Occurrence of ventricular arrhythmias in patients receiving acute and chronic infusions of milrinone.
Milrinone is a promising new inotrope, but its arrhythmogenic potential has not been defined. We monitored ventricular arrhythmias during a 24-hour baseline and 48-hour milrinone infusion period in 12 patients with chronic heart failure. Patients were characterized by a mean age of 58 years and a left ventricular ejection fraction of 21%. Nine (75%) were male, nine had primary idiopathic dilated cardiomyopathy, and three had coronary artery disease. None had a history of cardiac arrest or sustained ventricular tachyarrhythmia. Milrinone was given as a loading dose (mean 53 micrograms/kg/10 min; range 37.5 to 75) followed by a 48-hour maintenance infusion (mean 0.53 micrograms/kg/min; range 0.25 to 0.75). Acutely, cardiac index increased by 27% and pulmonary wedge pressure decreased by 30% during milrinone; changes were maintained during continued therapy. Ventricular arrhythmia response was variable, with no significant overall difference. However, a trend toward increased ectopic activity was noted. No sustained tachyarrhythmias occurred. Mean frequency of premature ventricular complexes (PVCs) was 87 +/- 48 PVCs/hr (x +/- SEM) during baseline monitoring and 141 +/- 69/hr following infusion of the drug (p = 0.08). Mean frequency of couplets was 6.0 +/- 4.9/hr before drug infusion and 14.3 +/- 11.0/hr during infusion (p = 0.21). Mean frequency of runs was 0.9 +/- 0.8/hr before and 2.7 +/- 2.4/hr during drug infusion (p = 0.29). Two patients met criteria for proarrhythmia (increased PVCs of greater than 4x and/or repetitive forms of greater than 10x. However, neither proarrhythmia patient required reduction in the dosage of milrinone or additional antiarrhythmic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000139:chemically induced* / Q000503:physiopathology; D002316:Cardiotonic Agents / Q000009:adverse effects*; D004334:Drug Administration Schedule; D005260:Female; D006333:Heart Failure / Q000188:drug therapy* / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007263:Infusions, Parenteral; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D020105:Milrinone; D011728:Pyridones / Q000009:adverse effects*; D013997:Time Factors
D002316:Cardiotonic Agents; D011728:Pyridones; D020105:Milrinone