Incidence and significance of inducible supraventricular tachyarrhythmias in patients with chronic myocardial infarction.

In order to evaluate the incidence and significance of inducible supra-ventricular (SVTA) in patients with chronic myocardial infarction (MI), the results of systematic programmed atrial stimulation were compared in two groups of patients: 150 patients (group I) without MI or underlying heart disease, studied for syncope or conduction disturbances, 296 patients (group II) studied after an acute Mi (greater than 1 month). None of them had spontaneous SVTA, and 24-h Holter monitoring showed no SVTA. The atrial stimulation programme used one and two extra stimuli delivered during sinus rhythm and atrial pacing (600 ms and 10% less than the sinus cycle length). A sustained (S) (greater than 30 s) supraventricular tachycardia (SVT) (atrial flutter, fibrillation, tachycardia) was induced in 17 patients in group I (11%) and in 120 patients in group II (40.5%). In group II inducible SVTA could not be correlated with the occurrence of a SVT during acute MI, the location of MI, the value of LV ejection fraction (EF), the incidence of inducible sustained ventricular tachycardia (VT), or fibrillation (VF). However, inducible SVTA could be correlated with a significantly shorter effective atrial refractory period (197 +/- 23 ms vs 220 +/- 35 ms, P less than 0.001) and a shorter retrograde block cycle length (518 +/- 215 vs 585 +/- 215 ms, P less than 0.03). The patients in group II were followed-up for at least 6 months; 12 of them developed sustained episodes of supraventricular tachycardia; 11 of them had inducible SVTA (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

[Frequency of the onset of supraventricular tachyarrhythmias as a function of underlying heart disease]. / Fréquence du déclenchement des tachyarythmies supraventriculaires en fonction de la cardiopathie sous-jacente.

The prevalence of inducible ventricular arrhythmias is related to the underlying pathology. This study was undertaken to determine the prevalence of supraventricular tachyarrhythmias (SVT), atrial tachycardia, flutter or fibrillation, sustained for over 30 seconds. Programmed atrial stimulation was used to deliver 1 or 2 extrastimuli during sinus and paced rhythm in 230 subjects without obvious cardiac disease (149 without and 81 with spontaneous SVT) and 432 patients with documented cardiac pathology (407 without and 25 with spontaneous SVT). The incidence of inducible SVT with respect to that of spontaneous SVT and in relation to cardiac pathology was as follows: (table; see text) The prevalence of inducible SVT in patients without spontaneous SVT was related to the type of pathology: (table; see text) These results show that in patients with spontaneous SVT the induction of the arrhythmia was facilitated by the presence of underlying cardiac pathology (sensitivity increasing from 67% to 88%). In patients without spontaneous SVT, the nature of the underlying disease was related to the prevalence of inducible SVT, the risk being major in SA block, right ventricular dysplasia and mitral valve prolapse (60-80%) and moderate in dilated CMP and myocardial infarction (35 to 40%).