An experimental production of ventricular tachycardia by hyperosmotic solutions in dogs.

Abstract

injections into the left anterior descending (LAD) and left circumflex (LCX) coronary arteries were separately performed in twenty dogs using various hyperosmotic solutions. Ventricular tachycardia (VT) was induced in all dogs studied, by injections of solutions having higher osmolality, whereas solutions with relatively lower osmolality did not produce VT. VT was induced in 100% of trials by injections of 30% saline into the LAD. Injections into the LCX of both 10% and 30% saline also elicited VT in 100%. The VT was produced under classic total cardiac denervation combined with intravenous propranolol (0.6 mg/kg) and atropine (0.15 mg/kg). Atrioventricular (A-V) block caused by surgical section of the distal part of the His bundle did not effectively block the production of VT. Reliability of this rather simple technique appears to provide us with a new experimental model. ventricular tachycardia; intracoronary injection; hyperosmolality; cardiac denervation In a previous paper (Abe 1979), this author reported successful production of VT with injections of hyperosmotic solutions into the left main coronary artery (LMC) of the canine heart, in which the LMC was separated from both the LAD and LCX by aorta (Ao)-LAD and Ao-LCX bypass grafting. In this laboratory, the effects of selective injections of hyperosmotic solutions into the LAD and LCX were subsequently investigated in anesthetized dogs, and it was observed that VT could be induced with this technique in all the dogs studied. The characteristics of VT thus elicited are described in this report. Although certain techniques inducing VT in clinical cases with a considerably high frequency have been reported by Wellens, Josephson and others (Wellens et al. 1972(Wellens et al. , 1974(Wellens et al. , 1976Wellens 1975;Josephson et al. 1978), a reliable method to produce VT in experimental animals has not been reported. The present papar demonstrates the feasibility of this rather simple technique. METHODSTwenty mongrel dogs weighing between 19 and 42 kg (average, 25.9 kg) were anesthetized with intramuscular pentobarbital sodium (35 mg/kg), intubated with a cuffed

Observations with endocardial electrography on ventricular tachycardia by intracoronary saline in dogs.

“…In the previous papers (Abe 1979(Abe , 1980 it was reported that VT could be induced with 100% incidence by intracoronary injections of hyperosmotic (10 or 30%) saline, and this finding was confirmed also in the present experiments. Moreover, the present experiments revealed that the VT was reproducibly induced by 10% saline in all of the experimental animals, and, therefore, this rather simple technique appears to be reliable for the production of VT in animal study because of its sureness and reproducibility.…”

“…--ventricular tachycardia; intracoronary injection; endocardial electrography The incidence of VT per se is not quite high, although many methods for experimental production of VT in animal study have been reported (Siebecker et al 1961;Scherf and Bornemann 1967;Wallace et al 1967;Bellet 1971;Lown et al 1977) and ventricular tachyarrhythmias including VT can be induced by these methods. In the previous reports (Abe 1979(Abe , 1980) the author demonstrated with surface electrocardiography (ECG) that VT could be successfully elicited by intracoronary injections of hyperosmotic solutions in canine hearts with 100% incidence. In the present experiments VT produced by intracoronary hyperosmotic saline was studied with endocardial electrography.…”

“…In the previous reports (Abe 1979(Abe , 1980) the author demonstrated with surface electrocardiography (ECG) that VT could be successfully elicited by intracoronary injections of hyperosmotic solutions in canine hearts with 100% incidence. In the present experiments VT produced by intracoronary hyperosmotic saline was studied with endocardial electrography.…”