<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.3 20210610//EN" "JATS-journalpublishing1-3.dtd">
<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="en"><front><journal-meta><journal-id journal-id-type="publisher-id">rpcardio</journal-id><journal-title-group><journal-title xml:lang="en">Rational Pharmacotherapy in Cardiology</journal-title><trans-title-group xml:lang="ru"><trans-title>Рациональная Фармакотерапия в Кардиологии</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">1819-6446</issn><issn pub-type="epub">2225-3653</issn><publisher><publisher-name>«SILICEA-POLIGRAF» LLC</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.20996/1819-6446-2021-10-18</article-id><article-id custom-type="elpub" pub-id-type="custom">rpcardio-2584</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>NOTES FROM PRACTICE</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>КЛИНИЧЕСКИЙ ОПЫТ</subject></subj-group></article-categories><title-group><article-title>Long-term Results of Drug and Interventional Treatment in Patients with Morphologically Verified Idiopathic Arrhythmias</article-title><trans-title-group xml:lang="ru"><trans-title>Отдаленные результаты медикаментозного и интервенционного лечения у пациентов с морфологически верифицированной природой идиопатических аритмий</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-5253-793X</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Благова</surname><given-names>О. В.</given-names></name><name name-style="western" xml:lang="en"><surname>Blagova</surname><given-names>O. V.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Благова Ольга Владимировна</p></bio><bio xml:lang="en"><p>Olga V. Blagova</p></bio><email xlink:type="simple">blagovao@mail.ru</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-9587-6707</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Недоступ</surname><given-names>А. В.</given-names></name><name name-style="western" xml:lang="en"><surname>Nedostup</surname><given-names>A. V.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Недоступ Александр Викторович</p></bio><bio xml:lang="en"><p>Alexander V. Nedostup</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-1107-3753</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Коган</surname><given-names>Е. А.</given-names></name><name name-style="western" xml:lang="en"><surname>Kogan</surname><given-names>E. A.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Коган Евгения Александровна</p></bio><bio xml:lang="en"><p>Evgeniya A. Kogan</p></bio><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>Первый Московский государственный медицинский университет им. И.М. Сеченова (Сеченовский Университет)</institution><country>Россия</country></aff><aff xml:lang="en"><institution>I.M. Sechenov First Moscow State Medical University (Sechenov University)</institution><country>Russian Federation</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2021</year></pub-date><pub-date pub-type="epub"><day>03</day><month>11</month><year>2021</year></pub-date><volume>17</volume><issue>5</issue><fpage>729</fpage><lpage>737</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Blagova O.V., Nedostup A.V., Kogan E.A., 2021</copyright-statement><copyright-year>2021</copyright-year><copyright-holder xml:lang="ru">Благова О.В., Недоступ А.В., Коган Е.А.</copyright-holder><copyright-holder xml:lang="en">Blagova O.V., Nedostup A.V., Kogan E.A.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://www.rpcardio.online/jour/article/view/2584">https://www.rpcardio.online/jour/article/view/2584</self-uri><abstract><sec><title>Aim</title><p>Aim. To study the late results of medical and interventional treatment in patients with morphologically verified nature of idiopathic arrhythmias.</p></sec><sec><title>Methods</title><p>Methods. The prospective study included 20 patients (mean age 43.1±11.3 years, 10 female) with atrial fibrillation (AF), supraventricular and ventricular extrasystole, supraventricular and ventricular tachycardia, conduction disturbance without structural heart changes. In addition to the standard examination, the level of anti-heart antibodies was initially determined; endomyocardial biopsy (EMB) of the right ventricle with PCR study for the viral genome; DNA diagnostics (n=4), coronary angioraphy (n=6), skin biopsy (n=1) were performed. The median follow-up was 134 [128; 138] months.</p></sec><sec><title>Results</title><p>Results. By EMB in the initial examination were diagnosed: active (n=8)/borderline (n=3) infectious immune myocarditis; parvovirus-positive endomyocarditis (n=1); undifferentiated vasculitis (n=2); myocardial vasculitis (n=1); Fabry disease (n=1); arrhythmogenic right ventricular dysplasia (n=1); unspecified cardiomyopathy (n=2). Anti-heart antibodies were the most important in myocarditis diagnosis and monitoring. All patients with myocarditis/vasculitis (n=15) received its basic therapy: acyclovir (n=10); immunoglobulin G 10-12.5 g (n=2); hydroxychloroquine 200 mg/day (n=15); glucocorticoids (n=14); azathioprine 150 mg/day (n=2). The late results were evaluated in all patients with myocarditis. Initially, in 62.5% of patients a resistance of AF to all antiarrhythmic drugs was noted. After treatment the average frequency of AF paroxysms decreased (from 8 [5; 8] to 3 [1,25; 7,75] points). By the end of the follow-up, six patients underwent radiofrequency ablation (RFA) for AF, the full effect was achieved once. All patients without RFA have AF partially or completely resistant to drugs. Two patients (without RFA) died from ischemic stroke/ pulmonary embolism.</p></sec><sec><title>Conclusion</title><p>Conclusion. Using EMB the causes of idiopathic arrhythmias (mainly AF) were diagnosed: immune inflammatory diseases in 75% and genetic in 25% of patients. As a result of complex treatment, the general burden of arrhythmias has decreased. But the presence of myocarditis and primary cardiomyopathy, without reducing the cardiac contractility and dilatation, does not allow achieving a stable antiarrhythmic effect. Lethality for 11 years was 10%. The causes of death were thromboembolic complications.</p></sec></abstract><trans-abstract xml:lang="ru"><sec><title>Цель</title><p>Цель. Изучить отдаленные результаты медикаментозного и интервенционного лечения у больных с морфологически верифицированной природой идиопатических аритмий.</p></sec><sec><title>Материал и методы</title><p>Материал и методы. В проспективное исследование включены 20 больных (средний возраст 43,1±11,3 лет, 10 женщин) с фибрилляцией предсердий (ФП), наджелудочковой и желудочковой экстрасистолией, наджелудочковой и желудочковой тахикардией, нарушениями проводимости без структурных изменений сердца. Дополнительно к стандартному обследованию исходно проведены определение уровня антикардиальных антител, эндомиокардиальная биопсия (ЭМБ) правого желудочка с исследованием на вирусный геном методом полимеразной цепной реакции; по показаниям выполнены ДНК-диагностика (n=4), коронарография (n=6), биопсия кожи (n=1). С учетом верифицированной природы аритмий назначена дифференцированная терапия, эффективность комплексного лечения оценена в отдаленные сроки. Медиана длительности наблюдения составила 134 [128; 138] мес.</p></sec><sec><title>Результаты</title><p>Результаты: При ЭМБ в рамках исходного обследования были диагностированы: активный (n=8)/пограничный (n=3) инфекционно-иммунный миокардит; парвовирус-позитивный эндомиокардит (n=1); недифференцированный васкулит (n=2); миокардиальный васкулит (n=1); болезнь Фабри (n=1); аритмогенная дисплазия правого желудочка (n=1); неуточненная кардиомиопатия (n=2). Наибольшей значимостью в диагностике миокардита обладали антикардиальные антитела, динамика которых отслеживалась в процессе терапии. Всем больным с миокардитом/васкулитом (n=15) проводилась базисная терапия: ацикловир (n=10), внутривенный иммуноглобулин 10-12,5 г (n=2), гидроксихлорохин 200 мг/сут (n=15), глюкокортикоиды (n=14), азатиоприн 150 мг/сут (n=2). Отдаленные результаты прослежены у всех больных с миокардитом. Исходно у 62,5% отмечалась резистентность ФП к антиаритмическим средствам, на фоне лечения средняя частота пароксизмов ФП снизилась с 8 [5; 8] до 3 [1,25; 7,75] баллов. К окончанию срока наблюдения радиочастотная аблация (РЧА) по поводу ФП выполнена 6 больным, полный эффект достигнут однократно. У всех больных без РЧА сохраняется ФП, частично или полностью устойчивая к антиаритмическим средствам. Два пациента (без РЧА) умерли от ишемического инсульта/тромбоэмболии легочной артерии.</p></sec><sec><title>Заключение</title><p>Заключение. С помощью ЭМБ в качестве причины идиопатических аритмий (преимущественно, ФП) диагностированы иммунно-воспалительные заболевания у 75% и генетические – у 25% пациентов. В целом бремя аритмии в результате комплексного лечения уменьшилось, однако наличие миокардита и первичных кардиомиопатий, не приводя к снижению сократимости и дилатации полостей сердца, не позволило достичь стойкого аритмического эффекта. Летальность за 11 лет составила 10%, и была обусловлена тромбоэмболическими осложнениями.</p></sec></trans-abstract><kwd-group xml:lang="ru"><kwd>идиопатические аритмии</kwd><kwd>фибрилляция предсердий</kwd><kwd>экстрасистолия</kwd><kwd>эндомиокардиальная биопсия</kwd><kwd>миокардит</kwd><kwd>иммуносупрессивная терапия</kwd><kwd>радиочастотная аблация</kwd></kwd-group><kwd-group xml:lang="en"><kwd>idiopathic arrhythmias</kwd><kwd>atrial fibrillation</kwd><kwd>extrasystole</kwd><kwd>endomyocardial biopsy</kwd><kwd>myocarditis</kwd><kwd>immunosuppressive therapy</kwd><kwd>radiofrequency ablation</kwd></kwd-group><funding-group><funding-statement xml:lang="ru">Исследование проведено при поддержке Сеченовского Университета</funding-statement><funding-statement xml:lang="en">The study was performed with the support of the Sechenov University</funding-statement></funding-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Kirchhof P, Benussi S, Kotecha D, et al.; ESC Scientific Document Group. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J. 2016;37(38):2893-962. DOI:10.1093/eurheartj/ehw210.</mixed-citation><mixed-citation xml:lang="en">Kirchhof P, Benussi S, Kotecha D, et al.; ESC Scientific Document Group. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J. 2016;37(38):2893-962. DOI:10.1093/eurheartj/ehw210.</mixed-citation></citation-alternatives></ref><ref id="cit2"><label>2</label><citation-alternatives><mixed-citation xml:lang="ru">Priori SG, Blomström-Lundqvist C, Mazzanti A, et al.; ESC Scientific Document Group. 2015 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: The Task Force for the Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death of the European Society of Cardiology (ESC). Endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC). Eur Heart J. 2015;36(41):2793-867. DOI:10.1093/eurheartj/ehv316.</mixed-citation><mixed-citation xml:lang="en">Priori SG, Blomström-Lundqvist C, Mazzanti A, et al.; ESC Scientific Document Group. 2015 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: The Task Force for the Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death of the European Society of Cardiology (ESC). Endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC). Eur Heart J. 2015;36(41):2793-867. DOI:10.1093/eurheartj/ehv316.</mixed-citation></citation-alternatives></ref><ref id="cit3"><label>3</label><citation-alternatives><mixed-citation xml:lang="ru">Gorenek B, Fisher JD, Kudaiberdieva G, et al. Premature ventricular complexes: diagnostic and therapeutic considerations in clinical practice: A state-of-the-art review by the American College of Cardiology Electrophysiology Council. J Interv Card Electrophysiol. 2020;57(1):5-26. DOI:10.1007/s10840-019-00655-3.</mixed-citation><mixed-citation xml:lang="en">Gorenek B, Fisher JD, Kudaiberdieva G, et al. Premature ventricular complexes: diagnostic and therapeutic considerations in clinical practice: A state-of-the-art review by the American College of Cardiology Electrophysiology Council. J Interv Card Electrophysiol. 2020;57(1):5-26. DOI:10.1007/s10840-019-00655-3.</mixed-citation></citation-alternatives></ref><ref id="cit4"><label>4</label><citation-alternatives><mixed-citation xml:lang="ru">Caforio AL, Pankuweit S, Arbustini E, et al.; European Society of Cardiology Working Group on Myocardial and Pericardial Diseases. Current state of knowledge on aetiology, diagnosis, management, and therapy of myocarditis: a position statement of the European Society of Cardiology Working Group on Myocardial and Pericardial Diseases. Eur Heart J. 2013;34(33):2636-48. DOI:10.1093/eurheartj/eht210.</mixed-citation><mixed-citation xml:lang="en">Caforio AL, Pankuweit S, Arbustini E, et al.; European Society of Cardiology Working Group on Myocardial and Pericardial Diseases. Current state of knowledge on aetiology, diagnosis, management, and therapy of myocarditis: a position statement of the European Society of Cardiology Working Group on Myocardial and Pericardial Diseases. Eur Heart J. 2013;34(33):2636-48. DOI:10.1093/eurheartj/eht210.</mixed-citation></citation-alternatives></ref><ref id="cit5"><label>5</label><citation-alternatives><mixed-citation xml:lang="ru">Благова О.В., Недоступ А.В., Коган Е.А. и др. «Идиопатические» аритмии как симптомлатентной болезни сердца: опыт постановки нозологического диагноза с помощью эндомиокардиальной биопсии. Кардиология и Сердечно-Сосудистая Хирургия. 2010;3(1):56-63.</mixed-citation><mixed-citation xml:lang="en">Blagova OV, Nedostup AV, Kogan EA, et al. «Idiopathic» arrhythmias as a symptom of latent cardiac disease: nosologic diagnostics using endomyocardial biopsy. Kardiologiyai Serdechno-Sosudistaya Hirurgiya. 2010;3(1):56-63 (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit6"><label>6</label><citation-alternatives><mixed-citation xml:lang="ru">Благова О.В., Недоступ А.В., Коган Е.А., и др. Возможности биопсии миокарда в верификации диагноза миокардита у больных с «идиопатическими» аритмиями. Кардиология. 2013;53(11):21-30.</mixed-citation><mixed-citation xml:lang="en">Blagova OV, Nedostup AV, Kogan EA, et al. [Possibilities myocardial biopsy in the diagnosis of myocarditis verification in patients with idiopathic arrhythmias]. Kardiologiia. 2013;53(11):21-30 (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit7"><label>7</label><citation-alternatives><mixed-citation xml:lang="ru">Frustaci A, Chimenti C, Bellocci F, et al. Histological substrate of atrial biopsies in patients with lone atrial fibrillation. Circulation.1997;96(4):1180-4. DOI:10.1161/01.cir.96.4.1180.</mixed-citation><mixed-citation xml:lang="en">Frustaci A, Chimenti C, Bellocci F, et al. Histological substrate of atrial biopsies in patients with lone atrial fibrillation. Circulation.1997;96(4):1180-4. DOI:10.1161/01.cir.96.4.1180.</mixed-citation></citation-alternatives></ref><ref id="cit8"><label>8</label><citation-alternatives><mixed-citation xml:lang="ru">Баталов Р.Е., Роговская Ю.В., Рябов В.В., и др. Идиопатическая форма фибрилляции предсердий, воспаление и клинические результаты радиочастотной аблации. Российский Кардиологический Журнал. 2014;12(116):7-12. DOI:10.15829/1560-4071-2014-12-7-12.</mixed-citation><mixed-citation xml:lang="en">Batalov RE, Rogovskaya YV, Ryabov VV, et al. Idiopathic form of atrial fibrillation, inflammation and clinical results of radiofrequency ablation. Russian Journal of Cardiology. 2014;(12):7-12 (In Russ.) DOI:10.15829/1560-4071-2014-12-7-12.</mixed-citation></citation-alternatives></ref><ref id="cit9"><label>9</label><citation-alternatives><mixed-citation xml:lang="ru">Грохотова В.В., Татарский Р.Б., Лебедев Д.С., и др. Катетерная аблация некоронарогенных желудочковых тахиаритмий – ранняя и отдаленная эффективность процедуры в зависимости от этиологии нарушений ритма. Сердце. 2014;13(1):3-10.</mixed-citation><mixed-citation xml:lang="en">Grohotova VV, Tatarskij RB, Lebedev DS, et al. Catheter ablation of non-coronarogenic ventricular tachyarrhythmias: an early and long-term effectiveness of the procedure depending on the etiology of rhythm disturbances. Serdce. 2014;13(1):3-10 (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit10"><label>10</label><citation-alternatives><mixed-citation xml:lang="ru">Недоступ А.В., Благова О.В., Коган Е.А., и др. Миокардиальный васкулит: нозологическая принадлежность, клиническая картина, диагностика, лечение. Кардиология и Сердечно-Сосудистая Хирургия. 2011;4(3):85-92.</mixed-citation><mixed-citation xml:lang="en">Nedostup AV, Blagova OV, Kogan EA, et al. Myocardial vasculitis: nosological affiliation, clinical presentation, diagnosis, treatment. Kardiologiyaiserdechno-sosudnstayahirurgiya, 2011; 4(3): 85-92 (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit11"><label>11</label><citation-alternatives><mixed-citation xml:lang="ru">Сафиуллина А.А., Ускач Т.М., Жиров И.В., и др. Миокардит предсердий у пациентки с артериитом Такаясу. Терапевтический Архив. 2019;91(6):103-9. DOI:10.26442/00403660.2019.06.000047.</mixed-citation><mixed-citation xml:lang="en">Safiullina AA, Uskach TM, Zhirov IV, et al. Atrial myocarditis in a patient with Takayasu arteritis. Ter Arkhiv. 2019;91(6):103-9 (In Russ.) DOI:10.26442/00403660.2019.06.000047.</mixed-citation></citation-alternatives></ref><ref id="cit12"><label>12</label><citation-alternatives><mixed-citation xml:lang="ru">Благова О.В., Недоступ А.В., Коган Е.А. Глава 3. Синдром нарушений ритма и проводимости сердца («идиопатические» аритмии). В: Благова О.В., Недоступ А.В., Коган Е.А. Болезни миокарда и перикарда: от синдромов к диагнозу и лечению. М.: ГЭОТАР-Медиа; 2019. с. 83-202.</mixed-citation><mixed-citation xml:lang="en">Blagova OV, Nedostup AV, Kogan EA. Chapter 3. Syndrome of rhythm and heart conductivity disorders ("idiopathic" arrhythmias). V. В: Blagova OV, Nedostup AV, Kogan EA. Myocardial and pericardial diseases: from syndromes to diagnosis and treatment. Moscow: GEOTAR-Media; 2019. p. 83-202 (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit13"><label>13</label><citation-alternatives><mixed-citation xml:lang="ru">Killu AM, Mehta N, Zheng Q, et al. Endomyocardial biopsy at the time of ablation or device implantation. J Interv Card Electrophysiol. 2018;52(2):163-9. DOI:10.1007/s10840-018-0358-7.</mixed-citation><mixed-citation xml:lang="en">Killu AM, Mehta N, Zheng Q, et al. Endomyocardial biopsy at the time of ablation or device implantation. J Interv Card Electrophysiol. 2018;52(2):163-9. DOI:10.1007/s10840-018-0358-7.</mixed-citation></citation-alternatives></ref><ref id="cit14"><label>14</label><citation-alternatives><mixed-citation xml:lang="ru">Pavlicek V, Kindermann I, Wintrich J, et al. Ventricular arrhythmias and myocardial inflammation: Long-term follow-up of patients with suspected myocarditis. Int J Cardiol. 2019;274:132-7. DOI:10.1016/j.ijcard.2018.07.142.</mixed-citation><mixed-citation xml:lang="en">Pavlicek V, Kindermann I, Wintrich J, et al. Ventricular arrhythmias and myocardial inflammation: Long-term follow-up of patients with suspected myocarditis. Int J Cardiol. 2019;274:132-7. DOI:10.1016/j.ijcard.2018.07.142.</mixed-citation></citation-alternatives></ref><ref id="cit15"><label>15</label><citation-alternatives><mixed-citation xml:lang="ru">Vasichkina E, Poghosyan H, Mitrofanova L, et al. Right ventricular endomyocardial biopsy in children and adolescents with drug-refractory arrhythmia. Cardiol Young. 2017;27(3):435-42. DOI:10.1017/S1047951116000688.</mixed-citation><mixed-citation xml:lang="en">Vasichkina E, Poghosyan H, Mitrofanova L, et al. Right ventricular endomyocardial biopsy in children and adolescents with drug-refractory arrhythmia. Cardiol Young. 2017;27(3):435-42. DOI:10.1017/S1047951116000688.</mixed-citation></citation-alternatives></ref><ref id="cit16"><label>16</label><citation-alternatives><mixed-citation xml:lang="ru">Vassalini M, Verzeletti A, Restori M, De Ferrari F. An autopsy study of sudden cardiac death in persons aged 1-40 years in Brescia (Italy). J Cardiovasc Med (Hagerstown). 2016;17(6):446-53. DOI:10.2459/JCM.0000000000000234.</mixed-citation><mixed-citation xml:lang="en">Vassalini M, Verzeletti A, Restori M, De Ferrari F. An autopsy study of sudden cardiac death in persons aged 1-40 years in Brescia (Italy). J Cardiovasc Med (Hagerstown). 2016;17(6):446-53. DOI:10.2459/JCM.0000000000000234.</mixed-citation></citation-alternatives></ref><ref id="cit17"><label>17</label><citation-alternatives><mixed-citation xml:lang="ru">Frustaci A, Caldarulo M, Buffon A, et al. Cardiac biopsy in patients with "primary" atrial fibrillation. Histologic evidence of occult myocardial diseases. Chest. 1991;100(2):303-6. DOI:10.1378/chest.100.2.303.</mixed-citation><mixed-citation xml:lang="en">Frustaci A, Caldarulo M, Buffon A, et al. Cardiac biopsy in patients with "primary" atrial fibrillation. Histologic evidence of occult myocardial diseases. Chest. 1991;100(2):303-6. DOI:10.1378/chest.100.2.303.</mixed-citation></citation-alternatives></ref><ref id="cit18"><label>18</label><citation-alternatives><mixed-citation xml:lang="ru">Frustaci A, Verardo R, Grande C, et al. Arrhythmic Phenotype of Myocarditis Sustained by a Prominent Infiltration of Conduction Tissue. Circ Cardiovasc Imaging. 2019;12(8):e009448. DOI:10.1161/CIRCIMAGING.119.009448.</mixed-citation><mixed-citation xml:lang="en">Frustaci A, Verardo R, Grande C, et al. Arrhythmic Phenotype of Myocarditis Sustained by a Prominent Infiltration of Conduction Tissue. Circ Cardiovasc Imaging. 2019;12(8):e009448. DOI:10.1161/CIRCIMAGING.119.009448.</mixed-citation></citation-alternatives></ref><ref id="cit19"><label>19</label><citation-alternatives><mixed-citation xml:lang="ru">Andreini D, Dello Russo A, Pontone G, et al. CMR for Identifying the Substrate of Ventricular Arrhythmia in Patients With Normal Echocardiography. JACC Cardiovasc Imaging. 2020;13(2 Pt 1):410-21. DOI:10.1016/j.jcmg.2019.04.023.</mixed-citation><mixed-citation xml:lang="en">Andreini D, Dello Russo A, Pontone G, et al. CMR for Identifying the Substrate of Ventricular Arrhythmia in Patients With Normal Echocardiography. JACC Cardiovasc Imaging. 2020;13(2 Pt 1):410-21. DOI:10.1016/j.jcmg.2019.04.023.</mixed-citation></citation-alternatives></ref><ref id="cit20"><label>20</label><citation-alternatives><mixed-citation xml:lang="ru">Lakkireddy D, Turagam MK, Yarlagadda B, et al. Myocarditis Causing Premature Ventricular Contractions: Insights From the MAVERIC Registry. Circ Arrhythm Electrophysiol. 2019;12(12):e007520. DOI:10.1161/CIRCEP.119.007520.</mixed-citation><mixed-citation xml:lang="en">Lakkireddy D, Turagam MK, Yarlagadda B, et al. Myocarditis Causing Premature Ventricular Contractions: Insights From the MAVERIC Registry. Circ Arrhythm Electrophysiol. 2019;12(12):e007520. DOI:10.1161/CIRCEP.119.007520.</mixed-citation></citation-alternatives></ref><ref id="cit21"><label>21</label><citation-alternatives><mixed-citation xml:lang="ru">Goette A, Kalman JM, Aguinaga L, et al. EHRA/HRS/APHRS/SOLAECE expert consensus on atrial cardiomyopathies: Definition, characterization, and clinical implication. Heart Rhythm. 2017;14(1):e3-e40. DOI:10.1016/j.hrthm.2016.05.028.</mixed-citation><mixed-citation xml:lang="en">Goette A, Kalman JM, Aguinaga L, et al. EHRA/HRS/APHRS/SOLAECE expert consensus on atrial cardiomyopathies: Definition, characterization, and clinical implication. Heart Rhythm. 2017;14(1):e3-e40. DOI:10.1016/j.hrthm.2016.05.028.</mixed-citation></citation-alternatives></ref></ref-list><fn-group><fn fn-type="conflict"><p>The authors declare that there are no conflicts of interest present.</p></fn></fn-group></back></article>
