Wolff–Parkinson–White syndrome

Wolff-Parkinson-White (WPW) Syndrome is a combination of the presence of a congenital accessory pathway and episodes of tachyarrhythmia.

WPW syndrome is characterized by a double stimulation of the ventricles. A premature conduction wave via accessory pathways (pre-excitation) stimulates the portions of the ventricles nearest the atrium; then the ventricles depolarize as a result of the conduction wave which proceeds normally through the atrioventricular (AV) node.

The clinical significance of this syndrome depends on the appearance of (supraventricular) reentry tachycardias.

History of Wolff–Parkinson–White syndrome

1909 – Retrospective review of published case reports looking for evidence of ventricular preexcitation shows the earliest example of WPW published is from August Hoffmann (1862-1929) published in MMW 1909; 56(2): 2259-2262

1909 WPW Hoffmann via VON KNORRE
Remastered ECG from original white on black images via Von Knorre GH. The earliest published electrocardiogram showing ventricular preexcitation. Pacing Clin Electrophysiol. 2005 Mar;28(3):228-230

1913Albert Frank Stanley Kent (1863-1958) described, in the human heart, a communication between the right atrium and ventricle, in the lateral aspect.

The muscular connection between auricle and ventricle in the heart of man is not single and confined to the A.V. bundle, but it is multiple. One point at which a muscular connection between auricle and ventricle exists is situated at the right margin of the heart. The coordinated action of the chambers of the heart is to some extent dependent upon the integrity of muscular connections other than that which exists in the A.V. bundle. It is proposed, for purposes of identification, to refer to the connection described as the “right lateral auriculo-ventricular” connection.

Kent AFS 1913

The short PR interval and slurred initial portion of the QRS complex were first noted by:

1913 – Cohn and Fraser – Paroxysmal tachycardia and the effect of stimulation of the vagus nerve by pressure. Heart. 1913

Paroxysmal tachycardia and the effect of stimulation of the vagus nerve by pressure
Lead II; Paroxysmal tachycardia relieved by ‘deep breathing’; short PR and delta wave. Heart 1913

1915Frank Norman Wilson (1890–1952) published a case in which ‘the vagus influenced the form of the ventricular complex of the electrocardiogram

1921 – Alfred M. Wedd (1887–1967) described 6 cases of Paroxysmal tachycardia with reference to nomotopic tachycardia and role of extrinsic cardiac nerves. Two of the cases displayed short PR, slurred upstroke of the QRS, later to be identified as the delta wave.

Wedd 1921 short PR and delta wave tachycardia
19 year old with paroxysmal tachycardia. Wedd AM. Arch Intern Med, 1921

1929 – Francis Bach (1900-1975) published the case of paroxysmal tachycardia of forty-eight years’ duration and right branch bundle block. The patient had been reviewed by Bach in 1928, but was initially reviewed by Sir James Mackenzie and Dr. Parkinson at the London Hospital in 1914. The initial ECG post tachycardia resolution from 1914 in which ‘wave in Lead II is quite atypical‘ is shown:

1929 Bach WPW paroxysmal tachycardia of forty-eight years' duration and right branch bundle block
Lead II (from 1914). Bach F. Proc R Soc Med, 1929

1928 – On April 2 a young man was referred to Paul Dudley White because his physician was perplexed by the occurrence of paroxysmal atrial fibrillation in a healthy individual. White was preparing for visits to overseas medical centers and took the ECGs with him.

  • Vienna: the tracing was deemed to represent nothing more unusual than bundle-branch block and atrioventricular (AV) nodal rhythm
  • London: Parkinson was interested and found a further seven cases to add to the four from Boston.

1930Wolff L, Parkinson J, and White PD publish the eleven cases as definitive description of the syndrome – ‘Bundle Branch Block with Short P-R Interval in Healthy Young People Prone to Paroxysmal Tachycardia.’ A review of the literature confirmed and acknowledged the previously described cases as above. Wolff, Parkinson, and White erroneously thought that the wide QRS complex was caused by a type of bundle-branch block.

WPW 1930 Fig 6
Fig 6. Case III. WPW 1930

1933Charles C. Wolferth (1887-1965) and Francis Clark Wood (1901-1990) suggested that the abnormal slurring of the initial part of the QRS complex, and prolongation of the QRS complex were not due to bundle-branch block but to:

…an actual acceleration of the passage of the impulse from the auricle to a section of the ventricle…in keeping with the possibility that an accessory pathway of AV conduction such as described by Kent (1913) between the right auricle and right ventricle could be responsible for the phenomenon manifested by these cases

Wolferth CC, Wood FC. 1933
1933 Wolferth and Wood Bundle of kent and WPW

Fig 4. Schematic representation to illustrate the hypothesis of premature transmission of the impulse through the bundle of Kent to the right ventricle. The shaded area represents the section which is activated before the impulse reaches the ventricles through the bundle of His. This mechanism would account for the short PR interval, the widening of the QRS complex and the slurring of the initial deflection.
Fig 5. Schematic representation showing the path of an impulse which might be responsible for exciting a paroxysm of supraventricular tachycardia or auricular fibrillation. Wolferth CC, Wood FC. 1933

1944 – Marcel Segers with colleagues J. Lequime and H. Denolin are credited with proposing the Δ to represent the triangle shape at the base of the upsloping QRS complex. They described the ‘… deformation of the PQ segment is the result of a supplementary electrical deflection that we propose to call Δ‘ . This became more commonly described as the ‘delta wave

Delta wave 1944 Segers Fig 10

However, Segers et al actually proposed that the Δ wave was a discrete a discrete and autonomous wave between P and Q. They did state that the wave could fuse with the base of QRS complex (figure C) to form a slurred upstroke, and attributed the Δ wave fusion with the bundle branch phenomenon of WPW (Figure D)

1944 Segers et al Delta wave origin
Fig 1 (a, b, c, d) Segers et al 1944

Schéma a: Onde Δ représentée par une simple inclinaison du segment PQ.

Schéma b ; Tracé avec onde Δ complètement autonome : le point Q se marque nettement après Δ , et dans ces conditions les intervalles PQ et QRS gardent en réalité une valeur normale.

Schéma c : Tracé avec onde Δ formant un « pied » accolé à QRS : l’onde Q correspond au point d’inflexion séparant Δ et R. Le pointillé montre l’évolution de l’onde Δ se poursuivant pendant toute la durée du complexe ventriculaire, selon l’hypothese de Eckey et Schäfer; cette onde diphasique viendrait se superposer au complexe ventriculaire normal et déterminerait ainsi le décalage de ST et la déformation de T.

Schéma d: Les ondes Δ et QRS sont complètement fusionnées en un complexe unique et élargi du type bloc de branche (syndrome de Wolff, Parkinson et White); le point Q et le sommet R ne sont plus visibles et l’onde T se présente en « forme d’escalier »

Segers et al 1944

Diagram a: Δ wave represented by a simple tilt of the PQ segment.

Diagram b; Plot with completely autonomous Δ wave: the Q point is clearly marked after Δ , and under these conditions the PQ and QRS intervals actually keep a normal value.

Diagram c: Plot with Δ wave forming a “foot” attached to QRS: the Q wave corresponds to the point of inflection separating Δ and R. The dotted line shows the evolution of the Δ wave continuing throughout the duration of the complex ventricular, according to the hypothesis of Eckey and Schäfer; this diphasic wave would come to be superimposed on the normal ventricular complex and would thus determine the shift of ST and the deformation of T.

Diagram d: Δ and QRS waves are completely fused into a single, enlarged bundle-branch block-like complex (Wolff-Parkinson-White syndrome); the Q point and the R vertex are no longer visible and the T wave appears in a “staircase shape”

Segers et al 1944

1951 – White appreciated that the conduction disturbance was not due to bundle branch block, but rather to rapid conduction of the depolarizing impulse from the atrium to one or the other ventricles as proposed by Wolferth and Wood in 1933. He recorded a case and his thoughts in the fourth edition of his single-authored book, Heart Disease in which he refers to the conduction disorder as “An odd electrocardiograhic anomaly, probably congenital in origin…

The functional aspects of this reentrant pathway were confirmed by electrophysiological studies in the 1960s with subsequent correction of this disorder by surgical interruption of the pathway, or, as is now done, by catheter directed radiofrequency ablation.

Associated Persons


Historical references

Eponymous term review review

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BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Emergency physician, Sir Charles Gairdner Hospital.  Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |

MBBS (UWA) CCPU (RCE, Biliary, DVT, E-FAST, AAA) Adult/Paediatric Emergency Medicine Advanced Trainee in Melbourne, Australia. Special interests in diagnostic and procedural ultrasound, medical education, and ECG interpretation. Editor-in-chief of the LITFL ECG Library. Twitter: @rob_buttner

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