WPW and Brugada Syndrome & JVP - Free MCQ Practice Test with solutions,

Individuals experiencing symptomatic Wolff-Parkinson-White (WPW) syndrome should avoid treatment with calcium channel blockers or digoxin due to the risk of:

• Increased rapid ventricular rates
• Development of atrial fibrillation or atrial flutter

These conditions can lead to significant hemodynamic collapse.

The ECG displays a normal sinus rhythm accompanied by left axis deviation. There is a brief PR interval with a broad QRS complex indicating a prolonged upstroke of the QRS (delta wave).

• The prolonged upstroke, with a slight alteration in slope, is evident in leads V3 and V4.
  
• The presence of an accessory pathway, known as the Bundle of Kent, can account for these irregularities, and the boy is diagnosed with Wolf-Parkinson-White syndrome.

In cases with a positive family history of sudden death or recurrent syncope episodes, the preferred treatment is an implantable cardioverter defibrillator. This device can administer a DC shock to terminate a life-threatening arrhythmia.

The clinical diagnosis for the patient is Wolff-Parkinson-White syndrome. Patients with this condition possess a bypass tract that facilitates the conduction of impulses directly from the atria to the ventricles, circumventing the decremental properties of the AV node.

• An invasive electrophysiological study is advisable to determine if the pathway results in rapid ventricular rates.
• During the same procedure, a curative catheter ablation can be performed.
• B-blockers and vagal manoeuvres may be applied at the onset of an episode.

Exercise on a treadmill can induce sympathetic stimulation, which may trigger arrhythmias; hence, it is not recommended for patients with W.P.W. Rapid pre-excited tachycardia should be managed with electrical cardioversion or by administering intravenous procainamide or ibutilide.

• The condition arises from a reduced inward sodium current in the epicardium of the right ventricle (RV) outflow tract.
• A decrease in the action potential dome in the RV epicardium, caused by the unopposed I_To potassium outward current, leads to a significant shortening of the action potential.
• The substantial potential difference between the normal endocardium and the rapidly depolarised RV outflow epicardium results in ST-segment elevation in V1-V3 during sinus rhythm, which increases the likelihood of local ventricular reentry.

• This syndrome has been observed in individuals of all genders and ethnic backgrounds, following an autosomal dominant inheritance pattern.
• It is most prevalent in young males (~75%) and is suspected to contribute to the Sudden and Unexpected Nocturnal Death Syndrome (SUDS) noted in Southeast Asian men.
• The ventricular arrhythmia typically manifests at rest or during sleep.
• Fever and other sodium channel-blocking agents can also trigger ventricular arrhythmias.

'a' wave in JVP indicates Atrial contraction.

• Lung cancer can exhibit metastasis to heart leading to development of pericardial effusion.
• As more fluid would have accumulated, patient developed cardiac tamponade leading to hypotension and full neck veins.
• Y descent is absent in cardiac tamponade.
• Due to swinging motion of heart in a sac of fluid, Electrical alternans is seen.
• Kussmaul sign is a paradoxical rise of JVP on inspiration. But in tamponade, due to extreme magnitude of pressure in pericardial space, Kussmaul sign becomes absent.

Normal JVP is between 5 and 8 cm of water. An increased JVP suggests right-sided CHF. The Kussmaul sign is observed in constrictive pericarditis, but it is absent in cardiac tamponade. Canon a waves are present in cases of AV dissociation, ventricular tachycardia, or junctional tachycardia.

The a wave indicates the contraction of the right atrium just after the P wave on an electrocardiogram, occurring before the first heart sound (S1).

• The a wave is absent in cases of atrial fibrillation.
• A canonical a wave is observed with atrioventricular (AV) dissociation or complete heart block, resulting from right atrial contraction against a closed tricuspid valve.
• Conditions such as wide complex tachycardia, including ventricular tachycardia, can also affect the a wave.
• A pronounced a wave is typically noted in patients with diminished right ventricular compliance, such as those experiencing right ventricular failure.

A wave in JVP results from atrial contraction.

• In atrial fibrillation, the atria are twitching, which diminishes their power to a point where a wave is absent.
• Heart block will present with large a waves.
• Tricuspid Regurgitation is characterised by absent x waves and large v waves.
• Constrictive Pericarditis displays a prominent y descent.