Coexisting paroxysmal ventricular tachycardia and idioventricular rhythm in acute myocardial infarction

Ventricular Rhythms in Acute Myocardial Infarction

“…Some authors have claimed the rarity of such coexistence [17], while others have been impressed with the contrary [4], From the above it seems that rather convincing clinical evidence is being accumulated in the literature and probably in many intensive cardiac care units, indicating that there are many patients who develop, in the early phase of acute myocardial infarc tion, ventricular arrhythmias resembling the accelerated idioventricular type, but differing from it in course, duration and prognosis. The perti nent literature suggests that these variants may be produced either by a varying exit block from a rapid parasystolic focus [2,17,19], or by concealed or manifest re-entry created by slowed conduction within an area of enhanced phase 4 activity [4,20]. Similar mechanisms have been invoked to explain the appearance of random, nonparasystolic ventricular extrasystoles [19,24,25], It has been noted on the screening of routine electrocardiograms that such extrasystoles and even slow ventricular tachycardia with an irregular rate have been associated with cardiac disease and with other serious arrhythmias [23].…”

“…More recently, however, there have been an increasing number of reports describing the coexistence of both slow and rapid ventricular rhythms with identical configuration in the same patient [4,10]. Some authors have claimed the rarity of such coexistence [17], while others have been impressed with the contrary [4], From the above it seems that rather convincing clinical evidence is being accumulated in the literature and probably in many intensive cardiac care units, indicating that there are many patients who develop, in the early phase of acute myocardial infarc tion, ventricular arrhythmias resembling the accelerated idioventricular type, but differing from it in course, duration and prognosis. The perti nent literature suggests that these variants may be produced either by a varying exit block from a rapid parasystolic focus [2,17,19], or by concealed or manifest re-entry created by slowed conduction within an area of enhanced phase 4 activity [4,20].…”