CASE REPORT verapamil, paroxysmal supraventricular tachycardia
Verapamil in the Treatment of Maternal Paroxysmal Supraventricular Tachycardia Paroxysmal supraventricular tachycardia (PSVT) is seen somewhat frequently in the emergency department but less frequently during pregnancy. Although verapamil is widely used as the drug of choice for PSVT with a narrow QRS complex in a hemodynamically stable patient, the acute IV use of verapami] during pregnancy has not been well studied. Only a limited number of case reports document its safety and efficacy in the treatment of maternal or fetal PSVT. In general, the use of medication during pregnancy requires careful assessment of both the maternal and fetal risks versus benefits and documentation of patient consent. Because it crosses the placenta, one of the major concerns with the acute use of IV verapamil centers around the drug's potential effect on fetal heart rate. The case we present describes the occurrence of PSVT on two separate occasions in a woman in the third trimester of pregnancy. In both episodes, as much as 10 mg IV verapami] was given with resulting successful conversion to normal sinus rhythm. Fetal heart monitoring during drug administration failed to show significant change in fetal heart rate. [Byerly WG, Hartmann A, Foster DE, Tannenbaum AK: Verapami] in the treatment of maternal paroxysmal supraventricular tachycardia. Ann Emerg Med May 199I;20:552-554.]
INTRODUCTION Paroxysmal supraventricular tachycardia (PSVT) is r o u t i n e l y diagnosed and treated in the e m e r g e n c y department. PSVT during pregnancy, however, is a l e s s - c o m m o n ED presentation. A l t h o u g h IV verapami] is generally considered the pharmacological agent of choice for the acute treatm e n t of supraventricular tachycardia w i t h a narrow QRS complex, i there are few reports or studies on its safety and efficacy in the t r e a t m e n t of m a t e r n a l or fetal SVT. 2-s We present the case of a w o m a n in the third t r i m e s t e r of pregnancy who received IV v e r a p a m i l on two separate occasions for the t r e a t m e n t of PSVT w i t h o u t apparent adverse fetal effects.
Wesley G Byerly, PharmD* Winston-Salem, North Carolina Anthony Hartmann, MDt Dianne E Foster, PharmD~ Alan K Tannenbaum, MD§ New Brunswick, New Jersey From the Drug Information Service, Department of Pharmacy, North Carolina Baptist Hospital, Winston-Salem, North Carolina;* the Departments of Emergency Medicinet and Pharmacy,~- Robert Wood Johnson University Hospital, New Brunswick, New Jersey; and the Division of Cardiovascular Diseases and Hypertension, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, New Brunswick, New Jersey.§ Received for publication January 25, 1989. Revision received July 25, 1990. Accepted for publication September 17, 1990. Address for reprints: Wesley G Byedy, PharmD, Drug Information Service, North Carolina Baptist Hospital, 300 South Hawthorne Road, Winston-Salem, North Carolina 27103.
CASE REPORT A 22-year-old w o m a n , G1P o at six and one-half m o n t h s ' gestation, presented to the ED w i t h a h i s t o r y of rapid heartbeat for a p p r o x i m a t e l y two hours. O n a d m i s s i o n to the ED, the p a t i e n t was awake, alert, and m i l d l y anxious but in no acute distress. Her blood pressure was 120/74 m m Hg; pulse, 180; respirations, 26; and temperature, 36.6 C. T h e lungs were clear bilaterally, and no m u r m u r s or rubs were appreciated on cardiac auscultation. A n ECG showed a regular SVT w i t h narrow complexes at a rate of 170 w i t h o u t delta waves (Figure 1). T h e physical e x a m i n a t i o n was otherwise w i t h i n n o r m a l limits. Fetal heart r h y t h m was regular at a rate of 150. The patient's pregnancy had been w i t h o u t complication, and she denied any personal or f a m i l y h i s t o r y of cardiac p r o b l e m s or Wolff-ParkinsonW h i t e syndrome. The p a t i e n t stated that she had experienced one similar episode of rapid heartbeat a p p r o x i m a t e l y three years earlier that was selfl i m i t e d and for w h i c h she had sought no m e d i c a l evaluation or t r e a t m e n t . Initially, Valsalva m a n e u v e r and carotid massage were tried but failed to slow the patient's heart rate. Several a t t e m p t s at ice w a t e r s t i m u l a t i o n to the face were also unsuccessful. After discussion of the risks and benefits
116/552
Annals of Emergency Medicine
20:5 May 1991
VERAPAMIL Byerly et al
of the remaining alternatives for terminating the arrhythmia with the patient, it was decided to administer IV v e r a p a m i l w i t h c o n t i n u o u s fetal monitoring. A total of 10 mg was given over ten minutes in two 5-mg boluses. Repeat carotid massage then converted the patient to normal sinus rhythm. Her pulse was 90; blood pressure, 108/60 m m Hg; and ECG, n o r m a l . The fetal h e a r t m o n i t o r showed no change in heart rate during verapamil administration. The patient was monitored in the ED and discharged on no medications, and cardiology follow-up was scheduled. One week later, the patient returned to the ED with a similar complaint. Before arrival, she experienced palpitations and some lightheadedness. Again, she was found to be in regular SVT with narrow QRS complex at a rate of 180 without evidence of Wolff-Parkinson-White syndrome and with blood pressure of 130/74 m m Hg. Vagal maneuvers were unsuccessful. Therefore, after a discussion with the patient of alternative therapies, IV verapami] was given at a dose of 10 mg over ten minutes with fetal heart rate monitoring. After verapamil administration, the patient remained in PSVT, and no change was seen in fetal heart rate, which averaged 150 to 160. A subsequent decrease in the patient's blood pressure to 88/40 m m Hg was corrected by fluid administration and placing the p a t i e n t supine. Fetal heart rate remained unchanged. Because of continued SVT and the transient hypotension, electrical cardioversion was considered. However, before e a r d i o v e r s i o n , t h e p a t i e n t spontaneously converted to normal sinus r h y t h m and was later discharged from the ED. The remainder of her pregnancy was uneventful; three months after verapamil cardioversion, the patient delivered a fullterm n o r m a l infant w i t h o u t difficulty.
DISCUSSION I n patients with PSVT, 80% to 100% will convert to normal sinus r h y t h m after t r e a t m e n t w i t h verapamil.~ In patients with atrial flutter or fibrillation and a rapid vent r i c u l a r r e s p o n s e , v e r a p a m i l decreases the v e n t r i c u l a r rate b u t generally does not result in conversion to normal sinus rhythm.~ Although verapamil is the current drug 20:5 May 1991
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Verapamil in the Treatment of Maternal Paroxysmal Supraventricular Tachycardia Paroxysmal supraventricular tachycardia (PSVT) is seen somewhat frequently in the emergency department but less frequently during pregnancy. Although verapamil is widely used as the drug of choice for PSVT with a narrow QRS complex in a hemodynamically stable patient, the acute IV use of verapami] during pregnancy has not been well studied. Only a limited number of case reports document its safety and efficacy in the treatment of maternal or fetal PSVT. In general, the use of medication during pregnancy requires careful assessment of both the maternal and fetal risks versus benefits and documentation of patient consent. Because it crosses the placenta, one of the major concerns with the acute use of IV verapamil centers around the drug's potential effect on fetal heart rate. The case we present describes the occurrence of PSVT on two separate occasions in a woman in the third trimester of pregnancy. In both episodes, as much as 10 mg IV verapami] was given with resulting successful conversion to normal sinus rhythm. Fetal heart monitoring during drug administration failed to show significant change in fetal heart rate. [Byerly WG, Hartmann A, Foster DE, Tannenbaum AK: Verapami] in the treatment of maternal paroxysmal supraventricular tachycardia. Ann Emerg Med May 199I;20:552-554.]
INTRODUCTION Paroxysmal supraventricular tachycardia (PSVT) is r o u t i n e l y diagnosed and treated in the e m e r g e n c y department. PSVT during pregnancy, however, is a l e s s - c o m m o n ED presentation. A l t h o u g h IV verapami] is generally considered the pharmacological agent of choice for the acute treatm e n t of supraventricular tachycardia w i t h a narrow QRS complex, i there are few reports or studies on its safety and efficacy in the t r e a t m e n t of m a t e r n a l or fetal SVT. 2-s We present the case of a w o m a n in the third t r i m e s t e r of pregnancy who received IV v e r a p a m i l on two separate occasions for the t r e a t m e n t of PSVT w i t h o u t apparent adverse fetal effects.
Wesley G Byerly, PharmD* Winston-Salem, North Carolina Anthony Hartmann, MDt Dianne E Foster, PharmD~ Alan K Tannenbaum, MD§ New Brunswick, New Jersey From the Drug Information Service, Department of Pharmacy, North Carolina Baptist Hospital, Winston-Salem, North Carolina;* the Departments of Emergency Medicinet and Pharmacy,~- Robert Wood Johnson University Hospital, New Brunswick, New Jersey; and the Division of Cardiovascular Diseases and Hypertension, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, New Brunswick, New Jersey.§ Received for publication January 25, 1989. Revision received July 25, 1990. Accepted for publication September 17, 1990. Address for reprints: Wesley G Byedy, PharmD, Drug Information Service, North Carolina Baptist Hospital, 300 South Hawthorne Road, Winston-Salem, North Carolina 27103.
CASE REPORT A 22-year-old w o m a n , G1P o at six and one-half m o n t h s ' gestation, presented to the ED w i t h a h i s t o r y of rapid heartbeat for a p p r o x i m a t e l y two hours. O n a d m i s s i o n to the ED, the p a t i e n t was awake, alert, and m i l d l y anxious but in no acute distress. Her blood pressure was 120/74 m m Hg; pulse, 180; respirations, 26; and temperature, 36.6 C. T h e lungs were clear bilaterally, and no m u r m u r s or rubs were appreciated on cardiac auscultation. A n ECG showed a regular SVT w i t h narrow complexes at a rate of 170 w i t h o u t delta waves (Figure 1). T h e physical e x a m i n a t i o n was otherwise w i t h i n n o r m a l limits. Fetal heart r h y t h m was regular at a rate of 150. The patient's pregnancy had been w i t h o u t complication, and she denied any personal or f a m i l y h i s t o r y of cardiac p r o b l e m s or Wolff-ParkinsonW h i t e syndrome. The p a t i e n t stated that she had experienced one similar episode of rapid heartbeat a p p r o x i m a t e l y three years earlier that was selfl i m i t e d and for w h i c h she had sought no m e d i c a l evaluation or t r e a t m e n t . Initially, Valsalva m a n e u v e r and carotid massage were tried but failed to slow the patient's heart rate. Several a t t e m p t s at ice w a t e r s t i m u l a t i o n to the face were also unsuccessful. After discussion of the risks and benefits
116/552
Annals of Emergency Medicine
20:5 May 1991
VERAPAMIL Byerly et al
of the remaining alternatives for terminating the arrhythmia with the patient, it was decided to administer IV v e r a p a m i l w i t h c o n t i n u o u s fetal monitoring. A total of 10 mg was given over ten minutes in two 5-mg boluses. Repeat carotid massage then converted the patient to normal sinus rhythm. Her pulse was 90; blood pressure, 108/60 m m Hg; and ECG, n o r m a l . The fetal h e a r t m o n i t o r showed no change in heart rate during verapamil administration. The patient was monitored in the ED and discharged on no medications, and cardiology follow-up was scheduled. One week later, the patient returned to the ED with a similar complaint. Before arrival, she experienced palpitations and some lightheadedness. Again, she was found to be in regular SVT with narrow QRS complex at a rate of 180 without evidence of Wolff-Parkinson-White syndrome and with blood pressure of 130/74 m m Hg. Vagal maneuvers were unsuccessful. Therefore, after a discussion with the patient of alternative therapies, IV verapami] was given at a dose of 10 mg over ten minutes with fetal heart rate monitoring. After verapamil administration, the patient remained in PSVT, and no change was seen in fetal heart rate, which averaged 150 to 160. A subsequent decrease in the patient's blood pressure to 88/40 m m Hg was corrected by fluid administration and placing the p a t i e n t supine. Fetal heart rate remained unchanged. Because of continued SVT and the transient hypotension, electrical cardioversion was considered. However, before e a r d i o v e r s i o n , t h e p a t i e n t spontaneously converted to normal sinus r h y t h m and was later discharged from the ED. The remainder of her pregnancy was uneventful; three months after verapamil cardioversion, the patient delivered a fullterm n o r m a l infant w i t h o u t difficulty.
DISCUSSION I n patients with PSVT, 80% to 100% will convert to normal sinus r h y t h m after t r e a t m e n t w i t h verapamil.~ In patients with atrial flutter or fibrillation and a rapid vent r i c u l a r r e s p o n s e , v e r a p a m i l decreases the v e n t r i c u l a r rate b u t generally does not result in conversion to normal sinus rhythm.~ Although verapamil is the current drug 20:5 May 1991
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