History

Fact Explanation
Palpitations Anomalous atrioventricular excitation develops due to the presence of an accessory pathway between the atria and the ventricles which is a congenital anomaly (Wolff-parkinson-white syndrome).[1] The atria and ventricles are usually separated from each other by fibrous rings and the only connection lies at the AV node. The accessory pathway leads to development of tachyarrhythmias.[2] These are perceived by the patient as abnormal or fast heart beats.[3]
Dizziness and Syncope Due to diminished blood flow to the cerebrum. Cardiac output is reduced due to rapid heart rate.[2]
Chest discomfort/ chest pain The cardiac arrhythmia may be perceived as chest discomfort.
Breathing difficulty Due to pulmonary congestion. Anxiety may also contribute to breathing difficulty.[2]
Incidental finding The condition may be identified as an incidental finding on electrocardiography.[3]
The patient may present with cardiac arrest / sudden cardiac death Due to an acute onset catastrophic dysrhythmia.[3]
References
  1. WOLFF L, PARKINSON J, WHITE, PD. Bundle-branch block with short P-R interval in healthy young people prone to paroxysmal tachycardia. American Heart Journal, 1930, 5, 685-704.
  2. KULIG J., KOPLAN B. A.. Wolff-Parkinson-White Syndrome and Accessory Pathways. Circulation [online] December, 122(15):e480-e483 [viewed 15 July 2014] Available from: doi:10.1161/CIRCULATIONAHA.109.929372
  3. SETHI KK, DHALL A, CHADHA DS, GARG S, MALANI SK, MATHEW OP. WPW and preexcitation syndromes. J Assoc Physicians India [online] 2007 Apr:10-5 [viewed 15 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/18368860

Examination

Fact Explanation
Physical examination is usually normal Majority of patients will have no abnormality on examination of the cardiovascular system.[1]
Cardiovascular system examination : tachycardia The pulse rate would be elevated. The patient can develop supraventricular tachycardia, atrial fibrillation or atrial flutter leading to a rapid ventricular rate. [1]
Cardiovascular system examination : Irregularly irregular pulse In atrial fibrillation the pulse rhythm is irregular.[2] In other atrial tachycardias the rhythm would be regular.
Cardiovascular system examination : Variable pulse volume Different cardiac outputs at each ventricular contraction results in a change in the pulse volume. The ventricular filling is affected due to the arrhythmia.
Cardiovascular system examination : On auscultation variable intensity of the first heart sound In atrial fibrillation the irregular atrial activity results in variable cardiac filling times for each cardiac cycle.[2]
Cardiovascular system examination : Hypotension During an acute episode the blood pressure may drop due to lowered cardiac output.
Respiratory system examination : Fine crepitations Due to pulmonary congestion. This is secondary to ineffective pumping out of blood by the heart due to increased heart rate.
Assessment of Airway, Breathing and Circulation Patients who present with cardiac arrest require prompt resuscitation. Inspect the mouth for objects which could cause obstruction - secretions, dentures. Observe for chest movements. Listen and feel for breathing. Pulse rate, blood pressure, capillary refill time will provide an assessment of the circulation.
Features of associated cardiac diseases Wolff-parkinson-white syndrome is associated with other cardiac diseases such as cardiomyopathies, Ebstein anomaly, Hypertrophic cardiomyopathy, transposition of the great arteries. etc.
References
  1. AL-KHATIB SM, PRITCHETT EL. Clinical features of Wolff-Parkinson-White syndrome. Am Heart J [online] 1999 Sep, 138(3 Pt 1):403-13 [viewed 15 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/10467188
  2. DEWAR RI, LIP GY. Identification, diagnosis and assessment of atrial fibrillation Heart [online] 2007 Jan, 93(1):25-28 [viewed 15 July 2014] Available from: doi:10.1136/hrt.2006.099861

Differential Diagnoses

Fact Explanation
Atrial fibrillation(AF) Atrial fibrillation is chaotic and irregular atrial rhythm at 300-600bpm. The ventricular rate is increased to a less lower rate. Atrial fibrillation may be cardiac or non-cardiac in origin. The main causes are ischemic heart disease, heart failure, hypertension, valvular heart disease, pulmonary embolism, pneumonia, electrical changes etc.[1] AF can be divided as acute, chronic and paroxysmal AF. The patient may be asymptomatic or experience chest pain, palpitations, dyspnoea and syncope. On physical examination the pulse will be irregularly irregular, the first heart sound will be of varied intensity. Perform a complete physical examination to exclude non-cardiac causes of AF. ECG will show an irregular baseline, absent P waves and irregular QRS complexes.[1]
Atrial flutter Atrial flutter occurs due to continuous atrial depolarization causing an elevated atrial rate to approximately 300bpm and a ventricular rate of 150bpm.[2] The disease presentation is similar to Atrial fibrillation. Diagnosis can be achieved by the ECG pattern : It will show a characteristic saw tooth pattern with a 2:1 block.
Atrial ectopic beats Ectopic depolarizations originating from ectopic site can also lead to tachycardia with an increased ventricular rate. Patient presentation is typically with a history of missed beats or extra beats. The causes are usually cardiac in origin : Myocardial infarction, ischemic heart disease, cardiomyopathies etc.[3] Ectopic electrical activity can be diagnosed by ECG.
Exclude conditions which may cause tachycardia Non-cardiac causes such as hyperthyroidism, anemia, renal failure, pneumonia, fever, drugs may cause tachycardia or rapid heart rate.
References
  1. IWASAKI Y.-K., NISHIDA K., KATO T., NATTEL S.. Atrial Fibrillation Pathophysiology: Implications for Management. Circulation [online] December, 124(20):2264-2274 [viewed 13 July 2014] Available from: doi:10.1161/​CIRCULATIONAHA.111.019893
  2. LEE K, YANG Y, SCHEINMAN M. Atrial flutter: A review of its history, mechanisms, clinical features, and current therapy. Current Problems in Cardiology [online] 2005 March, 30(3):121-167 [viewed 13 July 2014] Available from: doi:10.1016/j.cpcardiol.2004.07.001
  3. MYERBURG RJ, SUNG RJ, GERSTENBLITH G, MALLON SM, CASTELLANOS A JR. Ventricular ectopic activity after premature atrial beats in acute myocardial infarction. Br Heart J [online] 1977 Sep, 39(9):1033-1037 [viewed 13 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC483365

Investigations - for Diagnosis

Fact Explanation
Electrocardiography (ECG) The diagnosis of WPW syndrome is made by ECG findings. Holter monitoring may be used to monitor the cardiac electrical activity for 24 hours. Classic ECG changes identified : narrow PR interval, widened QRS complex & Delta wave (slow rise of the upstroke of QRS complex).[1] [2]
Thyroid function test Rule out hyperthyroidism which may cause tachyarrhythmias.
Full blood count Anemia may lead to rapid heart rate.
Serum creatinine, blood urea, serum electrolytes. Renal failure can induce a rapid heart rate.
References
  1. ROSNER MH, BRADY WJ JR, KEFER MP, MARTIN ML. Electrocardiography in the patient with the Wolff-Parkinson-White syndrome: diagnostic and initial therapeutic issues. Am J Emerg Med [online] 1999 Nov, 17(7):705-14 [viewed 15 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/10597097
  2. MARK DG, BRADY WJ, PINES JM. Preexcitation syndromes: diagnostic consideration in the ED. Am J Emerg Med [online] 2009 Sep, 27(7):878-88 [viewed 15 July 2014] Available from: doi:10.1016/j.ajem.2008.06.013

Investigations - Followup

Fact Explanation
Echocardiography Echocardiography is used assess left ventricular function.[1] Associated cardiac conditions such as cardiomyopathy, congenital heart diseases can also be excluded.
Electrophysiological studies Uses of Electrophysiological studies : Find the location of the accessory pathway, determine the electrophysiological properties of the abnormal pathway, determine response to drug therapy.[2]
References
  1. CHANDRA MS, KERBER RE, BROWN DD, FUNK DC. Echocardiography in Wolff-Parkinson-White syndrome. Circulation [online] 1976 Jun, 53(6):943-6 [viewed 15 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/131657
  2. BECKMAN KAREN J., GALLASTEGUI JOSE L., BAUMAN JERRY L., HARIMAN ROBERT J.. The predictive value of electrophysiologic studies in untreated patients with Wolff-Parkinson-White syndrome. Journal of the American College of Cardiology [online] 1990 March, 15(3):640-647 [viewed 15 July 2014] Available from: doi:10.1016/0735-1097(90)90639-7

Management - General Measures

Fact Explanation
Patient education and counseling The patient should be provided information about the condition, complications, triggering factors and treatment options available. Counsel the patient regarding the risk of sudden cardiac arrest and occupational risks.
Management plan should be individualized The most appropriate treatment option should be selected following consideration of the disease presentation, severity of symptoms, risks to patient and patient wishes/ expectations. Treatment options include expectant management, anti-arrhythmic drug therapy, radio-frequency ablation and surgical therapy.[1]
References
  1. BERRY VA. Wolff-Parkinson-White syndrome and the use of radiofrequency catheter ablation. Heart Lung [online] 1993 Jan-Feb, 22(1):15-25 [viewed 15 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/8420852

Management - Specific Treatments

Fact Explanation
Management of acute episodes Patients who present in a collapsed unconscious state require prompt resuscitation. Assess and support the airway, breathing and circulation. If the patient is in cardiac arrest administer advanced life support. Assess the rhythm of heart. Use electrical cardioversion if the arrhythmia is causing haemo-dynamic instability. Medical management depends on the type of tachy-arrhythmia that has developed. Patients experiencing atrial fibrillation/ atrial flutter can be managed with calcium channel blockers - verapamil, diltiazem or beta-blockers - Propranolol or digoxin. For junctional tachycardia (AVRT & AVNRT) vagal manoeuvres followed by adenosine or beta-blocker therapy can be used.[1]
Treat precipitants of arrhythmia attacks Conditions which may precipitate or worsen dysarrhythmia such as coronary heart disease, valvular heart disease cardiomyopathy, pericarditis, electrical/metabolic disturbances hyperthyroidism, anemia etc should be treated appropriately.[1]
Conservative observation Asymptomatic patients diagnosed incidentally by ECG can be observed expectantly.[2]
Radiofrequency ablation This is the treatment of choice for many symptomatic patients and patients who experience episodes of arrhythmia. Indications : Symptomatic patients, Patients at high risk of cardiac arrest/sudden cardiac death, asymptomatic patients with occupational, live hood hazards and patients who develop rapid ventricular rates following atrial tachyarrhythmias. Catheters inserted via the femoral vessels are advanced to the heart. The accessory pathway is located and ablated using radiofrequency thermal energy.[3] This procedure can be used in any age group and has a high success rate.[4] Advantages of the procedure are that it is curative and eliminates the need for lifelong medication. Prophylactic radio-frequency ablation is currently being increasingly used in asymptomatic patients with high risk of dysarrhythmia as there is a marked reduction in arrhythmic events.[5]
Anti-arrhythmic medications Anti-arrhythmic agents can be used to slow the conduction via the accessory pathway and block conduction through the AV node. Agents that can be used are : Class 1c drugs – flecainide, Class 3 drugs – amiodarone, sotalol, Class 4 drugs – verapamil.[6] Dual therapy with class 1a and class 4 agents can be used. Commonly used drugs are propranolol, lidocaine, Procainamide, amiodarone, sotalol.[7] Even though used in practice long term anti-arrhythmic therapy has low success rate in preventing paroxysmal arrhythmic episodes. This mode of therapy is considered for patients contraindicated for radio-frequency ablation.
Open heart surgery Use of open heart surgery has diminished with the use of radio-frequency ablation. This may be considered if repeated attempts of radio-frequency ablation fail to improve the patient’s condition. Newer modified close heart surgeries which are simple and less invasive are being experimented with.[8]
Management of pregnant patients During the antenatal period manage the patient with anti-arrhythmic drugs such as sotalol and flecainide. Radio-frequency ablation may be considered after pregnancy.[9]
References
  1. BLOMSTROMLUNDQVIST C. ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias—executive summary A Report of the American College of Cardiology/American HeartAssociation Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines(Writing Committee to Develop Guidelines for the Management of Patients With Supraventricular Arrhythmias)Developed in collaboration with NASPE–Heart Rhythm Society. European Heart Journal [online] 2003 October, 24(20):1857-1897 [viewed 15 July 2014] Available from: doi:10.1016/j.ehj.2003.08.002
  2. KULIG J., KOPLAN B. A.. Wolff-Parkinson-White Syndrome and Accessory Pathways. Circulation [online] December, 122(15):e480-e483 [viewed 15 July 2014] Available from: doi:10.1161/CIRCULATIONAHA.109.929372
  3. WELLENS H. J. J.. Catheter Ablation of Cardiac Arrhythmias : Usually Cure, but Complications May Occur. Circulation [online] 1999 January, 99(2):195-197 [viewed 15 July 2014] Available from: doi:10.1161/01.CIR.99.2.195
  4. CALKINS H. Catheter ablation of accessory pathways is associated with an excellent long-term prognosis. European Heart Journal [online] 2001 April, 22(7):532-533 [viewed 15 July 2014] Available from: doi:10.1053/euhj.2000.2523
  5. PAPPONE C, SANTINELLI V, MANGUSO F, AUGELLO G, SANTINELLI O, VICEDOMINI G, GULLETTA S, MAZZONE P, TORTORIELLO V, PAPPONE A, DICANDIA C, ROSANIO S. A randomized study of prophylactic catheter ablation in asymptomatic patients with the Wolff-Parkinson-White syndrome. N Engl J Med [online] 2003 Nov 6, 349(19):1803-11 [viewed 15 July 2014] Available from: doi:10.1056/NEJMoa035345
  6. CHUNG EK. Wolff-Parkinson-White Syndrome--current views. Am J Med [online] 1977 Feb, 62(2):252-66 [viewed 15 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/299982
  7. WELLENS HJ, LIE KI, BäR FW, WESDORP JC, DOHMEN HJ, DüREN DR, DURRER D. Effect of amiodarone in the Wolff-Parkinson-White syndrome. Am J Cardiol [online] 1976 Aug, 38(2):189-94 [viewed 15 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/952262
  8. GUIRAUDON GM, KLEIN GJ, GULAMHUSEIN S, JONES DL, YEE R, PERKINS DG, JARVIS E. Surgical repair of Wolff-Parkinson-White syndrome: a new closed-heart technique. Ann Thorac Surg [online] 1984 Jan, 37(1):67-71 [viewed 15 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/6691739
  9. TAN H. Treatment of tachyarrhythmias during pregnancy and lactation. European Heart Journal [online] 2001 March, 22(6):458-464 [viewed 15 July 2014] Available from: doi:10.1053/euhj.2000.2130