Resuscitation (2006) 71, 115—121 CASE REPORT Short QT syndrome: A case report and review of literatureଝ Li Xiong Lu ∗, Wei Zhou, Xingyu Zhang, Qin Cao, Kanglong Yu, Changqing Zhu Department of Emergency and critical care, Renji Hospital, Shanghai Jiaotong University School of Medicine, 1630 Dongfang Road, Shanghai 200127, China Received 21 December 2005; received in revised form 15 March 2006; accepted 20 March 2006 KEYWORDS Summary The short QT syndrome has been recently recognised as a genetic ion Tachycardia; channel dysfunction. This new clinical entity is associated with an incidence of sud- Ventricular; den cardiac death, syncope, and atrial fibrillation in otherwise healthy individuals. Genetics; The distinctive ECG pattern consists of an abnormally short QT interval, a short or Death; even absent ST segment and narrow T waves. A 30-year-old resuscitated woman Sudden cardiac; with short QT syndrome is described together with an example of the classic ECG characteristics. A short-coupled variant of torsade de pointes was reveal on Holter Syncope; recordings. The implantable cardioveter defibrillator seems to be the therapy of Short QT syndrome; choice to prevent from sudden cardiac death. Quinidine proved to be efficient in Channelopathy prolonging the QT interval and rendering ventricular tachyarrhythmias non-inducible in patients with a mutation in KCNH2 (HERG). Our preliminary data suggest amio- darone combined with ␤-blocker may be helpful in treating episodes of polymorphic ventricular tachycardia for patients with an unknown genotype. Because the short QT syndrome often involves young patients with an apparently normal heart, it is imperative for physicians to recognize the clinical features of the short QT syndrome in making a timely correct diagnosis. © 2006 Elsevier Ireland Ltd. All rights reserved. Introduction recurrent life-threatening events and require more attention from the emergency physician. In the Syncope is a common disorder, constituting up to majority of cardiac syncope patients, a structural 3% of all visits to emergency department. Cardiac or functional abnormality can be identified, but in syncope patients are often associated with a risk of 5—10% of sudden cardiac death patients, the heart is apparently normal, so-called ion channel disease or ion channelopathy.1,2 Because the symptoms of ଝ A Spanish translated version of the summary of this article syncope or palpitation are transient and may escape appears as Appendix in the online version at 10.1016/j.resuscitation.2006.03.011. detection, and no identifiable heart disease can be ∗ Corresponding author. Tel.: +86 21 68383242. detected despite thorough clinic examination, it is E-mail address: [email protected] (L.X. Lu). a challenge for emergency physicians to recognise 0300-9572/$ — see front matter © 2006 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.resuscitation.2006.03.011 116 L.X. Lu et al. ion channel disease. As yet, a few families affected tial episode of ventricular fibrillation suggested with the short QT syndrome have been identified it may be a deterioration from polymorphic ven- but other cases have probably been overlooked.3,4 tricular tachycardia. We report a case of short QT syndrome and the knowledge to date on this little recognised disor- On arrival in the emergency department she der is presented. was alert. General physical examination revealed a puffy woman, mildly dyspnoeic, and pink in colour. Temperature was normal, respiratory rate Case presentation was 22/min. Her oxygen saturation, as measured by pulse oximetry, was 98%. Pulse rate was 64/min and regular. Blood pressure was 110/60 mmHg in At approximately 21:00 h, a 30-year-old Chinese the right upper arm. She had no jugular venous dis- female developed rapid palpitations and chest tention. Precordial examination revealed no chest tightness, followed by a witnessed episode of syn- deformity, with quiet precordium, and no thrill. cope with urinary incontinence. She regained con- Cardiac examination revealed a regular rate and sciousness immediately with no neurological seque- rhythm without murmurs, rubs or gallops. The lung lae. After three similar syncopal attacks within 3 h fields were clear with equal air entry. Neurological she was taken to the nearest hospital by her family examination and the remaining physical examina- members. tion was unremarkable. She had palpitations and chest tightness on exer- No clinical or laboratory evidence of rheumatic tion 3 months ago. fever was found. All laboratory investigations The patient had no history of cardiovascular dis- including three sets of cardiac enzymes were nor- ease and rheumatic fever. There was no history of mal. Two-dimensional echocardiography showed no sudden death in her family. She had no other medi- structural abnormality and a normal ejection frac- cal history and was receiving no regular medication. tion. Chest radiography was normal. She is the youngest of six siblings. No electrolytes A routine 12-lead electrocardiogram showed abnormalities were detected. The patient had an sinus rhythm with a heart rate of 70, a QT interval of urgent computed tomography scan of the head, 270 ms (Bazzett-corrected QT interval of 292 ms), which was normal. On the second day, after a total and a peaked T waves (Figure 2). of five syncopal or presyncope episodes the patient On the evening of hospital admission, the patient was transferred to our hospital for further treat- underwent Holter monitoring for 24 h during which ment. she complained several episodes of rapid palpi- During the transfer to our hospital she suffered a tations. Coinciding with the attack, monitoring cardiac arrest with ventricular fibrillation and was revealed episodes of 6- to 12-beat runs of torsade resuscitated with an external defibrillator in the de pointes with very short coupling intervals. A 24- ambulance (Figure 1). h Holter monitor recorded 57 ventricular ectopic The patient did not have continuous ECG moni- beats/24 h, 10 episodes of self-terminating poly- toring in the ambulance morphic ventricular tachycardia (Figure 3). • A: The left part of the rhythm strip was obtained She was diagnosed to be suffering from short QT in lead II as a routine evaluation in ambulance. syndrome. • B: It happened that the patient developed an After documented episodes of ventricular tachy- episode of syncope and seizure like activity just cardia, it was treated with metoprolol, amio- after the routine ECG was completed, so the ECG darone, and magnesium. Metoprolol (12.5 mg b.d.) was restarted promptly and showed ventricular was stopped the next morning because of con- tachycardia. She was successfully resuscitated cern about bradycardia developing. Amiodarone by cardioversion. Thus, the recording paper in was given as a 150 mg bolus IV over 10 min, fol- Figure 1 is continuous but there was a break in lowed by a continuous infusion of 800 ␮g/min for the ECG trace and the onset of arrhythmia was 24 h, reducing to 400 ␮g/min for 24 h. Finally oral not recorded, but the QRS morphology of the ini- amiodarone was given. Over the next few days, Figure 1 Rhythm strip showing ventricular fibrillation recorded during seizure in ambulance. Short QT syndrome 117 Figure 2 Twelve-lead electrocardiogram. she did not have any further episodes of ventric- spectively in 1993. It was not until 2000 that Gussak ular tachycardia. The QT interval remained short, et al.6 proposed a short QT syndrome as a new however, and small fluctuations of QTc interval was inherited clinical syndrome. In 2003, the definitive documented which could not be explained by the familial link between short QT syndrome and sud- variation of the heart rate, the use of drugs and den death was demonstrated by Gaita et al.7 other probable factors influencing the QT interval. The short QT syndrome forms a distinct clinical For economic considerations, she did not have elec- entity. It is characterized by a short QT interval, trophysiological testing and an ICD implant. Two a short or even absent ST segment and tall, nar- weeks later, she was discharged on amiodarone. row and peaked T waves in the precordial leads, During the 12-month follow-up period, the patient and sudden cardiac death in individuals with an did not have any further syncope or palpitations. apparently normal heart.3,4,6—8 These subjects also had a high incidence of atrial arrhythmia. Individu- als with short QT syndrome frequently complain of Discussion palpitations and may have syncope. Short QT syn- drome is associated with an increased risk of sudden Long QT intervals in the ECG have been associ- cardiac death, most likely due to ventricular fibril- ated with sudden cardiac death. Little is known lation. Most individuals will have a family history about the clinical implication of a short QT inter- of unexplained or sudden death at a young age, val. Tremendous strides have been made in recent palpitations, or atrial fibrillation. The electrocar- years in the diagnosis and treatment of sudden car- diographic characteristics of short QT syndrome are diac death in individuals with an apparently normal a short QT interval, typically ≤320 ms, that does heart. Algra et al.5 first suggested that patients not change significantly with the heart rate. Some- with a short QT interval had an increased risk of times a lack of adaptation or paradoxical behavior sudden death by analyzing Holter recordings retro- of the QT interval with various heart rates was 118 L.X. Lu et al. Figure 3 Holter monitoring showed self-terminating polymorphic ventricular tachycardia and short QT interval. The coupling interval of the first beat of the polymorphic ventricular tachycardia was very short. observed.9 Tall, symmetrical and peaked T waves testing. There are currently no guidelines for the often also are noted. Individuals may also have an diagnosis of short QT syndrome. underlying atrial fibrillation.