Surdocardiac syndrome of Jervell and Lange-Nielsen, with prolonged QT interval present at birth, and severe anaemia and syncopal attacks in childhood.

A case of the surdocardiac syndrome of Jervell and Lange-Nielsen, with prolonged QT interval in the electrocardiogram at birth, is described. The affected girl presented 3 1/2 years later with severe iron deficiency anaemia, despite apparently adequate nutrition. At the age of 4 1/2 years she had a sudden attack of unconsciousness. Treatment with the beta-adrenoceptor blocker practolol was started and 3 years after initiation of this treatment she has been free from syncopal attacks. The QT interval remains prolonged. Her brother also had severe iron deficiency anaemia and had several attacks of unconsciousness before he died suddenly at the age of 3 1/2 years.     

Surdocardiac syndrome of Jervell and Lange-Nielsen, with prolonged QT interval present at birth, and severe anaemia and syncopal attacks in childhood.

A case of the surdocardiac syndrome of Jervell and Lange-Nielsen, with prolonged QT interval in the electrocardiogram at birth, is described. The affected girl presented 3 1/2 years later with severe iron deficiency anaemia, despite apparently adequate nutrition. At the age of 4 1/2 years she had a sudden attack of unconsciousness. Treatment with the beta-adrenoceptor blocker practolol was started and 3 years after initiation of this treatment she has been free from syncopal attacks. The QT interval remains prolonged. Her brother also had severe iron deficiency anaemia and had several attacks of unconsciousness before he died suddenly at the age of 3 1/2 years.     

The use of oral labetalol in the treatment of arrhythmias associated with the long QT syndrome

A 7-year-old white boy with the long QT syndrome began to experience recurrent syncope associated with torsade de pointes ventricular tachycardia in spite of beta-blocker therapy. The patient was therefore given a combined alpha- and beta-blocking agent (labetalol) with complete suppression of the syncopal episodes. This suggests a role for combined alpha- and beta-blocking agents in the therapy of arrhythmias associated with the long QT syndrome.     

Left cardiac sympathectomy prevents exercise-induced QTc prolongation in congenital long QT syndrome

Congenital long QT syndrome (LQTS) is a group of ion channel disorders of ventricular myocytes caused by mutations of genes that encode these ion channels. The main clinical features of LQTS are syncope, cardiac arrest and QT prolongation on body surface electrocardiogram. The present study reports on the case of a 42-year-old female patient with a 10-year history of LQTS and syncopal attacks resistant to beta-blocker therapy. Treadmill exercise testing in this patient increased the corrected QT interval (QTc) from 0.48 s to 0.54 s and reduced the amplitude of the T wave. Left cardiac sympathectomy did not affect the resting heart rate or QTc but it prevented exercise-induced T wave reduction and QTc prolongation. Therefore, sympathetic activation plays a key role in exerciseinduced QT prolongation and changes in T wave morphology in patients with congenital LQTS.     

24例长QT综合征的诊疗经验

目的总结长QT综合征(LQTS)的诊疗经验。方法回顾分析24例已确立诊断为长QT综合征和尖端扭转性室性心动过速(Tdp)的临床病例,对其临床和心电图特点进行分析。结果24例中,女22例、男2例,年龄最小9岁。14例为原发性LQTS,其中4例有明确家族史。10例继发性LQTS中,5例为房室传导阻滞继发,4例为低钾血症、1例为药物继发。所有患者均有晕厥症状,1例伴听力障碍,8例症状发作前有明确的诱发因素,2例在休息或睡眠时发作。22例QTc延长,8例原发性LQTS患者心电图具特异性改变。所有原发性LQTS患者均给予β受体阻滞剂治疗,2例行左侧胸交感神经切除术,3例置入起搏器,1例置入埋藏式心脏转复除颤器。患者入院后发作Tdp时,给硫酸镁、异丙肾上腺素、起搏器或电复律治疗有效。结论原发性LQTS,女性居多,发病年龄早,多数患者发病前有明确的诱发因素;继发性LQTS纠正病因后即能治愈。     

Predictive factors for an effective beta-blocker therapy in Chinese patients with congenital long QT syndrome: A multivariate regression analysis

OBJECTIVE:

To investigate the factors that may predict the effectiveness of beta-blocker therapy for congenital long QT syndrome (LQTS) in a Chinese patient population.

METHODS:

Twenty-six LQTS patients were treated with oral propranolol (n=16) or metoprolol tartrate (n=10) for 38 months. Clinical symptoms, heart rate, corrected QT interval (QTc) and left ventricular ejection fraction were assessed before and after the therapy.

RESULTS:

Cardiac events were reduced by more than 50% in 22 patients with beta-blocker therapy. The average number of syncopes/patient and the average frequency of syncopes/patient/year in the responders were reduced from 16.2±5.1 to 1.1±0.9 (P<0.01) and from 4.5+1.2 to 0.7+0.6 (p<0.01), respectively. The QTc was also reduced from 0.56±0.06 s to 0.50±0.03 s. There was no significant difference in the reduction of syncopes and QTc in patients treated with propranolol and metoprolol tartrate. Multivariate regression analysis showed no correlation between the reduction in syncopal attacks and patients’ age, sex, heart rate or left ventricular function (P>0.05). QTc reduction was the only independent predictive factor for syncope control (R=0.81, P<0.001).

CONCLUSIONS:

Oral beta-blockers are an effective therapy for Chinese patients with LQTS. A significant reduction in QTc is highly indicative of treatment success with beta-blockers.     

A case of congenital long QT syndrome associated with T wave alternans]

A case was presented in which a rare T wave alternans occurred in association with congenital long QT syndrome. A 71-year-old woman, who had experienced several syncopal attacks per year for the previous forty years, was admitted for further evaluation of the syncope. She had a family history of sudden death (sister) and QT prolongation (son). Electrocardiogram showed a corrected QT interval of 0.68 seconds. Treadmill exercise-tolerance test revealed both T wave alternans immediately after exercise and torsades de pointes 150 seconds after exercise. The syncope was induced by the mental excitation. A prolonged corrected QT interval reduced from 0.70 seconds to 0.58 seconds by the correction of her serum potassium and magnesium. The effect of propranolol, verapamil, phenytoin or mexiletine on T wave alternans and ventricular arrhythmia was evaluated by the treadmill exercise-tolerance test. The treatment with propranolol was most effective.     

Combined use of beta-adrenergic blocking agents and long-term cardiac pacing for patients with the long QT syndrome.

OBJECTIVE. The objective of this study was to review our current experience using a combination of beta-adrenergic blocking agents and long-term cardiac pacing to treat patients with the idiopathic long QT syndrome. BACKGROUND. Patients with the idiopathic long QT syndrome are at high risk for sudden cardiac death. Before combination therapy, 20 of the 21 study patients experienced either cardiac arrest (n = 8) or syncope (n = 18) and 11 had documented polymorphous ventricular tachycardia. Nine of these patients had not responded to isolated beta-blocker therapy and five had not responded to isolated left cervicothoracic sympathectomy. METHOD. All patients were treated with combined beta-blocker therapy and long-term cardiac pacing at a rate designed to normalize the QT interval. RESULTS. Cardiac pacing at rates of 70 to 125 beats/min resulted in shortening of the QT and corrected QT (QTc) intervals from 517 +/- 78 and 541 +/- 62 ms to 404 +/- 37 and 479 +/- 41 ms, respectively. The mean follow-up interval after institution of pacing was 55 +/- 45 months. The only sudden death occurred in a patient who had discontinued beta-blocker therapy. Syncope occurred in four patients, two of whom had interrupted pacemaker function due to lead fracture. Pacemaker problems, partly attributable to the specific rate required for QT interval shortening and to avoidance of T wave sensing, were relatively common. No patient who continued the combination therapy died, but 10% of these patients had a recurrence of symptoms. CONCLUSIONS. Combination therapy with a beta-blocker and cardiac pacing appears to be a highly effective primary therapy for symptomatic patients with the long QT syndrome and to provide excellent adjunctive therapy for patients who require insertion of an automatic internal defibrillator.     

The long QT syndrome in pediatric age: prognosis and risk factor

AIM: Long QT syndrome is a rare arrhythmic disease with a low incidence in the general population. There are no sure clinical or electrocardiografic parameters that could lead to a correct prognostic stratification in patients affected by this syndrome. The correlation between the incidence of a sudden death or dangerous ventricular arrhythmias and the duration of QTc interval is still a controversial topic. METHODS: Twenty nine children affected by QT long syndrome were admitted to the Division of Pediatric Cardiology of the Casa del Sole Hospital of Palermo (Italy). Their diagnosis was made by electrocardiogram (ECG). The average age of the patients was 7.6 years. The average follow-up was 4 years and three months. A therapy whit beta-blocker was administered to all the children. During the follow-up of 4 year and three months, patients were genotyped. Twenty-three out of 29 children had at least one relative affected by the syndrome. Three of them had a familiar dead because of this syndrome and everyone had a duration of maximum QTc higher than the cut off (P=0.0002). All the people who died had not followed the therapy with beta-blocker. Patients with a maximum QTc recorded <500 had not familiar death by this syndrome. RESULTS: Holter and echocardiogram recorded periodically during the observation did not show dangerous arrhythmic events. All children maintained a good health during the follow-up. CONCLUSION: Although conducted on a small study population, the data analysis recorded during this study suggests that in patients affected by QT long syndrome younger than 16 years old undergoing a beta-blocker therapy the prognosis is excellent. The duration of QTc interval appears as a negative prognostic factor, although the beta-blocker therapy has been reduced considerably the incidence of sudden death.     

Romano-Ward syndrome and left stellectomy. General review apropos of a recent case]

A new familial case of the Romano-Ward syndrome in a young girl of 21 years is reported. A progressive worsening of the condition with multiple syncopal attacks, together with difficulty in controlling the patient, lead us to carry out a left stellate ganglionectomy. The operation did not lead to any shortening of the QT interval. It appeared in the end that propranolol was the most effective way of preventing the syncopal attacks.     

Pregbalin induced recurrent syncopal attacks with prolong QT interval

Long QT syndrome may lead to fatal dysrhythmia. Prolongation of QT interval due to pregabalin has been shown in rats and no data is available in humans. We report a 80‐year‐old female patient using pregabalin. She was presented to emergency room with syncope attacks. Her admission electrocardiography demonstrated prolonged QT interval. After excluding the possible causes of the long QT syndrome, we attributed prolonged QT interval to pregabalin therapy. After discontinuation of pregabalin QT interval returned to normal range and patient experienced no further syncope attacks. It is first time for documentation of prolonged QT due to pregabalin in humans.     

Stress-induced polymorphous ventricular tachyarrhythmias in two brothers: Unusual pattern of inheritance in the long QT syndrome

Two brothers, 10 and 9 years old, are reported who were treated for years with antiepileptic drugs until the cardiac origin of their syncopal attacks was discovered. Our findings are consistent with the diagnosis of long QT syndrome, although no other family members are affected and only intermittent and mostly borderline QT prolongation could be found. Diagnostic difficulties and genetic implications are discussed.     

Syncope and long QT syndrome with an initially normal QT interval

We present two patients who were admitted to our Hospital because of repetitive syncopal attacks. The study previous to their admission included electrocardiograms in which the QT interval was normal. During their admission, an striking lengthening of the QT interval, in addition to other criteria of the long QT syndrome, was observed in both patients. We suggest that one normal measurement of the QT interval should not rule out this diagnosis.     

Congenital long QT syndrome: 50 years of electrophysiological research from cell to bedside

Congenital long QT syndrome (LQTS) is a group of ion channel disorders of ventricular myocytes due to genetic mutations. The main symptoms of LQTS are pre-syncopal or syncopal attacks and cardiac arrest. Anti-adrenergic therapy with beta-blockers has been the mainstay of treatment. Left cardiac sympathectomy has also been used as an alternative in those in whom beta-blockers failed. ICDs are highly effective in preventing mortality and should be the first choice of therapy for those with cardiac arrest as the first symptom or those with LQT3 genotype not responding to anti-adrenergic therapy alone. Research on new therapeutic options, specifically those targeting at defective genes or mutant ion channels, may provide more effective treatment for this rare but potentially fatal electrophysiological disorder.     

The long QT syndrome: a prospective international study

During the past 4 years 196 patients with the idiopathic long QT syndrome were enrolled in a prospective international study conducted to obtain a better understanding of the clinical course of this unusual repolarization disorder. The mean patient age was 24 years, 64% were female, and 88% had family members with QT prolongation. During an average follow-up of 26 months per patient, four patients died suddenly (1.3% per year) and 27 patients had one or more syncopal episodes (8.6% per year). Multivariate analysis identified congenital deafness, history of syncope, female gender, and a documented episode of torsades de pointes or ventricular fibrillation as independent risk factors for postenrollment syncope or sudden death. Two types of treatment (left stellate ganglionectomy and beta-blocker therapy) were associated with a significant reduction in the occurrence of cardiac events during follow-up.     

Nicorandil abolished repolarisation alternans in a patient with idiopathic long QT syndrome

A 23 year old woman with idiopathic long QT syndrome had repeated syncopal attacks associated with torsades de pointes. T wave alternans (TWA) was recorded and the QT interval was abnormally prolonged during treadmill exercise test. Monophasic action potential (MAP) alternans also appeared after an abrupt shortening of the cycle length in electrophysiological study. After intravenous administration of nicorandil 6 mg, both TWA and MAP alternans disappeared.


Keywords: long QT syndrome; repolarisation alternans; nicorandil; potassium channels     

Prenatal molecular genetic diagnosis of congenital long QT syndrome by strategic genotyping

We demonstrate how genetic testing enabled a molecular prenatal diagnosis of congenital long QT syndrome in a 20-week fetus presenting with fetal bradycardia in the setting of maternal beta-blocker therapy. Before prenatal testing, strategic genotyping, based on a family history of a near drowning, was performed on a 3-generation family with clinically diagnosed long QT syndrome in which the affected mother was pregnant.     

Symptomatic Long QT Syndrome Coexisting with Asymptomatic Acetylcholine-induced Vasospasm

We herein report a rare case of long QT syndrome (LQTS) coexisting with acetylcholine (Ach)-induced vasospasm. A 31-year-old woman experienced cardiopulmonary arrest during running. LQTS was diagnosed by an electrocardiogram, and the coexistence of Ach-induced vasospam was determined by an Ach provocation test on coronary angiography. Although an implantable cardioverter defibrillator was placed, a beta-blocker was not prescribed for two reasons: first, the patient showed Ach-induced vasospasm alone with no symptoms and no ST change by Ach injection, and second, the use of beta-blockers alone in such patients carries a risk of vasospasm-induced ventricular fibrillation.     

Polymorphic familial incessant ventricular rhythm disorders with ventricular repolarization abnormalities: borderline form of the congenital long QT syndrome?

Two cases of polymorphic ventricular tachycardia (VT) are reported in siblings: the elder sister (18 years) was admitted to hospital because of syncope and ECG showed incessant attacks of VT. There was no obvious cardiac disease on echocardiography or cardiac catheterisation. A second syncopal attack occurred during Holter monitoring: this showed prolonged torsades de pointe which terminated spontaneously after a few minutes. Both syncopal attacks occurred at moments of intense emotional stress. Concomitantly, the duration of ventricular repolarisation was also observed to be increased. The attacks of polymorphic VT disappeared when the atrial rhythm accelerated, for example during exercise of isoprenaline infusion. It was not possible to induce VT by ventricular extrastimulation. The arrhythmia was controlled by nadolol and propafenone or flecainide. A familial investigation revealed that a younger brother had attacks of incessant VT with a long QT interval. The mother had frequent polymorphic ventricular extrasystoles and abnormal ST-T wave changes. The association of familial ventricular arrhythmias and long QT interval is suggestive of the Romano-Ward syndrome, but in this condition the intercritical ECG is normal except for the long QT. Conversely, in benign VT, the arrhythmia disappears during atrial pacing and exercise but there have been a few reports of sudden death. Our two cases could represent an intermediary form between these two pathological entities.     

长QT综合征的临床特点和治疗

目的 :总结 9例先天性长QT综合征 (LQTS)的临床特点及相应的治疗效果。方法 :采集 9例患者的临床病史 ,接受静息和运动心电图、超声心动图及电解质检查 ,随访观察治疗效果。结果 :9例中 ,8例发作与运动或情绪激动有关 ,使用普奈洛尔或普奈洛尔加起搏器治疗 ;1例在睡眠中发病 ,使用临时起搏器加美西律治疗。1例因停药死亡 ,其余随访效果满意。结论 :针对LQTS患者的临床特点采用相应的治疗 ,可取得较满意的疗效