Electrocardiograms were recorded from 14 healthy adult cats (SPF) derived from a closed colony and anesthetized with ketamine hydrochloride. From each animal were taken seven tracings, i.e., the standard limb leads, the augmented unipolar leads, and the A-B (apex-base) lead. The QRS complexes with notch forms, and R' and S' waves increased in frequency in cats under ketamine hydrochloride anesthesia.

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Electrocardiographic and hemodynamic observations were performed on 12 adult mongrel dogs in which the septal artery had been ligated experimentally in order to investigate the influence of a ventricular septal injury on the cardiac function. The results obtained are summarized as follows.
1) Severe arrhythmia, such as ventricular tachycardia, was recorded in all the dogs just after the ligation of the septal artery and 40 percent of these dogs died after showing ventricular fibrillation within 30 minutes after the ligation.
2) An hour after the ligation of the septal artery was observed left ventricular failure which was indicated by a fall in aortic pressure and left ventricular systolic pressure, an elevation in left ventricular end-diastolic pressure, a decrease in peak positive dP/dt (the maximal rate of rise of left ventricular pressure), and a prolongation in left ventricular ejection time. Moreover, left ventricular failure was enhanced to some extent 3 months after the ligation.
3) Abnormal deviations of S-T segment, variation of T wave, prolongation of Q-T interval, and left bundle branch block (in one dog) were presented as electrocardiographic findings during the acute phase. They were supported by vectorcardiographic findings, but disappeared during the chronic phase.
4) Pathological examination of the heart 3 months after the ligation showed that ischemic areas were localized to some restricted regions of the ventricular septum.
From these results, it is presumed that the ischemia and/or infarct of the ventricular septum may have exerted harmful influences on the cardiac function, even though areas involved in these changes are restricted to a small extent and the electrocardiography reveals no distinct abnormalities.

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A diagnosis of isolated pulmonary stenosis was made in a mongrel bitch of the Wire-haired Fox Terrier breed, 3 months of age weighing 3.5kg. The antemortem diagnosis was based on physical examination, hematologic examination, phonocardiography, electrocardiography, radiography and angiocardiography. Necropsy revealed pulmonary stenosis of supravalvular, valvular and subvalvular types at the same time. The present case may be the first one of pulmonary stenosis of the dog that has ever reported in Japan. This paper describes the rerults of clinical and pathologic examinations and etiological and surgical aspects of this anomaly.

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The transposition of great arteries with subaortic ventricular septal defect (VSD) and subvalvular pulmonic stenosis was found in an 11-month-old female Holstein-Friesian heifer. They were examined clinically and pathologically. Cyanosis, dyspnea and fever were observed in the heifer at the first medical examination. A systolic murmur was heard in the pulmonary and the aortic areas. Biventricular hypertrophy with the enhancement of the left ventricular electrical force was suggested from the high voltage of QRS complex on the electrocardiogram and the left-ward orientation of QRS loop on the vectorcardiogram. Polycythemia was presented in blood examination. The post-mortem findings were as follows: Complete transposition of the great arteries with subaortic VSD, obstruction of opening 3.5×2.0 cm in size, subvalvular pulmonic stenosis 1.5 cm in diameter, right ventricular hypertrophy, and mild left ventricular hypertrophy in the heart. As complication, brain abscess was observed.

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