Authors: Bryce Ferry, DO and Destiny F. Chau, MD - Arkansas Children’s Hospital/University of Arkansas for Medical Sciences, Little Rock, AR
A 7-year-old male child presents to the emergency room with a history of syncope while playing soccer. He also has a family history of sudden death at a young age. Workup demonstrates a normal electrocardiogram at rest, a structurally normal heart on transthoracic echocardiogram, and a right heart biopsy demonstrating normal myocardium. Genetic testing reveals a mutation in the RYR2 gene. Which of the following conditions is MOST LIKELY in this patient?
Correct!
Wrong!
Question of the Week 399
EXPLANATION
Syncope due to cardiac disease can be life-threatening. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare arrhythmogenic disorder characterized by bidirectional or polymorphic ventricular tachycardia (VT) that is triggered by an adrenergic surge secondary to exercise or emotional stress. CPVT may result from mutations in the cardiac ryanodine receptor gene (RYR2), which is inherited in an autosomal dominant pattern or the calsequestrin gene CASQ2, inherited in an autosomal recessive pattern. These genes are likely involved in calcium release from the sarcoplasmic reticulum. To date, other genes have also been implicated in CPVT.
The mean age of symptom presentation is between 7 and 12 years old with syncope being a common presenting sign. Diagnostic workup often reveals a normal resting baseline electrocardiogram (ECG) and a structurally normal heart on echocardiography. However, an exercise or pharmacologic stress test typically reveals bidirectional or polymorphic VT. In children who cannot perform a stress test, a Holter monitor or an event recorder can aid in detecting an abnormal ECG during periods of adrenergic stress. Typically, when the heart rate goes above a threshold of 100-120 beats per minute (BPM), the ECG will demonstrate premature ventricular complexes (PVCs) followed by short runs of non-sustained VT. With continued stress, the VT can degenerate into ventricular fibrillation (VF). Self-resolution of the arrhythmia can occur when the stress occurs over a short time period.
The first line treatment of CPVT is nonselective beta blockers, such as nadolol, often at high doses to achieve clinical effectiveness. It may also be clinically indicated to add flecainide or a calcium-channel blocker to beta blocker therapy. With persistent syncope or progression to cardiac arrest, the recommendation is an implantable cardioverter defibrillator. When left untreated, CPVT will result in cardiac arrest in up to 30% and recurrent syncope in up to 80% of affected patients.
Anesthetic management for patients with CPVT centers on preventing periods of adrenergic stress and catecholamine surges. To this point, a patient's emotional distress and pain should be anticipated and prevented. It is imperative that beta blockers are continued during the perioperative period. Adrenergic drugs are to be avoided and tachycardia should be promptly treated. Prevention of postoperative nausea and vomiting and adequate pain control is important. Patients with the cardiac ryanodine gene (RYR2) do not seem susceptible to malignant hyperthermia, which is linked to the RYR1 receptor.
Arrhythmogenic cardiomyopathy, also known as arrhythmogenic right ventricular dysplasia/cardiomyopathy, is a rare non-ischemic cardiomyopathy in which the right ventricular myocardium is replaced by fibrofatty tissue that may lead to arrythmias, dyspnea, and possible syncopal episodes. Arrhythmogenic cardiomyopathy can develop during childhood, but most cases arise during the third to fourth decade of life. Long QT syndrome can present similarly to CPVT with regards to emotional or physical stress but instead displays prolongation of the QT interval on the resting ECG. Brugada syndrome may also present with syncope, but often has characteristic ECG findings of variable ST segment abnormalities. This patient's presentation, diagnostic findings, and genetic results are most consistent with catecholaminergic polymorphic ventricular tachycardia.
REFERENCES
Pflaumer A, Davis AM. Guidelines for the diagnosis and management of catecholaminergic polymorphic ventricular tachycardia. Heart Lung Circ. 2012;21(2):96-100.
Omiya K, Mitsui K, Matsukawa T. Anesthetic management of a child with catecholaminergic polymorphic ventricular tachycardia undergoing insertion of implantable cardioverter defibrillator : a case report.JA Clin Rep. 2020;6(1):16.
Staikou C, Chondrogiannis K, Mani A. Perioperative management of hereditary arrhythmogenic syndromes. Br J Anaesth. 2012;108(5):730-744.
Brugada J, Campuzano O, Arbelo E, Sarquella-Brugada G, Brugada R. Present status of Brugada syndrome: JACC State-of-the-Art Review. J Am Coll Cardiol. 2018;72(9):1046-1059.
Shah SR, Park K, Alweis R. Long QT Syndrome: A comprehensive review of the literature and current evidence. Curr Probl Cardiol. 2019;44(3):92-106.
Gandjbakhch E, Redheuil A, Pousset F, Charron P, Frank R. Clinical diagnosis, imaging, and genetics of arrhythmogenic right ventricular cardiomyopathy/dysplasia: JACC State-of-the-Art Review. J Am Coll Cardiol. 2018;72(7):784-804.
Syncope due to cardiac disease can be life-threatening. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare arrhythmogenic disorder characterized by bidirectional or polymorphic ventricular tachycardia (VT) that is triggered by an adrenergic surge secondary to exercise or emotional stress. CPVT may result from mutations in the cardiac ryanodine receptor gene (RYR2), which is inherited in an autosomal dominant pattern or the calsequestrin gene CASQ2, inherited in an autosomal recessive pattern. These genes are likely involved in calcium release from the sarcoplasmic reticulum. To date, other genes have also been implicated in CPVT.
The mean age of symptom presentation is between 7 and 12 years old with syncope being a common presenting sign. Diagnostic workup often reveals a normal resting baseline electrocardiogram (ECG) and a structurally normal heart on echocardiography. However, an exercise or pharmacologic stress test typically reveals bidirectional or polymorphic VT. In children who cannot perform a stress test, a Holter monitor or an event recorder can aid in detecting an abnormal ECG during periods of adrenergic stress. Typically, when the heart rate goes above a threshold of 100-120 beats per minute (BPM), the ECG will demonstrate premature ventricular complexes (PVCs) followed by short runs of non-sustained VT. With continued stress, the VT can degenerate into ventricular fibrillation (VF). Self-resolution of the arrhythmia can occur when the stress occurs over a short time period.
The first line treatment of CPVT is nonselective beta blockers, such as nadolol, often at high doses to achieve clinical effectiveness. It may also be clinically indicated to add flecainide or a calcium-channel blocker to beta blocker therapy. With persistent syncope or progression to cardiac arrest, the recommendation is an implantable cardioverter defibrillator. When left untreated, CPVT will result in cardiac arrest in up to 30% and recurrent syncope in up to 80% of affected patients.
Anesthetic management for patients with CPVT centers on preventing periods of adrenergic stress and catecholamine surges. To this point, a patient's emotional distress and pain should be anticipated and prevented. It is imperative that beta blockers are continued during the perioperative period. Adrenergic drugs are to be avoided and tachycardia should be promptly treated. Prevention of postoperative nausea and vomiting and adequate pain control is important. Patients with the cardiac ryanodine gene (RYR2) do not seem susceptible to malignant hyperthermia, which is linked to the RYR1 receptor.
Arrhythmogenic cardiomyopathy, also known as arrhythmogenic right ventricular dysplasia/cardiomyopathy, is a rare non-ischemic cardiomyopathy in which the right ventricular myocardium is replaced by fibrofatty tissue that may lead to arrythmias, dyspnea, and possible syncopal episodes. Arrhythmogenic cardiomyopathy can develop during childhood, but most cases arise during the third to fourth decade of life. Long QT syndrome can present similarly to CPVT with regards to emotional or physical stress but instead displays prolongation of the QT interval on the resting ECG. Brugada syndrome may also present with syncope, but often has characteristic ECG findings of variable ST segment abnormalities. This patient's presentation, diagnostic findings, and genetic results are most consistent with catecholaminergic polymorphic ventricular tachycardia.
REFERENCES
Pflaumer A, Davis AM. Guidelines for the diagnosis and management of catecholaminergic polymorphic ventricular tachycardia. Heart Lung Circ. 2012;21(2):96-100.
Omiya K, Mitsui K, Matsukawa T. Anesthetic management of a child with catecholaminergic polymorphic ventricular tachycardia undergoing insertion of implantable cardioverter defibrillator : a case report.JA Clin Rep. 2020;6(1):16.
Staikou C, Chondrogiannis K, Mani A. Perioperative management of hereditary arrhythmogenic syndromes. Br J Anaesth. 2012;108(5):730-744.
Brugada J, Campuzano O, Arbelo E, Sarquella-Brugada G, Brugada R. Present status of Brugada syndrome: JACC State-of-the-Art Review. J Am Coll Cardiol. 2018;72(9):1046-1059.
Shah SR, Park K, Alweis R. Long QT Syndrome: A comprehensive review of the literature and current evidence. Curr Probl Cardiol. 2019;44(3):92-106.
Gandjbakhch E, Redheuil A, Pousset F, Charron P, Frank R. Clinical diagnosis, imaging, and genetics of arrhythmogenic right ventricular cardiomyopathy/dysplasia: JACC State-of-the-Art Review. J Am Coll Cardiol. 2018;72(7):784-804.
