Pregnancy in a patient with idiopathic long QT syndrome

CARDIAC ARRHYTHMIAS DURING PREGNANCY: A CLINICAL APPROACH

Physiologic changes in maternal haemodynamics, hormones and autonomic properties contribute to arrhythmias in pregnancy. While arrhythmias most commonly occur in pregnant women with structural heart disease or those with a history of cardiac arrhythmias, they can also occur de novo in women with no documented cardiac disease.

Brief review: anesthetic implications of long QT syndrome in pregnancy

PURPOSE

To review the effects of the long QT syndrome (LQTS) in the parturient and the current anesthetic management of patients with LQTS.

SOURCE

Relevant articles were obtained from a MEDLINE search spanning the years 1980-2006 and a PubMed search spanning the years 1949-2006. Bibliographies of retrieved articles were searched for additional articles.

PRINCIPAL FINDINGS

The prevalence of LQTS in the developed world is one per 1,100 to 3,000 of the population. Clinically, LQTS is characterized by syncope, cardiac arrest and occasionally, by a history of seizures. The QT interval can also be prolonged by drugs, electrolyte imbalances, toxins and certain medical conditions. Long QT syndrome patients are at risk of torsades de pointes and ventricular fibrillation. Medical management aims to reduce dysrhythmia frequency. The LQTS is subdivided into different groups (LQT1-6) depending on the cardiac ion channel abnormality. Torsades can be precipitated by adrenergic stimuli such as stress or pain (LQT1 and 2), sudden noises (LQT2) or whilst sleeping (LQT3). Patients with LQTS require careful anesthetic management as they are at high risk of torsades perioperatively despite minimal data on the effects of anesthetic agents on the QT interval. While information on effects of LQTS in pregnancy is limited, the incidence of dysrhythmia increases postpartum. Isolated case reports of patients with LQTS women highlight several peripartum dysrhythmias.

CONCLUSION

An understanding of LQTS and the associated risk factors contributing to dysrhythmias is important for anesthesthesiologists caring for parturients with LQTS.

Arrhythmias in the pregnant patient: Current concepts in evaluation and management

Maternal arrhythmias during pregnancy may jeopardize the health of both mother and fetus. The correct identification of the arrhythmia is critical in the pregnant patient. Treatment should be reserved for arrhythmias that are hemodynamically unstable or cause debilitating symptoms. When medications are deemed necessary, the physician should use as few drugs as possible at the lowest effective doses and choose drugs with a history of safe use in pregnancy. Resuscitation of a pregnant patient in cardiac arrest should be modified with regard to the normal physiologic changes of pregnancy. With careful management, most of these challenging patients will have excellent outcomes.

Effect of vaginal delivery on the Q-Tc interval in a patient with the long Q-T (Romano-Ward) syndrome

Twelve ECG leads were monitored continuously during peripartum in a 23-year-old Japanese woman diagnosed as having the long Q-T (Romano-Ward) syndrome. Corrected Q-T (Q-Tc) intervals determined by 2 investigators blinded from the clinical informations disclosed that the Q-Tc interval increased during labor, suggesting that physical and/or emotional stress during labor might cause prolonged Q-Tc intervals in women with the long QT syndrome.

New-onset ventricular tachycardia during pregnancy

During evaluation for palpitations, presyncope, or syncope, seven pregnant women had documented ventricular tachycardia. Before pregnancy none had a history of significant cardiac disease or symptomatic arrhythmia. The tachycardia rate ranged from 117 to 250 beats/min and lasted up to 65 seconds. Arrhythmia evaluation in five of the patients suggested catecholamine-sensitive ventricular tachycardia. This diagnosis was supported by either a positive relation to exercise or isoproterenol infusion, suppression of arrhythmia by beta-blockade or sleep, and lack of induction of arrhythmia by programmed electrical stimulation of the heart. The arrhythmias resolved in one patient soon after evaluation and in one other patient after 2 months of controlling therapy. Five other patients continued to receive therapy throughout pregnancy. Delivery was accomplished in all patients without significant maternal or neonatal complications.

Anaesthesia for caesarean section in a patient with Jervell, Lange-Nielsen syndrome

The anaesthetic management of a patient with Jervell, Lange-Nielsen syndrome (a form of congenitally prolonged QT interval) requiring emergency Caesarean section is presented. An epidural anaesthetic using 3-chloroprocaine produced a safe and satisfactory anaesthetic for the procedure in a patient prone to ventricular arrhythmias and cardiac arrest. High levels of circulating catecholamines have been postulated as one of the causes of the arrhythmias in these patients, making it advisable to select drugs and techniques known to minimize catecholamine levels. Although communication can be difficult in these profoundly deaf patients, it is important in order to reduce the emotional stress. Elective Caesarean sections under general anaesthesia have been reported; it appears that a well planned regional anaesthetic is equally safe.