Assessment of Heart Rate Variability in Children with Mitral Valve Prolapse.

BACKGROUND: Mitral valve prolapse (MVP) is a heart valve anomaly with specific electrocardiographic findings and arrhythmia. A predominant sympathetic tone and diminished vagal activity have been reported especially in symptomatic MVP patients. OBJECTIVES: In the current study, we aim to review heart rate variability (HRV) parameters of MVP children in order to determine if there is an impaired autonomic regulation. METHODS: The data of children with MVP were retrospectively analyzed. Demographic characteristics, body mass index, symptomatology, MVP type and mitral regurgitation, MVP-related electrocardiographic changes, arrhythmia, and HRV parameters in 24-h Holter monitoring were recorded. HRV parameters of the control group were obtained from children applying for sport participation. Statistical significance limit was accepted as p < 0.05. RESULTS: 154 of the patients (74.8%) were girls, the median age was 13.58 ± 2.99 years. While MVP patients had shorter PR intervals, those who had syncope had longer PR intervals. Short PR distance may be a feature of MVP, long PR distance may be a condition associated with syncope with the underlying paroxysmal atrioventricular block. Moreover, the minimum heart rate was significantly lower in the MVP group compared to the control and there were no significant differences in terms of remaining parameters. The number of low LF values was higher in MVP patients than the control. Comparing HRV values of groups by gender, we found that overall HRV parameters were lower in girls with MVP while minimum, maximum, and average heart rate were lower in boys with MVP. CONCLUSION: Impaired HRV associated with MVP could be age, gender, and symptom related. In addition, low LF may indicate impaired baroreflex sensitivity in MVP patients.

Pediatric Electrocardiography Interpretation: Where We Are Now?

OBJECTIVE: Electrocardiography (ECG) is an important diagnostic tool used in the early diagnosis and treatment of arrhythmias and conduction disorders. Pediatricians need to interpret the ECGs correctly and be able to decide the situations that require pediatric cardiology consultation. In this study, we aimed to determine the ECG evaluation competencies of pediatricians. The obtained data will serve as a guide for the development of a training module. MATERIALS AND METHODS: Pediatric residents and specialists were included in the study. A questionnaire was sent to the participants via Google Forms. In this questionnaire, participants were asked to evaluate whether 10 ECG samples were normal or abnormal, detect the abnormality in the ECGs, define the specific diagnosis, and indicate how confident they were in their evaluation. A total of 242 participants, 160 of whom were pediatric residents and 82 were pediatricians, were included in the study. RESULTS: The mean knowledge level of the participants was 17 ± 4.1 out of 30 points. Electrocardiography knowledge score increased with increasing age, increasing experience after graduation from medical school, increasing seniority during residency training, and increasing self-confidence in ECG interpretation. A significant difference was found between the ECG knowledge scores of those who attended an ECG course after graduation and those who did not. The rate of correctly defining the distinction between normal and abnormal was 93.7%. The rate of detecting pathologies in ECGs accurately and correct identification of specific diagnosis was 56.7%. CONCLUSION: The accuracy level of pediatricians in ECG evaluation is low. Electrocardiography trainings are needed to develop ECG assessment skills.

A Rare Case of Wolff-Parkinson-White Syndrome Associated with Right Atrial Aneurysm.

Wolff-Parkinson-White syndrome is rarely associated with a right atrial aneurysm. However, when such a condition occurs, it will be hard to manage since pre-excitation will be induced as long as the aneurysm persists. A 14-year-old female patient received emergency treatment for irregular wide QRS complex tachycardia in our center, and a pre-excitation pattern was then observed on the surface electrocardiogram. An initial electrophysiological study revealed a high-risk right posterior accessory pathway that was resistant to both radiofrequency and irrigated radiofrequency ablations. Subsequently, fluoroscopy showed that this was due to a right atrial aneurysm. Although successful ablation with irrigated radiofrequency was performed in the second procedure, the procedure was considered suboptimal due to the association of aneurysm. Accordingly, we initiated anti-thrombotic and anti-arrhythmic drug therapy. We decided to omit surgery and followed the case under medical treatment for 2 years without complications. Here, we report this rare coexistence and our treatment approach in detail.

Molecular Approach of Hereditary Arrhythmias, Long QT Syndrome, and Arrhythmogenic Right Ventricular Cardiomyopathy.

BACKGROUND: Hereditary cardiac arrhythmias result from mutations in various genes encoding ion channels. One major channelopathy is long QT syndrome, which has excel- lent genetic and clinical heterogeneity. Arrhythmogenic right ventricular cardiomyopa- thy, another hereditary arrhythmia type, also shows high genetic heterogeneity and variable expressivity. Next-generation sequencing is an effective tool to reveal the dis- ease's underlying genetic etiology. METHODS: In this study, we performed clinical exome sequencing or gene panel including cardiac arrhythmia and cardiomyopathy-associated genes by next-generation sequenc-ing in 13 unrelated patients. RESULTS: Five pathogenic or likely pathogenic mutations, including three novel mutations, were found in the total cases. CONCLUSION: This research shows a strong genetic heterogeneity in the disease. In addi- tion, the study revealed that patients with QT interval prolongation on electrocardio- gram might also have mutations in genes that are not associated with long QT syndrome, such as MYLK2 and DSG2. Therefore, our data helped expand the molecular scope of long QT syndrome. It is necessary to study with a broad perspective to elucidate the underly- ing molecular etiology in patients with hereditary cardiac arrhythmias.

Minimally invasive permanent pacemaker implantation immediately after birth: from delivery room to heart surgery.

INTRODUCTION: Congenital atrioventricular block is diagnosed in uterine life, at birth, or early in life. Atrioventricular blocks can be life threatening immediately at birth so urgent pacemaker implantation techniques are requested. Reasons can be cardiac or non-cardiac, but regardless of the reason, operations are challenging. We aimed to present technical procedure and operative results of pacemaker implantation in neonates. MATERIALS AND METHODS: Between June 2014 and February 2021, 10 neonates who had congenital atrioventricular block underwent surgical operation to implant permanent epicardial pacemaker by using minimally invasive technique. Six of the patients were female and four of them were male. Mean age was 4.3 days (0-11), while three of them were operated on the day of birth. Mean weight was 2533 g (1200-3300). RESULTS: Operations were achieved through subxiphoidal minimally skin incision. Epicardial 25 mm length dual leads were implanted on right ventricular surface and generators were fixed on the right (seven patients) or left (three patients) diaphragmatic surface by incising pleura. There were no complication, morbidity, and mortality related to surgery. CONCLUSION: Few studies have characterised the surgical outcomes following epicardial permanent pacemaker implantation in neonates. The surgical approach is attractive and compelling among professionals so we aimed to present the techniques and results in patients who required permanent pacemaker implantation in the first month of life.

Clinical and genetic characteristics and course of congenital long QT syndrome in children: A nine-year single-center experience.

OBJECTIVE: Long QT syndrome (LQTS) is an inherited primary arrhythmia syndrome associated with life-threatening ventricular arrhythmias and sudden death. This study aimed to report the clinical and genetic characteristics and outcomes of children diagnosed as having LQTS in a tertiary pediatric cardiology center in Turkey. METHODS: This was a retrospective review of pediatric patients diagnosed as having LQTS at our center from January 2011 to April 2020. RESULTS: A total of 145 patients (76 males) were included, with a mean age of 9.2±4.5 years and a mean weight of 35.7±18.5 kg; 38 (26.2%) were identified as having LQTS during family screening, whereas a significant proportion of patients were asymptomatic at presentation, 15 patients (10.3%) were diagnosed after previous cardiac arrest, and 26 patients (18%) had syncope. The mean Schwartz score was 4.5 points (range, 3-7.5 points). Furthermore, 107 patients (82%) were confirmed to have a pathogenic mutation for LQTS genes. All patients received beta-blockers. Implantable cardioverter-defibrillator insertion was performed in 34 patients (23.4%). Left or bilateral cardiac sympathetic denervation was performed in 9 patients (6.2%). Median follow-up time was 35.6±25.8 months. Five (3.4%) patients died during the follow-up. Statistical analyses of risk factors for major cardiac events revealed that the QTc was >500 ms and that T wave alternans, high Schwartz score, and Jervell and Lange-Nielsen syndrome were strong and significant predictors of cardiac events. CONCLUSION: LQTS has a variety of clinical manifestations. Patients' symptoms ranged between asymptomatic and sudden cardiac death (SCD). By raising the awareness of physicians regarding the disease, SCD might be prevented in the early period.

Cryoablation with an 8-mm tip catheter for typical AVNRT in children: a single center 5-year experience.

BACKGROUND: In children with typical atrioventricular nodal reentrant tachycardia (tAVNRT), cryoablation is preferred over radiofrequency ablation (RFA) because of its safety profile and acceptable long-term success rates. In this study, we have assessed the utility of 8-mm tip cryocatheters for tAVNRT ablation in our center. METHODS: All pediatric AVNRT patients who underwent cryoablation with an 8-mm tip cryocatheter in our center between 2013 and 2018 were included. EnSite™ (St. Jude Medical Inc., St. Paul, MN, USA) was used in all patients. RESULTS: A total of 120 patients (64 females, 53%) were included in this study, and the mean age was 13.9 years with a standard deviation of 2.5 years. Eleven patients (9.1%) had structural heart disease, and 12 patients (10%) had additional arrhythmia substrate. The mean number of effective cryolesions was 8 with a standard deviation of 2.3. Fluoroscopy was used in three patients (2.5%). There were minor complications in only four patients (3.3%)-transient first-degree atrioventricular block or transient incomplete right bundle branch block. Acute success rate of cryoablation was 108/120 (90%). In twelve patients, cryoablation was suboptimal, or it failed. The procedure was completed successfully with RFA in the same session in ten patients. Overall acute success rate of ablation (Cryo ± RFA) was 98.5%. During a mean follow-up period of 24.6 months with a standard deviation of 11.3 months, three patients had recurrence (2.5%). Time between the beginning of the effective cryolesion and termination of AVNRT was found associated with acute success of cryoablation (p = 0.013). CONCLUSIONS: Cryoablation of AVNRT with an 8-mm tip catheter in children appears to be safe, with an acceptable acute success rate and a low recurrence rate. A faster termination of AVNRT during the cryolesion, slowing down before ending with atrioventricular block, is a good indicator for acute success.

Clinical characteristics of hypertrophic cardiomyopathy in children: An 8-year single center experience.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is the second most common pediatric cardiomyopathy. Although there is a large body of literature about HCM in adults, there is limited information on HCM in childhood. We evaluated various aspects of pediatric HCM patients treated at our center. METHODS: We identified 152 pediatric patients with HCM between October 2011 and October 2019. Clinical history, invasive (ICD, pacemaker, electrophysiologic study, catheter ablation therapy) and non-invasive (ECG, holter moniterization, echocardiography, cardiac MR, genetic study, medicam treatment) data were collected and evaluated. RESULTS: The mean ± standard deviation age of patients was 8.9 ± 5.7 years (1 month-18 years) and 67.8% were male. The most frequent clinical symptoms were murmur and palpitations. Three cases (2%) had aborted sudden death as the first manifestation of HCM. Of these patients, 120 (78.9%) had non-syndromic HCM and 32 (27.2%) had syndromic HCM. Asymmetric septal hypertrophy was common (48.3%) in the non-syndromic group, whereas concentric hypertrophy was common (56.2%) in syndromic group. Left ventricular outflow tract obstruction (LVOTO) occurred in 39 (25.6%) patients. Nine (5.9%) patients underwent electrophysiologic study and/or ablation and 16 patients underwent surgical intervention. Implantable cardioverter defibrillator (ICD) insertion was performed in 38 patients (26 transvenous, 12 epicardial). ICDs were inserted in three (7.9%) patients for secondary prevention; in the remaining patients (92.1%) the devices were placed for primary prevention. Mean SD follow-up time was 27.1 ± 22 months. Five (3.3%) patients died during the follow-up. No patient had heart transplantation or a long-term assistive device. CONCLUSION: The etiology of HCM is heterogeneous and present at any age. It is important to determine the timing of surgery and potential risks for sudden cardiac arrest. As most cases of HCM are familial, evaluation of family members at risk should be a routine component of clinical management.

Aortic cusp ablation for premature ventricular contractions and ventricular tachycardia in children: a 5-year single-center experience.

PURPOSE: Aortic cusps might be the source of supraventricular or ventricular arrhythmias. For many years, aortic cusp ablation has been widely used to treat premature ventricular contractions (PVCs) and ventricular tachycardia (VT). However, the data on the outcomes of this procedure in children are limited. The study aimed to convey or describe our own aortic cusp ablation experiences in children and, thus, contribute to the literature. METHODS: The focus was pediatric cases of ventricular arrhythmia in which the origin of the PVCs was ablated above the Valsalva. The sample comprised patients who underwent aortic cusp ablation between 2013 and 2018. The demographic characteristics, noninvasive test results, procedure details, and follow-up results for the patients were noted. RESULTS: The 3D EnSite Precision cardiac mapping system and limited fluoroscopy were used. A total of 26 procedures were performed on 22 patients. The mean age was 14.4 ± 3.0 (9-19) years, and the mean weight was 57.3 ± 17.5 (27-99) kg. The mean follow-up period after the first presentation was 38.6 ± 22.9 (3-72) months. There were significant differences in the values of the transition index, V2S/V3R, IIR/IIIR, aVRS/aVLS ratio, and QRS polarity in I at various locations. The most common ablation site was the left coronary cusp (LCC). Radio frequency (RF) ablation, cryoablation, and irrigated RF ablation were found to be effective energy sources in 15, 4, and 3 patients, respectively. Patients who underwent ablation at the LCC-right coronary cusp (RCC) commissure were more likely to present with only VT and to experience worsening symptoms. Twelve patients had previously undergone ablation of the right ventricular outflow tract (RVOT). Ablation in the RVOT had been previously performed in all the patients who eventually underwent ablation at the RCC and the LCC-RCC commissure. CONCLUSION: Aortic cusp ablation can be safely performed in children. The careful evaluation of previous noninvasive tests provides important data for determining the location. There might be significant differences in the signs and requirements on the basis of the locations during mapping and ablation.

Electrophysiologic characteristics and catheter ablation results of tachycardia-induced cardiomyopathy in children with structurally normal heart.

OBJECTIVE: The aim of this study is to present electrophysiologic characteristics and catheter ablation results of tachycardia-induced cardiomyopathy (TIC) in children with structurally normal heart. METHODS: We performed a single-center retrospective review of all pediatric patients with TIC, who underwent an electrophysiology study and ablation procedure in our clinic between November 2013 and January 2019. RESULTS: A total of 26 patients, 24 patients with single tachyarrhythmia substrates and two patients each with two tachyarrhythmia substrates, resulting with a total of 28 tachyarrhythmia substrates, underwent ablation for TIC. The median age was 60 months (2-214 months). Final diagnoses were supraventricular tachycardia (SVT) in 24 patients and ventricular tachycardia (VT) in two patients. The most common SVT mechanisms were focal atrial tachycardia (31%), atrioventricular reentrant tachycardia (27%), and permanent junctional reciprocating tachycardia (15%). Radiofrequency ablation (RFA) was performed in 15 tachyarrhythmia substrates, and cryoablation was performed in 13 tachyarrhythmia substrates, as the initial ablation method. Acute success in ablation was achieved in 24 out of 26 patients (92%). Tachycardia recurrence was observed in two patients (8%) on follow-up, who were treated successfully with repeated RFA later on. Overall success rates were 92% (24 out of 26) in patients and 93% (26 out of 28) in substrates. On echocardiography controls, the median left ventricular recovery time was 3 months (1-24 months), and median reversible remodeling time was 6 months (3-36 months). CONCLUSION: TIC should be kept in mind during differential diagnosis of dilated cardiomyopathy. Pediatric TIC patients can be treated successfully and safely with RFA or cryoablation. With an early diagnosis of TIC and quick restoration of the normal sinus rythm, left ventricular recovery, and remodeling may be facilitated.

A rare indication of permanent pacemaker implantation in children: congenital long QT syndrome.

Congenital Long QT Syndrome (LQTS) is a dangerous arrhythmic disorder that can be diagnosed in children with bradycardia. It is characterised by a prolonged QT interval and torsades de pointes that may cause sudden death. Long QT syndrome is an ion channelopathy with complex molecular and physiological infrastructure. Unlike the acquired type, congenital LQTS has a genetic inheritance and it may be diagnosed by syncope, stress in activity, cardiac dysfunction, sudden death or sometimes incidentally. Permanent pacemaker implantation is required for LQTS with resistant bradycardia even in children to resolve symptoms and avoid sudden death.

Transcatheter radiofrequency pulmonary valve perforation in newborns with pulmonary atresia/intact ventricular septum: Echocardiographic predictors of biventricular circulation.

OBJECTIVE: We report a single-institute experience of neonatal transvenous radiofrequency pulmonary valve perforation for pulmonary atresia/intact ventricular septum, with echocardiographic predictors of biventricular circulation. METHODS: Data were reviewed retrospectively for all neonates who underwent primary transvenous pulmonary valve perforation for pulmonary atresia/intact ventricular septum between January 2008 and November 2018 at our institution. We compared patients who need systemic-to-pulmonary shunt or ductal stenting with patients who did not need. RESULTS: During the study period, 31 patients with pulmonary atresia/intact ventricular septum underwent successful radiofrequency pulmonary valve perforation and balloon dilation of the pulmonary valve. There was no procedure-related mortality. Sixteen patients (52%) needed systemic-to-pulmonary shunt or ductal stenting after initial procedure. Among the survivors (follow-up time of 1 to 11.5 years), 15 patients had a biventricular circulation and 6 patients had 1 and 1/2 ventricular circulation. Two patients are awaiting for Fontan operation. Both the TV/MV annulus ratio (>0.85) and tricuspid valve z-score (>-1) were found to be a good predictor of a biventricular outcome in our cohort. CONCLUSIONS: Percutaneous radiofrequency pulmonary valve perforation and balloon valvotomy is an effective and safe primary treatment strategy for neonates with pulmonary atresia/intact ventricular septum. Ductal stenting or systemic-to-pulmonary shunt may be required in the majority of patients who had smaller right heart components. Preselection of patients according to tricuspid valve z-score and TV/MV annulus ratio allows predicting biventricular circulation.

Tricuspid annular plane systolic excursion and mitral annular plane systolic excursion cardiac reference values in 1300 healthy children: Single-center results.

BACKGROUND: Tricuspid annular plane systolic excursion (TAPSE) and mitral annular plane systolic excursion (MAPSE) are two echocardiographic parameters which provide reliable information about the longitudinal myocardial functions of the right and left ventricles in both adult and pediatric population. The aim of this study was to determine the TAPSE and MAPSE reference values in healthy children aged 0-18 years. METHODS AND RESULTS: This prospective study included 1300 healthy children evaluated with two-dimensional echocardiography. In addition to routine echocardiographic examination, the right and left ventricular systolic functions were assessed by TAPSE and MAPSE measurements. Statistical analyses were carried out in the groups of subjects stratified according to age and body surface area. The mean and standard deviation values and z-scores of TAPSE and MAPSE were developed in each group. CONCLUSIONS: The determination of reference values for TAPSE and MAPSE in healthy children will be of guidance in the evaluation of both healthy children and those with congenital or acquired heart diseases in which the right and left ventricular systolic functions are affected. The reference values obtained will contribute to the clinical practice and the future studies.

Successful left coronary cusp cryoablation in an adolescent with premature ventricular extrasystoles-associated cardiomyopathy.

Ventricular arrhythmias arising from coronary cusps are not uncommon. However, the mapping and ablation of outflow tract ventricular arrhythmias originating from aortic cusps can be challenging. Radiofrequency ablation of this area can cause rare but serious complications. This was a report of a 17-year-old male patient with very frequent, nonsustained ventricular tachycardia attacks and premature ventricular contraction-induced cardiomyopathy. The origin of the ventricular arrhythmia was determined to be the left coronary cusp, and the patient was treated successfully with cryoablation. In high-risk areas, cryoablation is an effective and safe alternative method.

Successful radiofrequency ablation of accessory pathway associated with left atrial appendage aneurysm in a low birthweight premature patient.

Ergül Y, Öztürk E, Özgür S. Successful radiofrequency ablation of accessory pathway associated with left atrial appendage aneurysm in a low birthweight premature patient. Turk J Pediatr 2019; 61: 142-146. Tachyarrhythmias are common cardiac arrhythmias in newborns and infants. We present a premature case with a 2.4-kg birth weight, with non-immune hydrops due to supraventricular tachycardia. Despite the combination of amiodarone, esmolol and flecainide, tachyarrhythmia could not be controlled and radiofrequency ablation was applied due to left ventricular dysfunction. After the procedure the rhythm returned to normal sinus and left ventricular functions improved rapidly. The follow-up of the case continues without any problems. In this presentation, successful ablation of the accessory pathway associated with structural heart disease have been covered in the youngest and smallest patient to date.

Clinical features and arrhythmic complications of patients with pediatric-onset arrhythmogenic right ventricular dysplasia.

OBJECTIVE: Arrhythmogenic right ventricular dysplasia (ARVD) is a myocardial genetic disease that occurs primarily in the right ventricle. Patients with ARVD may present with severe ventricular arrhythmias, syncope, and cardiac arrest. The purpose of this study is to evaluate the clinical features and arrhythmic complications of patients with pediatric-onset ARVD. METHODS: Patients diagnosed with ARVD between January 2010 and January 2019 were included in this study. RESULTS: A total of 19 patients with ARVD were evaluated. Of them, 15 patients were male, and their mean age was 12±4 years. The most common symptoms were palpitations (n=6), syncope (n=4), and heart failure symptoms (n=2). Five patients were asymptomatic. Thirteen patients had an epsilon wave; all patients ≥14 years had a T wave inversion in V1-3. Premature ventricular contractions (PVCs) were observed in 15 patients, and ventricular tachycardia (VT) was observed in 9 patients. All patients underwent cardiac magnetic resonance imaging (MRI). Echocardiography and cardiac MRI of two patients were normal at the time of admission; patients were in the concealed phase, and the diagnosis was made by ECG, Holter monitoring, and genetic findings. We administered a beta-blocker in all patients. Two patients underwent an electrophysiological study and ablation because of PVC/VT. An implantable cardiac defibrillator was implanted in 8 patients. The mean follow-up period was 21.5±11 months. Two patients were deceased with incessant VT and heart failure, and one patient was deceased with multiorgan dysfunction after biventricular assist device implantation (n=3). CONCLUSION: Diagnosis of pediatric-onset ARVD might be much more difficult in children. Sudden cardiac death might be prevented in the early period by raising the awareness of physicians about the disorder. Prevention of sudden death with implantable cardiac defibrillators is crucial in the management of these patients. It should be kept in mind that children with structurally normal hearts may present with an earlier concealed phase and can be diagnosed with ARVD.

Evaluation of long-term cardiac side effects of anthracycline chemotherapy by conventional and non-conventional echocardiographic methods in childhood cancer survivors.

OBJECTIVE: Anthracycline chemotherapeutic agents carry the well-recognised risk of cardiac toxicity. The aim of this study was to determine the long-term effect of anthracycline chemotherapy on the biventricular function in childhood cancer survivors using tissue Doppler imaging and two-dimensional speckle tracking echocardiography. PATIENTS AND METHODS: The study included 45 survivors of childhood cancers and 50 healthy age-matched control patients. Cardiac function was prospectively studied with conventional echocardiography, tissue Doppler imaging, and speckle tracking echocardiography after completion of treatment. The same analysis was performed on matched controls. RESULTS: There was no difference in age, gender, height, and weight between the study and control groups. The mean anthracycline dose was 240 ± 106 mg/m2 and the mean remission duration was 8.2 ± 5 years (1-20 years) in the study group. Conventional echocardiography showed similar ejection fraction, shortening fraction, and left ventricle end-diastolic diameter in both groups. Mitral lateral and septal tissue Doppler imaging showed normal but according to control group relatively sub-normal systolic and diastolic function in patient group. The global longitudinal and circumferential strain and strain rates were significantly lower in the patient group compared to control group. Correlation analysis revealed a negative and significant correlation between total anthracycline dose and global longitudinal and circumferential strain and strain rates. CONCLUSION: Sub-clinical systolic and diastolic dysfunction may not be detected by conventional echocardiographic methods which are frequently used in daily practice. Sub-clinical systolic and diastolic dysfunction may be detected more sensitively by echocardiographic method such as speckle tracking echocardiography in childhood cancer survivors.

Congenital long-QT syndrome in type 1 diabetes: a unique association.

Kurnaz E, Savas Erdeve S, Özgür S, Keskin M, Özbudak P, Çetinkaya S, Aycan Z. Congenital long-QT syndrome in type 1 diabetes: a unique association. Turk J Pediatr 2019; 61: 791-793. In contrast to acquired long QT syndrome (LQTS), congenital LQTS is a relatively rare channelopathy with an incidence of 1/2,500. We describe a patient found to have a prolonged QTc in the setting of newly diagnosed Type 1 DM. To the best of our knowledge, this unique association has not been previously reported. Currently, it is shown that glucose ingestion aggravated cardiac repolarization disturbances in LQT2 patients and prolonged the cardiac repolarization phase in healthy controls. Our case presented to the hospital with syncope after increased glucose level. Therefore, it seems that increased glucose level may have prolonged QTc interval and aggravated cardiac repolarization disturbances in the presented case. By this report, we want to emphasize the importance of hyperglycaemia in congenital LQTS.