scholarly journals Adeno-associated virus-mediated CASQ2 delivery rescues phenotypic alterations in a patient-specific model of recessive catecholaminergic polymorphic ventricular tachycardia

2016 ◽  
Vol 7 (10) ◽  
pp. e2393-e2393 ◽  
Author(s):  
Francesco Lodola ◽  
Diego Morone ◽  
Marco Denegri ◽  
Rossana Bongianino ◽  
Hiroko Nakahama ◽  
...  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
R. P. Pölönen ◽  
K. Penttinen ◽  
H. Swan ◽  
K. Aalto-Setälä

Mutations in the cardiac ryanodine receptor (RYR2) are the leading cause for catecholaminergic polymorphic ventricular tachycardia (CPVT). In this study, we evaluated antiarrhythmic efficacy of carvedilol and flecainide in CPVT patient-specific induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) carrying different mutations in RYR2. iPSC-CMs were generated from skin biopsies of CPVT patients carrying exon 3 deletion and L4115 or V4653F mutation in RYR2 and of a healthy individual. Ca2+ kinetics and drug effects were studied with Fluo-4 AM indicator. Carvedilol abolished Ca2+ abnormalities in 31% of L4115F, 36% of V4653F, and 46% of exon 3 deletion carrying CPVT cardiomyocytes and flecainide 33%, 30%, and 52%, respectively. Both drugs lowered the intracellular Ca2+ level and beating rate of the cardiomyocytes significantly. Moreover, flecainide caused abnormal Ca2+ transients in 61% of controls compared to 26% of those with carvedilol. Carvedilol and flecainide were equally effective in CPVT iPSC-CMs. However, flecainide induced arrhythmias in 61% of control cells. CPVT cardiomyocytes carrying the exon 3 deletion had the most severe Ca2+ abnormalities, but they had the best response to drug therapies. According to this study, the arrhythmia-abolishing effect of neither of the drugs is optimal. iPSC-CMs provide a unique platform for testing drugs for CPVT.


Author(s):  
Granitz Christina ◽  
Jirak Peter ◽  
Strohmer Bernhard ◽  
Pölzl Gerhard

Abstract Background  Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a severe genetic arrhythmogenic disorder characterized by adrenergically induced ventricular tachycardia manifesting as stress-induced syncope and sudden cardiac death. While CPVT is not associated with dilated cardiomyopathy (DCM) in most cases, the combination of both disease entities poses a major diagnostic and therapeutic challenge. Case summary  We present the case of a young woman with CPVT. The clinical course since childhood was characterized by repetitive episodes of exercise-induced ventricular arrhythmias and a brady-tachy syndrome due to rapid paroxysmal atrial fibrillation and sinus bradycardia. Medical treatment included propranolol and flecainide until echocardiography showed a dilated left ventricle with severely depressed ejection fraction when the patient was 32 years old. Cardiac magnetic resonance imaging revealed non-specific late gadolinium enhancement. Myocardial inflammation, however, was excluded by subsequent endomyocardial biopsy. Genetic analysis confirmed a mutation in the cardiac ryanodine receptor but no pathogenetic variant associated with DCM. Guideline-directed medical therapy for HFrEF was limited due to symptomatic hypotension. Over the next months, the patient developed progressive heart failure symptoms that were finally managed by heart transplantation. Discussion  Management in patients with CPVT and DCM is challenging, as Class I antiarrhythmic drugs are not recommended in structural heart disease and prophylactic internal cardioverter-defibrillator implantation without adjuvant antiarrhythmic therapy can be detrimental. Regular echocardiographic screening for DCM is recommendable in patients with CPVT. A multidisciplinary team of heart failure specialists, electrophysiologists, geneticists, and imaging specialists is needed to collaborate in the delivery of clinical care.


Sign in / Sign up

Export Citation Format

Share Document