Sustained ventricular tachycardia as a marker of inadequate myocardial perfusion during the acute phase of myocardial infarction.
BACKGROUND
Sustained ventricular tachycardia (VT) complicating the acute phase of myocardial infarction (AMI) is a quite rare event but with short-term unfavorable prognosis. The clinical characteristics as well as the therapeutic implications have not yet been well defined.


OBJECTIVE
This paper attempts to prove that VT may be considered a marker of inadequate myocardial perfusion after thrombolysis.


METHODS
To assess the clinic-electroangiographic characteristics and prognosis of patients with VT occurring within the first 4 days of an AMI, a case-control study was carried out in 23 patients from a total of 1,100 patients (1.9%) hospitalized with AMI between March 1993 and July 1997. These patients were compared with a control group of 131 patients hospitalized consecutively. A statistical analysis was made using the chi-square test, t-test, and logistic regression.


RESULTS
There were no differences among groups with regard to age, gender, and area of necrosis. Average time for the onset of VT was 26 h (range 0-92 h). Sixteen patients underwent coronary angiography: 4 patients had left main coronary artery disease, 2 had single-vessel disease, 8 had lesions in two vessels, and 2 had triple-vessel disease. Univariate analysis showed that patients with VT had a higher incidence of creatine phosphokinase (CPK)-MB peak > 300 UI/l (61 vs. 30%; p<0.001), more frequent occurrence of previous AMI (48 vs. 17%; p<0.001), and acute intraventricular conduction disorders (26 vs. 4%; p<0.001). Furthermore, these patients suffered ischemia previous to VT more frequently (65 vs. 11%; p<0.0001), and had a greater mortality rate than that in the control group (35 vs. 4%; p<0.0001). In the multivariant analysis, the variables related to the occurrence of VT were CPK-MB peak > 300 IU/l (OR 5.9; 95% CI 1.6-21), acute intraventricular conduction disorders (OR 9.02; 95% CI 1.7-48), and ischemia immediately prior to VT (odds ratio [OR] 19.64; 95% confidence interval [CI] 5.3-73).


CONCLUSIONS
Ventricular tachycardia may be considered a marker of inadequate myocardial perfusion after thrombolysis; therefore, a more aggressive revascularization treatment in these patients would be advisable. The profile of patients with AMI, hospitalized in the coronary care unit, who will likely suffer from VT is previous AMI, CPK-MB peak > 300, acute intraventricular conduction disorders, Killip > I, and ischemia previous to VT.
Servicio de Medicina Intensiva Y Unidad Coronaria, Hospital Son Dureta, Barcelona, Spain.
M Fiol
MF
Sala
J Pérez
JP
Bárcena
J I Ayestarán
JI
Rota
J Velasco
JV
Roca
Carrillo A
CA
López
J M Raurich
JM
Puigdevall
J Guindo
JG
Soldevilla
A Bayés
AB
de Luna
D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology; D015425:Myocardial Reperfusion; D012044:Regression Analysis; D017180:Tachycardia, Ventricular / Q000209:etiology*; D015912:Thrombolytic Therapy