Current Concepts: Evaluation of Patients with Palpitations
Zimetbaum P, Josephson M
NEJM. May 7, 1998- volume 338, number 19
Intro:
Palpitations are usually benign but can be a manifestation of potentially life-threatening conditions.
Common presentations:
- Flip-flopping in chest: heart feels like it stops, then start again; usually caused by PVC/PAC
- Rapid-fluttering in chest: may result from atrial or ventricular arrhythmias including sinus tach.
- Pounding in neck: caused by dissociation of atrial and ventricular contractions (atria contract against closed tricuspid/mitral valves cannon A waves which are perceived as neck pulsations).
- When rapid and regular, most typical of re-entrant supraventricular arrhythmias, particularly av nodal tachycardia.
- When irregular and less sustained, can be a result of PVCs
- Palpitations a/w anxiety/panic reactions: difficult for pt. to assess whether anxiety preceded or resulted from palpitations. Should not make this dx until true arrhythmic causes excluded, esp. in young women-
- Recent study of 107 pts with electrophysiologically documented re-entrant SVT, 67% met criteria for panic d/o, 30% were given dx of panic, stress, anxiety d/o, with avg. of 3.3 yrs b/n initial presentation to MD and definitive dx of SVT
- Palpitations during catecholamine excess:
- Can be seen with idiopathic ventricular tachycardias, esp. those arising from right ventricular outflow tract. These pts have structurally normal hearts and most often present in the 2nd/3rd decades of life and are a/w dizziness or syncope.
- Supraventricular tachycardias (esp. a-fib) may be induced during exercise or termination of exercise
- Long QT syndrome characteristically causes palpitations due to polymorphic v. tach. During periods of emotional stress or vigorous exercise.
- Inappropriate sinus tach. Manifests as palpitations with minimal exertion/emotional stress (mostly young women)
- Palpitations a/w position:
- With av nodal tach, palpitations occur after standing from bent over position, and resolve after lying down.
- Palpitations while lying in bed, esp. supine or left lateral decub. position, may be a result of premature beats which occur more frequently at slow heart rates.
- Palpitations a/w syncope/near-syncope: should prompt a search for v. tach. Occasionally may be due to SVT (results from acute vasodilation, rapid heart rate with low cardiac output).
Diagnostic evaluation:
- History
- Physical exam
- Check for murmurs (ex. midsystolic click of MVP or harsh holosystolic murmur along left sternal border which gets louder with valvalva as with hypertrophic obstructive cardiomyopathy)
- 12 lead EKG
- short PR and delta waves ventricular pre-excitation and substrate for SVT (Wolff-Parkinson-White)
- LVH with deep Qs in I, AVL, V4-V6 hypertrophic obstructive cardiomyopathy
- LVH with left atrial abnormality substrate for a. fib.
- Q waves of a prior MI prompts more extensive search for v-tach.
Diagnostic testing: recommended in the following groups:
1. those in whom the initial diagnostic evaluation suggests an arrhythmic cause
2. those at high risk (organic heart disease or myocardial abnormality that can lead to serious arrhythmias)
3. those who remain anxious to have a specific explanation for their symptoms
Management:
If there is no evidence of heart disease and palpitations are nonsustained and well tolerated, outpatient monitoring and reassurance recommended.
Most sustained supraventricular/ventricular arrhythmias causing palpitations involve electrophysiologic evaluation and management (ex. Radio-frequency ablation)
The following is a breakdown of diagnoses in patients who underwent ambulatory monitoring:
NSR 35%
Sinus tach 29%
Supraventricular tachycardia 18%
PVCs 12%
A. fib. 6%
PVCs and nonsustained v. tach. are found in a substantial number of patients with palpitations and in patients with structurally normal hearts and are NOT a/w increased mortality.
In cases in which atrial or ventricular ectopy render the patient incapacitated, treatment with b-blockers are recommended. Avoid other anti-arrhythmic medications as they can be pro-arrhythimic as well.
