Impact of adaptive cardiac resynchronization therapy in patients with systolic heart failure: Beyond QRS duration and morphology.

BACKGROUND: Mechanical and electrical restoration by cardiac resynchronization therapy (CRT) with adaptive pacing algorithm (aCRT) in heart failure patients with a moderately wide (120-149 ms) QRS has not been fully evaluated. The purpose of this study was to investigate the therapeutic effect of aCRT compared with conventional biventricular CRT (BiV-CRT) regardless of QRS morphology. METHODS: Seventeen consecutive patients with a QRS ≥120 ms, regardless of morphology, underwent CRT device implantation with an aCRT pacing algorithm. Propensity score matched analysis was performed to evaluate the impact of aCRT on the improvement in mechanical and electrical parameters after CRT device implantation using historical controls (HC) from the clinical registry of BiV-CRT (START trial). RESULTS: Left ventricular (LV) volume significantly decreased after CRT in all patients in both the aCRT and HC groups. The difference in relative reduction of LV end-systolic volume (LVESV) was not significantly different between the 2 arms. QRS shortening after CRT was significantly greater in the aCRT group than in the BiV-CRT group, and the difference was prominent in patients with a moderately wide QRS (120-149 ms). In patients with a moderately wide QRS, the relative reduction in LVESV [39 (29-47)% vs. 2 (-6-20)%, p = 0.04] and proportion of LV volume responders (90% vs. 38%, p = 0.04) were significantly greater in the aCRT group than in the HC group. The proportion of volume responders was not significantly different in patients with a wide QRS (≥150 ms). CONCLUSIONS: The aCRT algorithm improved electrical and mechanical parameters in patients with a moderately wide QRS, regardless of QRS morphology.

Case of atrial tachycardia originating from giant coronary sinus connected to persistent left superior vena cava: successful catheter ablation guided by noncontact mapping.

Radiofrequency (RF) catheter ablation is widely applied to tachyarrhythmia associated not only with structurally normal hearts but also with relatively mild cardiac anomalies. We present a case of 35 year-old female complaining of exercise-induced frequent palpitations caused by atrial tachycardia (AT) originating from giant coronary sinus (CS) connected to persistent left superior vena cava. AT was sensitive to intravenous ATP administration. Electrophysiological study partly using noncontact balloon of EnSite system clarified that two foci of AT were located at the orifice and the distal inner lumen of giant CS. After repetitive applications of RF energy to these origins, AT was not induced by drip infusion of isoproterenol. AT was not evoked by exercise without antiarrhythmic drugs 15 months after the RF ablation. This case indicates that RF ablation guided by noncontact mapping technique should be considered as a therapeutic regimen for AT associated with mild cardiac malformations.

Case of paroxysmal atrial fibrillation improved after the administration of proton pump inhibitor for associated reflux esophagitis.

A 64-year-old man had demonstrated palpitations caused by paroxysmal atrial fibrillation (AF) documented by ambulatory electrocardiographic monitoring. Effectiveness of antiarrhythmic agent (disopyramide: 300 mg/day) was limited. Based on the gastrointestinal endoscopic findings, proton pump inhibitor (PPI: rabeprazole, 10 mg/day) was administered to eliminate heart burn due to reflux esophagitis. Symptoms of paroxysmal AF and reflux esophagitis were confusing due to the anatomical proximity of the diseased organs and concomitant occurrence in the evening and when in a supine position. After the additional PPI therapy, not only was reflux esophagitis improved subjectively and endoscopically but also paroxysms of AF markedly reduced. Because esophagus is attached to left atrial posterior wall and the role of inflammatory process on the development of AF is highlighted, amelioration of reflux esophagitis by PPI may have been followed by the remarkable reduction of paroxysms of AF.