Unexpected finding in an adult with ventricular fibrillation and an accessory pathway: non-compaction cardiomyopathy

IntroductionIn this report, we demonstrate a patient presenting with anout-of-hospital cardiac arrest due to ventricular fibrillation(VF). At the hospital the presence of an accessory path-way could be seen on the surface electrocardiogram(ECG). Surprisingly, cardiac imaging also showed thepresence of isolated left ventricular non-compaction car-diomyopathy (INVM).INVMwasfirstdescribedin1984byEngberdingetal.as an unclassified cardiomyopathy [1]. It is assumed to bethe result of an arrest of the compaction process duringthe normal development of the heart (week 5–8). InINVM, the spaces within the intertrabeculated meshworkpersist with deep recesses and no other cardiac abnormal-ities [1, 2]. Clinical presentation of INVM includesheart failure, thromboembolic events and arrhythmias[1, 3, 5, 7]. Conduction abnormalities and arrhythmiasobserved in INVM patients are left or right bundlebranch block, supraventricular tachycardia and ventric-ular tachycardia [1–3, 5–10].However,thepresenceofanaccessorypathwayandINVMin one patient with VF has never been described before.Case reportA 19-year-old female presented to the emergency depart-ment after an out-of-hospital cardiac arrest due to VF.After alcohol consumption she jumped off a 1 m highpier into the water. While dressing she complained ofdizziness, palpitations and breathlessness. She collapsednear her car and lost consciousness. The paramedics ar-rived within 7 min and provided cardiopulmonary resus-citation. VF was documented on arrival (Fig. 1). Afterthree DC shocks sinus rhythm resumed and due to a lowGlasgow Coma Score she was intubated. At the intensivecardiac care unit therapeutichypothermia was induced for24 h. She regained consciousness without any signs ofpersistent neurological injury. Anamnestic there were noprevious palpitations or (near) collapses. The patient hadnoted that she was relatively quickly exhausted duringphysical exercise. Despite this, she played field hockeywithout any restraints. Her family history was negative forcardiovascular diseases, arrhythmias or sudden cardiacdeath. The 12-lead ECG after defibrillation showed pre-


Introduction
In this report, we demonstrate a patient presenting with an out-of-hospital cardiac arrest due to ventricular fibrillation (VF). At the hospital the presence of an accessory pathway could be seen on the surface electrocardiogram (ECG). Surprisingly, cardiac imaging also showed the presence of isolated left ventricular non-compaction cardiomyopathy (INVM).
However, the presence of an accessory pathway and INVM in one patient with VF has never been described before.

Case report
A 19-year-old female presented to the emergency department after an out-of-hospital cardiac arrest due to VF. After alcohol consumption she jumped off a 1 m high pier into the water. While dressing she complained of dizziness, palpitations and breathlessness. She collapsed near her car and lost consciousness. The paramedics arrived within 7 min and provided cardiopulmonary resuscitation. VF was documented on arrival ( Fig. 1). After three DC shocks sinus rhythm resumed and due to a low Glasgow Coma Score she was intubated. At the intensive cardiac care unit therapeutic hypothermia was induced for 24 h. She regained consciousness without any signs of persistent neurological injury. Anamnestic there were no previous palpitations or (near) collapses. The patient had noted that she was relatively quickly exhausted during physical exercise. Despite this, she played field hockey without any restraints. Her family history was negative for cardiovascular diseases, arrhythmias or sudden cardiac death. The 12-lead ECG after defibrillation showed pre-excitation with delta waves (positive in I, aVL, V1-6; negative in II, III, aVF) suggestive of a right-sided posteroseptal accessory pathway (Fig. 1). Therefore, during hospitalisation, the patient underwent an electrophysiology study. Figure 2 shows a Kent potential recorded at a right-sided posteroseptal bypass tract. The accessory pathway was successfully ablated at this site. The surface ECG after the ablation procedure showed no preexcitation (PR 122 ms) and no delta waves (Fig. 1). Hence, VF was most likely due to the presence of an  (Fig. 3). Based on this finding, a subcutaneous ICD was implanted for secondary prevention in this 19-year-old patient.

Discussion
The prevalence of INVM differs between 0.014 % (adult series) and 0.14 % in paediatric series [3]. Reported differences in the prevalence of INVM are probably caused by increased awareness of the existence of the disease over time. The true prevalence may be even higher, because only symptomatic patients are screened for INVM [2]. Echocardiography is useful for diagnosing INVM but recently MRI has proven to be more accurate for diagnosing INVM [1,[4][5][6]. The time course of development of ventricular tachyarrhythmia in INVM patients is at present unknown but an ICD is recommended for primary prevention of ventricular tachyarrhythmia [1][2][3][6][7][8][9][10] So far, an accessory pathway has only been described in two adult and four paediatric INVM patients. However, an adolescent patient with a Wolff-Parkinson-White syndrome and INVM presenting with VF has to our knowledge never been described before. Based on clinical data, it is impossible to determine whether VF was the result of either the INVM or atrial fibrillation with fast conduction over the accessory pathway.
In conclusion, we describe a 19-year-old patient who presented with an out-of-hospital cardiac arrest due to VF in the  presence of a right-sided posteroseptal located accessory pathway. Surprisingly, we also found an INVM.
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Conflict of interests None declared
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