eMedicine Specialties > Cardiology > Arrhythmias

Syncope: Treatment & Medication

Author: Jatin Dave, MD, MPH, Instructor, Department of Medicine, Department of Internal Medicine, Division of Aging, Harvard Medical School; Staff Physician, Brigham and Women's Hospital
Coauthor(s): Revat Lakhia, MD, Visiting Staff, Department of Internal Medicine, Brigham and Women's Hospital; Graduate Student in Public Health, Department of Health Science, West Chester University of Pennsylvania
Contributor Information and Disclosures

Updated: Aug 24, 2009

Treatment

Medical Care

The treatment strategy in patients with syncope depends entirely on the level of certainty of the symptom's etiology, an estimate of recurrence of symptoms, an estimation of potential risk with future recurrence, and the occupation of the patient.

  • Neurocardiogenic (vasovagal or reflex) syncope
    • A number of therapeutic strategies are available.
    • Patients with rare episodes with a specific trigger (eg, drawing blood) generally do not require specific therapy.
    • In some patients with more frequent symptoms, nonpharmacologic measures may be adequate. These include fluid and sodium loading, avoidance of triggering situations (eg, hot tubs), support stockings to reduce venous pooling, and others. Discontinuation of offending medications (eg, nitrates) that are not necessary also may be helpful.
    • Drug therapy for patients with neurocardiogenic syncope may include beta-blockers, selective serotonin reuptake inhibitors, fludrocortisone, midodrine, theophylline, disopyramide, scopolamine, and hyoscyamine.
    • Permanent pacemakers have been shown to be effective in patients whose syncope is refractory and has a significant cardioinhibitory component. Pacemakers are frequently useful in patients with carotid sinus hypersensitivity.
  • Orthostatic hypotension
    • In younger patients, orthostatic hypotension may be reflective of a dysautonomia.
    • In elderly patients, orthostatic hypotension may be due to other medical conditions such as diabetes mellitus or medications. Nonpharmacologic measures, such as dangling the legs over the side of the bed before slowly arousing and use of support stockings, may be helpful.
    • In young patients and in those without a history of hypertension, fluid and sodium expansion may improve symptoms; fludrocortisone and midodrine are frequently helpful in this setting.
    • If hypertension is present, modification of the medical regimen may improve symptomatic orthostasis. Blood pressure must be monitored carefully if therapy with fludrocortisone or midodrine is undertaken.
  • Bradyarrhythmias: Unless the sinus node or AV conduction abnormality is attributable to a medication that can be discontinued safely, a permanent pacemaker is generally indicated for patients with symptomatic bradycardia.
  • Ventricular tachyarrhythmias
    • In patients with significant structural heart disease, ventricular tachyarrhythmias are possible potentially life-threatening causes of syncope. In these patients, the documentation of a sustained episode of VT, ventricular fibrillation, or EP testing results documenting a high risk for ventricular tachyarrhythmias is generally an indication for ICD implantation.
    • For patients in whom ICD implantation is not appropriate or desired, medical therapy with amiodarone is also an option.
  • Supraventricular tachycardia: In patients with supraventricular tachycardia causing syncope or patients with preexcitation (WPW syndrome) and syncope, radiofrequency catheter ablation is generally suggested.
  • Structural heart disease: For patients with syncope attributable to structural heart disease (eg, aortic stenosis, hypertrophic cardiomyopathy, pulmonary hypertension), treatment is generally directed at the underlying organic cardiovascular condition.

Surgical Care

Pacemakers and ICDs are frequently implanted in patients with syncope.

  • Pacemaker implantation
    • Pacemakers are implanted in patients with syncope due to bradyarrhythmias (sinus node dysfunction or AV block).
    • Pacemakers may be of benefit in patients with refractory neurally mediated (ie, reflex or vasovagal) syncope with a prominent cardioinhibitory component, but this remains controversial.
  • ICD implantation
    • ICDs are implanted in patients with syncope in whom ventricular tachyarrhythmias are determined to have caused the syncope or in those who have structural heart disease and a high risk for life-threatening ventricular arrhythmias, but they are generally not implanted to prevent syncope.
    • Patients with idiopathic VT and cardiac arrest due to WPW syndrome are not treated with ICDs. Patients with idiopathic VT may be treated with drugs or catheter ablation; the prognosis is excellent if the heart is structurally normal. Patients with WPW syndrome and syncope (or sudden death) should undergo EP studies and radiofrequency catheter ablation.

Consultations

Patients with recurrent syncope or syncope in the setting of significant structural heart disease should generally be referred to a cardiac electrophysiologist.

Diet

Dietary recommendations depend on the underlying conditions. Patients with neurocardiogenic syncope in the setting of structurally normal hearts are generally recommended to increase their intake of fluid and sodium. Dehydration predisposes patients to vasovagal episodes.

Activity

Activity recommendations depend on the patient's underlying conditions. For patients with recurrent syncope, working at heights, scuba diving, and driving are generally proscribed until the syncope is treated successfully. In some US states, physicians are required to report patients with syncope to the state's drivers' license bureau.

Medication

Pharmacologic therapy is used most commonly in patients with neurally mediated (ie, vasovagal) syncope.

Beta-adrenergic blocking agents

May help block the vasovagal reflex by their negative inotropic effects.


Propranolol (Inderal)

Class II antiarrhythmic, nonselective beta-blocker with membrane-stabilizing activity that decreases automaticity of contractions.

Adult

IR: 10-40 mg PO qid
SR: 40-160 mg PO qd

Pediatric

2-4 mg/kg/d PO divided q6-8h

Coadministration with aluminum salts, barbiturates, NSAIDs, penicillins, calcium salts, cholestyramine, and rifampin may decrease effects; calcium channel blockers, cimetidine, loop diuretics, and MAOIs may increase toxicity; toxicity of hydralazine, haloperidol, benzodiazepines, and phenothiazines may increase

Documented hypersensitivity; uncompensated CHF; bradycardia; cardiogenic shock; AV conduction abnormalities; obstructive lung disease (eg, asthma, COPD)

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Beta-adrenergic blockade may decrease signs of acute hypoglycemia and hyperthyroidism; abrupt withdrawal may exacerbate symptoms of hyperthyroidism, including thyroid storm; withdraw drug slowly and monitor closely


Metoprolol (Lopressor, Toprol XL)

Selective beta1-adrenergic receptor blocker that decreases automaticity of contractions.
During IV administration, carefully monitor blood pressure, heart rate, and ECG.

Adult

25-100 mg PO bid

Pediatric

1-5 mg/kg/d PO divided bid

Aluminum salts, barbiturates, NSAIDs, penicillins, calcium salts, cholestyramine, and rifampin may decrease bioavailability and plasma levels, possibly resulting in decreased pharmacologic effects; toxicity may increase with coadministration of sparfloxacin, phenothiazines, astemizole, calcium channel blockers, quinidine, flecainide, and contraceptives; may increase toxicity of digoxin, flecainide, clonidine, epinephrine, nifedipine, prazosin, verapamil, and lidocaine

Documented hypersensitivity; uncompensated CHF; bradycardia; asthma; cardiogenic shock; AV conduction abnormalities; COPD

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Beta-adrenergic blockade may reduce signs and symptoms of acute hypoglycemia and may decrease clinical signs of hyperthyroidism; abrupt withdrawal may exacerbate symptoms of hyperthyroidism, including thyroid storm; monitor patient closely and withdraw drug slowly; during IV administration, carefully monitor blood pressure, heart rate, and ECG

Selective serotonin reuptake inhibitors

May be effective in patients with neurally mediated syncope, although the reason for this is not clear.


Fluoxetine (Prozac)

Selectively inhibits presynaptic serotonin reuptake with minimal or no effect on the reuptake of norepinephrine or dopamine.

Adult

20-80 mg PO qd

Pediatric

Not established; 5-20 mg PO qd suggested

Increases toxicity of diazepam and trazodone by decreasing clearance; also increases toxicity of MAOIs and highly protein-bound drugs; alcohol, cimetidine, sertraline, phenothiazines, and warfarin increase toxicity

Documented hypersensitivity; concurrent administration with MAOIs or administration within 14 d of discontinuing MAOIs

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Caution in hepatic impairment and history of seizures; MAOIs should be discontinued at least 14 d before initiating therapy
According to a recent FDA review, "Adults being treated with antidepressant medicines, particularly those being treated for depression, should be watched closely for worsening of depression and for increased suicidal thinking or behavior"


Paroxetine (Paxil)

Potent selective inhibitor of neuronal serotonin reuptake. Also has a weak effect on norepinephrine and dopamine neuronal reuptake. For maintenance therapy, make dose adjustments to maintain patient on lowest effective dose. Reassess periodically to determine need for continued treatment.

Adult

10 mg/d PO initially; use increments of 10 mg/d prn; dose changes should occur at intervals of at least 1 wk; usual dose range is 10-60 mg/d; not to exceed 60 mg/d

Pediatric

<18 years: Not established
>18 years: Administer as in adults

Phenobarbital and phenytoin decrease effects; alcohol, cimetidine, sertraline, phenothiazines, and warfarin increase toxicity

Documented hypersensitivity; concurrent administration with MAOIs or administration within 14 d of discontinuing MAOIs

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in history of seizures, mania, renal disease, and cardiac disease
According to a recent FDA review, "Adults being treated with antidepressant medicines, particularly those being treated for depression, should be watched closely for worsening of depression and for increased suicidal thinking or behavior"

Corticosteroids

Can be of benefit in patients with neurally mediated syncope and syncope due to orthostatic hypotension.


Fludrocortisone (Florinef)

Used to increase standing blood pressure. Acts to increase sodium retention and expand plasma volume.

Adult

0.05-0.1 mg PO qd/bid

Pediatric

Not established; 0.05-0.1 mg PO qd

Antagonizes effects of anticholinergics; rifampin, hydantoins, and barbiturates decrease effects; decreases salicylate levels; may potentiate effects of vasopressin

Documented hypersensitivity; systemic fungal infections

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Taper dose gradually when therapy is discontinued; caution in Addison disease, potassium loss, and sodium retention; papilledema may occur; monitor electrolytes

Alpha-adrenergic agonists

Peripherally acting alpha-agonists can be of benefit in patients with neurally mediated syncope and syncope due to orthostatic hypotension.


Midodrine (ProAmatine)

Active metabolite, desglymidodrine, is an alpha-1 agonist.

Adult

5-10 mg PO tid/qid

Pediatric

Not established

Drugs that stimulate alpha-adrenergic agonists may enhance or potentiate pressor effects of midodrine; coadministration with cardiac glycosides may enhance or precipitate bradycardia

Documented hypersensitivity; acute renal disease; severe organic heart disease; pheochromocytoma urinary retention; thyrotoxicosis; persistent and excessive supine hypertension

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Monitor supine blood pressure; caution in patients with diabetes or visual complications; discontinue and reevaluate if any signs or symptoms suggesting bradycardia occur

Methylxanthines

May be of benefit in patients with neurally mediated syncope.


Theophylline (Theo-Dur, Theo-24)

Potentiates exogenous catecholamines and stimulates endogenous catecholamine release and diaphragmatic muscular relaxation, which, in turn, stimulate bronchodilation. For bronchodilation, near-toxic levels (eg, >20 mg/dL) are usually required.

Adult

100-200 mg SR PO bid

Pediatric

Not established

Aminoglutethimide, barbiturates, carbamazepine, ketoconazole, loop diuretics, charcoal, hydantoins, phenobarbital, phenytoin, rifampin, isoniazid, and sympathomimetics may decrease effects; effects may increase with allopurinol, beta-blockers, ciprofloxacin, corticosteroids, disulfiram, quinolones, thyroid hormones, ephedrine, carbamazepine, cimetidine, erythromycin, macrolides, propranolol, and interferon

Documented hypersensitivity; uncontrolled arrhythmias; peptic ulcers; hyperthyroidism; uncontrolled seizure disorders

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in patients with peptic ulcers, hypertension, tachyarrhythmias, hyperthyroidism, and compromised cardiac function; do not inject IV solution >25 mg/min; patients diagnosed with pulmonary edema or liver dysfunction are at greater risk of toxicity because of reduced drug clearance

Class IA antiarrhythmic agents

Negative inotropic agents may be of benefit in patients with neurally mediated syncope.


Disopyramide (Norpace)

Has anticholinergic, peripheral vasoconstrictive, and negative inotropic effects. Decreases conduction velocity and myocardial excitability.

Adult

100-300 mg SR PO bid

Pediatric

Not established

Phenytoin, rifampin, and phenobarbital may decrease effects; toxicity increases with erythromycin and sparfloxacin; levels of digoxin increase; avoid QT-prolonging drugs

Documented hypersensitivity; preexisting second- or third-degree AV block; coadministration with sparfloxacin; history of complete heart block; sick sinus syndrome, cardiogenic shock; CHF; prolonged baseline QTc (>460 ms)

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in patients with preexisting urinary retention, QT interval prolongation, hypotension during initiation of therapy, and angle-closure glaucoma (including family history)

Anticholinergic agents

May be of benefit in patients with neurally mediated syncope.


Scopolamine (Transderm Scop Patch)

Blocks action of acetylcholine at parasympathetic sites in smooth muscle, secretory glands, and CNS. Antagonizes histamine and serotonin action.
Transdermal scopolamine may be the most effective agent for motion sickness. Use in vestibular neuronitis is limited by its slow onset of action.

Adult

1.5 mg TD patch

Pediatric

Not established

Antipsychotic effectiveness of phenothiazines may be decreased with coadministration; adverse anticholinergic effects may be increased by concurrent therapy, and phenothiazine dosages should be adjusted prn; coadministration with TCAs may increase adverse anticholinergic effects (eg, dry mouth, constipation, urinary retention) due to additive effect (TCAs with less anticholinergic activity may be beneficial)

Documented hypersensitivity; primary glaucoma (including initial stages); pyloric obstruction; toxic megacolon; hepatic disease; paralytic ileus; severe ulcerative colitis; renal disease; obstructive uropathy; myasthenia gravis

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in elderly persons because of increased incidence of glaucoma; large doses may suppress intestinal motility and precipitate or aggravate toxic megacolon; anticholinergics may aggravate hiatal hernia associated with reflux esophagitis; patients with prostatism can have dysuria and may require catheterization; use cautiously in patients with asthma or allergies; a reduction in bronchial secretions can lead to inspissation and formation of bronchial plugs


Hyoscyamine (Levsin)

Blocks action of acetylcholine at parasympathetic sites in smooth muscle, secretory glands, and CNS, which, in turn, has antispasmodic effects.

Adult

0.125-0.25 mg IR PO/SL tid/qid ac and hs

Pediatric

Not established

Effects decrease when used concurrently with antacids; toxicity increases when used concurrently with phenothiazines, amantadine, haloperidol, MAOIs, and TCAs

Documented hypersensitivity; obstructive uropathy; narrow-angle glaucoma; myasthenia gravis; obstructive GI tract disease

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in elderly persons; some products contain sodium metabisulfite, which can cause allergic-type reactions; caution in patients with coronary artery disease

More on Syncope

Overview: Syncope
Differential Diagnoses & Workup: Syncope
Treatment & Medication: Syncope
Follow-up: Syncope
Multimedia: Syncope
References
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References

  1. Brignole M, Alboni P, Benditt DG, et al. Guidelines on management (diagnosis and treatment) of syncope--update 2004. Europace. Nov 2004;6(6):467-537.

  2. Cannom DS. A critical appraisal of indications for the implantable cardioverter defibrillator (ICD). Clin Cardiol. May 1992;15(5):369-72. [Medline].

  3. Chen-Scarabelli C, Scarabelli TM. Neurocardiogenic syncope. BMJ. Aug 7 2004;329(7461):336-41.

  4. Connolly SJ, Sheldon R, Roberts RS, Gent M. The North American Vasovagal Pacemaker Study (VPS). A randomized trial of permanent cardiac pacing for the prevention of vasovagal syncope. J Am Coll Cardiol. Jan 1999;33(1):16-20. [Medline].

  5. Grubb BP, Kosinski DJ. Syncope resulting from autonomic insufficiency syndromes associated with orthostatic intolerance. Med Clin North Am. Mar 2001;85(2):457-72. [Medline].

  6. Kapoor WN. Syncope. N Engl J Med. Dec 21 2000;343(25):1856-62. [Medline].

  7. Kapoor WN. Current evaluation and management of syncope. Circulation. Sep 24 2002;106(13):1606-9.

  8. Linzer M, Yang EH, Estes NA 3rd, et al. Diagnosing syncope. Part 1: Value of history, physical examination, and electrocardiography. Clinical Efficacy Assessment Project of the American College of Physicians. Ann Intern Med. Jun 15 1997;126(12):989-96. [Medline].

  9. Linzer M, Yang EH, Estes NA 3rd, et al. Diagnosing syncope. Part 2: Unexplained syncope. Clinical Efficacy Assessment Project of the American College of Physicians. Ann Intern Med. Jul 1 1997;127(1):76-86. [Medline].

  10. Soteriades ES, Evans JC, Larson MG. Incidence and prognosis of syncope. N Engl J Med. Sep 19 2002;347(12):878-85. [Medline].

  11. Sutton R, Brignole M, Menozzi C, et al. Dual-chamber pacing in the treatment of neurally mediated tilt-positive cardioinhibitory syncope: pacemaker versus no therapy: a multicenter randomized study. The Vasovagal Syncope International Study (VASIS) Investigators. Circulation. Jul 18 2000;102(3):294-9. [Medline].

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Further Reading

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Keywords

syncope, loss of consciousness, loss of postural tone, decreased cerebral perfusion, brainstem hypoxia, carotid sinus pressure, coronary artery disease, nonischemic cardiomyopathy, non-ischemic cardiomyopathy, ventricular tachyarrhythmia, congenital long QT syndrome, Wolff-Parkinson-White syndrome, WPW syndrome, Brugada syndrome, hypertrophic cardiomyopathy, syncopal episode, blackout, dizzy spell, seizure, dizziness, aortic stenosis, pulmonary embolus, pulmonary hypertension, acute myocardial infarction, acute MI, tamponade, aortic dissection, atrial fibrillation, atrial flutter, supraventricular tachycardia, SVT, torsades de pointes, ventricular tachycardia, VT, ventricular fibrillation, AV block, atrioventricular block, A/V block, A-V block, sick sinus syndrome, implanted cardioverter/defibrillators, ICDs

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Contributor Information and Disclosures

Author

Jatin Dave, MD, MPH, Instructor, Department of Medicine, Department of Internal Medicine, Division of Aging, Harvard Medical School; Staff Physician, Brigham and Women's Hospital
Disclosure: Nothing to disclose.

Coauthor(s)

Revat Lakhia, MD, Visiting Staff, Department of Internal Medicine, Brigham and Women's Hospital; Graduate Student in Public Health, Department of Health Science, West Chester University of Pennsylvania
Revat Lakhia, MD is a member of the following medical societies: Medical Council of India
Disclosure: Nothing to disclose.

Medical Editor

Hanumant Deshmukh, MD †, Former Chief of Cardiology, Veterans Affairs Medical Center; Former Associate Professor, Department of Medicine, Rosalind Franklin University of Medicine and Science
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Brian Olshansky, MD, Professor of Medicine, Department of Internal Medicine, University of Iowa College of Medicine
Brian Olshansky, MD is a member of the following medical societies: American Autonomic Society, American College of Cardiology, American College of Chest Physicians, American College of Physicians, American College of Sports Medicine, American Federation for Clinical Research, American Heart Association, Cardiac Electrophysiology Society, Heart Rhythm Society, and New York Academy of Sciences
Disclosure: Guidant/Boston Scientific Honoraria Speaking and teaching; Medtronic Honoraria Speaking and teaching; Guidant/Boston Scientific Consulting fee Consulting; Reliant Grant/research funds Other; Novartis Honoraria Speaking and teaching; Novartis Consulting fee Consulting

CME Editor

Amer Suleman, MD, Consultant in Electrophysiology and Cardiovascular Medicine, Department of Internal Medicine, Division of Cardiology, Medical City Dallas Hospital
Amer Suleman, MD is a member of the following medical societies: American College of Physicians, American Heart Association, American Institute of Stress, American Society of Hypertension, Federation of American Societies for Experimental Biology, Royal Society of Medicine, and Society of Cardiac Angiography and Interventions
Disclosure: Nothing to disclose.

Chief Editor

Michael E Zevitz, MD, Assistant Professor of Medicine, Finch University of the Health Sciences, The Chicago Medical School; Consulting Staff, Private Practice
Michael E Zevitz, MD is a member of the following medical societies: American College of Cardiology, American College of Physicians, American Medical Association, and Michigan State Medical Society
Disclosure: Nothing to disclose.

 
 
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