[Identification using thoracic electromapping of patients with sustained postinfarct ventricular tachycardia. Preliminary results of a new method of analysis of ST-T isoarea maps]. / Identificazione mediante elettromappe toraciche di pazienti con tachicardia ventricolare sostenuta post-infartuale. Risultati preliminari di un nuovo metodo di analisi delle mappe isoaree di ST-T.

Recent studies have demonstrated that body surface maps (BSM) can be employed as non-invasive diagnostic tool for recognizing cardiac states at risk for repetitive ventricular arrhythmias in patients (pts) with old infarction. Our study reports preliminary results of a new method of statistical analysis of ST-T isoarea maps for identifying patients with post-infarction sustained ventricular tachycardia. 38 pts with previous myocardial infarction have been studied, 25 without and 13 with sustained ventricular tachycardia (VT). The two groups of pts did not differ significantly for age, site of infarction and ejection fraction. BSM have been recorded by means of an automated 35-channels instrument from 140 thoracic leads. For each lead ST-T deflection area has been calculated in microV.sec and taken as input variables for stepwise discriminant analysis which allowed identification of the integral values significantly discriminant (for F less than 0.15) between the two groups. Canonical analysis has been applied to identified values to obtain, by canonical coefficients, linear combination of the values for the highest correlation with the two groups of pts. To test the power of the method, the two groups of pts have been divided randomly in a learning set (17 pts without and 9 pts with VT) and a test set (8 pts without and 4 pts with VT).(ABSTRACT TRUNCATED AT 250 WORDS)

Dipyridamole-induced ischemia as a prognostic marker of future adverse cardiac events in adult patients with hypertrophic cardiomyopathy. Echo Persantine Italian Cooperative (EPIC) Study Group, Subproject Hypertrophic Cardiomyopathy.

BACKGROUND: Myocardial ischemia may play a role in the natural history of hypertrophic cardiomyopathy (HCM). To assess the relative prevalence and the prognostic value of dipyridamole-induced ischemia, 79 patients with HCM and without concomitant coronary artery disease (53 men; mean age, 46+/-15 years) underwent a high-dose (up to 0.84 mg/kg over 10 minutes) dipyridamole test with 12-lead ECG and two-dimensional echo monitoring and were followed up for a mean of 6 years. METHODS AND RESULTS: Twenty-nine patients (37%) showed ECG (ie, ST depression > or = 2 mV) signs of myocardial ischemia during dipyridamole test (group 1), whereas 50 (63%) had a negative test (group 2). No patient had transient wall motion abnormalities during the dipyridamole test. During the follow-up, 16 events (ie, left ventricular or atrial enlargement, unstable angina, syncope, atrial fibrillation, and bundle-branch block) occurred in 29 patients in group 1 and 5 in 50 patients in group 2 (55% versus 10%, P<.001). Patients with a positive dipyridamole test showed worse 72-month event-free survival rates compared with patients with a negative test (36.2% versus 84.2%, P<.001). A forward stepwise event-free survival analysis identified dipyridamole test positivity by ECG criteria (chi2=19.7, P=.0001), rest gradient (chi2=11.3, P=.0008), and age (chi2=4.1; P=.0413) as independent and additive predictors of subsequent events. CONCLUSIONS: ECG signs of myocardial ischemia elicited by dipyridamole are frequent in patients with HCM and identify patients at higher risk of cardiac events, suggesting a potentially important pathogenetic role of inducible myocardial ischemia in determining adverse cardiac events in these patients.