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Table of Contents
Year : 2023  |  Volume : 14  |  Issue : 1  |  Page : 53-55

Syncope and QT prolongation associated with the use of herbal product and m-RNA vaccination in a young woman

Department of Cardiology, Bakirköy Dr. Sadi Konuk Education and Research Hospital, Istanbul, Turkey

Date of Submission29-Sep-2022
Date of Acceptance15-Nov-2022
Date of Web Publication14-Feb-2023

Correspondence Address:
Dr. Cennet Yildiz
Department of Cardiology, Bakirkoy Dr. Sadi Konuk Education and Research Hospital, Istanbul
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/injms.injms_119_22

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Herein, we report a case of a 31-year-old woman with syncope due to QT prolongation 36 h after the second dose of Pfizer-BioNTech vaccination. During her comprehensive history taking, she admitted the use of herbal preparation. Her initial electrocardiogram showed a QTc interval of 690 ms, and she was interned to the intensive care unit (ICU). Her biochemical findings revealed no evidence of electrolyte abnormalities, and oral propranolol was started. During ICU monitorization, she developed polymorphic ventricular tachycardia, which subsequently degenerated into ventricular fibrillation. Genetic investigation identified KCNQ1 mutation, and ICD implantation was performed. The patient was discharged with mexiletine and propranolol treatment, and the outpatient clinic follow-up was recommended.

Keywords: Herbal product, QT prolongation, syncope, vaccination

How to cite this article:
Pirhan O, Yildiz C. Syncope and QT prolongation associated with the use of herbal product and m-RNA vaccination in a young woman. Indian J Med Spec 2023;14:53-5

How to cite this URL:
Pirhan O, Yildiz C. Syncope and QT prolongation associated with the use of herbal product and m-RNA vaccination in a young woman. Indian J Med Spec [serial online] 2023 [cited 2023 May 29];14:53-5. Available from: http://www.ijms.in/text.asp?2023/14/1/53/369607

  Introduction Top

Syncope is a serious symptom, causes of which can range from benign conditions to life-threatening disorders. Long QT syndrome (LQTS) is one of the reasons for the occurrence of syncope. The main feature of LQTS is the prolongation of the QT interval, which causes polymorphic ventricular tachycardia and death. It can be inherited or caused by electrolyte abnormalities, drugs, herbal medicines, and inflammatory conditions. Although the mechanism of QT prolongation is common for most etiologies, there exists a considerable variability in individual responses.

  Case Report Top

A 31-year-old woman without a medical history of cardiac disease had been vaccinated with the second dose of the Pfizer-BioNTech vaccine on December 12, 2021. Thirty-six hours after the vaccination, she was brought to the emergency department with an attack of loss of consciousness. There was no family history of cardiac disease and/or cardiac death. On physical examination, her blood pressure was 120/80 mmHg, heart rate was 80/min, body temperature was 36.7°C, and oxygen saturation was 95%. Her initial biochemical tests revealed mildly elevated hs-Troponin T (86.41 ng/l), aspartate transaminase (34.5 IU/L), alanine transaminase (37.6 IU/L), white blood cell count (13.83 103/μL) with neutrophilia (8.47 103/μL), D-dimer (0.55 μg/FEU/mL), pro-BNP (211 ng/L), normal renal function tests (urea: 22.9 mg/dl, creatinine: 0.67 mg/dl), glucose (121 mg/dl), CRP (2 mg/dl), and serum electrolyte levels (calcium: 9.48 mg/dl, sodium: 135 mmol/L, potassium: 3.7 mmol/L, magnesium: 2.08 mg/dl, and chloride: 99 mmol/L). [Figure 1]a shows her first electrocardiogram (ECG) with sinus rhythm and a QTc interval of 690 ms. There was no evidence of myocardial ischemia. Her nasopharyngeal swab specimen for COVID-19 was negative, and she denied any contact with COVID-19-positive people. She did not have any sign and symptom of COVID-19 and any other infectious diseases. Her neurological examination was normal, and cranial diffusion-weighted magnetic resonance imaging (MRI) and computed tomography (CT) did not show any intracranial abnormality. The thorax CT did not reveal any pulmonary pathology, including pulmonary embolism and signs of COVID-19 pneumonia. Thorough questioning of her medical history revealed the use of herbal preparation. She said she had been taking those preparations for 2 days before hospital admission. After initial check in the emergency department, empirical oral propranolol treatment was started, and she was interned to the cardiac intensive care unit (ICU).
Figure 1: (a) First ECG recorded in the emergency department, (b) Torsades de pointes, (c) Control ECG of the patient after hospital discharge

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During her ICU monitorization, cardiac arrest due to torsades de pointes [Figure 1]b developed, which was immediately defibrillated, and intravenous lidocaine infusion was administered. Her control biochemical analysis was normal with respect to serum electrolyte levels. In order to exclude coronary artery disease, coronary angiography was performed, which showed a normal coronary artery anatomy. Echocardiography demonstrated a normal ejection fraction. We did not find any echocardiographic evidence of pericarditis and/or myocarditis. Cardiac MRI with a contrast enhancement revealed a normal result with an ejection fraction value of 60%. [Figure 2] depicts her cardiac MRI images. Her hs-Troponin T levels rose maximally up to 200.9 ng/l. The genetic test revealed autosomal dominant heterozygous KCNQ1 c.1097G>Ap. Arg366Gln variant. The diagnosis of type 1 LQTS was made, and ICD implantation was performed. The patient was discharged with oral propranolol and mexiletine therapy, and the outpatient clinic follow-up was recommended. Her QTc interval was decreased down to 520 ms. [Figure 1]c shows the ECG taken during the outpatient clinic visit.
Figure 2: Cardiac MRI images of the subject

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  Discussion Top

LQTS is a cardiac ion channel repolarization abnormality characterized by the lengthening of QT interval on surface ECG. Although it has been classified according to etiology as congenital or acquired, nowadays, it became more apparent that multilevel complex interactions of various factors working together in the same patient. Congenital LQTS is usually resulted from the genetic abnormality of cardiac ion channels involved in cardiac action potential formation. Its prevalence is estimated at about 1/2000 live births. Syncope is usually the first clinical symptom of congenital LQTS. Acquired LQTS is more common than the congenital form and conventionally regarded as an adverse reaction to drugs or a consequence of electrolyte abnormalities.

In our case, there was an association between syncope and BioNTech vaccination. Syncope occurred 36 h after vaccination. In addition, our patient's PCR test was negative, and during the initial evaluation, we did not find any other clinical finding suggesting an alternative diagnosis. Apart from QTc prolongation, her ECG did not show any other abnormalities. Her echocardiographic and cardiac MRI examinations were normal, which made the diagnosis of myocarditis unlikely. She had mild leukocytosis with neutrophilia. After thorough questioning, she admitted the use of some herbal medicines. The preparation she used contained Carthamus tinctorius, Petroselinum crispum, Carica papaya, Aloe barbadensis, Elettaria cardamomum, Hibiscus sabdariffa, Camellia sinensis, Malva sylvestris.

Herbal products have been used for centuries to treat a variety of diseases. Most people think that the use of such products is safer and has less adverse effects compared to prescribed drugs. Since herbal products are classified as food products, they do not undergo the same strict regulation as traditional medications. QT prolongation and syncope have been reported with the use of some herbal preparations such as Pueraria mirifica and ibogaine.[1],[2] During our literature review, we did not find any report of cardiac adverse effects of the product she used.

In recent years, clinical and preclinical studies have provided new evidence about the role of inflammation in cardiac electrophysiology. Inflammatory heart diseases, such as myocarditis, are commonly associated with QT prolongation and subsequent ventricular arrhythmias.[3] Patients with systemic autoimmune-inflammatory diseases have been shown to have a higher risk of sudden cardiac death compared to controls.[4] Furthermore, systemic inflammatory activity was positively correlated with QTc interval in healthy controls.[5] Elevated levels of tumor necrosis factor-alpha increase the action potential duration by reducing rapid, slow rectifier and transient outward potassium currents, whereas interleukin-1 (IL-1) and IL-6 enhance the activity of L-type calcium current.[6] Besides, the activation of the central sympathetic system leads to differences in the conductivity of calcium and potassium ions with the resultant increase in the action potential duration.[7]

COVID-19 m-RNA vaccines contain spike-encoding nucleoside-modified m-RNA. After entry to the cell, m-RNA induces synthesis of viral spike protein, which in turn initiates immune response and provides protection against virus. Nowadays, with an increase in the number of vaccinated people, acute myocarditis cases have been observed, especially in young adult males after COVID-19 m-RNA vaccination. Different pathogenic pathways have been implicated in the development of cardiac damage. Aberrant immune response to m-RNA and/or molecular mimicry between viral spike protein and cardiac antigens are among the possible mechanisms.[8] During our literature review, we found one case report which described QT interval prolongation after the first dose of AstraZeneca vaccination. QTc interval was found to be increased to 600 ms, which was returned to normal after magnesium infusion.[9] Several lines of evidence have suggested that immune-inflammatory activity may modulate the clinical expression of congenital LQTS by increasing the electrical instability of cardiomyocyte. Silva Marques et al. reported ventricular fibrillation episodes in a 23-year-old woman with congenital LQTS during influenza infection.[10] Likewise, Amin et al. reported two type 2 LQTS patients who had QTc interval prolongation, torsade de pointes, and ventricular fibrillation and syncope attacks during intermittent fever spikes.[11] Inflammatory response might increase the susceptibility of these patients to arrhythmias.

  Conclusion Top

COVID-19 vaccination elicits an immune response and provides a broad antiviral protection. During this sensitive period, the use of preparations with unknown side effects should be avoided. Patients should be informed about the use and potential side effects of these preparations.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Kashiwa A, Hosaka Y, Takahashi K, Ohno S, Wada Y, Makiyama T, et al. Pueraria mirifica, an estrogenic tropical herb, unveiled the severity of type 1 LQTS caused by KCNQ1-T587M. J Arrhythm 2021;37:1114-6.  Back to cited text no. 1
Steinberg C, Deyell MW. Cardiac arrest after ibogaine intoxication. J Arrhythm 2018;34:455-7.  Back to cited text no. 2
Ukena C, Mahfoud F, Kindermann I, Kandolf R, Kindermann M, Böhm M. Prognostic electrocardiographic parameters in patients with suspected myocarditis. Eur J Heart Fail 2011;13:398-405.  Back to cited text no. 3
Maradit-Kremers H, Crowson CS, Nicola PJ, Ballman KV, Roger VL, Jacobsen SJ, et al. Increased unrecognized coronary heart disease and sudden deaths in rheumatoid arthritis: A population-based cohort study. Arthritis Rheum 2005;52:402-11.  Back to cited text no. 4
Kazumi T, Kawaguchi A, Hirano T, Yoshino G. C-reactive protein in young, apparently healthy men: Associations with serum leptin, QTc interval, and high-density lipoprotein-cholesterol. Metabolism 2003;52:1113-6.  Back to cited text no. 5
Fernández-Velasco M, Ruiz-Hurtado G, Hurtado O, Moro MA, Delgado C. TNF-alpha downregulates transient outward potassium current in rat ventricular myocytes through iNOS overexpression and oxidant species generation. Am J Physiol Heart Circ Physiol 2007;293:H238-45.  Back to cited text no. 6
Martelli D, Yao ST, McKinley MJ, McAllen RM. Reflex control of inflammation by sympathetic nerves, not the vagus. J Physiol 2014;592:1677-86.  Back to cited text no. 7
Vojdani A, Kharrazian D. Potential antigenic cross-reactivity between SARS-CoV-2 and human tissue with a possible link to an increase in autoimmune diseases. Clin Immunol 2020;217:108480.  Back to cited text no. 8
Azdaki N, Farzad M. Long QT interval and syncope after a single dose of COVID-19 vaccination: A case report. Pan Afr Med J 2021;40:67.  Back to cited text no. 9
Silva Marques J, Veiga A, Nóbrega J, Correia MJ, de Sousa J. Electrical storm induced by H1N1 A influenza infection. Europace 2010;12:294-5.  Back to cited text no. 10
Amin AS, Herfst LJ, Delisle BP, Klemens CA, Rook MB, Bezzina CR, et al. Fever-induced QTc prolongation and ventricular arrhythmias in individuals with type 2 congenital long QT syndrome. J Clin Invest 2008;118:2552-61.  Back to cited text no. 11


  [Figure 1], [Figure 2]


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