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Optimização da programação da terapêutica de ressincronização cardíaca por ecocardiograma: avaliação do impacto sobre a capacidade funcional

2009; Linguagem: Inglês

10.5031/v1i1.ria1064

1989-9777

Nuno Cortez‐Dias, L. Sargento, Marta Valente, Ana Bernardes, Sara Neto, Ana Rebola, Carla Bogalho, João de Sousa, Mário G. Lopes,

Cardiac Arrhythmias and Treatments

Background: Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in patients with severe heart failure and left bundle branch block, left ventricular (LV) dilatation and severely compromised LV systolic function. Since 25-35% of those patients conventionally treated with CRT do not improve, new strategies for CRT optimization should been investigated. Objectives: To evaluate the impact of the echoguided CRT reprogramming in patients chronically treated with biventricular (BiV) pacemaker and under stable pharmacological therapeutic. Methods: A convenient sample of clinically stable patients treated with BiV pacemaker for at least 12 months was submitted to echo-guided CRT reprogramming. Maximum and minimum atrioventricular (AV) delay limits to test were identified by pulsed-wave Doppler evaluation of transmitral flow, under progressive 10 ms increments, and the optimal AV delay was identified by the greatest velocity-time integral (VTI) at LV outflow tract (LVOT). The best ventricular stimulation pattern (LV-only, simultaneous BiV and sequential BiV pacing) and optimal VV delay were also determined by the highest LVOT VTI, using progressive 20 ms increments (from -60ms to +60ms). New York Heart Association (NYHA) functional class, NTproBNP, Quality of life score assessed by the Minnesota Living with Heart Failure Questionnaire (LHFQ), 6-min walk test, LV ejection fraction, LV stroke volume and cardiac output were assessed at the initial evaluation and 1 and 3 months after CRT reprogramming. During the investigation period no change in the pharmacological therapeutic was allowed. Results: 10 patients were studied (7 men, 63±8 years old), with an ejection fraction of 29±12%. After CRT reprogramming, none of the patients worsened. NYHA functional class (p=0,039) and LHFQ score (p=0,011) significantly improved in the first month after CRT optimization and remained stable thereafter. The systolic volume (p=0,025) and cardiac output (p=0,025) also significantly improved. Nonetheless, NT-proBNP (p=0,066) and distance in 6-min walking test (p=0,678) did not significantly improved. Conclusion: Although the reduced number of patients evaluated demands caution in extracting conclusions, these results suggest that echo-guided CRT reprogramming can induce additional clinical improvements (particularly in quality of life parameters), even in those patients that were considered “responders” to CRT.