Wolff-Parkinson-White syndrome pathophysiology

Jump to navigation Jump to search
https://https://www.youtube.com/watch?v=9MDRKId2d0Q%7C350}}

Wolff-Parkinson-White syndrome Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Differentiating Wolff-Parkinson-White syndrome from other Diseases

Epidemiology and Demographics

Risk Factors

Natural History, Complications and Prognosis

Diagnosis

Approach

History and Symptoms

Electrocardiogram

EKG Examples

Other Diagnostic Studies

Treatment

Risk Stratification

Cardioversion

Medical Therapy

Catheter Ablation

Prophylaxis

Consensus Statement

Case Studies

Case #1

Wolff-Parkinson-White syndrome pathophysiology On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Wolff-Parkinson-White syndrome pathophysiology

CDC onWolff-Parkinson-White syndrome pathophysiology

Wolff-Parkinson-White syndrome pathophysiology in the news

Blogs on Wolff-Parkinson-White syndrome pathophysiology

Directions to Hospitals Treating Deep vein thrombosis

Risk calculators and risk factors for Wolff-Parkinson-White syndrome pathophysiology

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sara Zand, M.D.[2] Cafer Zorkun, M.D., Ph.D. [3]

Overview

In normal individuals, electrical activity in the heart is initiated in the sinoatrial (SA) node (located in the right atrium), propagates to the atrioventricular (AV) node, and then through the bundle of His to the ventricles of the heart. Individuals with Wolf-parkinson-White (WPW) have an accessory pathway, known as the bundle of Kent, that communicates between the atria and the ventricles. The conduction through the accessory pathway can be bidirectional (most commonly), only retrogarde (less common), or only antegrade (least common). The most common type of tachycardia associated with WPW is atrioventricular reciprocating tachycardia (AVRT). The accessory pathway does not share the rate-slowing properties of the AV node; therefore, the combination of an accessory pathway and cardiac arrhythmia can trigger ventricular fibrillation, a leading cause of sudden cardiac death.

Pathophysiology

Accessory Pathway

The accessory pathway is characterized by:[4]

  • Conducting electrical stimulus faster than the AV node
  • Longer refractory period compared to the AV node
  • A non-decremental conduction in response to an increased paced rates

Electrical Activity

Normal Electrical Activity

Shown below is an image depicting the conduction system in the normal heart.

The conduction system in the normal heart
The conduction system in the normal heart
  • The AV node serves an important function as a "gatekeeper", limiting the electrical activity that reaches the ventricles.
  • In situations where the atria generate excessively rapid electrical activity (such as atrial fibrillation or atrial flutter), the AV node limits the number of signals conducted to the ventricles.
  • For example, if the atria are electrically activated at 300 beats per minute, half those electrical impulses may be blocked by the AV node, so that the ventricles are stimulated at only 150 beats per minute—resulting in a pulse of 150 beats per minute.


  • Another important property of the AV node is that it slows down individual electrical impulses.
  • This is manifested on the electrocardiogram as the PR interval (the time from electrical activation of the atria to electrical activation of theventricles), which is usually shortened to less than 120 milliseconds in duration.

Electrical Activity in WPW

Shown below is an image depicting the normal conduction of electrical signals in the heart versus that in the presence of an accessory pathway.

[[File: Abnormal electrical pathway in WPW.jpeg|center| The normal conduction of electrical signals in the normalheart versus that in the presence of an accessory pathway

  • The conduction through the accessory pathway can be:
  • Bidirectional (most commonly): retrogarde (also known as concealed) as well as antegrade (also known as manifest, responsible for the ECG findings of delta wave and short PR interval)
  • Only retrogarde (less common)
  • Only antegrade (least common)


Associated Conditions

WPW syndrome is associated with the following disorders:

References

  1. Sorbo MD, Buja GF, Miorelli M, Nistri S, Perrone C, Manca S, Grasso F, Giordano GM, Nava A (1995). "The prevalence of the Wolff–Parkinson–White syndrome in a population of 116,542 young males". Giornale Italiano di Cardiologia (in Italian). 25 (6): 681–7. PMID 7649416.
  2. Munger TM, Packer DL, Hammill SC, Feldman BJ, Bailey KR, Ballard DJ, Holmes DR Jr, Gersh BJ (1993). "A population study of the natural history of Wolff–Parkinson–White syndrome in Olmsted County, Minnesota, 1953–1989". Circulation. 87 (3): 866–73. doi:10.1161/01.CIR.87.3.866. PMID 8443907.
  3. americanheart.org Atrial and Ventricular Depolarization Changes Last updated 11/24/2008.
  4. Obel OA, Camm AJ (1998). "Accessory pathway reciprocating tachycardia". Eur Heart J. 19 Suppl E: E13–24, E50–1. PMID 9717020.
  5. Sidhu J, Roberts R (October 2003). "Genetic basis and pathogenesis of familial WPW syndrome". Indian Pacing Electrophysiol J. 3 (4): 197–201. PMC 1502052. PMID 16943919.
  6. Rao MP, Panduranga P, Al-Mukhaini M, Al-Jufaili M (2012). "Ebstein anomaly in an adult presenting with wide QRS tachycardia: diagnostic and therapeutic dilemmas". Am J Emerg Med. 30 (5): 834.e1–4. doi:10.1016/j.ajem.2011.03.001. PMID 21570234. Unknown parameter |month= ignored (help)
  7. Bayar N, Canbay A, Uçar O, Aydoğdu S, Diker E (2010). "[Association of Gerbode-type defect and Wolff-Parkinson-White syndrome with Ebstein's anomaly]". Anadolu Kardiyol Derg (in Turkish). 10 (1): 88–90. PMID 20150013. Unknown parameter |month= ignored (help)
  8. Legius B, Van De Bruaene A, Van Deyk K; et al. (2010). "Behavior of Ebstein's anomaly: single-center experience and midterm follow-up". Cardiology. 117 (2): 90–5. doi:10.1159/000318041. PMID 20924185.
  9. Savini E, Capone PL (1994). "[Wolff-Parkinson-White, a study on the prevalence of the site of accessory pathways: relations between stability of pre-excitation, symptoms, cardiac arrhythmias and association of mitral valve prolapse with localization of pre-excitation]". Minerva Cardioangiol (in Italian). 42 (7–8): 339–43. PMID 7970027.
  10. Kruchina TK, Vasichkina ES, Egorov DF, Tatarskiĭ BA (2012). "[Asymptomatic ventricular pre-excitation in children: a 17 year follow-up study]". Kardiologiia (in Russian). 52 (5): 30–6. PMID 22839583.
  11. 11.0 11.1 11.2 "Wolff-Parkinson-White syndrome - Genetics Home Reference". Retrieved 15 April 2014.

Template:WH Template:WS