To ICD or not to ICD?

Abstract

Introduction: Survivors of ventricular fibrillation (VF) arrest constitute a challenging group of patients who require extensive investigations to identify the cause of the arrest and determine the most appropriate management. According to the ACC/AHA/HRS 2008 guidelines Implantable cardioverter-defibrillator (ICD) is indicated after exclusion of any completely reversible causes. Our case demonstrates the significance of investigating for unusual but reversible causes of VF arrest. Case report description: A 61-year-old woman was admitted from the community with general malaise, chest pain and breathlessness. Chest radiography revealed a left pleural effusion, cardiomegaly and pulmonary oedema. A CT pulmonary angiogram ruled out pulmonary emboli and an echocardiogram showed normal valves but globally reduced systolic function with EF=25%. Two days into her admission she sustained a VF cardiac arrest which was successfully terminated with direct current cardioversion. Subsequent coronary angiography revealed unobstructed coronary arteries. Two days later, she developed a macular rash with «butterfly» distribution on her face. Following a renal biopsy which revealed immune complex mediated mesangioproliferative glomerulonephritis compatible with class IIA or III lupus and cardiac MRI which showed oedema in the left ventricular wall, a new diagnosis of systemic lupus erythematosus (SLE) and related myocarditis was reached. After appropriate immunosuppressive therapy (mycophenolate mofetil and high dose prednisolone), her symptoms and left ventricular systolic function improved significantly (EF=55%). An ICD had been considered however in view of the significant improvement in LV systolic function with the treatment for lupus, it was felt that her future risk of arrhythmias was small and therefore an ICD was inappropriate. Discussion - Conclusion - Implication for clinical practice: Our patient demonstrates a case of new diagnosis of SLE that manifested itself as lupus myocarditis complicated with heart failure and VF arrest. First presentation of lupus with myocarditis and VF is uncommon, however reaching the correct diagnosis is important as due to the reversible nature of the condition and LV systolic function improvement with medical therapy, an ICD might not be appropriate. Therefore, in keeping with the current guidelines, we emphasise the importance of screening for reversible conditions when considering ICD therapy for secondary prevention of malignant arrhythmias and argue that for some patients «resisting» implanting an ICD too quickly before full investigations are completed is essential.