title: Cardiac resynchronization therapy in patients with end-stage inotrope-dependent class IV heart failure.
abstract: Although cardiac resynchronization therapy (CRT) is beneficial in patients with drug-refractory New York Heart Association (NYHA) class III/IV heart failure (HF) and left ventricular (LV) dyssynchrony, CRT efficacy is not well established in patients with more advanced HF on inotropic support. Ten patients (age 55 +/- 13 years) with inotrope-dependent class IV HF (nonischemic [n = 6] and ischemic [n = 4]) received a CRT implantable cardioverter-defibrillator device. QRS duration was 153 +/- 25 ms (left branch bundle block [n = 7], intraventricular conduction delay [n = 2], and QRS <120 ms [n = 1]). The indication for CRT was based on either electrocardiographic criteria (n = 9) or echocardiographic evidence of LV dyssynchrony (n = 1). Intravenous inotropic therapy consisted of dobutamine (n = 6; 4.3 +/- 1.9 microg/kg/min) or milrinone (n = 4; 0.54 +/- 0.19 microg/kg/min) as inpatient (n = 3) or outpatient (n = 7) therapy for 146 +/- 258 days before CRT. One patient required ventilatory support before and during device implantation. All patients were alive at follow-up 1,088 +/- 284 days after CRT. Three patients underwent successful orthotopic cardiac transplantation after 56, 257, and 910 days of CRT. HF improved in 9 patients to NYHA classes II (n = 5) and III (n = 4). Intravenous inotropic therapy was discontinued in 9 of 10 patients after 15 +/- 14 days of CRT. LV volumes decreased (end-diastolic from 226 +/- 78 to 212 +/- 83 ml; p = 0.08; end-systolic from 174 +/- 65 to 150 +/- 78 ml; p <0.01). LV ejection fraction increased (23.5 +/- 4.3% to 32.0 +/- 9.1%; p <0.05). No implantable cardioverter-defibrillator shocks were recorded, and antitachycardia therapy for ventricular tachyarrhythmias was delivered in 1 patient. In conclusion, patients with end-stage inotrope-dependent NYHA class IV HF and LV dyssynchrony may respond favorably to CRT with long-term clinical benefit and improved LV function.
authors.affiliation: Division of Cardiology, Tampa General Hospital, University of South Florida College of Medicine, Tampa, Florida, USA. bherweg@hsc.usf.edu
authors.forename: Bengt
authors.initials: B
authors.lastname: Herweg
authors.forename: Arzu
authors.initials: A
authors.lastname: Ilercil
authors.forename: Ray
authors.initials: R
authors.lastname: Cutro
authors.forename: Robert
authors.initials: R
authors.lastname: Dewhurst
authors.forename: Sendhil
authors.initials: S
authors.lastname: Krishnan
authors.forename: Mark
authors.initials: M
authors.lastname: Weston
authors.forename: S Serge
authors.initials: SS
authors.lastname: Barold
mesh_terms: D000328:Adult; D000368:Aged; D002304:Cardiac Pacing, Artificial; D002316:Cardiotonic Agents / Q000008:administration & dosage*; D017147:Defibrillators, Implantable; D004280:Dobutamine / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System; D006333:Heart Failure / Q000150:complications / Q000628:therapy*; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D020105:Milrinone / Q000008:administration & dosage; D012720:Severity of Illness Index; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000628:therapy*
chemical_list: D002316:Cardiotonic Agents; D004280:Dobutamine; D020105:Milrinone