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Effects of Angiotensin‐Converting Enzyme Inhibitor Therapy on QT Dispersion Post Acute Myocardial Infarction
Author(s) -
KASSOTIS JOHN,
MONGWA MBU,
REDDY C.V.R.
Publication year - 2003
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1046/j.1460-9592.2003.t01-1-00148.x
Subject(s) - medicine , myocardial infarction , cardiology , qt interval , aspirin , enalapril , angiotensin converting enzyme , ace inhibitor , blood pressure
KASSOTIS, J., et al .: Effects of Angiotensin‐Converting Enzyme Inhibitor Therapy on QT Dispersion Post Acute Myocardial Infarction.The aim of this study was to determine the effect of an angiotensin‐converting enzyme inhibitor (ACEI), initiated within 24 hours of an acute myocardial infarction (AMI), on the QT dispersion (QT d ). ACEIs have proven beneficial in improving left ventricular remodeling, following an AMI while contributing to a reduction in sudden cardiac death (SCD). A prolonged QT d is a marker of electrical instability predisposing to ventricular arrhythmias and SCD. No one has looked at the effects on the QT d of ACEI therapy initiated within 24 hours of an AMI. The study included 239 consecutive patients who presented with an AMI between January 1, 1998 and December 31, 1998. A total of 105 patients had never been treated with an ACEI, and 51 patients were started on enalapril within 24 hours of presentation. Patient demographics were similar in both groups. All patients were treated with aspirin and β‐blocker therapy. A baseline QT d was determined and recalculated on days 3–4 and 6–7 following the AMI. There was no significant difference in the baseline QT d , heart rate, QT c min , and QT c max between the two groups. On days 3–4 the QT d in the treatment group (A) was39.2 ± 19.4 ms, as opposed to84.4 ± 31.2 msin the control group (B) (P = 1.0E‐06). This reduction in QT d was accounted for by a significant difference in the QT c max . The QT d shortened in both groups on days 6–7 with a QT d of30.0 ± 17.5in group A and a QT d of54.1 ± 26.3in group B(P = 1.0E‐05). There was a significant difference in ejection fraction (EF) between the two groups with the ACEI treated group exhibiting a lower EF, (0.403 (A), 0.494 (B),P < 0.043). The mean dose of enalapril was 6.45 mg daily in the treatment group. ACEIs have been previously shown to reduce the QT d after two months of therapy following an AMI. This study shows that the beneficial effects of ACEI occur early following administration of the drug. The authors speculate that the reduction in SCD conferred by ACEI therapy may be attributed to its effect on reducing the degree of ventricular dispersion of repolarization following a myocardial infarction. (PACE 2003; 26[Pt. I]:843–848)