Ventricular Tachycardia: The Spectrum Continues to Broaden
Report of Naxos Disease
Naxos disease is a recessively inherited arrhythmogenic right ventricular cardiomyopathy (ARVC) in which the cardiac phenotype is associated with palmoplantar keratoderma and woolly hair.1 A 55-year-old female of Asian-Indian origin presented with recurrent palpitation and syncope. She was not known to have had any significant illness in the past except for lesions on her palm and the sole of her foot. She did not have any conventional risk factors for coronary artery disease except for her postmenopausal status. Physical examination revealed woolly hair (Figure 1) and palmoplantar keratosis (Figure 2 and Figure 3). Cardiovascular examination revealed tachycardia with heart rate of 180/min. ECG showed ventricular tachycardia with a left bundle-branch block contour and left axis deviation (Figure 4). She was treated with lignocaine which reversed the tachycardia. ECG during sinus rhythm showed T-wave inversion in leads V1, V2, V3, and V4. Epsilon waves were not present. Skiagram of the chest was normal. Transthoracic echocardiogram showed right ventricular dilatation with localized akinetic areas and saccular aneurysmal segments (Movie). She was diagnosed with ARVC because she satisfied 1 major criterion (localized right ventricle aneurysms) and 2 minor criteria (ECG during sinus rhythm showing inverted T waves in right precordial leads and sustained left bundle-branch block type ventricular tachycardia).2 The biochemical investigations were unremarkable. None of her family members had a similar illness.
ARVC is a heart muscle disease of unknown etiology that causes arrhythmias, heart failure, and sudden death. In one subgroup of patients, ARVC is associated with woolly hair, palmoplantar keratoderma, and autosomal recessive inheritance known as Naxos disease, because of its identification in individuals from the island of Naxos, Greece.3 Woolly hair is present at birth, whereas keratoderma becomes clinically apparent during the first year of life. Cardiac events including ventricular arrhythmias, sudden death, and heart failure are not manifest until late puberty.4 All patients show a variable degree of either right ventricular dilatation or dysfunction or both. Both ventricles may be involved in some patients. In some cases, the left ventricle dilates and becomes hypokinetic, which suggests idiopathic dilated cardiomyopathy.5 The responsible gene in Naxos disease is a deletion mutation in plakoglobin, a constituent of the cardiac and skin cells desmosomes and adherence junctions. This gene was mapped in chromosome 17q 21.1 Naxos disease is associated with malignant ventricular tachycardia. The tachycardia shows a left bundle-branch block pattern and usually is refractory to antiarrhythmic therapy. Radiofrequency ablation, arrhythmia surgery, or implantable cardioverter-defibrillator implantation may be necessary in some cases.6
The online-only Data Supplement, which contains a movie, can be found at http://circ.ahajournals.org/cgi/content/full/114/4/e60/DC1.
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Coonar AS, Protonotarios N, Tsatsopoulou A, Needham EWA, Houlston RS, Cliff S. Gene for arrhythmogenic right ventricular cardiomyopathy with diffuse nonepidermolytic palmoplantar keratoderma and woolly hair (Naxos disease) maps to 17q21. Circulation. 1998; 97: 2049–2058.