients)
   4. Patients who are extremely anxious about symptoms and require an explanation
   5. Electrolyte levels, renal function, and thyroid hormone levels should be obtained
   6. Ambulatory ECG Monitoring is recommended for most patients
   7. Consider invasive Electrophysiology Study (EPS) for patients at high risk
4. Ambulatory ECG Monitoring
   1. Holter Monitor is a 24 hour recorder worn for 1-2 days
   2. Continuous loop event recorders - activated by patient when symptoms develop [3]
   3. In general, 2 weeks of continuous loop monitoring is most cost effective [3]
   4. Ambulatory monitoring when organic disease is unlikely and further evaluation needed
5. Exercise Treatmill Testing (ETT)
   1. For symptoms developing during or following exercise
   2. May detect SVT, atrial fibrillation, idiopathic VTach, nonsustained VTach
6. EPS
   1. Indicated for documented rapid pulse without clear etiology on ECG
   2. Palpitations preceding a syncopal event
   3. Any tachyarrhythmia may be involved (VTach more common in syncope)

D. Management

1. Organic heart disease must be treated aggressively
   1. Revascularization may be required
   2. Implantable cardioverter defibrillator (ICD) or amiodarone
2. Simple Ectopy
   1. Premature beats in the absence of heart disease are very common
   2. ß-blocking agents may be effective
3. Other Arrhythmias
   1. SVT is usually treated with EPS ablation
   2. Atrial fibrillation / flutter usually requires rate control
   3. QT prolonging drugs should be stopped
4. Panic Disorder
   1. Anxiety medications may be effective
   2. ß-adrenergic blockers are often very effective

References

1. Zimetbaum P and Josephson ME. 1998. NEJM. 338(19):1369
2. Weber BE and Kapoor WN. 1996. Am J Med. 100(2):138
3. Zimetbaum PJ, Kim K, Josephson ME, Goldberger A. 1998. Ann Intern Med. 128(11):890