The Effects Of AV/VV Delay Optimization In Patients With Cardiac Resynchronization Therapy By Echocardiography

Background Cardiac resynchronization therapy (CRT) refractory heart failure is the significant progress non-drug therapy, and its effectiveness and safety has been more than domestic clinical trials, but still have 1/3CHF clinical treatment of patients with no response to CRT. Now that the dynamic optimization AV/VV interphase can improve the curative effect of CRT. Tissue doppler echocardiography, because its non-invasive, high spatial and temporal resolution and a quantitative analysis of the characteristics of CRT, in this paper the action mechanism, choose appropriate patients, optimization program evaluation and follow-up visit wrestle with unique role has been widely used clinically.Objective To observe the mid-term and long-term effectiveness of cardiac resynchronization therapy (CRT) optimized AV/VV delay for patients with congestive heart failure(CHF).Methods 19 patients with refractory heart failure received CRT device implantation. Pacing parameters were tested, and AV/VV interval was optimized by the guidance of echocardiography during follow-up period. The effectiveness of CRT was evaluated in terms of echocardiography,tissue Doppler,ECG and BNP during follow-up period.Result The best optimized AV delay was between 120ms and 180ms(158.33±19.46)ms the best optimized VV delay was between 4ms and 28m(s15.83±7.12)ms, The heart function classification, quality of life, Distance of 6 minutes hall walk was significant increased ([255.71±21.58] to [397.37±11.35]m). The QRS interval decreased from ([138.79±16.06]ms to [105.53±8.80]ms P=0.001 ,P<0.05) . With significant reduction of left ventricular end-diastolic (LVEDD) ([73.53±9.41]mm vs. [54.11±3.41] P<0.05). The left ventricular ejection fraction (LVEF) was increased ([0.31±0.03] vs.[0.58±0.06]p<0.01). the velocity time integral of mistral regurgitation (VTI)was increased ( [14.69±1.48] vs [20.52±1.18] P<0.05 ), the plasma BNP degraded from {[1069.02±501.85]pg/ml to [81.26±31.51]pg/ml P<0.05}. The intra-ventricular and inter-ventricular asynchrony indexes were significantly improvedConclusion Dynamically optimized AV/VV delay of the pacemaker parameters improved the hemodynamics and enhanced the short-term,middle-term,long-term of CRT.