- Email: [email protected]
Pregnancy Increases Heart Rates During Paroxysmal Supraventricular Tachycardia
Canadian Journal of Cardiology 31 (2015) 820.e5 www.onlinecjc.ca
Letters to the Editor Pregnancy Increases Heart Rates During Paroxysmal Supraventricular Tachycardia To the Editor: It was reported that pregnancy can increase the risk of newonset and exacerbation of supraventricular tachycardia (SVT).1-3 However, the underlying mechanisms are not well known. Recently a 34-year-old woman was admitted with palpitation at 34 weeks gestation and also after delivery. A 12-lead electrocardiogram revealed a SVT. We found that SVT rate is faster during pregnancy than in the nonpregnant state (212 vs 181, shown in the Supplementary Material). To evaluate the effects of pregnancy on heart rates of SVT episodes, we reviewed the cases of SVT episodes during pregnancy between January 2010 and September 2014 admitted to the First Affiliated Hospital of Shantou University Medical College in Southern China. Data on 11 patients were obtained. All patients had no history of structural heart disease. Female patients, without structural heart disease, admitted for SVT in the same period and aged between 20 and 40 years were used as a control group. There were 47 patients in the control group. Only 10 patients with an SVT episode had electrocardiograms. We found that heart rates of patients with SVT episodes were faster during pregnant periods than in nonpregnant periods (Table 1). This suggests that pregnancy might increase the heart rates of patients with SVT episodes, which might be associated with exacerbation of SVT during pregnancy. Table 1. Heart rates of supraventricular tachycardia episodes in the pregnancy and nonpregnancy groups Group Total n Mean age SD, years Mean heart rate SD, beats per minute
Pregnancy
Nonpregnancy
P
11 27.27 4.29 184.00 17.80
10 31.40 6.52 166.30 19.40
0.10 0.033
A few limitations were apparent in the present study. First, the population of the study was small; a larger sample would be needed to verify the effects of pregnancy on heart rates of patients with SVT episodes. Second, as reported, only a few pregnant women experienced exacerbation of SVT; heart rates of some patients with SVT episodes might be not affected by pregnancy. The present study demonstrated that pregnancy-induced exacerbation of SVT might be associated with the increased heart rates of patients with SVT episodes. Min Yu, PhD Kaihong Yi, PhD Lihong Zhou, MS Xuerui Tan, PhD [email protected]
Disclosures The authors have no conflicts of interest to disclose. References 1. Tawam M, Levine J, Mendelson M, et al. Effect of pregnancy on paroxysmal supraventricular tachycardia. Am J Cardiol 1993;72:838-40. 2. Lee SH, Chen SA, Wu TJ, et al. Effects of pregnancy on first onset and symptoms of paroxysmal supraventricular tachycardia. Am J Cardiol 1995;76:675-8. 3. Silversides CK, Harris L, Haberer K, et al. Recurrence rates of arrhythmias during pregnancy in women with previous tachyarrhythmia and impact on fetal and neonatal outcomes. Am J Cardiol 2006;97:1206-12.
Supplementary Material To access the supplementary material accompanying this article, visit the online version of the Canadian Journal of Cardiology at www.onlinecjc.ca and at http://dx.doi.org/10. 1016/j.cjca.2015.01.016.
http://dx.doi.org/10.1016/j.cjca.2015.01.016 0828-282X/Ó 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
Letters to the Editor Pregnancy Increases Heart Rates During Paroxysmal Supraventricular Tachycardia To the Editor: It was reported that pregnancy can increase the risk of newonset and exacerbation of supraventricular tachycardia (SVT).1-3 However, the underlying mechanisms are not well known. Recently a 34-year-old woman was admitted with palpitation at 34 weeks gestation and also after delivery. A 12-lead electrocardiogram revealed a SVT. We found that SVT rate is faster during pregnancy than in the nonpregnant state (212 vs 181, shown in the Supplementary Material). To evaluate the effects of pregnancy on heart rates of SVT episodes, we reviewed the cases of SVT episodes during pregnancy between January 2010 and September 2014 admitted to the First Affiliated Hospital of Shantou University Medical College in Southern China. Data on 11 patients were obtained. All patients had no history of structural heart disease. Female patients, without structural heart disease, admitted for SVT in the same period and aged between 20 and 40 years were used as a control group. There were 47 patients in the control group. Only 10 patients with an SVT episode had electrocardiograms. We found that heart rates of patients with SVT episodes were faster during pregnant periods than in nonpregnant periods (Table 1). This suggests that pregnancy might increase the heart rates of patients with SVT episodes, which might be associated with exacerbation of SVT during pregnancy. Table 1. Heart rates of supraventricular tachycardia episodes in the pregnancy and nonpregnancy groups Group Total n Mean age SD, years Mean heart rate SD, beats per minute
Pregnancy
Nonpregnancy
P
11 27.27 4.29 184.00 17.80
10 31.40 6.52 166.30 19.40
0.10 0.033
A few limitations were apparent in the present study. First, the population of the study was small; a larger sample would be needed to verify the effects of pregnancy on heart rates of patients with SVT episodes. Second, as reported, only a few pregnant women experienced exacerbation of SVT; heart rates of some patients with SVT episodes might be not affected by pregnancy. The present study demonstrated that pregnancy-induced exacerbation of SVT might be associated with the increased heart rates of patients with SVT episodes. Min Yu, PhD Kaihong Yi, PhD Lihong Zhou, MS Xuerui Tan, PhD [email protected]
Disclosures The authors have no conflicts of interest to disclose. References 1. Tawam M, Levine J, Mendelson M, et al. Effect of pregnancy on paroxysmal supraventricular tachycardia. Am J Cardiol 1993;72:838-40. 2. Lee SH, Chen SA, Wu TJ, et al. Effects of pregnancy on first onset and symptoms of paroxysmal supraventricular tachycardia. Am J Cardiol 1995;76:675-8. 3. Silversides CK, Harris L, Haberer K, et al. Recurrence rates of arrhythmias during pregnancy in women with previous tachyarrhythmia and impact on fetal and neonatal outcomes. Am J Cardiol 2006;97:1206-12.
Supplementary Material To access the supplementary material accompanying this article, visit the online version of the Canadian Journal of Cardiology at www.onlinecjc.ca and at http://dx.doi.org/10. 1016/j.cjca.2015.01.016.
http://dx.doi.org/10.1016/j.cjca.2015.01.016 0828-282X/Ó 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.