Quinidine Lactate and Gluconate in the Sup- pression of Ectopic Ventricular Tachycardias Associated with Myocardial Infarction Control of Toxicity by Morphine

In dogs with myocardial infarction, produced by a standard technic, rapid persistent ectopic ventricular tachycardia develops. Intravenous quinidine lactate and quinidine gluconate effectively control the arrhythmia in 56 to 60 per cent of the animals, but produce toxic reactions in many of them. Morphine sulfate prevents vomiting and diarrhea from quinidine, but does not prevent convulsive movements. The most effective treatment of the arrhythmia was by use of morphine followed by quinidine gluconate. This combination was successful in 89 to 100 per cent of the cases. Principles for guidance in the treatment of severe ventricular arrhythmias have been drawn from these studies. Q UINIDINE has long been known to be effective in terminating ventricular tachycardias.'-6 In some cases, how-ever, it has failed,5 ' 6 and ventricular tachy-cardias have been produced by its administra-tion.1 ' 3', Fatal ventricular fibrillation has occurred during slow intravenous administration of quinidine to a patient with ventricular tachy-cardia which developed following myocardial infarction.8 Ventricular premature beats, brief paroxysms of ventricular tachycardia and transient ventricular fibrillation have been precipitated by quinidine in patients who were subject to spontaneous episodes of this kind.9 Toxic manifestations of other kinds, especially nausea and vomiting, are of frequent occur-rence upon intravenous administration of quinidine even when it succeeds in the aboli-tion of abnormal cardiac rhythms.2 ' 4 Quinidine is widely regarded as the drug of choice for the treatment of ventricular tachy-cardias in spite of the untoward occurrences.&apos