A Young Woman with Recurrent Atrial Fibrillation

Clinical Review & Education

JAMA Cardiology Clinical Challenge A Young Woman With Recurrent Atrial Fibrillation

Ashish H. Shah, MD, MD-Research, MRCP; Diego Delgado, MD, MSc; S. Lucy Roche, MB, ChB, MRCPCH, MD-Research

A Electrocardiogram B Transthoracic echocardiogram

Figure 1. A, Electrocardiogram demonstrating prominent and biphasic P-wave and ST-T segment abnormalities. B, Four-chamber view of transthoracic echocardiogram. aVF indicates augmented vector foot; aVL indicates augmented vector left arm; and aVR indicates augmented vector right arm.

An 18-year-old woman was referred to our adult congenital heart disease center for investigation of chest pain and atrial fibrillation (AF). She had reported intermittent chest pain WHAT WOULD YOU DO NEXT? without precipitating factors since the age of 8 years. This had been evaluated by a pediatric cardiologist and was felt to be noncardiac in nature. Persistence of pain and associ- A. Start diuretic, β-blocker, and ated distress eventually prompted referral to adolescent psychiatry. At age 17 years she angiotensin-converting enzyme experienced 3 episodes of AF, each treated with direct-current cardioversion. An electro- inhibitor physiologist commenced treatment with flecainide and warfarin. Warfarin was stopped after 6 months arrhythmia-free. At our clinic, she reported intermittent, nonexertional, atypi- B. Start diuretic, implant cal chest pain and exertional dyspnea with a gradual decline in exercise capacity,confirmed cardioverter defibrillator, by cardiopulmonary exercise test (oxygen consumption peak 65% predicted). Electrocar- and evaluate for cardiac diogram demonstrated sinus rhythm, a prominent biphasic p-wave, and occasionally pro- transplantation longed interval between the beginning of the electrocardiographic wave representing ventricular depolarization and the end of the T-wave (QT,QTcup to 594 milliseconds) (Figure 1A). Transthoracic echocardiogram revealed normal ventricular dimensions and systolic func- C. Discontinue flecainide, start tion with biatrial dilatation (left > right) (Figure 1B), dilated pulmonary veins, and abnor- amiodarone and warfarin mal diastolic filling. Cardiac magnetic resonance imaging with gadolinium confirmed dilatation of the atria, pulmonary veins, and inferior vena cava with normal ventricular size, mass, D. Proceed with electrophysiology and ejection fraction without enhancement suggestive of infarction, inflammation, or fi- study and AF ablation brosis. Pericardium was of normal thickness.

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Diagnosis 100 S S S S S S Idiopathic restrictive cardiomyopathy (iRCM) 90 RV 80 LV 70 What to Do Next 60 50 B. Start diuretic, implant cardioverter defibrillator, and evaluate for S S S S S S 40 cardiac transplantation 30 EDP EDP EDP EDP EDP EDP 20 10 D EDP D D EDP D EDP D EDP D EDP Discussion 0 D D EDP D D D D Resp The key to this diagnosis was recognizing the pattern of progres- SPO2 sive, nonspecific cardiac symptoms, abnormal electrocardiogram, and echocardiographic hallmarks of restrictive ventricular filling with Figure 2. Simultaneous left and right ventricular pressure tracing. EDP indicates normal systolic function. Cardiac catheterization confirmed left ven- end-diastolic pressure; LV indicates left ventricle; Resp indicates respiration; RV tricular end diastolic pressure of greater than 20 mm Hg (Figure 2) indicates right ventricle; and SpO2 indicates oxygen saturation by pulse exometer. and cardiac output of 1.5 L/min/m2. Atrial fibrillation is very unusual 2 in children and young adults and always warrants investigation for better than those with pure RCM. Elevated pulmonary artery pres- underlying pathology.This rare form of cardiomyopathy usually pre- sures and pulmonary vascular resistance are frequent, and assess- sents in childhood and has poor prognosis.1,2 Without heart trans- ment for transplantation should be initiated prior to hemodynamic 5 plantation, few patients survive into adult life. Deaths result from deterioration. heart failure, thromboembolic events, and arrhythmia.1,2 In 2013, the World Heart Federation endorsed the new MOGES Patient Outcome classification system: Morpho-functional, Organ involvement, Ge- The patient obtained limited benefit from diuretics. Owing to the netic/familial inheritance, Etiology, and heart failure Stage.3 By this risk of thromboembolism, her estrogen-containing contraceptive

nomenclature, our patient would be: MR,OH,GN,EG-Neg, and SD-3. was switched to a progesterone-only formulation and warfarin Readers are likely more familiar with phenotypical classification, recommenced. An implant cardioverter defibrillator was where RCM is characterized by normal or decreased volume of both implanted to mitigate the risk of sudden cardiac death. Genetic ventricles associated with biatrial enlargement, normal left ven- screening for cardiomyopathy and long QT were negative. Over tricular wall thickness, impaired ventricular filling with restrictive the following year, the patient reported progressive decline in physiology, and normal (or near normal) systolic function. Dys- exercise tolerance, confirmed by further reduction in peak oxygen pnea, exercise intolerance, fatigue, palpitations, and syncope are fre- consumption and a fall of blood pressure on exertion. Pulmonary quentpresentingfeatures.Physicalexaminationisoftennormal.Ech- artery pressures remained stable on serial hemodynamic assess- ocardiography often demonstrates marked biatrial enlargement with ment. Seventeen months after initial presentation, she underwent normal ventricular dimensions and systolic function. Cardiac cath- successful cardiac transplant. As expected, examination of the eterization typically reveals elevated left ventricular end diastolic explanted heart demonstrated biatrial dilatation, variable degree pressure, capillary wedge, and atrial pressures along with reduced of myocyte hypertrophy, interstitial fibrosis, and myofibril disarray. cardiac output.1 Cardiac biopsy is considered unnecessary for diag- After cardiac transplant, her exercise capacity improved and she nosis. Genetic pleiotropy, where 1 gene influences 2 or more phe- recommenced university to complete her studies. We present an notypically different traits, is common in patients with RCM and pa- interesting and unusual case of iRCM recognized in young adult- tients may develop hypertrophy with time.4 Transplant-free survival hood. Despite its rarity, it is imperative adult cardiologists are is usually limited to a few years.5 However, most series include out- aware of this condition because it is associated with a grave prog- liers (such as our patient) and those with an overlapping RCM/ nosis and rapid decline, with early referral for transplant the only hypertrophic cardiomyopathy phenotype may do somewhat viable treatment option.

ARTICLE INFORMATION Conflict of Interest Disclosures: All authors have 3. Arbustini E, Narula N, Dec GW, et al. Author Affiliations: Toronto Congenital Cardiac completed and submitted the ICMJE Form for The MOGE(S) classification for a phenotype- Centre for Adults, Peter Munk Cardiac Centre, Disclosure of Potential Conflicts of Interest and genotype nomenclature of cardiomyopathy. JAm Toronto General Hospital, Toronto, Ontario, Canada none were reported. Coll Cardiol. 2013;62(22):2046-2072. (Shah, Roche); Ted Rogers Centre of Excellence in Additional Contributions: We thank the patient for 4. Tariq M, Ware SM. Importance of genetic Heart Function, Peter Munk Cardiac Centre, granting permission to publish this information. evaluation and testing in pediatric cardiomyopathy. Toronto General Hospital, Toronto, Ontario, Canada World J Cardiol. 2014;6(11):1156-1165. (Delgado). REFERENCES 5. Fenton MJ, Chubb H, McMahon AM, Rees P, Corresponding Author: S. Lucy Roche, MB, ChB, 1. Cetta F, O’Leary PW, Seward JB, Driscoll DJ. Elliott MJ, Burch M. Heart and heart-lung MRCPCH, MD-Research, Toronto Congenital Idiopathic restrictive cardiomyopathy in childhood. transplantation for idiopathic restrictive Cardiac Centre for Adults, Peter Munk Cardiac Mayo Clin Proc. 1995;70(7):634-640. cardiomyopathy in children. Heart. 2006;92(1): Center, Toronto General Hospital, 2. Webber SA, Lipshultz SE, Sleeper LA, et al; 85-89. 585 University Ave, Toronto, ON M5G 2N2, Pediatric Cardiomyopathy Registry Investigators. Canada ([email protected]). Outcomes of restrictive cardiomyopathy in Published Online: June 22, 2016. childhood and the influence of phenotype. doi:10.1001/jamacardio.2016.0725. Circulation. 2012;126(10):1237-1244.

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