ABSTRACT
<p><b>BACKGROUND</b>Cardiac resynchronization therapy (CRT) is a major breakthrough in therapy for advanced heart failure patients; however, a number of key clinical research questions remain, perhaps most importantly the issue of why apparently suitable patients do not respond to CRT.</p><p><b>METHODS</b>Seven patients, six males and one female, aged (56.43 +/- 6.13) years, all diagnosed with dilated cardiomyopathy, were included in this study. They were all non-responders to CRT who underwent routine optimization postoperatively, and received optimal drug therapy. On the basis of biventricular pacing, titrating various atrioventricular (AV) intervals were performed to get the true fusional QRS complexes composed of biventricular pacing and AV intrinsic conduction. Then, the effects of AV intrinsic conduction during CRT were evaluated.</p><p><b>RESULTS</b>On the setting of AV intrinsic conduction during CRT, the true fusional QRS complexes were the narrowest, and all patients showed alleviation of symptoms, improvement of exercise tolerance, life quality and hemodynamic parameters during more than 6 months of follow-up.</p><p><b>CONCLUSIONS</b>Titrating AV intervals to get the true fusional QRS complexes composed of biventricular pacing and AV intrinsic conduction will be beneficial for non-responders to CRT. Maintaining AV intrinsic conduction during CRT may decrease the rates of non-responders to CRT.</p>
Subject(s)
Female , Humans , Male , Middle Aged , Atrioventricular Block , Therapeutics , Cardiac Pacing, Artificial , Echocardiography , Heart Failure , Therapeutics , Treatment OutcomeABSTRACT
<p><b>OBJECTIVE</b>To explore the effect of implantable automatic cardioverter defibrillator (ICD) on improvement of the prognosis of patients with ventricular tachycardia or fibrillation (VT/VF). To compare the advantages and disadvantages of ICD with antiarrhythmic drug, to select the best indication of ICD and review the protocol of the following-up of ICD patients, and present scientific evidence for the morebroad popularization who needs ICD in China.</p><p><b>METHODS</b>In 99 selected patients who had the indication of class I, 27 patients were treated by ICD (ICD group), and 72 patients were not (non-ICD group). Patients in the two groups had the similar basic clinical characteristics. The incidence of syncope, CPR, and VF in ICD group were more common than those in non-ICD group. Patients in the two groups received same basic therapy. The total mortality rate and the incidence of cardiac events in two groups were compared in 3 months, 6 months, 12 months and 15 months.</p><p><b>RESULTS</b>The total mortality rate and the incidence of cardiac events in ICD group were significantly lower than those in non-ICD group in the follow-up period. The mortality rate in ICD group is 0, and the mortality rate in non-ICD group is 20.8%.</p><p><b>CONCLUSIONS</b>(1) ICD treatment can decrease the incidence of cardiac events of patients with high risk of sudden cardiac death (SCD), and improve their survival. (2) The key measures to insure the efficacy, safety, and cost-effectiveness of ICD treatment is: to select the patients correctly, to optimize the implanting process and the follow-up, and use rational assistant therapy.</p>