M-MODE ECHOCARDIOGRAPHIC REFERENCE VALUES IN CATS IN THE FIRST THREE MONTHS OF LIFE

Thirty-five young cats were studied by echocardiography from the 2nd to 12th weeks of life to analyze correlation between body weight, body surface area, age and heart rate with fourteen echocardiographic parameters. There was a positive linear correlation (r = 0.49-0.78) between the independent variables (body weight, body surface area, age) and left ventricular wall thickness and diameter, aortic diameter and left atrial diameter, whereas there was a negative correlation (r = -0.39 and r = -0.43) between the heart rate and left ventricular diameter during systole and diastole. No linear dependence of the fractional shortening, ejection fraction, percentage thickening of the interventricular septum and left ventricular posterior wall, LA/AO ratio, and the ratio IVSED/LVWED to the independent variables was observed.     

Changes in the heart beat of puppies in the first twelve weeks of life

In 37 healthy pups and seven pups with congenital pulmonic stenosis ECG were recorded and the heart rate determined. Between the first week of life in healthy pups (mean = 230/min) and the twelfth week of life the heart rate in both groups at six weeks was 195/min and 180/min. At the end of the investigation the averaged heart rate was 167/min or 166/min respectively. In single weeks during the investigation a slightly increased heart rate occurred in a few dogs between the fourth and sixth week of life owing to an increased restlessness during this time span. The heart rate of newborn pups at the first day (mean = 215/min) was a little lower than the average in the first week of life.