Author + information
- Received October 18, 1985
- Revision received April 2, 1986
- Accepted April 16, 1986
- Published online September 1, 1986.
- Terrence J. Montague, MD*,†,**,
- David D. McPherson, MD*,
- David E. Johnstone, MD*,†,
- C. Anne Spencer, BSc*,
- Lucille D. Lalonde, MD*,
- Martin J. Gardner, MD* and
- B. Milan Horacek, PhD*,†
- ↵**Address for reprints: Terrence J. Montague, MD, Department of Medicine (Cardiology), Room 3054 - Ambulatory Care Centre, Victoria General Hospital, Halifax, Nova Scotia, Canada, B3H 2Y9.
To further define the capacity for recovery after acute phase electrical and mechanical injury in patients with Q wave myocardial infarction who were treated with standard measures, 120 lead body surface potential maps and radionuclide angiograms were recorded at day 5 before discharge and month 6 after infarction in 23 patients with a first infarction (12 anterior and 11 inferior by standard 12 lead electrocardiographic criteria). In addition to assessment of spatial changes in electrocardiographic and wall motion patterns, five quantitative variables were evaluated: minimal Q zone integral, ΣQ wave integral, maximal ST integral, left ventricular ejection fraction and left ventricular wall motion abnormality score. From day 5 to month 6 after infarction, the only change in the inferior infarction group was a gain in ΣQ wave (−91 ± 40 μV·s x 102to −68 ± 24 μV·s × 102; p < 0.05). In contrast, all variables improved over the same time period in the anterior infarction group: Q zone minimum, −34 ± 20 to −24 ± 13 μV·s (p < 0.05); ΣQ wave, −160 ± 122 x 102to −120 ± 90 μV·s × 102(p < 0.05); ST maximum, 44 ± 19 to 18 ± 9 μV·s (p < 0.01); ejection fraction, 54 ± 7 to 63 ± 17% (p < 0.05); and wall motion score, 6 ± 3 to 3 ± 3(p < 0.01). The major change in ST maximal integral occurred early (day 5 to discharge) and the improvement in ejection fraction occurred late (discharge to month 6 after infarction); change of the other variables was only apparent between day 5 and month 6.
In the anterior infarction group there were significant correlations between the temporal changes in both depolarization variables and ST maximal integral (r = 0.58) and between change in ejection fraction and wall motion abnormality score (r = 0.82). In the inferior infarction group the only intratechnique correlation was between temporal change in maximal Q zone and ΣQ wave (r = 0.71). There were no significant intertechnique correlations in either group. Thus, Q wave infarction is not an all or none phenomenon. Rather, acute phase indexes of electrical and mechanical function represent a balance of reversible and irreversible ischemic damage. Recovery appears to be gradual, independent, electrocardiographic versus ventriculographic and quantitatively disparate between clinical groups. The effects of post infarction therapeutic interventions on such indexes are, therefore, probably best assessed in specific groups, over relatively long periods and with randomized controls.
with the technical assistance of SHARON A. BLACK, RN, HELEN K. TREMAYNE, BSc, RN, PETER J. TRIDER, RTNM
- Received October 18, 1985.
- Revision received April 2, 1986.
- Accepted April 16, 1986.
- American College of Cardiology Foundation