Segmental wall motion abnormalities alter vulnerability to ventricular ectopic beats associated with acute increases in aortic pressure in patients with underlying coronary artery disease.
OBJECTIVE
To evaluate whether patients with coronary artery disease are susceptible to pressure related ventricular arrhythmias, and if so to identify possible risk factors.


METHODS
Interventional study.


METHODS
Metaraminol was given to 43 patients undergoing coronary arteriography for ischaemic heart disease to increase their aortic pressure, provided their systolic blood pressure was < 160 mm Hg and they were in sinus rhythm, without any ventricular ectopic activity (or with fewer than six ventricular ectopic beats a minute) during a five minute control period.


RESULTS
During the metaraminol infusion, systolic aortic pressure rose from 131 (15) to 199 (12) mm Hg (mean (SD)). Ventricular ectopy appeared (or ventricular ectopic beats increased by > 100%) in 13/43 patients. Ventricular ectopy was not related to age, sex, presence of hypertension, history of myocardial infarction, use of beta blockers, positive exercise test, number of vessels diseased, or heart rate change during metaraminol infusion. There was a strong relation between the appearance of ventricular arrhythmia and segmental wall motion abnormalities: 1/19 (5.3%, 95% confidence interval 0.1% to 26.0%) without abnormality; 2/12 (16.7%, 2.1% to 48.4%) with hypokinesia; and 10/12 (83.3%, 51.6% to 97.1%) with akinesia or dyskinesia, chi 2 = 22.7, p < 0.001). Ejection fraction was also a significant but not independent risk factor.


CONCLUSIONS
Patients with segmental wall motion abnormalities are predisposed to ventricular ectopic beats during an increase in systolic aortic pressure. This could be explained by associated electrophysiological inhomogeneity. The presence of mechanical inhomogeneity, as may occur in postinfarction akinesia or dyskinesia, may affect the aortic pressure above which ventricular arrhythmias appear.
Siogas
K
K
Cardiology Department, University General Hospital, Leoforos Panepistimiou, Ioannina, Greece.
Pappas
S
S
Graekas
G
G
Goudevenos
J
J
Liapi
G
G
Sideris
D A
DA
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001011:Aorta / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D006328:Cardiac Catheterization / Q000009:adverse effects; D016009:Chi-Square Distribution; D017023:Coronary Angiography; D003327:Coronary Disease / Q000150:complications*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008680:Metaraminol; D008875:Middle Aged; D013318:Stroke Volume; D014662:Vasoconstrictor Agents; D018754:Ventricular Dysfunction / Q000139:chemically induced; D018879:Ventricular Premature Complexes / Q000209:etiology*
D014662:Vasoconstrictor Agents; D008680:Metaraminol