Reserva de fluxo coronariano e padrão de disfunção diastólica empacientes com cardiomiopatia dilatada

Introducao: Na cardiomiopatia dilatada (CMD) de origem nao isquemica uma reserva coronariana diminuida estaassociada a maior risco de morte e um dos possiveis mecanismos e o aumento das pressoes de enchimento doventriculo esquerdo. Objetivo: Avaliar a reserva de fluxo coronariano (RFC) pela Ecocardiografia Transtoracica (ETT) e comparar com graus de funcao diastolica.Metodos: Foram estudados 156 pacientes com CMD nao isquemica (101 homens, media etaria 53 ± 12 anos) e disfuncao sistolica importante. A funcao diastolica foi avaliada pelo fluxo transvalvar mitral, fluxo venoso pulmonar e Doppler tecidual, e classificada em: normal (Grau 0); alteracao de relaxamento (Grau I); padrao pseudonormal (Grau II); restritivo com reversao a manobra de Valsalva (grau III); e restritivo sem reversao a manobra de Valsalva (Grau IV). A RFC foi determinada pelo fluxo obtido com o Doppler pulsado na arteria descendente anterior e calculada como a relacao entre a velocidade diastolica maxima durante a hiperemia (dipiridamol, 0,84 mg/Kg) e no basal.Resultados: Todos os pacientes apresentavam disfuncao sistolica importante, fracao de ejecao media de 25,3 ± 5,7%; 86 pacientes (55%) apresentavam funcao diastolica grau 0 ou I, enquanto 70 pacientes (45%) apresentavam disfuncao diastolicagraus II, III e IV. A exequibilidade da medida de RFC foi de 90,4%. A RFC foi significativamente maior nos pacientes com funcao diastolica 0 ou I (2,2 ± 0,5) do que nos pacientes com disfuncao diastolica graus II, II e IV (1,9 ± 0,5; p Introduction: In patients with nonischemic dilated cardiomyopathy (DCM), decreased coronary flow reserve is associated with increased risk of death and one of the possible mechanisms is the increased left ventricular filling pressures. Objective: To evaluate the coronary flow reserve (CFR) by transthoracic echocardiography (TTE) and compare it with degrees of diastolicfunction in patients with DCM. Methods: We studied 156 patients with DCM (101 men, mean age 53±12 years) and severe systolic dysfunction. Diastolic function was assessed by mitral inflow, pulmonary venous flow and tissue Doppler, and classified as normal (grade 0), impaired relaxation pattern (Grade 1), pseudonormal pattern (Grade 2), reversible restrictive pattern during Valsalva maneuver (Grade 3) and irreversible restrictive pattern during Valsalva maneuver (Grade 4). The CFR was determined by pulsed Doppler in left anterior descending coronary artery and calculated as the ratio of the maximumdiastolic velocity during hyperemia (dipyridamole, 0.84 mg/kg) and baseline. Results: All patients had significant systolic dysfunction, with mean left ventricular ejection fraction of 25.3±5.7%. 86 patients (55%) had grade 0 or 1 diastolic function while 70 patients (45%) had grades II, III or IV of diastolic dysfunction. The feasibility of CFR obtained by TTE was 90.4%. The CFR was significantly higher in patients with diastolic dysfunction 0 or 1 (2.2±0.5) than in patients with diastolic dysfunction grades II, II or IV (1.9±0.5, p