Discussion

Sports are associated with an increased risk for sudden death in athletes who are affected by cardiovascular conditions predisposing to life-threatening ventricular arrhythmia during exercise. Cardiac screening with non-invasive examinations is a very important tool for identification of possible pathology and for the characterisation of electrical instability. Rhythm and conduction abnormalities are the first cardiovascular causes of sports disqualification. ^{Reference Steriotis3} Cardiac tumours are a rare cause of arrhythmias in clinical practice. ^{Reference Shenthar2}

The most common origins of PVC are the ventricular outflow tracts. ^{Reference Oomen, Dekker and Meijer4} However, on cardiac screening for competitive sports, inferior originated PVC was detected in our patient. Like these atypical originated PVCs when detected, it should be kept in mind that there may be a structural anomaly like mass. In such cases, examination with echocardiography will be helpful in recognising structural anomalies and if necessary, advanced investigation methods such as CT or MRI can be used. Our patient’s, who was detected mass with echocardiography, MRI results gave findings in favour to fibroma.

Primary cardiac tumours are rare. 75% of cardiac tumours are benign and have a reported incidence of 0.03–0.32% ^{Reference Rajput, Bishop and Limaiem5} Cardiac fibromas found in one quarter of cases, amongst tumours identified at postmortem in hearts of children between 1 and 15 years ^{Reference Bédard, Becker and Gatzoulis6} Cardiac fibromas are the second most common benign cardiac tumours in the children ^{Reference Rajput, Bishop and Limaiem5} which arise from heart fibroblasts. ^{Reference Zheng7} These tumours are mostly located in the left ventricular free wall or interventricular septum and less frequently in the right ventricle or atrial free wall. ^{Reference Maleszewski and Burke8} In our patient, it appeared as a mass extending to the lateral wall of the left ventricle, which is the most common localisation for fibromas. Clinical symptoms and signs of the tumour are chest pain, cardiomegaly, arrhythmias, and even sudden mortality. In some cases, cardiac tumours are asymptomatic as in our patient. Due to the non-specific nature of symptoms, many are diagnosed following an echocardiographic finding, ^{Reference Cordinhã1} as in the case presented.

Cardiac tumours are associated with wide variety of arrhythmias depending on the tumour type and the location of involvement. The arrhythmias resulting from cardiac tumours include atrial ectopics, atrial flutter, atrial fibrillation, Wolff–Parkinson–White syndrome, ventricular ectopics, ventricular tachycardia, torsades de pointes, atrioventricular blocks, and sudden death. The mechanism can be re-entry or triggered automaticity. In fibroma, clinically significant arrhythmias are more common than in any other cardiac tumours. Some form of cardiac arrhythmia is present in 64% of cases. Very frequent monomorphic PVCs and couplet PVCs were observed in our patient as well. Ventricular tachycardia and sudden death may occur in up to 30% of patients with cardiac fibroma. ^{Reference Shentar9}

Two-dimensional transthoracic echocardiography provides information in terms of mass localisation and size. Two-dimensional transthoracic echocardiography may underestimate the size of cardiac masses; the accurate size is possible only if a plane chances to encompass the complete long axis of the mass, but that may not occur especially the mass is mobile. With 3D echocardiography, the whole extent of mass is contained in the data and that would provide more reliable measurements. ^{Reference Asch, Biegansky, Panza and Weissman10} However, in our patient, there is no significant difference between two-dimensional transthoracic echocardiography and three-dimensional transthoracic echocardiography measurements. This may be due to immobility of the mass. In literature, 3D transoesophageal echocardiography was utilised to define the morphologic and spatial characteristics of cardiac and paracardial tumours in vivo, establish their relationships with adjacent structures, and assess the haemodynamic effects. ^{Reference Zavaleta, Morales, Vargas-Barro, Keirns and Fraustro11}

Using advanced imaging techniques such as CT and MRI helps to determine the characteristics of the cardiac mass. Cardiac CT often demonstrates partial calcifications in fibromas. ^{Reference Yılmaz, Demir, Önur, Yılbazbayhan and Dursun12} We preferred MRI for further examination in our patient because of superior tissue contrast, versatility in image planes ^{Reference Zavaleta, Morales, Vargas-Barro, Keirns and Fraustro11} , and radiation free. MRI is an important imaging technique in the evaluation of cardiac tumours. T1-weighted, T2-weighted, and gadolinium-enhanced sequences are used for anatomic definition and tissue characterisation. Because of their fibrous nature, the tumours are usually homogeneous and hypointense on T2-weighted MR and generally isointense or hypointense on T1-weighted images. Appearances after administration of gadolinium contrast material can demonstrate heterogeneous enhancement. ^{Reference Sparrow, Kurian, Jones and Sivananthan13} MRI findings of our patient were compatible with fibroma.

Different management strategies are suggested in the literature including surgical resection, single ventricle palliation, cardiac transplant, and conservative treatment with antiarrhythmic medications. ^{Reference Rajput, Bishop and Limaiem5} Cases showing the efficacy of amiodarone and/or beta-blockers in cardiac fibroma-associated arrhythmias have been reported in the literature. ^{Reference Rajput, Bishop and Limaiem5,Reference Miyake, Del Nido and Alexander14,Reference Jones, Ramcharan and Chaudhari15} Our presentation is original because it is a publication showing the efficacy of flecainide and beta-blocker in cardiac fibroma-associated PVCs. In cardiac tumours, the mechanism can be re-entry or triggered automaticity. Abnormal automaticity is thought to play a role in cases of elevated extracellular potassium, low intracellular pH, and catecholamine excess. ^{Reference Gaztanaga, Marchlinski and Betensky16} Flecainide blocks fast inwards sodium channels and slowly unbinds during diastole, prolonging the refractory period of the heart. Flecainide also prevents delayed rectifier potassium channels from opening, lengthening the action potential through ventricular and atrial muscle fibres.Reference Andrikopoulos, Pastromas and Tzeis¹⁷ Therefore, we started to our patient flecainide and beta-blocker combination treatment to minimise the risk of arrhythmia and symptoms. Our patient’s tumour was not amenable to resection due to its extensive invasion of myocardial tissue. To avoid cardiac surgery complications, it was decided to follow up in our patient because the fibroma that invaded the left ventricular apicolateral myocardial tissue was asymptomatic, life-threatening ventricular tachycardia was not observed, and PVCs were controlled with antiarrhythmic therapy. And his arrhythmia is under control with medical treatment for 2 years.