Medication Summary

The goals of pharmacotherapy are to reduce morbidity and prevent complications.

Class Summary

Vasodilators decrease preload and/or afterload.

Nitroglycerin sublingual (Nitrostat)

View full drug information

This agent causes relaxation of vascular smooth muscle by stimulating intracellular cyclic GMP; the result is a decrease in blood pressure. Dosage forms include SL, TD, and IV preparations. The distinction between short-acting preparations for treatment of acute attacks and long-acting preparations for prevention of recurrent episodes is important.

Administration of 300-400 µg of sublingual nitroglycerine) in order to increase average heart rate by approximately 20-25% over baseline to trigger abnormal responses in susceptible patients after a tilt stabilization phase of 5 minutes.^[4]

Class Summary

When given systemically, isoproterenol stimulates beta receptors in the heart, which produces positive inotropic and chronotropic effects. This results in increased cardiac output.

Isoproterenol (Isuprel)

View full drug information

Isoproterenol has sympathomimetic effects; specifically, beta1- and beta2-adrenergic receptor agonist activity.

Intravenous medication used in incremental doses (usually 3 µg/min) in order to increase average heart rate by approximately 20-25% over baseline to trigger abnormal responses in susceptible patients after a tilt stabilization phase of 20 minutes.^[4]

Class Summary

Isotonic sodium chloride (normal saline [NS]) is a standard crystalloid intravenous (IV) fluid used for initial volume resuscitation. It expands the intravascular and interstitial fluid spaces. Typically, about 30% of administered isotonic fluid stays intravascular; therefore, large quantities may be required to maintain adequate circulating volume.

Normal saline (NS, 0.9% NaCl)

NS restores interstitial and intravascular volume. Administer a 250-mL bolus of 0.9% NaCl for hypotension.

Moya A. Tilt testing and neurally mediated syncope: too many protocols for one condition or specific protocols for different situations?. Eur Heart J. 2009 Sep. 30(18):2174-6. [QxMD MEDLINE Link].
Fogoros R. 2nd Ed. Electrophysiologic testing. Cambridge, MA: Blackwell Science; 1995.
Moya A, Sutton R, et al. Guidelines for the diagnosis and management of syncope (version 2009): the Task Force for the Diagnosis and Management of Syncope of the European Society of Cardiology (ESC). Eur Heart J. 2009 Nov. 30(21):2631-71. [QxMD MEDLINE Link].
Benditt DG, Ferguson DW, Grubb BP, Kapoor WN, Kugler J, Lerman BB. Tilt table testing for assessing syncope. American College of Cardiology. J Am Coll Cardiol. 1996 Jul. 28(1):263-75. [QxMD MEDLINE Link].
Goldman L, Braunwald E. Primary cardiology. Philadelphia, PA: WB Saunders; 19.
Leman RB, Clarke E, Gillette P. Significant complications can occur with ischemic heart disease and tilt table testing. Pacing Clin Electrophysiol. 1999 Apr. 22(4 Pt 1):675-7. [QxMD MEDLINE Link].
Parry SW, Reeve P, Lawson J, Shaw FE, Davison J, Norton M. The Newcastle protocols 2008: an update on head-up tilt table testing and the management of vasovagal syncope and related disorders. Heart. 2009 Mar. 95(5):416-20. [QxMD MEDLINE Link].
Strickberger SA, Benson DW, Biaggioni I, Callans DJ, Cohen MI, Ellenbogen KA. AHA/ACCF scientific statement on the evaluation of syncope: from the American Heart Association Councils on Clinical Cardiology, Cardiovascular Nursing, Cardiovascular Disease in the Young, and Stroke, and the Quality of Care and Outcomes Research Interdisciplinary Working Group; and the American College of Cardiology Foundation In Collaboration With the Heart Rhythm Society. J Am Coll Cardiol. 2006 Jan 17. 47(2):473-84. [QxMD MEDLINE Link].
Barón-Esquivias G, Martínez-Rubio A. Tilt table test: state of the art. Indian Pacing Electrophysiol J. 2003. 3(4):239-52. [QxMD MEDLINE Link]. [Full Text].
Fouad-Tarazi F, Calcatti J, Christian R, Armstrong R, Depaul M. Blood volume measurement as a tool in diagnosing syncope. Am J Med Sci. 2007 Jul. 334(1):53-6. [QxMD MEDLINE Link]. [Full Text].
Guida P, Iacoviello M, Forleo C, Ferrara A, Sorrentino S, Balducci C. Prevalence, timing, and haemodynamic correlates of prodromes in patients with vasovagal syncope induced by head-up tilt test. Europace. 2009 Sep. 11(9):1221-6. [QxMD MEDLINE Link].
Brignole M. An Update on the Treatment of Vasovagal Syncope. HJC. 2004. 45:132-5. [Full Text].

Media Gallery

Patient undergoing upright tilt-table testing.
Tilt-table test.

of 2

Table 1. European Society of Cardiology 2009 Indications for Tilt-Table Testing ^[3]

Recommendations	Class	level
Tilt table is indicated in the case of an unexplained single syncopal episode in high-risk settings (eg, occurrence of, or potential risk of physical injury or with occupational implications)or recurrent episodes in the absence of organic heart disease, after cardiac causes of syncope have been excluded	I	B
Tilt testing is indicated when it is of clinical value to demonstrate susceptibility to reflex syncope to the patient	I	C
Tilt testing should be considered to discriminate between reflex and orthostatic hypotensive syncope	IIa	C
Tilt testing may be considered for differentiating syncope with jerking movement from epilepsy	IIb	C
Tilt testing may be indicated for evaluating patients with recurrent unexplained falls	IIb	C
Tilt testing may be indicated for evaluating patients with frequent syncope and psychiatric disease	IIb	C
Tilt testing is not recommended for assessment of treatment	III	B
Isoproterenol tilt testing is contraindicated in patients with ischemic heart disease	III	C

Table 1. Classification of Positive Responses to Tilt Testing ^[9]

Type 1 - Mixed	Heart rate falls at the time of syncope, but the ventricular rate does not fall to less than 40 beats/min^-1 or falls to less 40 beats/min^-1 for less than 10 s with or without asystole of less than 3 s. Blood pressure falls before the heart rate falls.
Type 2 - Cardioinhibitory	A) Cardioinhibition without asystole: heart rate falls to a ventricular rate less than 40 beats/min^-1 for more than 10 s, but asystole of more than 3 s does not occur before the heart rate falls. B) Cardioinhibition with asystole: Asystole occurs for more than 3 s. Blood pressure falls with or occur before the heart rate fall.
Type 3 - Vasodepressor	Heart rate does not fall more than 10% from its peak at the time of syncope.
	Exception 1. Chronotropic incompetence: No heart rate rise during the tilt testing (ie, less than 10% from the pre-tilt rate).
	Exception 2. Excessive heart rate rise: An excessive heart rate both at the onset of the position and throughout its duration before syncope (ie, greater than 130 beats/min^-1).