O diagnóstico da obstrução da via de saída do ventrículo esquerdo na cardiomiopatia hipertrófica

Abstract

Hypertrophic cardiomyopathy is a prevalent genetic disease characterized by left ventricular hypertrophy, presenting dynamic obstruction of outflow tract with subaortic gradient happening at rest in 30% of the cases. It is attributed to the intricate interaction between the anterior mitral leaflet, the interventricular septum and altered flow vectors generated in left ventricle along with changes in outflow tract geometry. Mitral regurgitation in varying degrees is found with or without association with structural deformities of the valve apparatus. The exercise echocardiogram evidences latent obstruction easily induced by exercise in 60 to 75% of nonobstructive forms. The determination of the gradient under this condition must be considered in routine investigation of patients with mild or no obstruction at rest. The evaluation of hypertrophic cardiomyopathy incorporates methods based on the ultrasound image, which, along with MRI, allow recognizing ventricular obstruction generating mechanisms, thus facilitating the diagnosis and management of obstructive and latent obstructive forms.

Undiagnosed hypertrophic obstructive cardiomyopathy during transcatheter aortic valve replacement: a case report

“…Rarer associated adverse effects in this relatively new modality are still being elucidated. There have been few case reports of hypertrophic obstructive cardiomyopathy (HOCM) after TAVR [9, 10] despite its relatively common association with aortic stenosis (AS) [11].…”

High left ventricular outflow tract gradient: Aortic stenosis, obstructive hypertrophic cardiomyopathy or both?

“…It is based on the presence of LV hypertrophy, frequently asymmetric and involving the IVS, in the absence of other causes. 8,11,13,15 AS is usually associated with a uniform or symmetric (i.e. concentric) distribution of LV hypertrophy, 16 although an asymmetric septal distribution is reported in around 10% of cases.…”

Gradiente elevado no trato de saída do ventrículo esquerdo: estenose aórtica, miocardiopatia hipertrófica obstrutiva ou ambas?

“…A MCH obstrutiva caracteriza-se pela presença de um gradiente ao nível do TSVE, ou menos frequentemente mesoventricular 11 , sensível a variações da pré-carga, pós-carga ou contratilidade 12 . Dado o carácter predominantemente dinâ-mico, o gradiente desenvolve-se na telessístole e a curva de velocidades de fluxo adquire um padrão assimétrico em dagger shape.…”

“…Este baseia-se na presença de hipertrofia ventricular esquerda, frequentemente assimétrica com envolvimento do SIV, na ausência de outra etiologia 8,11,13,15 . A EAo associa-se habitualmente a um padrão de hipertrofia uniforme com distribuição concêntrica 16 …”