Catecholaminergic polymorphic ventricular tachycardia differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mounika Reddy Vadiyala, M.B.B.S.[2]

Overview

Catecholaminergic polymorphic ventricular tachycardia must be differentiated from Arrhythmogenic right ventricular dysplasia, Short-coupled ventricular tachycardia (SC-torsade de pointes [TdP]), Long QT syndrome and Andersen-Tawil syndrome.

Differentiating Catecholaminergic polymorphic ventricular tachycardia from other Diseases

Catecholaminergic polymorphic ventricular tachycardia must be differentiated from other diseases that cause syncope, ventricular tachycardia, and sudden cardiac death, such as:

• Arrhythmogenic right ventricular dysplasia
• Short-coupled ventricular tachycardia (SC-torsade de pointes [TdP])
• Long QT syndrome
• Andersen-Tawil syndrome
• Brugada syndrome

Differentiating Catecholaminergic polymorphic ventricular tachycardia from other diseases on the basis of syncope, sudden cardiac death, and ventricular tachycardia

On the basis syncope, sudden cardiac death, and ventricular tachycardia, Catecholaminergic polymorphic ventricular tachycardia must be differentiated from Arrhythmogenic right ventricular dysplasia, Short-coupled ventricular tachycardia (SC-torsade de pointes TdP), Long QT syndrome, Andersen-Tawil syndrome and Brugada syndrome.

Diseases	Cause	Clinical manifestations	ECG		Structural abnormalities
			ECG during rest	ECG during exercise or stress
Catecholaminergic polymorphic ventricular tachycardia	Mutations in RYR2 and CASQ2 genes	Symptoms are exercise or emotion related Syncope Sudden cardiac death Ventricular tachycardia	Sinus bradycardia, Prominent U-waves, and Supraventricular arrhythmias	Monomorphic PVCs Polymorphic or bidirectional PVCs with bigeminy Polymorphic VT Bidirectional VT	-
Arrhythmogenic right ventricular dysplasia	Usually caused by mutations in genes encoding for desmosomal proteins.	Symptoms are usually exercise-related Syncope Ventricular tachycardia symptoms such as palpitations, dizziness Sudden cardiac death Symptoms and signs related to right ventricular failure may also be seen.	T-wave inversion in the right precordial leads. Epsilon waves. Right bundle branch block.	Left bundle branch block pattern during tachycardia	It primarily affects the right ventricle. Changes seen are: Fatty infiltration of the RV free wall Thinning of the RV myocardium RV Dilation and Regional Wall Motion Abnormalities
Short QT syndrome	Mutations in KCNH 2 gene for SQTS 1, KCNQ 1 for SQT 2, KCNJ 2 gene for SQTS 3, CACNA1C for SQTS 4, and CACNB2b for SQTS 5 Hypercalcemia Digoxin	Symptoms are not exercise-related or triggered Sudden death Syncope Atrial fibrillation and Palpitations. Physical examination is normal.	Short QTc interval (<320 ms) Lack of variability in the QTc with heart rate, Either a tall peaked T wave or Brugada pattern in V1 and V2, Early repolarization and paroxysmal atrial fibrillation as a rhythm.	-	-
Long QT syndrome	Mutations in genes encoding for sodium and potassium ion channels in the heart.	Symptoms are triggered by exercise, stress, certain drugs, etc Syncope Palpitations Sudden cardiac death	Prolongation of the QTc interval (>460 ms) Abnormal T-wave morphology	Prolongation of the QTc interval (>460 ms) Abnormal T-wave morphology	-
Andersen-Tawil syndrome	Mutation in KCNJ2 gene.	Symptoms are not related to adrenergic activation Syncope, Periodic paralysis, Ventricular arrhythmias, Muscular weakness, Seizures, Sudden cardiac death (low risk) Other significant findings include: Hypoplastic mandible, Micrognathia, Broad nose, Low set ears and Clinodactyly.	A long QTc (LQT) interval Characteristic T-U patterns Prominent U-wave A wide T-U junction Prolonged terminal T-wave Premature ventricular contractions(PVC) especially at "rest" Polymorphic ventricular tachycardia (PMVT) which is called bidirectional ventricular tachycardia (BiVT) VF on further deterioration which can lead to sudden death	-	-
Brugada syndrome	Mutation in SCN5A gene.	Symptoms occur predominantly during sleep or at rest Syncope Seizures Difficulty breathing Sudden death Other findings: Ventricular tachycardia	ST elevation in the right precordial leads Right Bundle Branch Block pattern Polymorphic ventricular tachycardia	-	-
Short-coupled ventricular tachycardia (SC-torsade de pointes TdP)	Unknown	Symptoms are not related to adrenergic stimuli Syncope Sudden cardiac death Ventricular tachycardia	Polymorphic ventricular tachycardia Typical TdP with a remarkably short coupling interval (always less then 300 ms) of the first TdP beat Multiple ventricular premature beats with short coupling interval	-	-