Short QT Syndrome Manifesting with Neonatal Atrial Fibrillation and Bradycardia

Short QT syndrome (SQTS) is a very rare, sporadic or autosomal dominant inherited channelopathy characterized by abnormally short QT intervals on the electrocardiogram and increased propensity to atrial and ventricular tachyarrhythmias and/or sudden cardiac death. Since its recognition as a distinct clinical entity in 2000, significant progress has been made in defining the clinical, molecular, and genetic basis of SQTS. To date, several causative gain-of-function mutations in potassium channel genes and loss-of-function mutations in calcium channel genes have been identified. The physiological consequence of these mutations is an accelerated repolarization, thus abbreviated action potentials and shortened QT interval with an increased inhomogeneity and dispersion of repolarization. Regarding other rare monogenetic arrhythmias, a genetic basis of atrial fibrillation was considered very unlikely until very recently. However, in the last decade the heritability of atrial fibrillation in the general population has been well described in several epidemiological studies. So far, more than 30 genes have been implicated in atrial fibrillation through candidate gene approach studies, and 14 loci were found to be associated with atrial fibrillation through genome-wide association studies. This genetic heterogeneity and the low prevalence of mutations in any single gene restrict the clinical utility of genetic screening in atrial fibrillation.

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Monogenic and oligogenic cardiovascular diseases: genetics of arrhythmias—short QT syndrome

ESC CardioMed ◽

10.1093/med/9780198784906.003.0150_update_001 ◽

2018 ◽

pp. 676-679

Author(s):

Erol Tülümen ◽

Martin Borggrefe

Keyword(s):

Atrial Fibrillation ◽

Genetic Basis ◽

Association Studies ◽

Single Gene ◽

Epidemiological Studies ◽

Candidate Gene Approach ◽

Loss Of Function ◽

Short Qt Syndrome ◽

Qt Intervals ◽

Qt Syndrome

Short QT syndrome (SQTS) is a very rare, sporadic or autosomal dominant inherited channelopathy characterized by abnormally short QT intervals on the electrocardiogram and increased propensity to atrial and ventricular tachyarrhythmias and/or sudden cardiac death. Since its recognition as a distinct clinical entity in 2000, significant progress has been made in defining the clinical, molecular, and genetic basis of SQTS. To date, several causative gain-of-function mutations in potassium channel genes and loss-of-function mutations in calcium channel genes have been identified. The physiological consequence of these mutations is an accelerated repolarization, thus abbreviated action potentials and shortened QT interval with an increased inhomogeneity and dispersion of repolarization. Regarding other rare monogenetic arrhythmias, a genetic basis of atrial fibrillation was considered very unlikely until very recently. However, in the last decade the heritability of atrial fibrillation in the general population has been well described in several epidemiological studies. So far, more than 30 genes have been implicated in atrial fibrillation through candidate gene approach studies, and more than 25 loci were found to be associated with atrial fibrillation through genome-wide association studies. This genetic heterogeneity and the low prevalence of mutations in any single gene restrict the clinical utility of genetic screening in atrial fibrillation.

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Short QT Syndrome and Atrial Fibrillation Caused by Mutation in KCNH2

Journal of Cardiovascular Electrophysiology ◽

10.1046/j.1540-8167.2005.40621.x ◽

2005 ◽

Vol 16 (4) ◽

pp. 394-396 ◽

Cited By ~ 214

Author(s):

KUI HONG ◽

PREBEN BJERREGAARD ◽

IHOR GUSSAK ◽

RAMON BRUGADA

Keyword(s):

Atrial Fibrillation ◽

Short Qt Syndrome ◽

Qt Syndrome

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KCNJ2mutation in short QT syndrome 3 results in atrial fibrillation and ventricular proarrhythmia

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1218154110 ◽

2013 ◽

Vol 110 (11) ◽

pp. 4291-4296 ◽

Cited By ~ 88

Author(s):

Makarand Deo ◽

Yanfei Ruan ◽

Sandeep V. Pandit ◽

Kushal Shah ◽

Omer Berenfeld ◽

...

Keyword(s):

Atrial Fibrillation ◽

Short Qt Syndrome ◽

Qt Syndrome

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Sinus bradycardia, junctional rhythm, and low-rate atrial fibrillation in Short QT syndrome during 20 years of follow-up: three faces of the same genetic problem

Cardiology in the Young ◽

10.1017/s1047951115001432 ◽

2015 ◽

Vol 26 (3) ◽

pp. 589-592 ◽

Cited By ~ 7

Author(s):

Daniela Righi ◽

Massimo S. Silvetti ◽

Fabrizio Drago

Keyword(s):

Atrial Fibrillation ◽

Sinus Bradycardia ◽

Sinus Node ◽

Sinus Node Dysfunction ◽

Short Qt Syndrome ◽

Junctional Rhythm ◽

Genetic Problem ◽

Qt Syndrome ◽

Low Rate

AbstractWe describe the case of an asymptomatic girl with sinus bradycardia and short QT interval at birth, junctional bradycardia in infancy requiring single-chamber pacemaker, atrial fibrillation in adolescence, and V141M mutation in the KCNQ1 gene. Atrial fibrillation recurred and became unresponsive to electrical or anti-arrhythmic therapy. During 20 years of follow-up, a progressive evolution from sinus node dysfunction to low-rate atrial fibrillation was observed.

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Short QT syndrome presenting with atrial fibrillation and LV hypertrophy

International Journal of Cardiology ◽

10.1016/j.ijcard.2011.07.084 ◽

2012 ◽

Vol 156 (1) ◽

pp. e9-e10

Author(s):

Agnieszka Zienciuk-Krajka ◽

Piotr Kukla ◽

Sebastian Stec ◽

Grzegorz Raczak

Keyword(s):

Atrial Fibrillation ◽

Short Qt Syndrome ◽

Qt Syndrome

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KCNQ1 V141M and Short QT Syndrome: are we dealing with a different entity?

European Heart Journal ◽

10.1093/ehjci/ehaa946.0453 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

G Garcia Ordonez ◽

A.E Reyes-Quintero ◽

A Garcia ◽

S Nava ◽

M.J Levinstein ◽

...

Keyword(s):

Atrial Fibrillation ◽

Ventricular Arrhythmias ◽

Categorical Variables ◽

Control Group ◽

Short Qt Syndrome ◽

Av Node ◽

Fetal Bradycardia ◽

Qt Syndrome ◽

Almost All ◽

Group 1

Abstract Short QT Syndrome (SQTS) is a highly malignant inherited primary electrical disease that is associated with ventricular arrhythmias and sudden cardiac death (SCD); despite this, some patients may present a different arrhythmic phenotype with supraventricular affection. One particular presentation can be notably separated from others. The V141M variant from the KCNQ1 gene frequently presents with fetal bradycardia, atrial fibrillation, sinus, and AV node dysfunction, but without a single reported event of ventricular arrhythmia. To perform a literature review and pool analysis of SQTS cases, and compare patients with the V141M mutation in KCNQ1 to other SQTS cases to determine if we are dealing with a different electrical disorder. We conducted a search in the Varsome, Mastermind, MEDLINE, PubMed, and ClinVar databases to identify SQTS patients and conduct a pooled analysis. Their age, gender, clinical presentation, ECG findings, genetic analysis, and follow-up assessment were collected for analysis. If the duration of the QT interval was not described, it was determined by direct measurements in published ECG. For the comparison between groups, SQTS patients, we separated into two main groups: Non-KCNQ1 V141M patients (Group 1) and positive KCNQ1 V141M mutation (Group 2). Categorical variables are expressed as percentages. The categorical variables were analyzed using chi-square or Fisher exact test when necessary. We gathered 56 patients with a diagnosis of SQTS from 27 previous publications combined with one other case followed by the authors. A total of 13 (23.2%) patients presented with the V141M KCNQ1 mutation, the majority of KCNQ1 V141M patients were female (10 [77%]). Patients from group 1 had a significantly higher rate of familiar SCD (53.4% vs. 18.1%; P=0.04). Patients from the latter group have a significant history of SND when compared to the control group (36.3% vs. 0; P=0.001). The presence of SCD showed no significant difference between the two groups; nevertheless, the difference regarding ventricular arrhythmias is well represented (41.8% vs. 0; P=0.01). Both sinus and AV node dysfunction were present in almost all V141M patients when compared to the control group; a statistical significance was found (P = >0.001 for both instances). On the same regard, almost all patients from de V141M group presented SVA (84.6% vs 28.5%; P=0.001), specifically atrial fibrillation was present in all but 2 patients from the V141M group, which was significant (84.6% vs 24.3%; P = >0.001). Finally, fetal bradycardia was present in most of the members of this group, in contrast with the control group, with no patients with this characteristic (P = >0.001). SQTS is a phenotypically heterogeneous disease with many genetic subtypes; we propose a differentiation between the common known presentations of this syndrome and the more defined phenotype of the KCNQ1 V141M mutation. First Mexican patient with SQTS Funding Acknowledgement Type of funding source: None

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Abstract 16213: Short QT Syndrome Case Study

Circulation ◽

10.1161/circ.142.suppl_3.16213 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Lawrenshey Charles ◽

Abdullah Al-Abcha ◽

Tyler Kemnic ◽

Zulfiqar Qutrio Baloch

Keyword(s):

Atrial Fibrillation ◽

Heart Rate ◽

Sudden Cardiac Death ◽

Sinus Rhythm ◽

Cardiac Death ◽

Normal Sinus Rhythm ◽

Short Qt Syndrome ◽

Icd Implantation ◽

Normal Sinus ◽

Qt Syndrome

Introduction: Short QT syndrome (SQTS) is a very rare genetic disease of the electrical system of the heart which is associated with an increase risk of abnormal cardiac rhythms and sudden cardiac death. First described in 2000 with the first genetic mutation associated with SQTS described in 2004. We present a case of Short QT syndrome in a 53 year old male. Case: A 53 year old male with a PMH of HTN, alcohol abuse, and tobacco dependence presented to the ED with palpitations. Patient endorsed that he was in his usual state of health the day prior to arrival. He went to bed after drinking alcohol and woke up suddenly pale and diaphoretic with dyspnea and a persistent feeling of impending doom. On arrival to the ED, he was tachypneic (26 breaths/min) with a heart rate of 163 bpm and a blood pressure of 100/80 mmHg. EKG showed atrial fibrillation with RVR. The patient converted to normal sinus rhythm after one dose of IV Cardizem 10 mg was administered for rate control. The next day he had multiple episodes of Torsades de Pointe and monomorphic ventricular tachycardia treated with synchronized cardioversion, 2g of magnesium, IV amiodarone and lidocaine drip. He was transferred to the ICU for further evaluation and monitoring. Repeat EKG showed normal sinus rhythm at 75 bpm and short QT (QT= 328). TTE showed normal biventricular size and function (LVEF 60-65%) with no valvular abnormalities. Dual chamber Implantable Cardioverter Defibrillator (ICD) was placed and outpatient genetic testing was scheduled. Discussion: SQTS is very rare with roughly 70 cases identified worldwide since the condition was discovered in 2000. It is a congenital channelopathy related to potassium channels and represented by a normal heart rate with accelerated cardiac repolarization. Normal QT range is 350-440 msec while SQTS range is 210-340 msec. Mutations in the KCNH2, KCNJ2, or KCNQ1 genes lead to enhanced flow of potassium ions across the membrane of cardiac muscle cells. Patients can present at any age with palpitations, syncope, atrial fibrillation, and sudden cardiac death. The cornerstone to diagnosing SQTS is an electrocardiogram. Patients with SQTS can be managed with ICD implantation, quinidine (especially with KCNH2 mutation), and sotalol (with other mutations other than KCNH2).

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