Catecholaminergic Polymorphic Ventricular Tachycardia in a Pregnant Woman

To editor: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare channelopathy with a prevalence of approximately 1:10,000–1:20,000. It is characterized by bidirectional or polymorphic ventricular tachycardia triggered by sympathetic stimulation. CPVT often remains undiagnosed until symptoms such as syncope or sudden cardiac arrest occur.1 However, the physiological changes in cardiovascular, autonomic, and hormonal functions during pregnancy may increase the risk of arrhythmias.2 Despite this, studies on the management of CPVT during pregnancy are limited. We present the case of a 24-year-old secundigravida at 8 weeks’ gestation, with a history of one miscarriage, who presented with exertion-induced palpitations. Electrocardiography revealed sinus tachycardia with polymorphic premature ventricular complexes (PVCs), and Holter monitoring detected bidirectional ventricular tachycardia (VT) post-exertion. Structural heart disease and suprarenal tumors were excluded via imaging. Symptoms intensified during the third trimester but were managed pharmacologically without the need for implantable cardioverter-defibrillator (ICD) implantation. The pregnancy resulted in a term delivery with no postpartum complications. Our report highlights the potential link between pregnancy-related changes and arrhythmia exacerbation in CPVT, supported by a scoping review of prior cases. A systematic search of PubMed or MEDLINE identified five relevant cases of CPVT in pregnancy (Supplementary Table 1, https://links.lww.com/MFM/A89). Written informed consent was obtained from the patient for this correspondence. The patient denied dizziness, chest pain, or fainting but reported several episodes of fainting during childhood. No family history of recurrent fainting, palpitations, or sudden cardiac arrest was noted. The patient had first experienced palpitations 12 months prior to pregnancy. Electrocardiography revealed sinus tachycardia with frequent polymorphic PVCs, including episodes of couplets, triplets, and runs of VT (Supplementary Fig. 1, https://links.lww.com/MFM/A89). Transthoracic echocardiography demonstrated normal cardiac motion, good systolic function, and a left ventricular ejection fraction of 61%, indicating structurally normal heart function. Holter monitoring revealed baseline sinus rhythm with an average heart rate of 82 bpm, occasional premature atrial contractions (< 1%), 42% premature ventricular contractions, and symptomatic episodes of couplets, triplets, bigeminy, and trigeminy. Non-sustained bidirectional VT was observed during light activity. The Bruce protocol exercise stress test showed no signs of ischemia, and hemodynamic responses were appropriate for the patient’s blood pressure and heart rate. Cardiac MRI revealed a normal heart structure. Prior to pregnancy, a contrast-enhanced MSCT of the abdomen had been performed to rule out sympathetic abnormalities due to a suprarenal tumor, with no findings of any suspicious tumor. During her pregnancy, the patient was managed by a multidisciplinary team, including an obstetrician, maternal cardiologist, anesthesiologist, and perinatologist. At 8 weeks of gestation, the patient continued to experience occasional palpitations. She was prescribed bisoprolol (2.5 mg once daily), which she had been using before pregnancy. Although the palpitations became less frequent in the second trimester, they reappeared in the third trimester without any associated symptoms. At 30 weeks of gestation, Holter monitoring revealed 30% multifocal PVCs, along with single, couplet, triplet, bigeminy, and trigeminy patterns. Non-sustained bidirectional VT episodes (longest duration, 21 seconds) were observed without symptoms. Fetal surveillance was normal, and fetal growth was appropriate for gestational age. At 37 weeks of gestation, a cesarean section was planned due to cephalopelvic disproportion caused by maternal passage factors, as determined by clinical pelvimetry. General anesthesia was administered for the cesarean, and the patient was closely monitored by the maternal cardiologist. No arrhythmia episodes or obstetric complications occurred during the surgery. The baby was delivered with a birth weight of 3060 grams, and APGAR scores were 8 at 1 minute and 9 at 5 minutes. The patient had no arrhythmia episodes during the postpartum period and was discharged on the third postoperative day. At the 1-week follow-up, the patient reported no recurrence of palpitations, and physical examination and ECG were normal. A 4-week exercise stress test showed no ischemia, and hemodynamic responses were appropriate. CPVT is an inherited arrhythmia with symptoms commonly developing between the ages of 7 and 12 years, although some patients present symptoms between the ages of 20 and 30 years.1 Our patient was diagnosed at age 24. Despite being one of the leading causes of sudden death in young individuals, CPVT is often asymptomatic, leading to delayed or missed diagnoses. A thorough literature search identified five case reports of pregnant women (aged 17–28 years) with CPVT, with an average gestational age of 23.8 weeks at the time of diagnosis. CPVT is caused by mutations in the ryanodine receptor 2 (RYR2) or calsequestrin 2 gene, inherited in autosomal dominant and autosomal recessive patterns, respectively.3–7 In patients without a family history of CPVT, it can occur due to sporadic mutations in the RYR2 gene.1 CPVT is typically asymptomatic or presents with recurrent syncope, stress-induced palpitations, dizziness, or lightheadedness.1,6 Our patient reported childhood syncope that resolved in adulthood but developed exertion-induced palpitations that worsened in the third trimester. Our scoping review identified that third-trimester palpitations are the most common manifestation of CPVT during pregnancy, likely reflecting pregnancy-enhanced catecholamine responses and elevated sympathetic activation.1,8 Diagnosing CPVT can be challenging, as resting ECGs are often normal. The cardiac exercise stress test is the primary diagnostic tool for CPVT.1 In our patient, the initial exercise stress test yielded normal results, possibly due to the test’s poor sensitivity for inducing complex arrhythmias.9 The patient’s subsequent Holter monitoring revealed worsening VT and PVC patterns during increased activity and heart rate, which, in the context of a structurally normal heart, confirmed the diagnosis of CPVT. Management of CPVT requires a tailored, multidisciplinary approach to prevent life-threatening arrhythmias. First-line treatment includes beta-blockers and non-pharmacological modifications, such as limiting strenuous activities and psychological stress.10 In refractory cases, flecainide, a Class 1c antiarrhythmic, may be added. Although a flecainide-beta blocker combination was clinically indicated for our patient, she remained on beta-blocker monotherapy due to insurance limitations. For patients with a history of cardiac arrest or persistent arrhythmias despite adequate pharmacological treatment, implantation of an ICD should be considered. In four of the five previously reported cases of CPVT in pregnancy, an ICD was implanted. In our patient and one other case,5 CPVT remained stable without the need for ICD implantation. Current evidence for managing CPVT during pregnancy is limited. While vaginal delivery is generally not contraindicated, previous reports have shown higher catecholamine levels during vaginal delivery.2 However, our scoping review indicates that favorable outcomes can be achieved with vaginal delivery under epidural anesthesia. In our case, a cesarean section was performed solely due to cephalopelvic disproportion, and both maternal and fetal outcomes were favorable throughout the perinatal period. Funding None. Conflicts of Interest None. Data Availability All data generated or analyzed during this study are included in this published article and its supplementary information files.