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Atrial fibrillation in pregnancy associated with oral terbutaline
2. Dizon-Townson D, Magee KP, Twickler DM, Cox SM. Coarctation of the abdominal aorta in pregnancy: Diagnosis by magnetic resonance imaging. Obstet Gynecol 1994;85: 817–9. 3. Galloway AC, Artman M, Spencer FB. Congenital heart disease. In: Schwartz SI, Shires GT, Spencer FC, eds. Principles of surgery. 7th ed. New York: McGraw-Hill, 1999: 791– 844. 4. Dessole S, D’Antona D, Ambrosini G, Fadda MC, Capobianco G. Pregnancy and delivery in young woman affected by isthmic coarctation of the aorta. Arch Gynecol Obstet 2000;263:145–7. 5. Kupferminc MJ, Lessing JB, Jaffa A, Vidne BA, Peyser MR. Fetomaternal blood flow measurements and management
of combined coarctation and aneurysm of the thoracic aorta in pregnancy. Acta Obstet Gynecol Scand 1993;72: 398 – 402. 6. Goodwin JF. Pregnancy and coarctation of the aorta. Clin Obstet Gynecol 1975;4:645–53. 7. Lip GYH, Singh SP, Beevers G. Aortic coarctation diagnosed after hypertension in pregnancy. Am J Obstet Gynecol 1998;179:814 –5. 8. Conti S, Wagner C, Fitzpatrick HF. Abdominal aortic coarctation and pregnancy. J Cardiovasc Surg 1980;21: 379 – 86.
Atrial Fibrillation in Pregnancy Associated With Oral Terbutaline
Since the late 1970s, terbutaline and ritodrine are the two beta-2-sympathomimetic medications used clinically to treat preterm labor. These medications primarily affect the beta-2 receptor, but are known to have beta-1 effects on the heart that include increases in ionotropy, chronotropy, conduction speed, excitability, and automatism. In a prospective study of continuous electrocardiographic monitoring of 30 pregnant women who received intravenous ritodrine as therapy for preterm labor, the only arrhythmia found was premature depolarizations in two women.1 A retrospective study by Perry et al found self-limited adverse effects in 0.54% of 8709 women given parenteral terbutaline with the only arrhythmias being nonsustained premature ventricular contractions and premature atrial contractions in 14 patients, for a rate of 1.6 of 1000 patients.2 Robertson et al reported arrhythmias in 2.3% of 343 women exposed to parenteral isoxsuprine or terbutaline, but they did not specify the type.3 The Physicians’ Desk Reference lists arrhythmias as an adverse effect of terbutaline, but it and similar resources did not state the type of arrhythmia or specify atrial fibrillation. A MEDLINE search of articles published from 1966 to 2001 using keywords “atrial fibrillation” and “pregnancy” yielded only one report of atrial fibrillation associated with these medications, but it was given parenterally, and the authors did not elaborate on the clinical course.4 Although the incidence appears to be exceedingly small, it is important to be aware that in addition to transient benign arrhythmias, this medication may cause atrial fibrillation requiring medical intervention.
Michael P. Carson, MD, Allan J. Fisher, MD, and William E. Scorza, MD Departments of Medicine and Obstetrics, Gynecology & Reproductive Sciences, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey; and the Division of General Internal Medicine, St. Peter’s University Hospital, New Brunswick, New Jersey
BACKGROUND: Terbutaline has direct effects on the cardiac conduction system, but when used to treat preterm labor it is rarely associated with clinically significant cardiac arrhythmias. Commonly used drug references did not list atrial fibrillation as a complication of terbutaline, and our literature search found only one case of atrial fibrillation that occurred with parenteral administration. CASE: A 30-year-old gravida 1 carrying a twin gestation at 35 weeks was taking 2.5 mg oral terbutaline four times daily for premature labor. She developed atrial fibrillation and was ultimately treated by chemical cardioversion with procainamide to restore normal sinus rhythm. CONCLUSION: This is the first report of atrial fibrillation during pregnancy associated with oral terbutaline. Atrial fibrillation should be added as a complication of oral terbutaline therapy. (Obstet Gynecol 2002;100:1096 –7. © 2002 by The American College of Obstetricians and Gynecologists.)
Reprints are not available. Address correspondence to: Michael Carson, MD, Saint Peter’s University Hospital, 254 Easton Avenue/ CARESBuilding,4thFloor,NewBrunswick,NJ08903;E-mail:mcarson @docisp.com.
1096
Received November 30, 2001. Received in revised form March 20, 2002. Accepted April 4, 2002.
CASE A nulliparous nurse in her 30s, carrying twins, presented with palpitations at 35 weeks’ gestation. Before pregnancy she noted a history of palpitations after consuming
VOL. 100, NO. 5, PART 2, NOVEMBER 2002 © 2002 by The American College of Obstetricians and Gynecologists. Published by Elsevier Science Inc.
0029-7844/02/$22.00 PII S0029-7844(02)02106-3
caffeine or chocolate. She did not have a history of hyperthyroidism. Her pregnancy had been complicated by an admission for preterm labor characterized by cervical dilation and effacement. She was discharged on 5 mg of oral terbutaline four times a day, but this was decreased to 2.5 mg 1 day before admission. At 9 PM the night of admission she had eaten a large bowl of chocolate-flavored breakfast cereal that contained approximately 0.1 mg of caffeine (personal communication, Kellogg’s customer service department). As references, a typical chocolate bar contains about 30 mg of caffeine and a cup of regular coffee 100 –200 mg. Soon thereafter she noticed an increased heart rate. After 2 hours of persistent symptoms she checked her radial pulse, found it to be 150 –160 beats per minute and went to the hospital where she denied dyspnea or chest pain. At the hospital, her systolic blood pressure was 95 mm Hg, which was her baseline from office visits. An electrocardiogram revealed atrial fibrillation with a ventricular response of 180 beats per minute. Critical care and obstetric medicine consultations were obtained. Digoxin was administered. Intravenous diltiazem did not control her ventricular response, so we changed to intravenous esmolol, which was effective at maintaining her heart rate between 100 and 120 beats per minute. Heparin was started immediately to decrease the risk of thrombosis. Due to regular contractions occurring every 5 minutes magnesium sulfate was started as a tocolytic. An echocardiogram showed a normal heart, thyroid-stimulating hormone was normal, and a pulmonary ventilation/perfusion scan was normal. Nine hours after presentation she remained hemodynamically stable, but her cervix had dilated from 1 to 3 cm. One gram of procainamide was given intravenously with no effect on her rhythm after 90 minutes. Because of her preterm labor and the possible need for surgical intervention, the decision was made to electrically cardiovert her back to sinus rhythm so that the heparin could be stopped. Although preparations were made for electrical cardioversion, she was given an additional 500 mg of procainamide that effected cardioversion to normal sinus rhythm. The beta-adrenergic antagonist esmolol was discontinued because of the known effect of enhancing uterine contractility and the concern that it would exacerbate the preterm labor. Diltiazem is a calcium-channel blocker that can slow heart rate and conduction through the atrioventricular node. Although it had failed earlier, once she was in sinus rhythm we felt it offered the best risk/benefit ratio to control heart rate without increasing uterine irritability. This medication was administered via continuous intravenous drip to control heart rate and, because it is also a calcium-channel blocker, theoretically exert a tocolytic effect similar to nifedipine. The magnesium sulfate tocolysis was halted due to less frequent
VOL. 100, NO. 5, PART 2, NOVEMBER 2002
contractions and the possible interaction with the calcium-channel blocker. On day 2 in hospital, she continued to be in normal sinus rhythm and was placed on oral diltiazem. On day 3 of admission she went into spontaneous labor and delivered her twin gestation vaginally. She was discharged from the hospital with the twins and without further complications. The diltiazem was discontinued and she was warned to avoid caffeine, chocolate, and beta-mimetics. At her 6-week follow-up appointment, the patient denied any problems.
COMMENT The risk of cardiac adverse effects from beta-agonist tocolytics is increased in the presence of comorbid factors such as preeclampsia, multifetal gestation, multiple tocolytics, and high intravenous sodium loads.2 The increased blood volume, heart rate, and catecholamine level associated with a twin gestation served to increase our patient’s susceptibility to the arrhythmogenic effects of terbutaline. Lone atrial fibrillation is defined as atrial fibrillation occurring in a patient without underlying heart disease and is known to occur during pregnancy. However, to our knowledge, this is the first report of atrial fibrillation associated with oral terbutaline, and only the second to associate the arrhythmia with this medication. Finally, a literature search did not reveal any cases of terbutaline-induced atrial fibrillation treated with chemical cardioversion to restore normal sinus rhythm. Therefore atrial fibrillation should be added as a complication of oral terbutaline therapy.
REFERENCES 1. Schneider EP, Jonas E, Tejani N. Detection of cardiac events by continuous electrocardiogram monitoring during ritodrine infusion. Obstet Gynecol 1988;71:361– 4. 2. Perry KG Jr, Morrison JC, Rust OA, Sullivan CA, Martin RW, Naef RW 3rd. Incidence of adverse cardiopulmonary effects with low-dose continuous terbutaline infusion. Am J Obstet Gynecol 1995;173:1273–7. 3. Robertson PA, Herron M, Katz M, Creasy RK. Maternal morbidity associated with isoxsuprine and terbutaline tocolysis. Eur J Obstet Gynec Reprod Biol 1981;11:371– 8. 4. Benedetti TJ. Maternal complications of parenteral betasympathomimetic therapy for premature labor. Am J Obstet Gynecol 1983;145:1– 6.
Received October 26, 2001. Received in revised form February 1, 2002. Accepted February 21, 2002.
Carson et al
Atrial Fibrillation and Terbutaline
1097
of combined coarctation and aneurysm of the thoracic aorta in pregnancy. Acta Obstet Gynecol Scand 1993;72: 398 – 402. 6. Goodwin JF. Pregnancy and coarctation of the aorta. Clin Obstet Gynecol 1975;4:645–53. 7. Lip GYH, Singh SP, Beevers G. Aortic coarctation diagnosed after hypertension in pregnancy. Am J Obstet Gynecol 1998;179:814 –5. 8. Conti S, Wagner C, Fitzpatrick HF. Abdominal aortic coarctation and pregnancy. J Cardiovasc Surg 1980;21: 379 – 86.
Atrial Fibrillation in Pregnancy Associated With Oral Terbutaline
Since the late 1970s, terbutaline and ritodrine are the two beta-2-sympathomimetic medications used clinically to treat preterm labor. These medications primarily affect the beta-2 receptor, but are known to have beta-1 effects on the heart that include increases in ionotropy, chronotropy, conduction speed, excitability, and automatism. In a prospective study of continuous electrocardiographic monitoring of 30 pregnant women who received intravenous ritodrine as therapy for preterm labor, the only arrhythmia found was premature depolarizations in two women.1 A retrospective study by Perry et al found self-limited adverse effects in 0.54% of 8709 women given parenteral terbutaline with the only arrhythmias being nonsustained premature ventricular contractions and premature atrial contractions in 14 patients, for a rate of 1.6 of 1000 patients.2 Robertson et al reported arrhythmias in 2.3% of 343 women exposed to parenteral isoxsuprine or terbutaline, but they did not specify the type.3 The Physicians’ Desk Reference lists arrhythmias as an adverse effect of terbutaline, but it and similar resources did not state the type of arrhythmia or specify atrial fibrillation. A MEDLINE search of articles published from 1966 to 2001 using keywords “atrial fibrillation” and “pregnancy” yielded only one report of atrial fibrillation associated with these medications, but it was given parenterally, and the authors did not elaborate on the clinical course.4 Although the incidence appears to be exceedingly small, it is important to be aware that in addition to transient benign arrhythmias, this medication may cause atrial fibrillation requiring medical intervention.
Michael P. Carson, MD, Allan J. Fisher, MD, and William E. Scorza, MD Departments of Medicine and Obstetrics, Gynecology & Reproductive Sciences, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey; and the Division of General Internal Medicine, St. Peter’s University Hospital, New Brunswick, New Jersey
BACKGROUND: Terbutaline has direct effects on the cardiac conduction system, but when used to treat preterm labor it is rarely associated with clinically significant cardiac arrhythmias. Commonly used drug references did not list atrial fibrillation as a complication of terbutaline, and our literature search found only one case of atrial fibrillation that occurred with parenteral administration. CASE: A 30-year-old gravida 1 carrying a twin gestation at 35 weeks was taking 2.5 mg oral terbutaline four times daily for premature labor. She developed atrial fibrillation and was ultimately treated by chemical cardioversion with procainamide to restore normal sinus rhythm. CONCLUSION: This is the first report of atrial fibrillation during pregnancy associated with oral terbutaline. Atrial fibrillation should be added as a complication of oral terbutaline therapy. (Obstet Gynecol 2002;100:1096 –7. © 2002 by The American College of Obstetricians and Gynecologists.)
Reprints are not available. Address correspondence to: Michael Carson, MD, Saint Peter’s University Hospital, 254 Easton Avenue/ CARESBuilding,4thFloor,NewBrunswick,NJ08903;E-mail:mcarson @docisp.com.
1096
Received November 30, 2001. Received in revised form March 20, 2002. Accepted April 4, 2002.
CASE A nulliparous nurse in her 30s, carrying twins, presented with palpitations at 35 weeks’ gestation. Before pregnancy she noted a history of palpitations after consuming
VOL. 100, NO. 5, PART 2, NOVEMBER 2002 © 2002 by The American College of Obstetricians and Gynecologists. Published by Elsevier Science Inc.
0029-7844/02/$22.00 PII S0029-7844(02)02106-3
caffeine or chocolate. She did not have a history of hyperthyroidism. Her pregnancy had been complicated by an admission for preterm labor characterized by cervical dilation and effacement. She was discharged on 5 mg of oral terbutaline four times a day, but this was decreased to 2.5 mg 1 day before admission. At 9 PM the night of admission she had eaten a large bowl of chocolate-flavored breakfast cereal that contained approximately 0.1 mg of caffeine (personal communication, Kellogg’s customer service department). As references, a typical chocolate bar contains about 30 mg of caffeine and a cup of regular coffee 100 –200 mg. Soon thereafter she noticed an increased heart rate. After 2 hours of persistent symptoms she checked her radial pulse, found it to be 150 –160 beats per minute and went to the hospital where she denied dyspnea or chest pain. At the hospital, her systolic blood pressure was 95 mm Hg, which was her baseline from office visits. An electrocardiogram revealed atrial fibrillation with a ventricular response of 180 beats per minute. Critical care and obstetric medicine consultations were obtained. Digoxin was administered. Intravenous diltiazem did not control her ventricular response, so we changed to intravenous esmolol, which was effective at maintaining her heart rate between 100 and 120 beats per minute. Heparin was started immediately to decrease the risk of thrombosis. Due to regular contractions occurring every 5 minutes magnesium sulfate was started as a tocolytic. An echocardiogram showed a normal heart, thyroid-stimulating hormone was normal, and a pulmonary ventilation/perfusion scan was normal. Nine hours after presentation she remained hemodynamically stable, but her cervix had dilated from 1 to 3 cm. One gram of procainamide was given intravenously with no effect on her rhythm after 90 minutes. Because of her preterm labor and the possible need for surgical intervention, the decision was made to electrically cardiovert her back to sinus rhythm so that the heparin could be stopped. Although preparations were made for electrical cardioversion, she was given an additional 500 mg of procainamide that effected cardioversion to normal sinus rhythm. The beta-adrenergic antagonist esmolol was discontinued because of the known effect of enhancing uterine contractility and the concern that it would exacerbate the preterm labor. Diltiazem is a calcium-channel blocker that can slow heart rate and conduction through the atrioventricular node. Although it had failed earlier, once she was in sinus rhythm we felt it offered the best risk/benefit ratio to control heart rate without increasing uterine irritability. This medication was administered via continuous intravenous drip to control heart rate and, because it is also a calcium-channel blocker, theoretically exert a tocolytic effect similar to nifedipine. The magnesium sulfate tocolysis was halted due to less frequent
VOL. 100, NO. 5, PART 2, NOVEMBER 2002
contractions and the possible interaction with the calcium-channel blocker. On day 2 in hospital, she continued to be in normal sinus rhythm and was placed on oral diltiazem. On day 3 of admission she went into spontaneous labor and delivered her twin gestation vaginally. She was discharged from the hospital with the twins and without further complications. The diltiazem was discontinued and she was warned to avoid caffeine, chocolate, and beta-mimetics. At her 6-week follow-up appointment, the patient denied any problems.
COMMENT The risk of cardiac adverse effects from beta-agonist tocolytics is increased in the presence of comorbid factors such as preeclampsia, multifetal gestation, multiple tocolytics, and high intravenous sodium loads.2 The increased blood volume, heart rate, and catecholamine level associated with a twin gestation served to increase our patient’s susceptibility to the arrhythmogenic effects of terbutaline. Lone atrial fibrillation is defined as atrial fibrillation occurring in a patient without underlying heart disease and is known to occur during pregnancy. However, to our knowledge, this is the first report of atrial fibrillation associated with oral terbutaline, and only the second to associate the arrhythmia with this medication. Finally, a literature search did not reveal any cases of terbutaline-induced atrial fibrillation treated with chemical cardioversion to restore normal sinus rhythm. Therefore atrial fibrillation should be added as a complication of oral terbutaline therapy.
REFERENCES 1. Schneider EP, Jonas E, Tejani N. Detection of cardiac events by continuous electrocardiogram monitoring during ritodrine infusion. Obstet Gynecol 1988;71:361– 4. 2. Perry KG Jr, Morrison JC, Rust OA, Sullivan CA, Martin RW, Naef RW 3rd. Incidence of adverse cardiopulmonary effects with low-dose continuous terbutaline infusion. Am J Obstet Gynecol 1995;173:1273–7. 3. Robertson PA, Herron M, Katz M, Creasy RK. Maternal morbidity associated with isoxsuprine and terbutaline tocolysis. Eur J Obstet Gynec Reprod Biol 1981;11:371– 8. 4. Benedetti TJ. Maternal complications of parenteral betasympathomimetic therapy for premature labor. Am J Obstet Gynecol 1983;145:1– 6.
Received October 26, 2001. Received in revised form February 1, 2002. Accepted February 21, 2002.
Carson et al
Atrial Fibrillation and Terbutaline
1097