Complete left bundle branch block resolution during treatment with Mavacamten: a case report of a first-in-class scenario

Figures

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  Figure 1. Multimodal fixed panel showing asymmetric left ventricular hypertrophy in the parasternal long-axis view on echocardiography (A), mitral regurgitation jet on continuous-wave Doppler obscuring the left ventricular outflow tract gradient (B), subtle mid-wall late gadolinium enhancement in the mid-ventricular segments on cardiac magnetic resonance (C), mildly elevated native T1 mapping values in the interventricular septum on cardiac magnetic resonance (D).

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  Figure 2. Baseline 12-lead ECG performed before treatment initiation showing sinus rhythm at 55 b.p.m., normal atrioventricular conduction, complete left bundle branch block with relative repolarization abnormalities.

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  Figure 3. Evident left ventricular outflow tract obstruction before treatment initiation with maximal gradient at baseline of 62 mmHg (A) and during Valsalva manoeuvre equal to 79 mmHg (B).

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  Figure 4. Twelve-lead ECG performed after 4 weeks of treatment with mavacamten showing sinus rhythm at 55 b.p.m. and normal atrioventricular and intraventricular conduction, with left ventricular repolarization abnormalities compatible with left ventricular strain pattern.

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  Figure 5. Left ventricular outflow tract gradient at baseline (A) and during Valsalva manoeuvre (B) after 4 weeks of treatment with mavacamten 5 mg per day.