- Pediatric Syncope: High-Risk Conditions and Reasonable Approach. [Review]
- EMEmerg Med Clin North Am 2018; 36(2):305-321
- Syncope is a common presentation to the emergency room. Unlike in the adult population, most pediatric syncope has non-life-threatening causes, and minimal evaluation in the emergency department is a...
Syncope is a common presentation to the emergency room. Unlike in the adult population, most pediatric syncope has non-life-threatening causes, and minimal evaluation in the emergency department is appropriate with parental reassurance. Despite this benign prognosis, care must be made to find uncommon and potentially fatal causes. The primary purpose of evaluation of the patient with syncope is to determine whether the patient is at increased risk for death and needs either admission to the hospital or an expedited outpatient evaluation. This article reviews some of the most dangerous causes of syncope in the pediatric patient.
- Maximum QTc on Holter electrocardiography in children. [Journal Article]
- PIPediatr Int 2018; 60(6):507-512
- CONCLUSIONS: The present method of analyzing QTc on Holter ECG, in which automatic and manual measurements are combined, is practical and may be useful for diagnosis and risk stratification of LQTS.
- Cardiac autonomic neuropathy: Risk factors, diagnosis and treatment. [Review]
- WJWorld J Diabetes 2018 Jan 15; 9(1):1-24
- Cardiac autonomic neuropathy (CAN) is a serious complication of diabetes mellitus (DM) that is strongly associated with approximately five-fold increased risk of cardiovascular mortality. CAN manifes...
Cardiac autonomic neuropathy (CAN) is a serious complication of diabetes mellitus (DM) that is strongly associated with approximately five-fold increased risk of cardiovascular mortality. CAN manifests in a spectrum of things, ranging from resting tachycardia and fixed heart rate (HR) to development of "silent" myocardial infarction. Clinical correlates or risk markers for CAN are age, DM duration, glycemic control, hypertension, and dyslipidemia (DLP), development of other microvascular complications. Established risk factors for CAN are poor glycemic control in type 1 DM and a combination of hypertension, DLP, obesity, and unsatisfactory glycemic control in type 2 DM. Symptomatic manifestations of CAN include sinus tachycardia, exercise intolerance, orthostatic hypotension (OH), abnormal blood pressure (BP) regulation, dizziness, presyncope and syncope, intraoperative cardiovascular instability, asymptomatic myocardial ischemia and infarction. Methods of CAN assessment in clinical practice include assessment of symptoms and signs,cardiovascular reflex testsbased on HR and BP, short-term electrocardiography (ECG), QT interval prolongation, HR variability (24 h, classic 24 h Holter ECG), ambulatory BP monitoring, HR turbulence, baroreflex sensitivity, muscle sympathetic nerve activity, catecholamine assessment and cardiovascular sympathetic tests, heart sympathetic imaging. Although it is common complication, the significance of CAN has not been fully appreciated and there are no unified treatment algorithms for today. Treatment is based on early diagnosis, life style changes, optimization of glycemic control and management of cardiovascular risk factors. Pathogenetic treatment of CAN includes: Balanced diet and physical activity; optimization of glycemic control; treatment of DLP; antioxidants, first of all α-lipoic acid (ALA), aldose reductase inhibitors, acetyl-L-carnitine; vitamins, first of all fat-soluble vitamin B1; correction of vascular endothelial dysfunction; prevention and treatment of thrombosis; in severe cases-treatment of OH. The promising methods include prescription of prostacyclin analogues, thromboxane A2 blockers and drugs that contribute into strengthening and/or normalization of Na+, K+-ATPase (phosphodiesterase inhibitor), ALA, dihomo-γ-linolenic acid (DGLA), ω-3 polyunsaturated fatty acids (ω-3 PUFAs), and the simultaneous prescription of ALA, ω-3 PUFAs and DGLA, but the future investigations are needed. Development of OH is associated with severe or advanced CAN and prescription of nonpharmacological and pharmacological, in the foreground midodrine and fludrocortisone acetate, treatment methods are necessary.
- Type 1 long QT syndrome and psychological stress in a laboratory setting. [Journal Article]
- JHJ Health Psychol 2018 Jan 01; :1359105317751617
- Trait-like sensitivity to stress in long QT syndrome patients has been documented previously. In addition, mental stress has been associated with symptomatic status of long QT syndrome. We examined w...
Trait-like sensitivity to stress in long QT syndrome patients has been documented previously. In addition, mental stress has been associated with symptomatic status of long QT syndrome. We examined whether the symptomatic type 1 long QT syndrome patients would be more sensitive to mental stress compared to asymptomatic patients and whether there would be differences in task-related physiological stress reactions between type 1 long QT syndrome patients and healthy individuals. The study population consisted of 21 symptomatic and 23 asymptomatic molecularly defined KCNQ1 mutation carriers, their 32 non-carrier relatives and 46 non-related healthy controls, with mean ages of 37, 39, 35 and 23 years, respectively. Electrocardiography was utilised to calculate inter-beat interval and high frequency and low frequency heart rate variability. Blood pressure was measured and mean arterial pressure and pulse pressure were calculated. Stress was induced using three different tasks: mental arithmetic, reaction time and public speech. Stress responses of symptomatic and asymptomatic type 1 long QT syndrome patients were not statistically different in any of the stress tasks. Short-term physiological stress reactivity of symptomatic type 1 long QT syndrome patients appears to be normal and does not enhance the risk assessment of asymptomatic mutation carriers.
- Hydroquinidine Prevents Life-Threatening Arrhythmic Events in Patients With Short QT Syndrome. [Journal Article]
- JACCJ Am Coll Cardiol 2017 Dec 19; 70(24):3010-3015
- CONCLUSIONS: We demonstrated for the first time that treatment with HQ was associated with a lower incidence of LAE in SQTS patients. These data point to the importance that quinidine, that in several countries has been removed from the market, remains available worldwide for patients with SQTS. In the present study, therapy with HQ has been proven to be safe, with a relatively low rate of side effects.
- Modeling the effects of amiodarone on short QT syndrome variant 2 in the human ventricles. [Journal Article]
- CPConf Proc IEEE Eng Med Biol Soc 2017; 2017:4273-4276
- CONCLUSIONS: Amiodarone at a high dose produced better therapeutic effects on SQT2 than at a low dose. This study provides new evidence that amiodarone at a high dose may be a potential pharmacological treatment for SQT2.
- Low Prevalence of Inappropriate Shocks in Patients With Inherited Arrhythmia Syndromes With the Subcutaneous Implantable Defibrillator Single Center Experience and Long-Term Follow-Up. [Journal Article]
- JAJ Am Heart Assoc 2017 Oct 17; 6(10)
- CONCLUSIONS: Our study supports the use of the subcutaneous ICD for both secondary and primary prevention of sudden cardiac death as a reliable alternative to the conventional transvenous ICD.
- Characteristics of electromechanical window in anesthetized rabbit models of short QT and long QT syndromes. [Journal Article]
- JTJ Toxicol Sci 2017; 42(5):579-587
- The current regulatory guidelines recommend the use of QT interval to assess the risk of arrhythmogenic potential of new chemical entities. Recently, the electromechanical window (EMW), the differenc...
The current regulatory guidelines recommend the use of QT interval to assess the risk of arrhythmogenic potential of new chemical entities. Recently, the electromechanical window (EMW), the difference in duration between electrical and mechanical systole, has been proposed as markers for drug-induced torsades de pointes (TdP); however, data of EMW in short QT model are not available. This study aimed to characterize the EMW as a marker for drug-induced ventricular arrhythmias in anesthetized rabbit model of long QT syndrome type 2 (LQT2) and short QT syndrome (SQTS) infused with reference compounds known to lengthen or shorten QT intervals. After rabbits were anesthetized with isoflurane, body surface electrocardiograms and left ventricular pressure were recorded. The LQT2 was produced by intravenous infusion with dofetilide (n = 6), quinidine (n = 6) and sotalol (n = 6) whereas the SQTS was induced by intravenous escalating concentrations of nicorandil (n = 7), pinacidil (n = 5) and cromakalim (n = 5). The EMW in anesthetized rabbits ranged from 1.3 to 53.3 msec. All three drugs known to lengthen QT intervals prolonged QT and QTcF interval while the EMW was markedly decreased to negative values. Pinacidil significantly produced QT and QTcF shortening and significantly abbreviated the EMW (p < 0.05). This study demonstrated that the EMW is associated with QT intervals (p < 0.001). It is negative in the presence of QT-prolonging drugs while it is more positive in the presence of QT-shortening drugs. The results suggest that the EMW in anesthetized rabbits can be used in drug safety evaluation in addition to the QT interval.
- Positional cloning of quantitative trait nucleotides for blood pressure and cardiac QT-interval by targeted CRISPR/Cas9 editing of a novel long non-coding RNA. [Journal Article]
- PGPLoS Genet 2017; 13(8):e1006961
- Multiple GWAS studies have reported strong association of cardiac QT-interval to a region on HSA17. Interestingly, a rat locus homologous to this region is also linked to QT-intervals. The high resol...
Multiple GWAS studies have reported strong association of cardiac QT-interval to a region on HSA17. Interestingly, a rat locus homologous to this region is also linked to QT-intervals. The high resolution positional mapping study located the rat QT-interval locus to a <42.5kb region on RNO10. This region contained no variants in protein-coding sequences, but a prominent contiguous 19bp indel polymorphism was noted within a novel predicted long non-coding RNA (lncRNA), which we named as Rffl-lnc1. To assess the candidacy of this novel lncRNA on QT-interval, targeted CRISPR/Cas9 based genome-engineering approaches were applied on the rat strains used to map this locus. Targeted disruption of the rat Rffl-lnc1 locus caused aberrant, short QT-intervals and elevated blood pressure. Further, to specifically examine the significance of the 19bp polymorphism within the Rffl-lnc1 locus, a CRISPR/Cas9 based targeted knock-in rescue model was constructed by inserting the 19bp into the strain which contained the deletion polymorphism. The knock-in alleles successfully rescued the aberrant QT-interval and blood pressure phenotypes. Further studies revealed that the 19bp polymorphism was necessary and sufficient to recapitulate the phenotypic effect of the previously mapped <42.5kb rat locus. To our knowledge, this study is the first demonstration of a combination of both CRISPR/Cas9 based targeted disruption as well as CRISPR/Cas9 based targeted knock-in rescue approaches applied for a mammalian positional cloning study, which defines the quantitative trait nucleotides (QTNs) within a rat long non-coding RNA as being important for the pleiotropic regulation of both cardiac QT-intervals and blood pressure.
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- In silico assessment of the effects of quinidine, disopyramide and E-4031 on short QT syndrome variant 1 in the human ventricles. [Journal Article]
- PlosPLoS One 2017; 12(6):e0179515
- CONCLUSIONS: The simulated pharmacological actions of quinidine exhibited antiarrhythmic effects on SQT1. This study substantiates a causal link between quinidine and QT interval prolongation in SQT1 and suggests that quinidine may be a potential pharmacological agent for treating SQT1 patients.