RYR2 p.R169L mutation and left ventricular hypertrophy in a child with emotion-triggered sudden death

2020 ◽  
Vol 30 (7) ◽  
pp. 1039-1042
Author(s):  
Utkarsh Kohli ◽  
Lisa Kuntz ◽  
Hemal M. Nayak
Keyword(s):  
Ventricular Tachycardia ◽  
Left Ventricular Hypertrophy ◽  
Ventricular Hypertrophy ◽  
Left Ventricular ◽  
Catecholaminergic Polymorphic Ventricular Tachycardia ◽  
Polymorphic Ventricular Tachycardia ◽  
Exercise Induced ◽  
In Vivo Effects

AbstractCatecholaminergic polymorphic ventricular tachycardia is a rare (prevalence: 1/10,000) channelopathy characterised by exercise-induced or emotion-triggered ventricular arrhythmias. There is an overall paucity of genotype-phenotype correlation studies in patients with catecholaminergic polymorphic ventricular tachycardia, and in vitro and in vivo effects of individual mutations have not been well characterised. We report an 8-year-old child who carried a mutation in the coding exon 8 of RYR2 (p.R169L) and presented with emotion-triggered sudden cardiac death. He was also found to have left ventricular hypertrophy, a combination which has not been reported before. We discuss the association between genetic variation in RYR2, particularly mutations causing replacement of arginine at position 169 of RYR2 and structural cardiac abnormalities.

Abstract 1079: Prevention of Fatal Arrhythmia in a Catecholaminergic Polymorphic Ventricular Tachycardia Mouse Model Carrying Calsequestrin-2 Mutation

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Hiroko Wakimoto ◽  
Ronny Alcalai ◽  
Lei Song ◽  
Michael Arad ◽  
Christine E Seidman ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Mouse Model ◽  
Peak Height ◽  
Mutant Mice ◽  
Catecholaminergic Polymorphic Ventricular Tachycardia ◽  
Polymorphic Ventricular Tachycardia ◽  
Study Drug Administration ◽  
Intracellular Ca

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a familial arrhythmia syndrome caused by mutations in the ryanodine receptor (RyR2) or calsequestrin-2 (CASQ2) genes and characterized by exercise or emotional stress-induced sudden death. Beta-adrenergic blockers are only partially effective and other agents have not been widely tested. Recent studies have shown that CPVT is mediated by increased Ca 2+ leak through the RyR2 channel. Our aim was to determine whether agents that inhibit intracellular Ca 2+ leak can effectively prevent CPVT. Methods: The efficacy of intraperitoneal (IP) propranolol (1mcg/g), Mg 2+ (0.002mEq/g), verapamil (8 mcg/g) and diltiazem (8 mcg/g) were tested both in vivo and in vitro using CASQ2 mutant mouse CPVT model. In vivo studies included ambulatory ECG recordings at rest and following epinephrine stress (0.4 mcg/g IP) at baseline and after study drug administration. Experiments for each drug were performed on separate days to avoid confounding effects. In vitro studies included intracellular Ca 2+ transient analysis on isolated cardiomyocytes from mutant mice with and without epinephrine (5.5 μM). Results: All 4 drugs restored sinus rhythm and reduced the frequency of VT episodes induced by epinephrine in CASQ2 mutant mice. Only verapamil completely prevented epinephrine-induced VT in 87% of the mice (p<0.01). Cardiomyocyte studies in basal conditions revealed that Mg 2+ and verapamil inhibited sarcomere contraction and normalized the prolonged Ca 2+ reuptake period in CASQ2 mutants, but did not decrease baseline Ca 2+ peak height. Epinephrine-stressed mutant myocytes had increased diastolic Ca 2+ levels, lower Ca 2+ peak height and spontaneous SR Ca 2+ release events that were partially prevented by verapamil and Mg 2+ . Verapamil was more effective than Mg 2+ in reducing the frequency of spontaneous Ca 2+ releases induced by epinephrine. Conclusions: All 4 agents can inhibit ventricular arrhythmia in CPVT mouse model; however verapamil appears most effective in preventing arrhythmia in vivo and in modifying intracellular abnormal calcium handling. Calcium antagonists might have therapeutic value in CPVT and other RyR2-mediated arrhythmias and should be considered for human clinical studies.

Abstract 15420: Resolving a Controversy: Inhibition of Cardiac Ryanodine Receptors is the Principal Mechanism of Antiarrhythmic Action of Flecainide in Catecholaminergic Polymorphic Ventricular Tachycardia

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Dmytro O Kryshtal ◽  
Daniel J Blackwell ◽  
Christian L Egly ◽  
Abigail N Smith ◽  
Suzanne M Batiste ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Sodium Channel ◽  
Sodium Channels ◽  
Catecholaminergic Polymorphic Ventricular Tachycardia ◽  
Polymorphic Ventricular Tachycardia ◽  
Antiarrhythmic Action ◽  
Channel Block ◽  
Principal Mechanism ◽  
Cardiac Sodium Channels

Rationale: The class Ic antiarrhythmic drug flecainide prevents ventricular tachyarrhythmia in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), a disease caused by hyperactive cardiac ryanodine receptor (RyR2) calcium (Ca) release. Although flecainide inhibits single RyR2 channels in vitro , reports have claimed that RyR2 inhibition by flecainide is not relevant for its mechanism of antiarrhythmic action and concluded that sodium channel block alone is responsible for flecainide’s efficacy in CPVT. Objective: To determine whether RyR2 block independently contributes to flecainide’s efficacy for suppressing spontaneous sarcoplasmic reticulum (SR) Ca release and for preventing ventricular tachycardia in vivo . Methods and Results: We synthesized N -methyl flecainide analogues (QX-FL and NM-FL) and showed that N -methylation reduces flecainide’s inhibitory potency on RyR2 channels but not on cardiac sodium channels. Antiarrhythmic efficacy was tested utilizing a calsequestrin knockout (Casq2-/-) CPVT mouse model. In membrane-permeabilized Casq2-/- cardiomyocytes — lacking intact sarcolemma and devoid of sodium channel contribution — flecainide, but not its analogues, suppressed RyR2-mediated Ca release at clinically relevant concentrations. In voltage-clamped, intact Casq2-/- cardiomyocytes pretreated with tetrodotoxin (TTX) to inhibit sodium channels and isolate the effect of flecainide on RyR2, flecainide significantly reduced the frequency of spontaneous SR Ca release, while QX-FL and NM-FL did not. In vivo , flecainide effectively suppressed catecholamine-induced ventricular tachyarrhythmias in Casq2-/- mice, whereas NM-FL did not, despite comparable sodium channel block. Conclusions: Flecainide remains an effective inhibitor of RyR2-mediated arrhythmogenic Ca release even when cardiac sodium channels are blocked. In mice with CPVT, sodium channel block alone was not enough to prevent arrhythmias. Hence, RyR2 inhibition by flecainide is critical for its mechanism of antiarrhythmic action.

Voltage Disturbances During Pregnancy

2017 ◽  
Author(s):  
Heather C. Nixon
Keyword(s):  
Ventricular Tachycardia ◽  
Left Ventricular Hypertrophy ◽  
Ventricular Hypertrophy ◽  
Well Being ◽  
Left Ventricular ◽  
Ventricular Ectopy ◽  
Conversion Therapy ◽  
St Segment ◽  
Assessment And Treatment ◽  
The Impact

This chapter covers the incidence, etiology, and treatment of the most common electrocardiogram and rhythm disturbances encountered during pregnancy. Baseline electrocardiogram changes associated with pregnancy include left ventricular hypertrophy and ST segment depressions secondary to anatomic and metabolic changes of pregnancy. The most common arrhythmias include atrial and ventricular ectopy, which are usually benign in nature. Supraventricular and ventricular tachycardia are also discussed in detail, along with the impact of antiarrhythmic and electrical conversion therapy on fetal and maternal well-being. An understanding of the pathophysiology, assessment, and treatment of these rhythm disturbances is requisite knowledge for all anesthesiologists to provide optimal and timely care to parturients.

scholarly journals Myocardial Metabolism in Endurance Exercise-Induced Left Ventricular Hypertrophy

2018 ◽  
Vol 11 (6) ◽  
pp. 928-930
Author(s):  
Meagan M. Wasfy ◽  
Courtney Foster Bibbo ◽  
Marcel Brown ◽  
James R. DeLuca ◽  
Francis Wang ◽  
...  
Keyword(s):  
Left Ventricular Hypertrophy ◽  
Endurance Exercise ◽  
Ventricular Hypertrophy ◽  
Myocardial Metabolism ◽  
Left Ventricular ◽  
Exercise Induced

scholarly journals Diagnosing Cardiac Amyloidosis: From Heart Failure to Electrical Storm

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Adithya T. Mathews ◽  
Abu-Sayeef Mirza ◽  
Chandrashekar Bohra ◽  
Akshay G. Mathews ◽  
Philip Ritucci-Chinni ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ventricular Tachycardia ◽  
Left Ventricular Hypertrophy ◽  
Cardiac Amyloidosis ◽  
Ventricular Hypertrophy ◽  
Diastolic Heart Failure ◽  
Diuretic Therapy ◽  
Left Ventricular ◽  
Electrical Storm ◽  
Rapid Progression

Cardiac amyloidosis is a condition when amyloid fibers are deposited in the extracellular space of the heart causing tachyarrhythmias, heart failure, or sudden cardiac death. We present a 71-year-old woman presenting with dyspnea on admission. Echocardiogram revealed diastolic heart failure and left ventricular hypertrophy with strain pattern concerning for an infiltrative process. She was discharged with diuretic therapy and scheduled for a cardiac magnetic resonance imaging. One week after discharge, she was readmitted with progressive shortness of breath and syncope. She was found to be in shock and had multiple episodes of cardiac arrest with both ventricular tachycardia and pulseless electrical activity. She developed electrical storm and eventually passed within 24 hours. Autopsy revealed gross cardiomegaly and left ventricular hypertrophy with Congo red staining revealing amyloid fibrils with apple-green birefringence. This case demonstrates the rapid progression of cardiac amyloidosis from acute-onset diastolic heart failure to uncontrollable ventricular tachycardia, and eventually death. We review the literature regarding multiple diagnostic modalities that facilitate the confirmation of cardiac amyloidosis.

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