br Discussion ATS is rare and there are few

Discussion ATS is rare, and there are few reports of pregnant patients with this condition. Subbiah et al. [6] reported a case of pregnancy complicated with ATS in which ventricular ectopy was also decreased during pregnancy. The mechanism underlying the reduction of VA in pregnant patients with ATS remains unclear but may be due to alterations in autonomic balance and significant changes in estrogen and progesterone levels during pregnancy. The same mechanism may explain why patients with LQTS have a reduced risk of cardiac events during pregnancy but an increased risk postpartum, especially patients with LQTS type 2 [7]. Nagase et al. [8] found that hygromycin b induced PVC in patients with ATS. However, the epinephrine concentration is maintained at the same level during pregnancy, compared with that in the nonpregnant state, and only elevates markedly during labor [9]. Epidural anesthesia can prevent an increase in epinephrine level during labor but cannot maintain it at a level lower than that in nonpregnant state [10]. Sympathetic nerve activity is increased during pregnancy, with a contrasting decrease in parasympathetic nerve activity [11]. Therefore, catecholamine levels and autonomic nerve activity cannot explain the significantly decreased VA in a patient with ATS. The production of several sex steroid hormones is increased during pregnancy. Estrogen is generally indicated to prolong QT interval, whereas progesterone and testosterone shorten QT interval. However, Kakusaka et al. [12] found that 17-beta-estradiol (E2) and estrone 3-sulfate (E1) prolong QT interval, whereas estriol (E3) does not. Given that the estrogen hormone E3 is primarily increased during pregnancy, the effects of estrogen on LQTS during pregnancy may be unimportant. Progesterone and testosterone levels are increased during pregnancy. The hormones were observed to have protective effects against rhythm disturbances in a congenital LQTS model [13,14] and play an important role in reducing peripartum cardiac events in patients with LQTS, particularly ATS. Our patient had a C-terminal mutation in KCNJ2 (G300V), which was reported previously. Frequent PVCs, NSVT, and bidirectional VT have been observed also among patients with this mutation [15]. Our patient had a good pregnancy outcome. However, because the clinical characteristics of each genotype of ATS appear to be different to some extent, we need further experience with patients with pregnancy-complicated ATS.
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Introduction Reports of successful implantation of implantable cardioverter-defibrillators (ICDs) are limited, and such implantations, which are performed to avoid the risk of a thoracotomy, are challenging in a small, select group of patients who have anatomical variations such as persistent left superior vena cava (SVC) [1–3]. There are rare case reports of successful ICD implantation in patients with acquired anatomical deformation. We successfully used an alternative maneuver to implant a transvenous lead system in a patient who had an acute angle between the brachiocephalic vein (BCV) and SVC.
Case report A 49-year-old woman with a medical history of tuberculosis-induced lung destruction was referred to the cardiology division after aborted sudden cardiac arrest in the emergency room. On physical examination, her heart rate and blood pressure were 78beats/min and 100/70mmHg, respectively. Initial laboratory test results, including electrolyte balance, were normal, and the electrocardiogram showed QT prolongation (QTc 580ms). Her previous medical records did not show any history of medication or organic heart disease. Her echocardiographic left ventricular ejection fraction was normal, and a coronary angiogram did not reveal critical coronary artery obstructions. However, an epinephrine QT stress test was positive (paradoxical QT response >30ms). Therefore, congenital long-QT syndrome was diagnosed, and implantation of a cardioverter-defibrillator system was decided for secondary prevention.