P168 A RARE CASE OF HYPERTROPHIC CARDIOMYOPATHY WITH HIGH RISK OF SUDDEN CARDIAC DEATH: WHAT CAN WE DO UNTIL MIECTOMY?

Abstract

Abstract A 43–year–old Indian man with obstructive hypertrophic cardiomyopathy (HCMO) and a family history of sudden death presented with heart palpitations associated with chest discomfort and syncope during moderate physical activity despite beta–blocker therapy at maximum dose (New York Heart Association–NYHA III). Transthoracic echocardiography demonstrated ejection fraction 55% and ventricular septum (SIV) (23 mm) and posterior wall hypertrophy (12 mm). There was evidence of dynamic left ventricular outflow tract obstruction (maximum LVOT gradient 30 mmHg at baseline and 45 mmHg after Valsalva) and systolic anterior movement of the amterior mitral flap responsible of moderate regurgitation. It also showed a bicuspid aortic valve with fusion of the right and left cusps and mild regurgitation. ECG Holter showed sporadic supraventricular premature ectopic beats and abnormality of the ventricular repolarization that were accentuated during exercise. Exercise stress test showed 3 mm ST depression in V4–V5 leads. Cardiac magnetic resonance (CMR) and Cardio–CT confirmed HCMO diagnosis and showed a junctional origin of the coronaries, a bifurcated interventricular artery, coronaries free from significant stenosis, intramural late gadolinium enhancement (LGE) of the mid–ventricular SIV and sub–endocardium LGE of the basal SIV. The high HCM– Sudden Cardiac Death Risk score and the presence of LGE on CMR identified a high–risk status and prompt consideration for primary prevention automatic implantable cardioverter defibrillator (AICD) therapy. Thus, in order to treat major life–threatening ventricular arrhythmias, AICD was placed (ESC guidelines 2014 Class IIa). Invasive treatment is indicated for symptomatic patients, NYHA class III and IV refractory to optimized medication and who have gradients in the LVOT. Aortic transvalvular–myectomy is the procedure with the longest experience and considered the gold standard. However, in this case surgical treatment was temporarily postponed. So a sequential rhythm pacing with reduced A–V delay was set up in order to induce a left bundle branch block and a “paradoxical” movement of the SIV with reduction of LVOT gradient. After 2 weeks the LVOT gradient was 20 mmHg and the symptoms were improved. This case suggests the usefulness of a single device for the treatment of different aspects in HCMO waiting to undergo surgical treatment: prevention of sudden cardiac death and improvement of symptoms refractory to medical therapy.